Science.gov

Sample records for altus cumulus electrification

  1. ALTUS Cumulus Electrification Study (ACES)

    NASA Technical Reports Server (NTRS)

    Kim, Tony; Blakeslee, Richard; Russell, Larry W. (Technical Monitor)

    2002-01-01

    The ALTUS Cumulus Electrification Study (ACES) is an uninhabited aerial vehicle (UAV)-based project that will investigate thunderstorms in the vicinity of the Florida Everglades in August 2002. ACES is being conducted to both investigate storm electrical activity and its relationship to storm morphology, and validate Tropical Rainfall Measurement Mission (TRMM) satellite measurements. In addition, as part of NASA's UAV-based science demonstration program, this project will provide a scientifically useful demonstration of the utility and promise of UAV platforms for Earth science and applications observations. Part of the demonstration involves getting approvals from the Federal Aviation Administration and the NASA airworthiness flight safety review board. ACES will employ the ALTUS II aircraft, built by General Atomics - Aeronautical Systems, Inc. Key science objectives simultaneously addressed by ACES are to: (1) investigate lightning-storm relationships, (2) study storm electrical budgets, and (3) provide Lightning Imaging Sensor validation. The ACES payload, already developed and flown on ALTUS, includes electrical, magnetic, and optical sensors to remotely characterize the lightning activity and the electrical environment within and around thunderstorms. ACES will contribute important electrical and optical measurements not available from other sources. Also, the high altitude vantage point of the UAV observing platform (up to 55,000 feet) offers a useful 'cloud-top' perspective. By taking advantage of its slow flight speed (70 to 100 knots), long endurance, and high altitude flight, the ALTUS will be flown near, and when possible, above (but never into) thunderstorms for long periods of time, allowing investigations to be conducted over entire storm life cycles. In addition, concurrent ground-based observations will enable the UAV measurements to be more completely interpreted and evaluated in the context of the thunderstorm structure, evolution, and

  2. The Altus Cumulus Electrification Study (ACES): A UAV-based Investigation of Thunderstorms

    NASA Technical Reports Server (NTRS)

    Blakeslee, Richard; Arnold, James E. (Technical Monitor)

    2001-01-01

    The Altus Cumulus Electrification Study (ACES) is a NASA-sponsored and -led science investigation that utilizes an uninhabited aerial vehicle (UAV) to investigate thunderstorms in the vicinity of the NASA Kennedy Space Center, Florida. As part of NASA's UAV-based science demonstration program, ACES will provide a scientifically useful demonstration of the utility and promise of UAV platforms for Earth science and applications observations. ACES will employ the Altus 11 aircraft, built by General Atomics-Aeronautical Systems, Inc. By taking advantage of its slow flight speed (70 to 100 knots), long endurance, and high-altitude flight (up to 55,000 feet), the Altus will be flown near, and when possible, above (but never into) thunderstorms for long periods of time, allowing investigations to be conducted over entire storm life cycles. Key science objectives simultaneously addressed by ACES are to: (1) investigate lightning-storm relationships, (2) study storm electrical budgets, and (3) provide Lightning Imaging Sensor validation. The ACES payload, already developed and flown on Altus, includes electrical, magnetic, and optical sensors to remotely characterize the lightning activity and the electrical environment within and around thunderstorms. The ACES field campaign will be conducted during July 2002 with a goal of performing 8 to 10 UAV flights. Each flight will require about 4 to 5 hours on station at altitudes from 40,000 ft to 55,000 ft. The ACES team is comprised of scientists from the NASA Marshall Space Flight Center and NASA Goddard Space Flight Centers partnered with General Atomics and IDEA, LLC.

  3. The Altus Cumulus Electrification Study (ACES): A UAV-Based Science Demonstration

    NASA Technical Reports Server (NTRS)

    Blakeslee, R. J.; Croskey, C. L.; Desch, M. D.; Farrell, W. M.; Goldberg, R. A.; Houser, J. G.; Kim, H. S.; Mach, D. M.; Mitchell, J. D.; Stoneburner, J. C.

    2003-01-01

    The Altus Cumulus Electrification Study (ACES) is an unmanned aerial vehicle (UAV)- based project that investigated thunderstorms in the vicinity of the Florida Everglades in August 2002. ACES was conducted to investigate storm electrical activity and its relationship to storm morphology, and to validate satellite-based lightning measurements. In addition, as part of the NASA sponsored UAV-based science demonstration program, this project provided a scientifically useful demonstration of the utility and promise of UAV platforms for Earth science and applications observations. ACES employed the Altus II aircraft, built by General Atomics - Aeronautical Systems, Inc. Key science objectives simultaneously addressed by ACES are to: (1) investigate lightning-storm relationships, (2) study storm electrical budgets, and provide Lightning Imaging Sensor validation. The ACES payload included electrical, magnetic, and optical sensors to remotely characterize the lightning activity and the electrical environment within and around thunderstorms. ACES contributed important electrical and optical measurements not available from other sources. Also, the high altitude vantage point of the UAV observing platform (up to 55,000 feet) provided cloud-top perspective. By taking advantage of its slow flight speed (70 to 100 knots), long endurance, and high altitude flight, the Altus was flown near, and when possible, over (but never into) thunderstorms for long periods of time that allowed investigations to be conducted over entire storm life cycles. An innovative real time weather system was used to identify and vector the aircraft to selected thunderstorms and safely fly around these storms, while, at the same time monitor the weather near our base of operations. In addition, concurrent ground-based observations that included radar (Miami and Key West WSRBD, NASA NPOL), satellite imagery, and lightning (NALDN and Los Alamos EDOT) enable the UAV measurements to be more completely

  4. Preliminary Optical And Electric Field Pulse Statistics From Storm Overflights During The Altus Cumulus Electrification Study

    NASA Technical Reports Server (NTRS)

    Mach, D. A.; Blakeslee, R. J.; Bailey, J. C.; Farrell, W. M.; Goldberg, R. A.; Desch, M. D.; Houser, J. G.

    2003-01-01

    The Altus Cumulus Electrification Study (ACES) was conducted during the month of August, 2002 in an area near Key West, Florida. One of the goals of this uninhabited aerial vehicle (UAV) study was to collect high resolution optical pulse and electric field data from thunderstorms. During the month long campaign, we acquired 5294 lightning generated optical pulses with associated electric field changes. Most of these observations were made while close to the top of the storms. We found filtered mean and median 10-10% optical pulse widths of 875 and 830 microns respectively while the 50-50% mean and median optical pulse widths are 422 and 365 microns respectively. These values are similar to previous results as are the 10-90% mean and median rise times of 327 and 265 microns. The peak electrical to optical pulse delay mean and median were 209 and 145 microns which is longer than one would expect from theoretical results. The results of the pulse analysis will contribute to further validation of the Optical Transient Detector (OTD) and the Lightning Imaging Sensor (LIS) satellites. Pre-launch estimates of the flash detection efficiency were based on a small sample of optical pulse measurements associated with less than 350 lightning discharges collected by NASA U-2 aircraft in the early 1980s. Preliminary analyses of the ACES measurements show that we have greatly increased the number of optical pulses available for validation of the LIS and other orbital lightning optical sensors. Since the Altus was often close to the cloud tops, many of the optical pulses are from low-energy pulses. From these low-energy pulses, we can determine the fraction of optical lightning pulses below the thresholds of LIS, OTD, and any future satellite-based optical sensors such as the geostationary Lightning Mapping Sensor.

  5. Lightning Optical Pulse Statistics from Storm Overflights During the Altus Cumulus Electrification Study

    NASA Technical Reports Server (NTRS)

    Mach, D. M.; Blakeslee, R. J.; Bailey, J. C.; Farrell, W. M.; Goldberg, R. A.; Desch, M. D.; Houser, J. G.

    2004-01-01

    The Altus Cumulus Electrification Study (ACES) was conducted during the month of August, 2002 in an area near Key West, Florida. One of the goals of this uninhabited aerial vehicle (UAV) study was to collect time resolved optical pulse data from thunderstorms. During the month long campaign, we acquired 5294 lightning generated optical pulses. Most of these observations were made while close to the top of the storms. We divided our data into two amplitude groups based on prior NASA U2 aircraft optical data and our pulse characteristics. The group of large pulses with radiance greater than 2.1 mW /sq m sr had mean and median 10 - 10% optical pulse widths of 765 and 735 microns respectively, the 50-50% pulse widths of 396 and 355 microns respectively, and 10-90% rise times of 290 and 260 microns. These values are very similar to the previous U2 based optical results The other group of pulses consisting of slightly more than a quarter of the total pulses observed had radiances less than the minimum values detected in the U2 study. The small pulses were narrower than the large pulses with 5040% mean and median values of 198 and 160 ps respectively. Only 12 % of the flashes contained only small pulses, minimizing the impact of this data on the estimates of detection efficiencies of the orbital instruments, the Lightning Imaging Sensor and Optical Transient Detector.

  6. Looking ever so much like an alien spacecraft, the Altus II remotely piloted aircraft shows off some

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Looking ever so much like an alien spacecraft, the Altus II remotely piloted aircraft shows off some of the instruments and camera lenses mounted in its nose for a lightning study over Florida flown during the summer of 2002. The Altus Cumulus Electrification Study (ACES), led by Dr. Richard Blakeslee of NASA Marshall Space Flight center, focused on the collection of electrical, magnetic and optical measurements of thunderstorms. Data collected will help scientists understand the development and life cycles of thunderstorms, which in turn may allow meteorologists to more accurately predict when destructive storms may hit. The Altus II, built by General Atomics Aeronautical Systems, Inc., is one of several remotely operated aircraft developed and matured under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. The program focused on developing airframe, propulsion, control system and communications technologies to allow unmanned aerial vehicles (UAVs) to operate at very high altitudes for long durations while carrying a variety of sensors, cameras or other instruments for science experiments, surveillance or telecommunications relay missions.

  7. Altus aircraft on runway

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The remotely piloted Altus aircraft flew several developmental test flights from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif., in 1996. The Altus--the word is Latin for 'high'--is a variant of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. It is designed for high-altitude, long-duration scientific sampling missions, and is powered by a turbocharged four-cylinder piston engine. The first Altus was developed under NASA's Environmental Research Aircraft and Sensor Technology program, while a second Altus was built for a Naval Postgraduate School/Department of Energy program. A pilot in a control station on the ground flew the craft by radio signals, using visual cues from a video camera in the nose of the Altus and information from the craft's air data system. Equipped with a single-stage turbocharger during the 1996 test flights, the first Altus reached altitudes in the 37,000-foot range, while the similarly-equipped second Altus reached 43,500 feet during developmental flights at Dryden in the summer of 1997. The NASA Altus also set an endurance record of more than 26 hours while flying a science mission in late 1996 and still had an estimated 10 hours of fuel remaining when it landed. Now equipped with a two-stage turbocharger, the NASA Altus maintained an altitude of 55,000 feet for four hours during flight tests in 1999.

  8. Altus I aircraft on lakebed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The remotely-piloted Altus I aircraft climbs away after takeoff from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the

  9. 27 CFR 9.77 - Altus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.77 Altus. (a) Name. The name of the viticultural area described in this section is “Altus.” (b) Approved maps. The appropriate maps for determining the boundaries of the Altus viticultural area are five U.S.G.S. maps in the...

  10. 27 CFR 9.77 - Altus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.77 Altus. (a) Name. The name of the viticultural area described in this section is “Altus.” (b) Approved maps. The appropriate maps for determining the boundaries of the Altus viticultural area are five U.S.G.S. maps in the...

  11. 27 CFR 9.77 - Altus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.77 Altus. (a) Name. The name of the viticultural area described in this section is “Altus.” (b) Approved maps. The appropriate maps for determining the boundaries of the Altus viticultural area are five U.S.G.S. maps in the...

  12. 27 CFR 9.77 - Altus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.77 Altus. (a) Name. The name of the viticultural area described in this section is “Altus.” (b) Approved maps. The appropriate maps for determining the boundaries of the Altus viticultural area are five U.S.G.S. maps in the...

  13. 27 CFR 9.77 - Altus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.77 Altus. (a) Name. The name of the viticultural area described in this section is “Altus.” (b) Approved maps. The appropriate maps for determining the boundaries of the Altus viticultural area are five U.S.G.S. maps in the...

  14. Altus I aircraft landing on Edwards lakebed runway 23

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The remotely-piloted Altus I aircraft lands on Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the craft by radio

  15. Altus I aircraft taking off from lakebed runway

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The remotely-piloted Altus I aircraft takes off from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet.

  16. Altus I aircraft in flight, retracting landing gear after takeoff

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The landing gear of the remotely piloted Altus I aircraft retracts into the fuselage after takeoff from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, was designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology project, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet.

  17. The electrification of spacecraft

    NASA Technical Reports Server (NTRS)

    Akishin, A. I.; Novikov, L. S.

    1985-01-01

    Physical and applied aspects of the electrification of space vehicles and natural celestial objects are discussed, the factors resulting in electrification of spacecraft are analyzed, and methods of investigating various phenomena associated with this electrification and ways of protecting spacecraft against the influence of static electricity are described. The booklet is intended for the general reader interested in present day questions of space technology.

  18. 75 FR 17852 - Amendment of Class E Airspace; Altus, OK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-08

    ... published in the Federal Register a final rule amending Class E airspace in the Altus, OK area (74 FR 68666... September 15, 2009, which is incorporated by reference in 14 CFR part 71.1. In rule FR Doc. E9-30283 published on December 29, 2009, (74 FR 68666) make the following correction: On page 68667, in the...

  19. Assessment of biogeochemical natural attenuation and treatment of chlorinated solvents, Altus Air Force Base, Altus, Oklahoma.

    PubMed

    Kennedy, Lonnie G; Everett, Jess W; Gonzales, James

    2006-02-10

    Biogeochemical reductive dechlorination (BiRD) is a newly recognized method for the remediation or natural attenuation of chlorinated solvents. Chlorinated solvents are rapidly treated by abiotic reaction with reduced mineral iron sulfides. Iron sulfides are formed by naturally occurring sulfate-reducing bacteria when sufficient SO(4)(2-) and organic carbon are present or supplied to sediments containing mineral iron. An example of site characterization focusing on BiRD is presented focusing on mineral phases. Methods demonstrated here may be employed at other sites to evaluate naturally occurring BiRD or to evaluate an engineered BiRD remediation. A field investigation was performed at a TCE contaminated site at Altus AFB with naturally high concentrations of SO(4)(2-) and Fe(III) minerals and where an accidental fuel spill provided organic carbon. In the area of this fuel spill significant mineral iron sulfides were found, sulfate was almost completely removed, and TCE was absent. Only small amounts of daughter products were found, further indicating that the BiRD pathway was operative. Mass balance data indicates all of the remaining TCE (182 kg) could be treated by the remaining FeS (66.5 kg) in the upper aquifer; however, the FeS was not co-located with TCE to enable complete reaction. Laboratory microcosm tests with FeS amended and FeS-rich sediment from Altus AFB also suggest that BiRD is capable of destroying TCE. The results suggest that an engineered BiRD treatment is possible for this site.

  20. Navajo Electrification Demonstraiton Project

    SciTech Connect

    Larry Ahasteen, Project Manager

    2006-07-17

    This is a final technical report required by DOE for the Navajo Electrification Demonstration Program, This report covers the electric line extension project for Navajo families that currently without electric power.

  1. 78 FR 50134 - Altus Pharmaceuticals, Inc., Blackhawk Capital Group BDC, Inc., Cargo Connection Logistics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... COMMISSION Altus Pharmaceuticals, Inc., Blackhawk Capital Group BDC, Inc., Cargo Connection Logistics Holding, Inc., Diapulse Corporation of America, Globus International Resources Corp., Kingston Systems, Inc... securities of Cargo Connection Logistics Holding, Inc. because it has not filed any periodic reports...

  2. Aerosol effect on the land-ocean contrast in thunderstorm electrification and lightning frequency

    NASA Astrophysics Data System (ADS)

    Shi, Z.; Tan, Y. B.; Tang, H. Q.; Sun, J.; Yang, Y.; Peng, L.; Guo, X. F.

    2015-10-01

    Numerical simulations are carried out to investigate the effect of aerosol on microphysical, electrification and lightning frequency in thunderstorm clouds. A two-dimensional (2-D) cumulus model with electrification and lightning process is used to investigate the difference of electrification and lightning process between continental and maritime thunderclouds. The results show that in the developing stage higher concentration aerosol in continental thundercloud leads to more cloud droplets and stronger updraft in continental thundercloud than in maritime thundercloud. The continental thundercloud with more ice particles production and larger size of graupel has stronger charge separation rate than that in maritime thundercloud. However, in the dissipation stage, the enhancement of cloud water content consumption lead to a lower cloud water content in continental thundercloud, leading weaker charge separation rate than that in maritime thundercloud. In addition, ice mass flux enhancement in continental thundercloud results in stronger lightning production. The continental thundercloud produces lightning frequency 1.5 times higher than maritime thundercloud.

  3. Chile rural electrification cooperation

    SciTech Connect

    Flowers, L.

    1997-12-01

    The author describes a joint program to use renewables for rural electrification projects in Chile. The initial focus was in a limited part of the country, involving wind mapping, pilot project planning, training, and development of methodologies for comparative evaluations of resources. To this point three wind hybrid systems have been installed in one region, as a part of the regional private utility, and three additional projects are being designed. Additional resource assessment and training is ongoing. The author points out the difficulties in working with utilities, the importance of signed documentation, and the need to look at these programs as long term because of the time involved in introducing such new technologies.

  4. NAVAJO ELECTRIFICATION DEMONSTRATION PROJECT

    SciTech Connect

    Terry W. Battiest

    2008-06-11

    The Navajo Electrification Demonstration Project (NEDP) is a multi-year project which addresses the electricity needs of the unserved and underserved Navajo Nation, the largest American Indian tribe in the United States. The program serves to cumulatively provide off-grid electricty for families living away from the electricty infrastructure, line extensions for unserved families living nearby (less than 1/2 mile away from) the electricity, and, under the current project called NEDP-4, the construction of a substation to increase the capacity and improve the quality of service into the central core region of the Navajo Nation.

  5. Red-based cumulus.

    PubMed

    Gedzelman, Stanley David

    2015-02-01

    Observations and model simulations of cumulus clouds whose bases are tinted red when the Sun is well above the horizon are presented. Conditions for seeing red bases include (1) a red underlying surface (which may consist of dust clouds, as from haboobs) with high albedo, (2) small fractional cloud cover when the Sun is far enough below the zenith for direct sunlight to illuminate much of the surface directly below and around cloud base, (3) optically thick clouds so that the bases are dark, and (4) clouds with bases that are near enough to the observer to appear high in the sky so that the admixture of scattered light from the intervening atmosphere is minimized.

  6. Interstate Electrification Improvement Project

    SciTech Connect

    Puckette, Margaret; Kim, Jeff

    2015-07-01

    The Interstate Electrification Improvement Project, publicly known as the Shorepower Truck Electrification Project (STEP), started in May 2011 and ended in March 2015. The project grant was awarded by the Department of Energy’s Vehicles Technology Office in the amount of $22.2 million. It had three overarching missions: 1. Reduce the idling of Class 8 tractors when parked at truck stops, to reduce diesel fuel consumption and thus U.S. dependence on foreign petroleum; 2. Stimulate job creation and economic activity as part of the American Reinvestment and Recovery Act of 2009; 3. Reduce greenhouse gas emissions (GHG) from diesel combustion and the carbon footprint of the truck transportation industry. The project design was straightforward. First, build fifty Truck Stop Electrification (TSE) facilities in truck stop parking lots across the country so trucks could plug-in to 110V, 220V, or 480VAC, and shut down the engine instead of idling. These facilities were strategically located at fifty truck stops along major U.S. Interstates with heavy truck traffic. Approximately 1,350 connection points were installed, including 150 high-voltage electric standby Transport Refrigeration Unit (eTRU) plugs--eTRUs are capable of plugging in to shore power1 to cool the refrigerated trailer for loads such as produce, meats and ice cream. Second, the project provided financial incentives on idle reduction equipment to 5,000 trucks in the form of rebates, to install equipment compatible with shore power. This equipment enables drivers to shut down the main engine when parked, to heat or cool their cab, charge batteries, or use other household appliances without idling—a common practice that uses approximately 1 gallon of diesel per hour. The rebate recipients were intended to be the first fleets to plug into Shorepower to save diesel fuel and ensure there is significant population of shore power capable trucks. This two part project was designed to complement each other by

  7. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS..., North Fork Red River, Okla. The Bureau of Reclamation, or its designated agent, shall operate the...

  8. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS..., North Fork Red River, Okla. The Bureau of Reclamation, or its designated agent, shall operate the...

  9. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS..., North Fork Red River, Okla. The Bureau of Reclamation, or its designated agent, shall operate the...

  10. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS..., North Fork Red River, Okla. The Bureau of Reclamation, or its designated agent, shall operate the...

  11. 33 CFR 208.26 - Altus Dam and Reservoir, North Fork Red River, Okla.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Altus Dam and Reservoir, North Fork Red River, Okla. 208.26 Section 208.26 Navigation and Navigable Waters CORPS OF ENGINEERS..., North Fork Red River, Okla. The Bureau of Reclamation, or its designated agent, shall operate the...

  12. Sustainability of TCE Removal in the Mulch Biowalls at Altus AFB

    EPA Science Inventory

    A permeable mulch biowall was installed in June 2002 at Landfill 3 (LF-03), Operable Unit 1 (OU-1), Altus AFB, Oklahoma. The demonstration was conducted by Parsons for the AFCEE Technology Transfer Outreach Office. The biowall is approximately 455 feet long, by 24 feet deep, by...

  13. 77 FR 4457 - Amendment of Class D Airspace; Altus AFB, OK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the.... SUPPLEMENTARY INFORMATION: History On October 28, 2011, the FAA published in the Federal Register a notice of proposed rulemaking to amend Class D airspace for Altus AFB, OK (76 FR 66866) Docket No....

  14. 76 FR 66866 - Proposed Amendment of Class D Airspace; Altus AFB, OK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ...'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant...: Authority: 49 U.S.C. 106(g); 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389... Federal Aviation Administration 14 CFR Part 71 Proposed Amendment of Class D Airspace; Altus AFB,...

  15. American Recovery and Reinvestment Act (ARRA) Federal Energy Management Program Technical Assistance Project 224 Altus Air Force Base Solar Technologies

    SciTech Connect

    Russo, Bryan J.

    2010-09-30

    The principal goal of this project was to evaluate altus Air Force Base for building integrated silicon or thin film module photovoltaic opportunities. This report documents PNNL's efforts and documents study conclusions.

  16. Truckstop -- and Truck!-- Electrification

    SciTech Connect

    Skip Yeakel

    2001-12-13

    The conclusions of this paper are: 0.5-1.5 G/H and/or BUSG/Y--how much time and money will it take to quantify and WHY BOTHER TO DO SO? No shortage of things to do re truckstop--+ truck!-- electrification; Better that government and industry should put many eggs in lots of baskets vs. all in one or few; Best concepts will surface as most viable; Economic appeal better than regulation or brute force; Launch Ground Freight Partnership and give it a chance to work; Demonstration is an effective means to educate, and learn from, customers--learning is a two way street; Research, Development, Demonstration, and Deployment (RD 3) are all important but only deployment gets results; TSE can start small in numbers of spaces to accommodate economically inspired growth but upfront plans should be made for expansion if meaningful idle reduction is to follow via TE; 110VAC 15A service/ parking space is minimal--if infrastructure starts like this, upfront plans must be made to increase capacity; Increased electrification of truckstop and truck alike will result in much better life on the road; Improved sleep will improve driver alertness and safety; Reduced idling will significantly reduce fuel use and emissions; Universal appeal for DOD, DOE, DOT, EPA, OEMs, and users alike; Clean coal, gas, hydro, nuclear, or wind energy sources are all distinctly American means by which to generate electricity; Nothing can compete with diesel fuel to serve mobile truck needs; stationary trucks are like power plants--they don't move and should NOT be powered by petroleum products whenever possible; Use American fueled power plants--electricity--to serve truck idling needs wherever practical to do so; encourage economic aspect; Create and reward industry initiatives to reduce fuel use; Eliminate FET on new trucks, provide tax credits (non highway fuel use and investment), provide incentives based on results; Encourage newer/ cleaner truck use; solicit BAAs with mandatory OEM/ fleet

  17. Summary of Cumulus Parameterization Workshop

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Starr, David OC.; Hou, Arthur; Newman, Paul; Sud, Yogesh

    2002-01-01

    A workshop on cumulus parameterization took place at the NASA Goddard Space Flight Center from December 3-5, 2001. The major objectives of this workshop were (1) to review the problem of representation of moist processes in large-scale models (mesoscale models, Numerical Weather Prediction models and Atmospheric General Circulation Models), (2) to review the state-of-the-art in cumulus parameterization schemes, and (3) to discuss the need for future research and applications. There were a total of 31 presentations and about 100 participants from the United States, Japan, the United Kingdom, France and South Korea. The specific presentations and discussions during the workshop are summarized in this paper.

  18. Electrification of Shaken Granular Media

    NASA Astrophysics Data System (ADS)

    Kara, Onur; Nordsiek, Freja; Lathrop, Daniel

    2015-11-01

    Granular charging of particle laden flows are widespread and has long been observed. Volcanic ash clouds, desert sandstorms, dust devils, thunderstorms and snowstorms all undergo electrification at large scale. However the mechanism by which such processes occur, is not yet well understood. We confine granular particles to an oscillating cylindrical chamber which is enclosed and sealed by two conducting plates. The primary measurement obtained is the voltage between the two plates. We find that collective effects occurring in the bulk of the material play a significant role in the electrification process. We extend the previous results by the addition of photodectection capabilities to the experimental chamber. We present simultaneous measurements of voltage and light emission.

  19. Lessons Learned from NASA UAV Science Demonstration Program Missions

    NASA Technical Reports Server (NTRS)

    Wegener, Steven S.; Schoenung, Susan M.

    2003-01-01

    During the summer of 2002, two airborne missions were flown as part of a NASA Earth Science Enterprise program to demonstrate the use of uninhabited aerial vehicles (UAVs) to perform earth science. One mission, the Altus Cumulus Electrification Study (ACES), successfully measured lightning storms in the vicinity of Key West, Florida, during storm season using a high-altitude Altus(TM) UAV. In the other, a solar-powered UAV, the Pathfinder Plus, flew a high-resolution imaging mission over coffee fields in Kauai, Hawaii, to help guide the harvest.

  20. Shallow cumulus rooted in photosynthesis

    NASA Astrophysics Data System (ADS)

    Vila-Guerau Arellano, J.; Ouwersloot, H.; Horn, G.; Sikma, M.; Jacobs, C. M.; Baldocchi, D.

    2014-12-01

    We investigate the interaction between plant evapotranspiration, controlled by photosynthesis (for a low vegetation cover by C3 and C4 grasses), and the moist thermals that are responsible for the formation and development of shallow cumulus clouds (SCu). We perform systematic numerical experiments at fine spatial scales using large-eddy simulations explicitly coupled to a plant-physiology model. To break down the complexity of the vegetation-atmospheric system at the diurnal scales, we design the following experiments with increasing complexity: (a) clouds that are transparent to radiation, (b) clouds that shade the surface from the incoming shortwave radiation and (c) plant stomata whose apertures react with an adjustment in time to cloud perturbations. The shading by SCu leads to a strong spatial variability in photosynthesis and the surface energy balance. As a result, experiment (b) simulates SCu that are characterized by less extreme and less skewed values of the liquid water path and cloud-base height. These findings are corroborated by the calculation of characteristics lengths scales of the thermals and clouds using autocorrelation and spectral analysis methods. We find that experiments (a) and (b) are characterized by similar cloud cover evolution, but different cloud population characteristics. Experiment (b), including cloud shading, is characterized by smaller clouds, but closer to each other. By performing a sensitivity analysis on the exchange of water vapor and carbon dioxide at the canopy level, we show that the larger water-use efficiency of C4 grass leads to two opposing effects that directly influence boundary-layer clouds: the thermals below the clouds are more vigorous and deeper driven by a larger buoyancy surface flux (positive effect), but are characterized by less moisture content (negative effect). We conclude that under the investigated mid-latitude atmospheric and well-watered soil conditions, SCu over C4 grass fields is characterized

  1. Role of rural electrification in development. [Monograph

    SciTech Connect

    Cecelski, E.; Glatt, S.

    1982-01-01

    The high capital costs of rural-electrification suggest that the assumption that the benefits experienced in developed countries can be duplicated in developing countries is questionable. This review of major issues involved in rural electrification examines the equity side of the socio-economic impacts of major projects in India and Colombia to see if cheap electricity can, with careful planning, become a stimulus for potential entrepreneurs. While the analysis identifies the need for systematic studies to establish the connection between rural electrification and development, the evidence does show that consumption is lower in rural areas both in the amount of electricity used and the percentage of people using it. Direct benefits occur in the productive sector, although the importance of availability and reliability over cost challenges the value of subsidies. Price does appear to be a major factor for small farmers in addition to credit availability and marketing. 45 references, 26 tables. (DCK)

  2. Flow Induced Electrification of Liquid Insulated Systems.

    NASA Astrophysics Data System (ADS)

    Washabaugh, Andrew Patrick

    1995-01-01

    The transport or motion of semi-insulating liquids has led to flow induced static electrification and catastrophic failures in several industries. While techniques for reducing the hazard have been developed, the roles of seemingly important parameters are poorly understood. The objective of this thesis was to measure and understand the fundamental parameters of the flow electrification process that, together with the laws of electroquasistatics and physicochemical hydrodynamics, can be used to predict the performance of complex flow systems, with particular attention to transformer applications. A rotating cylindrical electrode apparatus, which provided cylindrical Couette flow, was used to simulate flow electrification in an electric power transformer. The apparatus had Shell Diala A transformer oil filling the annulus between coaxial cylindrical stainless steel electrodes that were either bare metal, or covered by a thin copper sheet and/or EHV-Weidmann HiVal pressboard insulation. Extensive experiments characterized the time transient and steady state behavior of the electrification through measurements of the volume charge density, the terminal voltage, and the terminal current as the system was driven out of equilibrium by changes in the flow rate (inner cylinder rotation rates of 100-1400 rpm, Reynolds numbers of 5 times 10^3-5 times 10^5), temperature (15-70 ^circ), insulation moisture content (0.5-20 ppm in the oil), applied voltage (0-2 kV DC), and concentration of the non-ionizable anti-static additive 1,2,3 benzotriazole (BTA, 0-60 ppm). Generally, the electrification increased with flow rate and temperature but the BTA appeared to cause competing effects: it decreased the volume charge density on the liquid side of the interface (by a factor of 4), which reduces the electrification, but also decreased the oil conductivity (by a factor of 10), which enhances the electrification. A critical oil BTA concentration of 5 -8 ppm minimized the electrification

  3. Laboratory study of volcanic ash electrification

    NASA Astrophysics Data System (ADS)

    Alois, Stefano; Merrison, Jonathan

    2016-04-01

    Electrostatic forces play an important role in the dynamics of volcanic plumes, for example in ash dispersion and aggregation phenomena. Field measurements of ash electrification are often technically challenging due to poor access and there lacks an accepted physical theory to describe the electrical charge exchange which occurs during particle contact. The goal of the study is to investigate single particle electrification under controlled conditions using advanced laboratory facilities. A novel technique is presented, based on the use of a laser based velocimeter. Here an electric field is applied and the field-induced drift velocity of (micron-sized) ash grains is measured as well as the particles fall velocity. This allows the simultaneous determination of a suspended grains size and electrical charge. The experiments are performed in a unique environmental wind tunnel facility under controlled low-pressure conditions. Preliminary results of particle electrification will be presented.

  4. Incubating Innovation for Rural Electrification. Executive Summary

    SciTech Connect

    2013-07-01

    In June, the team held a workshop on ''Low Carbon Sustainable Rural Electrification'' in Salima, Malawi. Co-organized with the Government of Malawi's Department of Energy, this event gathered participants from the energy, telecom, non-profit, banking sectors as well as from governmental and international agencies to discuss the potential development of private led off-grid electrification in Malawi where only 9% of the population has currently access to electricity. A very active participation provided us with insightful feedback and valuable recommendations.

  5. Anomalous scaling of cumulus cloud boundaries

    PubMed

    Siebesma; Jonker

    2000-07-01

    The geometrical properties of cumulus clouds modeled by a numerical technique called large-eddy simulation are investigated. Surface-volume analyses reconfirm previous scaling results based on satellite data. This technique allows for the first time a direct analysis of the scaling behavior of cloud boundaries of individual clouds.

  6. Cumulus convection and the terrestrial water-vapor distribution

    NASA Technical Reports Server (NTRS)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  7. Satellite Multiangle Cumulus Geometry Retrieval: Case Study

    SciTech Connect

    Kassianov, Evgueni I.; Ackerman, Thomas P.; Marchand, Roger T.; Ovtchinnikov, Mikhail

    2003-02-08

    Most satellite-based analyses have been conducted using near nadir-viewing sensors. The Multi-angle Imaging SpectroRadiometer (MISR), recently launched on the National Aeronautics and Space Administration (NASA) Terra platform, provides high-resolution measurements of reflectance at nine different viewing angles. In this study, we examine the possible retrieval of detailed cumulus geometry using the new and unique MISR datasets. We suggested one approach and apply it to an early MISR dataset of small marine cumulus clouds. This paper also presents validation analysis of this technique with both independent ground-based radar measurements and a model-output inverse problem. Collocated and coincident MISR data and ground-based observations at the Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site form the basis of this validation. Future work will attempt to test the suggested approach with additional MISR scenes.

  8. Sky cover from MFRSR observations: cumulus clouds

    NASA Astrophysics Data System (ADS)

    Kassianov, E.; Barnard, J.; Berg, L. K.; Flynn, C.; Long, C. N.

    2011-01-01

    The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  9. Dual effects of hydrogen sulfide donor on meiosis and cumulus expansion of porcine cumulus-oocyte complexes.

    PubMed

    Nevoral, Jan; Petr, Jaroslav; Gelaude, Armance; Bodart, Jean-Francois; Kucerova-Chrpova, Veronika; Sedmikova, Marketa; Krejcova, Tereza; Kolbabova, Tereza; Dvorakova, Marketa; Vyskocilova, Alena; Weingartova, Ivona; Krivohlavkova, Lenka; Zalmanova, Tereza; Jilek, Frantisek

    2014-01-01

    Hydrogen sulfide (H2S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H2S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observed that the H2S donor, Na2S, accelerated oocyte in vitro maturation in a dose-dependent manner, following an increase of MPF activity around germinal vesicle breakdown. Concurrently, the H2S donor affected cumulus expansion, monitored by hyaluronic acid production. Our results suggest that the H2S donor influences oocyte maturation and thus also participates in the regulation of cumulus expansion. The exogenous H2S donor apparently affects key signal pathways of oocyte maturation and cumulus expansion, resulting in faster oocyte maturation with little need of cumulus expansion.

  10. Motility contrast imaging of live porcine cumulus-oocyte complexes

    NASA Astrophysics Data System (ADS)

    An, Ran; Turek, John; Machaty, Zoltan; Nolte, David

    2013-02-01

    Freshly-harvested porcine oocytes are invested with cumulus granulosa cells in cumulus-oocyte complexes (COCs). The cumulus cell layer is usually too thick to image the living oocyte under a conventional microscope. Therefore, it is difficult to assess the oocyte viability. The low success rate of implantation is the main problem for in vitro fertilization. In this paper, we demonstrate our dynamic imaging technique called motility contrast imaging (MCI) that provides a non-invasive way to monitor the COCs before and after maturation. MCI shows a change of intracellular activity during oocyte maturation, and a measures dynamic contrast between the cumulus granulosa shell and the oocytes. MCI also shows difference in the spectral response between oocytes that were graded into quality classes. MCI is based on shortcoherence digital holography. It uses intracellular motility as the endogenous imaging contrast of living tissue. MCI presents a new approach for cumulus-oocyte complex assessment.

  11. Airborne observations of electric fields around growing and decaying cumulus clouds

    NASA Technical Reports Server (NTRS)

    Giori, K. L.; Nanevicz, J. E.

    1991-01-01

    Airborne electric field data were gathered in an atmospheric electrification study near Cape Canaveral, FL. A Learjet 36A was instrumented with eight electric field meters (mills) and five different particle probes. The local electric field enhancements at each field mill site were determined under lab conditions and verified using in-flight data. The overdetermined system of eight equations (one for each field mill) was solved using a weighted least squares algorithm to compute the magnitude and direction of the ambient electric field. The signal processing system allowed the measured data to be expressed in terms of earth coordinates, regardless of the attitude of the aircraft. Thus, it was possible to take maximum advantage of the Learjet's speed and maneuverability in studying the electric field structure in the vicinity of the clouds. Data gathered while circling just outside the boundary of a growing cumulus cloud show a nonsymmetric pattern of electric field strength. Field intensity grew rapidly over a period of less than 10 minutes. The observed direction of the ambient electric field vector can be explained by an ascending motion of the charge centers of a classic tripole model of a thunderstorm.

  12. Lightning parameterization in a storm electrification model

    NASA Technical Reports Server (NTRS)

    Helsdon, John H., Jr.; Farley, Richard D.; Wu, Gang

    1988-01-01

    The parameterization of an intracloud lightning discharge has been implemented in our Storm Electrification Model. The initiation, propagation direction, termination and charge redistribution of the discharge are approximated assuming overall charge neutrality. Various simulations involving differing amounts of charge transferred have been done. The effects of the lightning-produced ions on the hydrometeor charges, electric field components and electrical energy depend strongly on the charge transferred. A comparison between the measured electric field change of an actual intracloud flash and the field change due to the simulated discharge show favorable agreement.

  13. Cloud condensation nuclei near marine cumulus

    NASA Technical Reports Server (NTRS)

    Hudson, James G.

    1993-01-01

    Extensive airborne measurements of cloud condensation nucleus (CCN) spectra and condensation nuclei below, in, between, and above the cumulus clouds near Hawaii point to important aerosol-cloud interactions. Consistent particle concentrations of 200/cu cm were found above the marine boundary layer and within the noncloudy marine boundary layer. Lower and more variable CCN concentrations within the cloudy boundary layer, especially very close to the clouds, appear to be a result of cloud scavenging processes. Gravitational coagulation of cloud droplets may be the principal cause of this difference in the vertical distribution of CCN. The results suggest a reservoir of CCN in the free troposphere which can act as a source for the marine boundary layer.

  14. Cumulus cloud venting of mixed layer ozone

    NASA Technical Reports Server (NTRS)

    Ching, J. K. S.; Shipley, S. T.; Browell, E. V.; Brewer, D. A.

    1985-01-01

    Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosols occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. The experiments utilized the airborne Ultra-Violet Differential Absorption Lidar (UV-DIAL) system. This system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Evening transects were obtained in the downwind area where the air mass had been advected. Space-height analyses for the evening flight show the cloud debris as patterns of ozone typically in excess of the ambient free tropospheric background. This ozone excess was approximately the value of the concentration difference between the mixed layer and free troposphere determined from independent vertical soundings made by another aircraft in the afternoon.

  15. Contact electrification field-effect transistor.

    PubMed

    Zhang, Chi; Tang, Wei; Zhang, Limin; Han, Changbao; Wang, Zhong Lin

    2014-08-26

    Utilizing the coupled metal oxide semiconductor field-effect transistor and triboelectric nanogenerator, we demonstrate an external force triggered/controlled contact electrification field-effect transistor (CE-FET), in which an electrostatic potential across the gate and source is created by a vertical contact electrification between the gate material and a “foreign” object, and the carrier transport between drain and source can be tuned/controlled by the contact-induced electrostatic potential instead of the traditional gate voltage. With the two contacted frictional layers vertically separated by 80 μm, the drain current is decreased from 13.4 to 1.9 μA in depletion mode and increased from 2.4 to 12.1 μA in enhancement mode at a drain voltage of 5 V. Compared with the piezotronic devices that are controlled by the strain-induced piezoelectric polarization charged at an interface/junction, the CE-FET has greatly expanded the sensing range and choices of materials in conjunction with semiconductors. The CE-FET is likely to have important applications in sensors, human–silicon technology interfacing, MEMS, nanorobotics, and active flexible electronics. Based on the basic principle of the CE-FET, a field of tribotronics is proposed for devices fabricated using the electrostatic potential created by triboelectrification as a “gate” voltage to tune/control charge carrier transport in conventional semiconductor devices. By the three-way coupling among triboelectricity, semiconductor, and photoexcitation, plenty of potentially important research fields are expected to be explored in the near future. PMID:25119657

  16. Electrification of Ash in Icelandic Volcanic Plumes

    NASA Astrophysics Data System (ADS)

    Nicoll, K.; Aplin, K. L.; Houghton, I.

    2014-12-01

    Volcanic ash is known to charge electrically, producing some of the most spectacular displays of lightning on the planet. Lightning activity within volcanic plumes can be sensed remotely using systems such as the United Kingdom Met Office long-range lightning detection network, ATDnet, which recorded over 16 000 lightning strokes during the 2011 Grimsvötn eruption in Iceland. These remote sensing techniques can only be fully exploited if the charging mechanisms in volcanic plumes are well understood. Although the exact details of ash charging processes will vary from one eruption to another, triboelectrification, fractoemission, and the ''dirty thunderstorm'' mechanism are all thought to play a role in the electrification of ash near the vent. In addition to near-vent charging, observations show that charging can also occur in volcanic plumes up to hundreds of kilometres from the source region. The sustained nature of this charge in the presence of electrically conducting air suggests that a self-charging mechanism through the action of ash-to-ash contact charging (triboelectrification), may also play a role in the electrification of volcanic ash. This work describes a laboratory investigation into triboelectric charging of ash from the 2010 and 2011 volcanic eruptions of Eyjafjallajökull and Grímsvötn in Iceland respectively. Consistently with previous work, we find that the particle size distribution plays an important role in the magnitude of charging generated, specifically in terms of the normalized span of the particle size distribution. As well as triboelectrificiation, natural radioactivity in some volcanic ash could also contribute to self-charging of volcanic plumes, which is also examined here.

  17. Plume Electrification: Laboratory and Numerical Experiments

    NASA Astrophysics Data System (ADS)

    Mendez, J. S.; Dufek, J.

    2012-12-01

    The spectacular lightning strokes observed during eruptions testify to the enormous potentials that can be generated within plumes. Related to the charging of individual ash particles, large electric fields and volcanic lightning have been observed at Eyjafjallajokull, Redoubt, and Chaiten, among other volcanoes. A number of mechanisms have been proposed for plume electrification, including triboelectric charging, charging from the brittle failure of rock, and charging due to phase change as material is carried aloft. While the overall electrification of the plume likely results from a combination of these processes, in the following work we focus on triboelectric charging—how a plume charges as particles collide with each other. To explore the role of triboelectric effects in plume charging we have conducted a number of small scale laboratory experiments similar to those designed by Forward et al (2009). Succinctly, the experiments consist of fluidizing an ash bed with nitrogen and monitoring the resulting currents induced by the moving particles. It is important to note that the reaction chamber only allows particle-particle interactions. The entire experimental setup is enclosed in a vacuum chamber, allowing us to carefully control the environment during experiments. Runs were carried out for different ash compositions, and driving pressures. We particularly focused on natural grain size distributions of ash and on quantifying not only the net charge but also the charging rate. Furthermore, we report on our progress to incorporate the collected data, namely charging rates, into a large eularian-eularian-lagrangian multiphase eruption dynamic model. Finally, to validate these results, we present our plans to deploy a large wireless sensor network of electrometers and magnetometers around active volcanoes to directly map the overhead E- and M-fields as an eruption occurs.

  18. Simulation of solar radiative transfer in cumulus clouds

    SciTech Connect

    Zuev, V.E.; Titov, G.A.

    1996-04-01

    This work presents a 3-D model of radiative transfer which is used to study the relationship between the spatial distribution of cumulus clouds and fluxes (albedo and transmittance) of visible solar radiation.

  19. Determination of the cumulus size distribution from LANDSAT pictures

    NASA Technical Reports Server (NTRS)

    Karg, E.; Mueller, H.; Quenzel, H.

    1983-01-01

    Varying insolation causes undesirable thermic stress to the receiver of a solar power plant. The rapid change of insolation depends on the size distribution of the clouds; in order to measure these changes, it is suitable to determine typical cumulus size distributions. For this purpose, LANDSAT-images are adequate. Several examples of cumulus size distributions will be presented and their effects on the operation of a solar power plant are discussed.

  20. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. The ACES lightning study used the Altus II twin turbo uninhabited aerial vehicle, built by General Atomics Aeronautical Systems, Inc. of San Diego. The Altus II was chosen for its slow flight speed of 75 to 100 knots (80 to 115 mph), long endurance, and high-altitude flight (up to 65,000 feet). These qualities gave the Altus II the ability to fly near and around thunderstorms for long periods of time, allowing investigations to be conducted over the entire life cycle of storms. The vehicle has a wing span of 55 feet and a payload capacity of over 300 lbs. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  1. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. The ACES lightning study used the Altus II twin turbo uninhabited aerial vehicle, built by General Atomics Aeronautical Systems, Inc. of San Diego. The Altus II was chosen for its slow flight speed of 75 to 100 knots (80 to 115 mph), long endurance, and high-altitude flight (up to 65,000 feet). These qualities gave the Altus II the ability to fly near and around thunderstorms for long periods of time, allowing investigations to be to be conducted over the entire life cycle of storms. The vehicle has a wing span of 55 feet and a payload capacity of over 300 lbs. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA,s Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  2. Apoptosis of postovulatory cumulus granulosa cells of the rat.

    PubMed

    Szołtys, M; Tabarowski, Z; Pawlik, A

    2000-12-01

    The process of apoptosis in the postovulatory cumulus granulosa cells was investigated in pregnant rats. Mature female Wistar rats, exhibiting a regular 4-day oestrous cycle, were placed with males on the day of pro-oestrus. The following day, on which spermatozoa were found in vaginal smears, was designated day 1 of pregnancy. The animals were killed just before ovulation (24.00 hours), on days 1 (5.00, 11.00, and 18.00 hours), and 2 ( 11.00 hours) of pregnancy. Excised ovaries and oviducts were submitted to a routine histological procedure and paraplast sections were subjected to detection of apoptotic cells using the TUNEL method. The cumulus granulosa cells of preovulatory follicles (24.00 hours) were negative for apoptotic staining. However, 5 h later a positive staining was observed in the oviduct ampulla and included the cumulus granulosa cells lying in the peripheral parts of postovulatory cumuli oophori, and the oviductal epithelial cells of this region. On the evening of day 1 almost all cumulus granulosa cells showed strong immunostaining while on day 2 at 11.00 hours only immunonegative clusters of remnants of cumulus granulosa cells were present in the distended ampulla region, while naked, two or more cell embryos were present in the further parts of oviduct. These results indicate that in the rat apoptosis of cumulus granulosa cells starts shortly after ovulation in the peripheral region. Epithelial ampullary cells surrounding ovulated cumuli show a massive apoptosis. PMID:11131018

  3. Effect of oocytectomy on glycosaminoglycan composition during cumulus expansion of porcine cumulus-oocyte complexes cultured in vitro.

    PubMed

    Nakayama, T; Inoue, M; Sato, E

    1996-12-01

    To investigate the role of oocytes in the accumulation of glycosaminoglycans during cumulus expansion, we analyzed the amount and composition of glycosaminoglycans in porcine intact and oocytectomized cumulus-oocyte complexes. Follicular fluid induced cumulus expansion in intact and oocytectomized cumulus-oocyte complexes cultured for over 24 h, but the degree of expansion in oocytectomized complexes reached only 76% of that in intact complexes after 24 h in culture. There were no differences in the amounts of [3H]glucosamine incorporated into each type of complex. Metabolic labeling studies on glycosaminoglycans with [3H]glucosamine and [35S]sulfate showed that the amounts of 3H- and 35S-labeled glycosaminoglycans increased, and rapidly so, from 16 h in culture. The 3H-labeled glycosaminoglycans at these high levels were digested by Streptomyces hyaluronidase or chondroitinase ABC, and the rate of increase in 3H-labeled glycosaminoglycans was reduced by oocytectomy. In contrast, the increased levels of 35S-labeled glycosaminoglycans were affected only by chondroitinase ABC, and oocytectomy was ineffective. In conclusion, follicular fluid promotes cumulus expansion, and the oocyte plays an essential role in the acute synthesis of hyaluronic acid, but not chondroitin sulfate, during cumulus expansion stimulated in vitro.

  4. Functional significance of cumulus expansion in the mouse: roles for the preovulatory synthesis of hyaluronic acid within the cumulus mass.

    PubMed

    Chen, L; Russell, P T; Larsen, W J

    1993-01-01

    Gonadotropin-stimulated expansion of the mouse cumulus oocyte complex (COC) in vitro, measured with a quantitative videographic method, is comparable to that observed to occur in vivo when medium is supplemented with porcine follicle stimulating hormone (pFSH), 10% fetal bovine serum (FBS), and 2.5 mM glucosamine or optimal concentrations of glutamine and glucose. In the absence of glucosamine, the volumetric expansion of COCs in vitro is never more than 25% of that occurring in its presence. The addition of 6-diazo-5-oxo-1-norleucine (DON), an inhibitor of glucosamine synthesis to medium supplemented with glutamine and glucose, completely inhibits cumulus expansion in vitro. This system was utilized to examine the relationship between cumulus expansion and fertilization rates, and the maintenance of fertilizability in culture. Successful fertilization (as determined by development to the 2-cell stage) was correlated with the quantity and quality of the expanded cumulus mass, and conversely, the spontaneous loss or mechanical removal of the cumulus was correlated with a loss of fertilizability following additional incubation in culture medium. In addition, the i.p. injection of DON inhibited cumulus expansion within the intact follicle and suppressed ovulation.

  5. First radar echoes from cumulus clouds

    NASA Technical Reports Server (NTRS)

    Knight, Charles A.; Miller, L. J.

    1993-01-01

    In attempting to use centimeter-wavelength radars to investigate the early stage of precipitation formation in clouds, 'mantle echoes' are rediscovered and shown to come mostly from scattering by small-scale variations in refractive index, a Bragg kind of scattering mechanism. This limits the usefulness of single-wavelength radar for studies of hydrometeor growth, according to data on summer cumulus clouds in North Dakota, Hawaii, and Florida, to values of reflectivity factor above about 10 dBZe with 10-cm radar, 0 dBZe with 5-cm radar, and -10 dBZe with 3-cm radar. These are limits at or above which the backscattered radar signal from the kinds of clouds observed can be assumed to be almost entirely from hydrometeors or (rarely) other particulate material such as insects. Dual-wavelength radar data can provide the desired information about hydrometeors at very low reflectivity levels if assumptions can be made about the inhomogeneities responsible for the Bragg scattering. The Bragg scattering signal itself probably will be a useful way to probe inhomogeneities one-half the radar wavelength in scale for studying cloud entrainment and mixing processes. However, this use is possible only before scattering from hydrometeors dominates the radar return.

  6. Transcriptomic analysis of cyclic AMP response in bovine cumulus cells.

    PubMed

    Khan, D R; Guillemette, C; Sirard, M A; Richard, F J

    2015-09-01

    Acquisition of oocyte developmental competence needs to be understood to improve clinical outcomes of assisted reproduction. The stimulation of cumulus cell concentration of cyclic adenosine 3'5'-monophosphate (cAMP) by pharmacological agents during in vitro maturation (IVM) participates in improvement of oocyte quality. However, precise coordination and downstream targets of cAMP signaling in cumulus cells are largely unknown. We have previously demonstrated better embryo development after cAMP stimulation for first 6 h during IVM. Using this model, we investigated cAMP signaling in cumulus cells through in vitro culture of cumulus-oocyte complexes (COCs) in the presence of cAMP raising agents: forskolin, IBMX, and dipyridamole (here called FID treatment). Transcriptomic analysis of cumulus cells indicated that FID-induced differentially expressed transcripts were implicated in cumulus expansion, steroidogenesis, cell metabolism, and oocyte competence. Functional genomic analysis revealed that protein kinase-A (PKA), extracellular signal regulated kinases (ERK1/2), and calcium (Ca(2+)) pathways as key regulators of FID signaling. Inhibition of PKA (H89) in FID-supplemented COCs or substitution of FID with calcium ionophore (A23187) demonstrated that FID activated primarily the PKA pathway which inhibited ERK1/2 phosphorylation and was upstream of calcium signaling. Furthermore, inhibition of ERK1/2 phosphorylation by FID supported a regulation by dual specific phosphatase (DUSP1) via PKA. Our findings imply that cAMP (FID) regulates cell metabolism, steroidogenesis, intracellular signaling and cumulus expansion through PKA which modulates these functions through optimization of ERK1/2 phosphorylation and coordination of calcium signaling. These findings have implications for development of new strategies for improving oocyte in vitro maturation leading to better developmental competence.

  7. Transcriptomic analysis of cyclic AMP response in bovine cumulus cells

    PubMed Central

    Khan, D. R.; Guillemette, C.; Sirard, M. A.

    2015-01-01

    Acquisition of oocyte developmental competence needs to be understood to improve clinical outcomes of assisted reproduction. The stimulation of cumulus cell concentration of cyclic adenosine 3′5′-monophosphate (cAMP) by pharmacological agents during in vitro maturation (IVM) participates in improvement of oocyte quality. However, precise coordination and downstream targets of cAMP signaling in cumulus cells are largely unknown. We have previously demonstrated better embryo development after cAMP stimulation for first 6 h during IVM. Using this model, we investigated cAMP signaling in cumulus cells through in vitro culture of cumulus-oocyte complexes (COCs) in the presence of cAMP raising agents: forskolin, IBMX, and dipyridamole (here called FID treatment). Transcriptomic analysis of cumulus cells indicated that FID-induced differentially expressed transcripts were implicated in cumulus expansion, steroidogenesis, cell metabolism, and oocyte competence. Functional genomic analysis revealed that protein kinase-A (PKA), extracellular signal regulated kinases (ERK1/2), and calcium (Ca2+) pathways as key regulators of FID signaling. Inhibition of PKA (H89) in FID-supplemented COCs or substitution of FID with calcium ionophore (A23187) demonstrated that FID activated primarily the PKA pathway which inhibited ERK1/2 phosphorylation and was upstream of calcium signaling. Furthermore, inhibition of ERK1/2 phosphorylation by FID supported a regulation by dual specific phosphatase (DUSP1) via PKA. Our findings imply that cAMP (FID) regulates cell metabolism, steroidogenesis, intracellular signaling and cumulus expansion through PKA which modulates these functions through optimization of ERK1/2 phosphorylation and coordination of calcium signaling. These findings have implications for development of new strategies for improving oocyte in vitro maturation leading to better developmental competence. PMID:26082143

  8. Surface-water quality assessment of the North Fork Red River basin upstream from Lake Altus, Oklahoma, 2002

    USGS Publications Warehouse

    Smith, S. Jerrod; Schneider, M.L.; Masoner, J.R.; Blazs, R.L.

    2003-01-01

    Elevated salinity in the North Fork Red River is a major concern of the Bureau of Reclamation W. C. Austin Project at Lake Altus. Understanding the relation between surface-water runoff, ground-water discharge, and surface-water quality is important for maintaining the beneficial use of water in the North Fork Red River basin. Agricultural practices, petroleum production, and natural dissolution of salt-bearing bedrock have the potential to influence the quality of nearby surface water. The U.S. Geological Survey, in cooperation with the Bureau of Reclamation, sampled stream discharge and water chemistry at 19 stations on the North Fork Red River and tributaries. To characterize surface-water resources of the basin in a systematic manner, samples were collected synoptically during receding streamflow conditions during July 8-11, 2002. Together, sulfate and chloride usually constitute greater than half of the dissolved solids. Concentrations of sulfate ranged from 87.1 to 3,450 milligrams per liter. The minimum value was measured at McClellan Creek near Back (07301220), and the maximum value was measured at Bronco Creek near Twitty (07301303). Concentrations of chloride ranged from 33.2 to 786 milligrams per liter. The minimum value was measured at a North Fork Red River tributary (unnamed) near Twitty (07301310), and the maximum value was measured at the North Fork Red River near Back (07301190), the most upstream sample station.

  9. Seeding cumulus in Florida: new 1970 results.

    PubMed

    Simpson, J; Woodley, W L

    1971-04-01

    In the Florida single cloud experiments, the main result of the statistical analyses is that the dynamic seeding effect on rainfall is large, positive, and significant. From all the 1968 and 1970 data together, the seeding effect is estimated to be larger than a factor of 3; that is, the seeded clouds rained more than three times as much as the controls after the seeding run. On fair days, defined objectively by percentage of area covered by showers, the seeding effect is shown to be larger than the overall average, but it may be negative on rainy days. Rainy days in the tropics are about 10 percent of the days with rain, but they produce about half the total rainfall. The applicability of our single cloud results to other areas is not established but seems hopeful for many tropical and subtropical regions. It can be assessed by cloud population studies together with our numerical model (25). Guidance for the next steps toward practical rainfall enhancement and toward the understanding and modification of cloud systems in storms may be provided by our study of merger clouds. Mergers are shown often to produce more than an order of magnitude more rain than isolated clouds on the same day, probably owing to dynamic invigoration of the merged cloud circulations. Results of our first small attempt toward inducing and documenting mergers in a multiple cloud seeding experiment appear promising. Although far from statistically conclusive, they have opened a new frontier in the science and technology of dynamic cloud modification. It is also hoped that the multiple cumulus seeding experiments will help to clarify the formation of "cloud clusters" and their role in large-scale circulations, thus contributing to the focal subject of the Global Atmospheric Research Program in the tropics.

  10. Charging of multiple interacting particles by contact electrification.

    PubMed

    Soh, Siowling; Liu, Helena; Cademartiri, Rebecca; Yoon, Hyo Jae; Whitesides, George M

    2014-09-24

    Many processes involve the movement of a disordered collection of small particles (e.g., powders, grain, dust, and granular foods). These particles move chaotically, interact randomly among themselves, and gain electrical charge by contact electrification. Understanding the mechanisms of contact electrification of multiple interacting particles has been challenging, in part due to the complex movement and interactions of the particles. To examine the processes contributing to contact electrification at the level of single particles, a system was constructed in which an array of millimeter-sized polymeric beads of different materials were agitated on a dish. The dish was filled almost completely with beads, such that beads did not exchange positions. At the same time, during agitation, there was sufficient space for collisions with neighboring beads. The charge of the beads was measured individually after agitation. Results of systematic variations in the organization and composition of the interacting beads showed that three mechanisms determined the steady-state charge of the beads: (i) contact electrification (charging of beads of different materials), (ii) contact de-electrification (discharging of beads of the same charge polarity to the atmosphere), and (iii) a long-range influence across beads not in contact with one another (occurring, plausibly, by diffusion of charge from a bead with a higher charge to a bead with a lower charge of the same polarity).

  11. A review of thunderstorm electrification processes

    SciTech Connect

    Saunders, C.P.R. )

    1993-04-01

    Recent developments in the area of thunderstorm electrification processes are reviewed. These processes have two main divisions: (a) convective, in which particles charged by ion capture are moved by convection currents to strengthen the electric field in the cloud, and (b) processes involving charge transfer during particle interactions, following which oppositely charged particles move apart in the updraft to form the observed charge centers. Type-b processes are further subdivided into inductive (relying on the preexistence of an electric field) and noninductive charge-transfer mechanisms, Field and laboratory evidence points to the importance of interactions between particles of the ice phase, in the presence of liquid water droplets, in separating electric charge in thunderstorms. Recent experimental studies have investigated the dependence of charge transfer on the size and relative velocity of the interacting particles and have determined the dependence of the sign of the charge transfer on temperature and cloud liquid water content. Field data upon which the laboratory simulations are based are obtained by increasingly sophisticated airborne and ground-based means. Calculations of electric field growth using experimental charge-transfer data in numerical models of the dynamical and microphysical development of thunderstorms show agreement with observations, although further refinement is required. Some directions for future research are outlined. 121 refs., 2 figs.

  12. Immature oocyte quality and maturational competence of porcine cumulus-oocyte complexes subpopulations.

    PubMed

    Alvarez, Gabriel Martin; Dalvit, Gabriel Carlos; Achi, María Verónica; Miguez, Marcelo Sergio; Cetica, Pablo Daniel

    2009-12-01

    Porcine immature oocyte quality (i.e., that of live oocytes at the germinal vesicle stage) was evaluated according to features of the surrounding cumulus, aiming to establish maturational competence of different subpopulations of such cumulus-oocyte complexes. Six subpopulations were identified: A1 (with a dense cumulus), A2 (with a translucent cumulus), B1 (with the corona radiata), B2 (partly naked oocytes), C (naked oocytes), D (with a dark cumulus). The percent incidence of live oocyte in these subpopulations changed significantly as related to cumulus features, however the occurrence of oocytes in the germinal vesicle stage was lower in class D only. Similar metaphase II rates achieved in A1, A2, B1 and B2 classes after in vitro maturation suggest that the nucleus may in fact mature in vitro, in spite of the different accompanying cumulus features which are typical of these classes. In contrast, a higher cytoplasmic maturation rate obtained in class A may indicate a stronger dependence of this variable upon cumulus features than that shown by nuclear maturation. When different types of cumulus expansion after in vitro maturation were considered (i.e., fully expanded cumulus, partly expanded cumulus, and partly naked oocyte), no differences were found in the percent of oocytes reaching metaphase II or cytoplasmic maturation. It is concluded that morphological features of the collected porcine cumulus-oocyte complexes (rather than cumulus behavior during culture) may be useful for selection of potentially competent oocytes for in vitro fertilization and embryo production. PMID:20067032

  13. Progesterone from the Cumulus Cells Is the Sperm Chemoattractant Secreted by the Rabbit Oocyte Cumulus Complex

    PubMed Central

    Guidobaldi, Héctor Alejandro; Teves, María Eugenia; Uñates, Diego Rafael; Anastasía, Agustín; Giojalas, Laura Cecilia

    2008-01-01

    Sperm chemotaxis in mammals have been identified towards several female sources as follicular fluid (FF), oviduct fluid, and conditioned medium from the cumulus oophorus (CU) and the oocyte (O). Though several substances were confirmed as sperm chemoattractant, Progesterone (P) seems to be the best chemoattractant candidate, because: 1) spermatozoa express a cell surface P receptor, 2) capacitated spermatozoa are chemotactically attracted in vitro by gradients of low quantities of P; 3) the CU cells produce and secrete P after ovulation; 4) a gradient of P may be kept stable along the CU; and 5) the most probable site for sperm chemotaxis in vivo could be near and/or inside the CU. The aim of this study was to verify whether P is the sperm chemoattractant secreted by the rabbit oocyte-cumulus complex (OCC) in the rabbit, as a mammalian animal model. By means of videomicroscopy and computer image analysis we observed that only the CU are a stable source of sperm attractants. The CU produce and secrete P since the hormone was localized inside these cells by immunocytochemistry and in the conditioned medium by enzyme immunoassay. In addition, rabbit spermatozoa express a cell surface P receptor detected by western blot and localized over the acrosomal region by immunocytochemistry. To confirm that P is the sperm chemoattractant secreted by the CU, the sperm chemotactic response towards the OCC conditioned medium was inhibited by three different approaches: P from the OCC conditioned medium was removed with an anti-P antibody, the attractant gradient of the OCC conditioned medium was disrupted by a P counter gradient, and the sperm P receptor was blocked with a specific antibody. We concluded that only the CU but not the oocyte secretes P, and the latter chemoattract spermatozoa by means of a cell surface receptor. Our findings may be of interest in assisted reproduction procedures in humans, animals of economic importance and endangered species. PMID:18725941

  14. Connective power: Solar electrification and social change in Kenya

    NASA Astrophysics Data System (ADS)

    Jacobson, Arne Edward

    Household solar photovoltaic systems have emerged as a key alternative to grid-based rural electrification in many developing countries. This may seem a victory for appropriate technology advocates, but my research indicates that the social significance of solar electrification in Kenya, which is among the largest developing country solar markets per capita, is far removed from the classic "small is beautiful" neo-populist vision of building small-scale alternatives to global capitalism. Instead, solar electrification is more closely connected to neo-liberal goals of market-based service provision and economic integration. In this study I combine quantitative and qualitative methods, including surveys, intra-household energy allocation studies, and historical analysis, to analyze the social significance of solar electrification in Kenya. I find that "connective" applications, including television, radio, and cellphones, are centrally important. Television is especially notable; the expansion of TV broadcasting to rural areas was a key condition for solar market development. Solar electricity is also used for lighting. In Kenya, income and work related uses of solar lighting are modest, while education uses are more significant. However, in many households, especially those with small systems, intra-household dynamics constrain key social uses (e.g. children's studying), as the energy is allocated to other uses. Social use patterns combine with access dynamics in Kenya's unsubsidized market to shape the social significance of solar electrification. Solar ownership is dominated by the rural upper and middle classes. Thus, productivity and education uses make small contributions to differentiation and middle class formation. Additionally, solar electrification's role in supporting rural television and radio use improves business advertisers' ability to expand consumer goods markets. These findings link solar electrification to important processes of rural development

  15. Advancing Models and Evaluation of Cumulus, Climate and Aerosol Interactions

    SciTech Connect

    Gettelman, Andrew

    2015-10-27

    This project was successfully able to meet its’ goals, but faced some serious challenges due to personnel issues. Nonetheless, it was largely successful. The Project Objectives were as follows: 1. Develop a unified representation of stratifom and cumulus cloud microphysics for NCAR/DOE global community models. 2. Examine the effects of aerosols on clouds and their impact on precipitation in stratiform and cumulus clouds. We will also explore the effects of clouds and precipitation on aerosols. 3. Test these new formulations using advanced evaluation techniques and observations and release

  16. The beneficial effects of cumulus cells and oocyte-cumulus cell gap junctions depends on oocyte maturation and fertilization methods in mice

    PubMed Central

    Zhou, Cheng-Jie; Wu, Sha-Na; Shen, Jiang-Peng; Wang, Dong-Hui; Kong, Xiang-Wei; Lu, Angeleem; Li, Yan-Jiao; Zhou, Hong-Xia; Zhao, Yue-Fang

    2016-01-01

    Cumulus cells are a group of closely associated granulosa cells that surround and nourish oocytes. Previous studies have shown that cumulus cells contribute to oocyte maturation and fertilization through gap junction communication. However, it is not known how this gap junction signaling affects in vivo versus in vitro maturation of oocytes, and their subsequent fertilization and embryonic development following insemination. Therefore, in our study, we performed mouse oocyte maturation and insemination using in vivo- or in vitro-matured oocyte-cumulus complexes (OCCs, which retain gap junctions between the cumulus cells and the oocytes), in vitro-matured, denuded oocytes co-cultured with cumulus cells (DCs, which lack gap junctions between the cumulus cells and the oocytes), and in vitro-matured, denuded oocytes without cumulus cells (DOs). Using these models, we were able to analyze the effects of gap junction signaling on oocyte maturation, fertilization, and early embryo development. We found that gap junctions were necessary for both in vivo and in vitro oocyte maturation. In addition, for oocytes matured in vivo, the presence of cumulus cells during insemination improved fertilization and blastocyst formation, and this improvement was strengthened by gap junctions. Moreover, for oocytes matured in vitro, the presence of cumulus cells during insemination improved fertilization, but not blastocyst formation, and this improvement was independent of gap junctions. Our results demonstrate, for the first time, that the beneficial effect of gap junction signaling from cumulus cells depends on oocyte maturation and fertilization methods. PMID:26966678

  17. Cumulus parameterizations in chemical transport models

    NASA Astrophysics Data System (ADS)

    Mahowald, Natalie M.; Rasch, Philip J.; Prinn, Ronald G.

    1995-12-01

    Global three-dimensional chemical transport models (CTMs) are valuable tools for studying processes controlling the distribution of trace constituents in the atmosphere. A major uncertainty in these models is the subgrid-scale parametrization of transport by cumulus convection. This study seeks to define the range of behavior of moist convective schemes and point toward more reliable formulations for inclusion in chemical transport models. The emphasis is on deriving convective transport from meteorological data sets (such as those from the forecast centers) which do not routinely include convective mass fluxes. Seven moist convective parameterizations are compared in a column model to examine the sensitivity of the vertical profile of trace gases to the parameterization used in a global chemical transport model. The moist convective schemes examined are the Emanuel scheme [Emanuel, 1991], the Feichter-Crutzen scheme [Feichter and Crutzen, 1990], the inverse thermodynamic scheme (described in this paper), two versions of a scheme suggested by Hack [Hack, 1994], and two versions of a scheme suggested by Tiedtke (one following the formulation used in the ECMWF (European Centre for Medium-Range Weather Forecasting) and ECHAM3 (European Centre and Hamburg Max-Planck-Institut) models [Tiedtke, 1989], and one formulated as in the TM2 (Transport Model-2) model (M. Heimann, personal communication, 1992). These convective schemes vary in the closure used to derive the mass fluxes, as well as the cloud model formulation, giving a broad range of results. In addition, two boundary layer schemes are compared: a state-of-the-art nonlocal boundary layer scheme [Holtslag and Boville, 1993] and a simple adiabatic mixing scheme described in this paper. Three tests are used to compare the moist convective schemes against observations. Although the tests conducted here cannot conclusively show that one parameterization is better than the others, the tests are a good measure of the

  18. Ground-Based Remote Retrievals of Cumulus Entrainment Rates

    SciTech Connect

    Wagner, Timothy J.; Turner, David D.; Berg, Larry K.; Krueger, Steven K.

    2013-07-26

    While fractional entrainment rates for cumulus clouds have typically been derived from airborne observations, this limits the size and scope of available data sets. To increase the number of continental cumulus entrainment rate observations available for study, an algorithm for retrieving them from ground-based remote sensing observations has been developed. This algorithm, called the Entrainment Rate In Cumulus Algorithm (ERICA), uses the suite of instruments at the Southern Great Plains (SGP) site of the United States Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility as inputs into a Gauss-Newton optimal estimation scheme, in which an assumed guess of the entrainment rate is iteratively adjusted through intercomparison of modeled liquid water path and cloud droplet effective radius to their observed counterparts. The forward model in this algorithm is the Explicit Mixing Parcel Model (EMPM), a cloud parcel model that treats entrainment as a series of discrete entrainment events. A quantified value for measurement uncertainty is also returned as part of the retrieval. Sensitivity testing and information content analysis demonstrate the robust nature of this method for retrieving accurate observations of the entrainment rate without the drawbacks of airborne sampling. Results from a test of ERICA on three months of shallow cumulus cloud events show significant variability of the entrainment rate of clouds in a single day and from one day to the next. The mean value of 1.06 km-¹ for the entrainment rate in this dataset corresponds well with prior observations and simulations of the entrainment rate in cumulus clouds.

  19. Hyaluronidase removal of the cumulus oophorus increases in vitro fertilization.

    PubMed

    Lavy, G; Boyers, S P; DeCherney, A H

    1988-10-01

    The effect of hyaluronidase removal of the cumulus oophorus on the in vitro fertilization rate of oocytes obtained from patients with poor oocyte fertilizability has been evaluated. Eighty-eight oocytes were obtained from 13 patients undergoing in vitro fertilization and embryo transfer (IVF-ET) for indications of male-factor, immunological, and idiopathic infertility. In addition, patients in whom fertilization did not occur on previous IVF cycles were evaluated in the study. The oocytes of each individual patient were randomly assigned into a treatment (removal of the cumulus; N = 40 oocytes) or nontreatment group (control; N = 48 oocytes). Hyaluronidase was used to remove the cumulus immediately following oocyte retrieval, and insemination was performed 6-8 hr later. The overall oocyte fertilization rate (both treated and untreated) was 42%. The treatment group demonstrated a higher rate of fertilization compared to the nontreatment group (55% vs 31%; P less than 0.05). Examination of various patient groups revealed a statistically significant difference in fertilization rates between the treated and the untreated oocytes only in the "no previous fertilization" group (60% vs 28%; P less than 0.05). A higher rate of fertilization of the treated oocytes was also seen in the immunologic infertility group, however, statistical significance was not achieved (50% vs 25%; P = 0.07). Only one clinical pregnancy was achieved in this group of 13 patients. We conclude that in this group of patients, removal of the cumulus prior to insemination may, in some cases, increase the fertilization potential of the oocyte.

  20. Near infrared reflection spectra of artificial cumulus clouds.

    PubMed

    Plummer, W T

    1969-10-01

    Reflection spectra are presented for artificial cumulus clouds with a progression of droplet sizes, including sizes common in natural clouds, over the wavelength range from 1.0 micro to 2.4 micro. A correction is made for gaseous absorption. The spectra show reflectivity minima at 1.16 micro, 1.41 micro, and 1.92micro which deepen as the droplets become larger and are in good agreement with reflection spectra of terrestrial clouds.

  1. Understanding Albrecht's model of trade cumulus cloud fields

    SciTech Connect

    Bretherton, C.S. )

    1993-07-15

    Using Albrecht's model, approximate analytical formulas are found for the dependence of the steady-state mean thermodynamic structure of a partly cloudy convective marine boundary layer on external parameters. The goals are to understand the physical factors that influence the vertical profiles of mean relative humidity, temperature, and fractional cloudiness within the cloud layer using the model to gain insight into the stratocumulus-trade cumulus transition in the subtropical trade wind regime, and to understand the sensitivity of the model to tunable internal parameters. A prototype model for trade cumulus boundary layers consists of a well-mixed subcloud layer topped by a cumulus layer and a sharp trade inversion. Precipitation is ignored and simple parameterizations for radiative cooling and fractional cloudiness are used. The analytical approximation agrees with exact steady-state numerical solutions of Albrecht's model. The cloud-base and the trade-inversion heights are not strongly dependent on adjustable parameters within the cloud model and are determined by bulk balances of radiative fluxes, surface fluxes, and subsidence in a manner similar to the more empirical model of Bets and Ridgway. The cloud-layer sounding and the cloud fraction are affected by external parameters only through changes in the cloud-base latent heat flux and the cloud thickness. The cloud fraction is sensitive to two tunable internal constants in the cloud model that affect rates of cloud entrainment and detrainment, respectively. For most choices of SST and upper-air conditions, these constants can be tuned to produce either a mainly saturated (stratocumulus-like) cloud layer or a trade cumulus-like layer with no environmental saturation. The sensitivity of cloud fraction to SST and mean subsidence is explored for two choices of these constants and the effect of unsteadiness due to downstream changes in external conditions are considered. 33 refs., 12 figs., 4 tabs.

  2. Morphological dynamics of cumulus-oocyte complex during oocyte maturation.

    PubMed

    Sato, E

    1998-01-01

    The recent advances on the cytoplasmic regulators of the induction of germinal vesicle break down, maturation and degeneration of oocytes, and glycosaminoglycan composition during cumulus expansion of cumulus-oocyte complexes are discussed. A) Inactive mitogen-activated protein kinases (MAPKs) are present in the oocytes at germinal vesicle (GV) stage, and are activated with germinal vesicle breakdown (GVBD), and remain highly active throughout maturation in porcine oocytes. Inactive MAPKs are localized in the cytoplasm of GV-arrested oocytes and active MAPKs were detected in the GV just before GVBD. B) Cumulus expansion of porcine cumulus-oocyte complexes (COCs) was reduced by oocy tectomy. The profile of total glycosaminoglycan synthesis was attributed to hyaluronic acid rather than chondroitin sulfate in intact COCs and oocytectomy reduced hyaluronic acid synthesis. C) The abnormalities of chromosomes and alpha-tubulin morphology were observed in the oocytes of c-mos deficient mice. MAPK activity of c-mos deficient oocytes did not significantly fluctuate throughout maturation and was clearly lower than that of wild-type oocytes. One of the most drastic abnormalities in c-mos knockout mouse oocytes was their entrance into the interphase instead of second meiosis after first polar body emission. D) Reverse transcriptase/polymerase chain reaction-Southern blot hybridization demonstrated positive expression of Fas in intraovarian mouse oocytes. In contrast, expression of Fas ligand was detected in granulosa cells. These findings were histologically confirmed by in situ hybridization with Fas- and FasL-specific probes. Co-culture of intact and zona-free eggs and granulosa cells demonstrated positive TUNEL staining only zona-free eggs.

  3. The use of photovoltaics for rural electrification in northwestern China

    SciTech Connect

    Wallace, W.L.; Li Jingming; Gao Shangbin

    1998-09-01

    The use of renewable energy technologies in China is becoming increasingly important to meet the needs of a large rural population. Solar and wind renewable resources in particular are available in regions of China that at present have no access to conventional grid power. Two regions in China that have an acute lack of electricity are a large region in northern and western China and the coastal island region of China. These regions have attracted the attention of the Chinese government in terms of increasing the quality of life and standard of living conditions of the rural population. These regions have also attracted the attention of domestic Chinese companies and of international companies, governments, and multilateral development organizations as a potential market for renewable energy rural electrification systems. This paper focuses on the bilateral cooperation between the US Department of Energy and China in providing assistance for the use of renewable technologies for rural electrification in northwestern China.

  4. Efficient System Design and Sustainable Finance for China's Village Electrification Program: Preprint

    SciTech Connect

    Ma, S.; Yin, H.; Kline, D. M.

    2006-08-01

    This paper describes a joint effort of the Institute for Electrical Engineering of the Chinese Academy of Sciences (IEE), and the U.S. National Renewable Energy Laboratory (NREL) to support China's rural electrification program. This project developed a design tool that provides guidelines both for off-grid renewable energy system designs and for cost-based tariff and finance schemes to support them. This tool was developed to capitalize on lessons learned from the Township Electrification Program that preceded the Village Electrification Program. We describe the methods used to develop the analysis, some indicative results, and the planned use of the tool in the Village Electrification Program.

  5. Continuous growth of cloud droplets in cumulus cloud

    NASA Astrophysics Data System (ADS)

    Gotoh, Toshiyuki; Suehiro, Tamotsu; Saito, Izumi

    2016-04-01

    A new method to seamlessly simulate the continuous growth of droplets advected by turbulent flow inside a cumulus cloud was developed from first principle. A cubic box ascending with a mean updraft inside a cumulus cloud was introduced and the updraft velocity was self-consistently determined in such a way that the mean turbulent velocity within the box vanished. All the degrees of freedom of the cloud droplets and turbulence fields were numerically integrated. The box ascended quickly inside the cumulus cloud due to the updraft and the mean radius of the droplets grew from 10 to 24 μm for about 10 min. The turbulent flow tended to slow down the time evolutions of the updraft velocity, the box altitude and the mean cloud droplet radius. The size distribution of the cloud droplets in the updraft case was narrower than in the absence of the updraft. It was also found that the wavenumeber spectra of the variances of the temperature and water vapor mixing ratio were nearly constant in the low wavenumber range. The future development of the new method was argued.

  6. Shorepower Truck Electrification Project (STEP) - Cumulative through June 2014

    SciTech Connect

    2014-08-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the use of shorepower at 50 planned American Recovery and Reinvestment Act (ARRA)-funded truck stop electrification (TSE) sites across the nation. Trucks participating in the study have idle-reduction equipment installed that was purchased with rebates through the ARRA. A total of 5,000 rebates will be approved.

  7. Shorepower Truck Electrification Project (STEP) - Cumulative through February 2015

    SciTech Connect

    2015-02-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the use of shorepower at 50 planned American Recovery and Reinvestment Act (ARRA)-funded truck stop electrification sites across the nation. Trucks participating in the study have idle-reduction equipment installed that was purchased with rebates through the ARRA. A total of 5,000 rebates will be approved.

  8. Shorepower Truck Electrification Project (STEP) - 2013 (Fact Sheet)

    SciTech Connect

    Not Available

    2014-01-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is evaluating and documenting the use of shorepower at 50 planned American Recovery and Reinvestment Act (ARRA)-funded truck stop electrification sites across the nation. Trucks participating in the study have idle-reduction equipment installed that was purchased with rebates through the ARRA. A total of 5,000 rebates will be approved.

  9. Final Report - Navajo Electrification Demonstration Project - FY2004

    SciTech Connect

    Kenneth L. Craig, Interim General Manager

    2007-03-31

    The Navajo Electrification Demonstration Project (NEDP) is a multi-year projects which addresses the needs of unserved Navajo Nation residents without basic electricity services. The Navajo Nation is the United States' largest tribe, in terms of population and land. An estimated 18,000 Navajo Nation homes do not have basic grid-tied electricity--and this third year of funding, known as NEDP-3, provided 351 power line extensions to Navajo families.

  10. Thundercloud electrification models in atmospheric electricity and meteorology

    NASA Technical Reports Server (NTRS)

    Parker, L. W.

    1980-01-01

    A survey is presented of presently-available theoretical models. The models are classified into three main groups: (1) convection models, (2) precipitation models, and (3) general models. The strengths and weaknesses of the models, their dimensionalities and degrees of sophistication, the nature of their inputs and outputs, and the various specific charging mechanisms treated by them, are considered. In results obtained to date, the convection models predict no significant electrification enhancement based on conductivity gradients and convection alone, with the assumed air circulation patterns. Results of the precipitation models show that the initial electrification can occur rapidly and stably through noninductive collision mechanisms involving ice, and breakdown-strength electric fields can relatively easily be achieved subsequently through the collisional-inductive mechanism. A critical difficulty of the collision mechanisms is imprecise knowledge of relaxation times versus contact times, which can easily lead to overestimates of electrification. The general model results tend to support those of the precipitation models in emphasizing the high potential effectiveness of the collisional-inductive mechanism.

  11. Selective binding of human cumulus cell-secreted glycoproteins to human spermatozoa during capacitation in vitro

    SciTech Connect

    Tesarik, J.; Kopecny, V.; Dvorak, M.

    1984-06-01

    The results of this study demonstrate that glycoproteins manufactured by human cumulus cells can be detected bound to human spermatozoa incubated in capacitational medium containing the labeled cumulus-cell secretions. Cumulus-cell-secreted glycoproteins were labeled with a mixture of /sup 3/H-methionine and /sup 3/H-tryptophan or with 3H-fucose, and the binding of the labeled compounds to spermatozoa was evaluated by autoradiography. The binding was highly selective, involving only approximately 1% of the samples of spermatozoa used. The results suggest that the binding of cumulus-cell-secreted glycoproteins to spermatozoa may represent a final and highly selective step in human sperm capacitation.

  12. Changes in streamflow and summary of major-ion chemistry and loads in the North Fork Red River basin upstream from Lake Altus, northwestern Texas and western Oklahoma, 1945-1999

    USGS Publications Warehouse

    Smith, S. Jerrod; Wahl, Kenneth L.

    2003-01-01

    Upstream from Lake Altus, the North Fork Red River drains an area of 2,515 square miles. The quantity and quality of surface water are major concerns at Lake Altus, and water-resource managers and consumers need historical information to make informed decisions about future development. The Lugert-Altus Irrigation District relies on withdrawals from the lake to sustain nearly 46,000 acres of agricultural land. Kendall's tau tests of precipitation data indicated no statistically significant trend over the entire 100 years of available record. However, a significant increase in precipitation occurred in the last 51 years. Four streamflow-gaging stations with more than 10 years of record were maintained in the basin. These stations recorded no significant trends in annual streamflow volume. Two stations, however, had significant increasing trends in the base-flow index, and three had significant decreasing trends in annual peak flows. Major-ion chemistry in the North Fork Red River is closely related to the chemical composition of the underlying bedrock. Two main lithologies are represented in the basin upstream from Lake Altus. In the upper reaches, young and poorly consolidated sediments include a range of sizes from coarse gravel to silt and clay. Nearsurface horizons commonly are cemented as calcium carbonate caliche. Finer-grained gypsiferous sandstones and shales dominate the lower reaches of the basin. A distinct increase in dissolved solids, specifically sodium, chloride, calcium, and sulfate, occurs as the river flows over rocks that contain substantial quantities of gypsum, anhydrite, and dolomite. These natural salts are the major dissolved constituents in the North Fork Red River.

  13. Proteolytic activity of the 26S proteasome is required for the meiotic resumption, germinal vesicle breakdown, and cumulus expansion of porcine cumulus-oocyte complexes matured in vitro.

    PubMed

    Yi, Young-Joo; Nagyova, Eva; Manandhar, Gaurishankar; Procházka, Radek; Sutovsky, Miriam; Park, Chang-Sik; Sutovsky, Peter

    2008-01-01

    The resumption of oocyte meiosis in mammals encompasses the landmark event of oocyte germinal vesicle (GV) breakdown (GVBD), accompanied by the modification of cell-to-cell communication and adhesion between the oocyte and surrounding cumulus cells. The concomitant cumulus expansion relies on microfilament-cytoskeletal remodeling and extracellular matrix (ECM) deposition. We hypothesized that this multifaceted remodeling event requires substrate-specific proteolysis by the ubiquitin-proteasome pathway (UPP). We evaluated meiotic progression, cytoskeletal dynamics, and the production of cumulus ECM in porcine cumulus-oocyte complexes (COCs) cultured with or without 10-200 microM MG132, a specific proteasomal inhibitor, for the first 22 h of in vitro maturation, followed by 22 h of culture with or without MG132. Treatment with 10 microM MG132 arrested 28.4% of oocytes in GV stage (vs. 1.3% in control), 43.1% in prometaphase I, and 16.2% in metaphase I, whereas 83.7% of control ova reached metaphase II (0% of MG132 reached metaphase II). The proportion of GV-stage ova increased progressively to >90% with increased concentration of MG132 (20-200 microM). Furthermore, MG132 blocked the extrusion of the first polar body and degradation of F-actin-rich transzonal projections (TZP) interconnecting cumulus cells with the oocyte. The microfilament disruptor cytochalasin E (CE) prevented cumulus expansion but accelerated the breakdown of TZPs. Ova treated with a combination of 10 microM MG132 and 10 microM CE underwent GVBD, despite the inhibition of proteasomal activity. However, 90.0% of cumulus-free ova treated with 10 microM MG132 remained in GV stage, compared with 16.7% GV ova in control. Cumulus expansion, retention of hyaluronic acid, and the deposition of cumulus ECM relying on the covalent transfer of heavy chains of inter-alpha trypsin inhibitor (IalphaI) were also inhibited by MG132. Cumulus expansion in control COCs was accompanied by the degradation of ubiquitin

  14. Navajo Electrification for Sustainable Development: The Potential Economic and Social Benefits

    ERIC Educational Resources Information Center

    Ballentine, Crystal; DeSouza, Anil; Bain, Craig; Majure, Lisa; Smith, Dean Howard; Turek, Jill

    2004-01-01

    The concomitant secondary consequences of an electrification program and the potential long-term benefits of such a program are described. An electrification program can stimulate a move toward true self-determination and self-sufficiency for the Navajo nation.

  15. An Empirical Cumulus Parameterization Scheme for a Global Spectral Model

    NASA Technical Reports Server (NTRS)

    Rajendran, K.; Krishnamurti, T. N.; Misra, V.; Tao, W.-K.

    2004-01-01

    Realistic vertical heating and drying profiles in a cumulus scheme is important for obtaining accurate weather forecasts. A new empirical cumulus parameterization scheme based on a procedure to improve the vertical distribution of heating and moistening over the tropics is developed. The empirical cumulus parameterization scheme (ECPS) utilizes profiles of Tropical Rainfall Measuring Mission (TRMM) based heating and moistening derived from the European Centre for Medium- Range Weather Forecasts (ECMWF) analysis. A dimension reduction technique through rotated principal component analysis (RPCA) is performed on the vertical profiles of heating (Q1) and drying (Q2) over the convective regions of the tropics, to obtain the dominant modes of variability. Analysis suggests that most of the variance associated with the observed profiles can be explained by retaining the first three modes. The ECPS then applies a statistical approach in which Q1 and Q2 are expressed as a linear combination of the first three dominant principal components which distinctly explain variance in the troposphere as a function of the prevalent large-scale dynamics. The principal component (PC) score which quantifies the contribution of each PC to the corresponding loading profile is estimated through a multiple screening regression method which yields the PC score as a function of the large-scale variables. The profiles of Q1 and Q2 thus obtained are found to match well with the observed profiles. The impact of the ECPS is investigated in a series of short range (1-3 day) prediction experiments using the Florida State University global spectral model (FSUGSM, T126L14). Comparisons between short range ECPS forecasts and those with the modified Kuo scheme show a very marked improvement in the skill in ECPS forecasts. This improvement in the forecast skill with ECPS emphasizes the importance of incorporating realistic vertical distributions of heating and drying in the model cumulus scheme. This

  16. Sensitivity of land surface and Cumulus schemes for Thunderstorm prediction

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Mohanty, U. C.; Kumar, Krishan

    2016-06-01

    The cloud processes play an important role in all forms of precipitation. Its proper representation is one of the challenging tasks in mesoscale numerical simulation. Studies have revealed that mesoscale feature require proper initialization which may likely to improve the convective system rainfall forecasts. Understanding the precipitation process, model initial condition accuracy and resolved/sub grid-scale precipitation processes representation, are the important areas which needed to improve in order to represent the mesoscale features properly. Various attempts have been done in order to improve the model performance through grid resolution, physical parameterizations, etc. But it is the physical parameterizations which provide a convective atmosphere for the development and intensification of convective events. Further, physical parameterizations consist of cumulus convection, surface fluxes of heat, moisture, momentum, and vertical mixing in the planetary boundary layer (PBL). How PBL and Cumulus schemes capture the evolution of thunderstorm have been analysed by taking thunderstorm cases occurred over Kolkata, India in the year 2011. PBL and cumulus schemes were customized for WSM-6 microphysics because WSM series has been widely used in operational forecast. Results have shown that KF (PBL scheme) and WSM-6 (Cumulus Scheme) have reproduced the evolution of surface variable such as CAPE, temperature and rainfall very much like observation. Further, KF and WSM-6 scheme also provided the increased moisture availability in the lower atmosphere which was taken to higher level by strong vertical velocities providing a platform to initiate a thunderstorm much better. Overestimation of rain in WSM-6 occurs primarily because of occurrence of melting and freezing process within a deeper layer in WSM-6 scheme. These Schemes have reproduced the spatial pattern and peak rainfall coverage closer to TRMM observation. It is the the combination of WSM-6, and KF schemes

  17. Vertical Velocities in Cumulus Convection: Implications for Climate and Prospects for Realistic Simulation at Cloud Scale

    NASA Astrophysics Data System (ADS)

    Donner, Leo

    2014-05-01

    Cumulus mass fluxes are essential controls on the interactions between cumulus convection and large-scale flows. Cumulus parameterizations have generally been built around them, and these parameterizations are basic components of climate models. Several important questions in climate science depend also on cumulus vertical velocities. Interactions between aerosols and convection comprise a prominent example, and scale-aware cumulus parameterizations that require explicit information about cumulus areas are another. Basic progress on these problems requires realistic characterization of cumulus vertical velocities from observations and models. Recent deployments of dual-Doppler radars are providing unprecedented observations, which can be compared against cloud-resolving models (CRMs). The CRMs can subsequently be analyzed to develop and evaluate parameterizations of vertical velocities in climate models. Vertical velocities from several cloud models will be compared against observations in this presentation. CRM vertical velocities will be found to depend strongly on model resolution and treatment of sub-grid turbulence and microphysics. Although many current state-of-science CRMs do not simulate vertical velocities well, recent experiments with these models suggest that with appropriate treatments of sub-grid turbulence and microphysics robustly realistic modeling of cumulus vertical velocities is possible.

  18. The Green Ocean Over the Amazon: Implications for Cloud Electrification

    NASA Technical Reports Server (NTRS)

    Williams, E.; Blakeslee, R.; Boccippio, D.; Arnold, James E. (Technical Monitor)

    2001-01-01

    A convective regime with distinct maritime characteristics (weak updraft, low CCN, prevalent coalescence and rainout, weak mixed phase reflectivity, low glaciation temperature, and little if any lightning) is documented over the Amazon basin of the South American continent, and dubbed the "green ocean". Radar, lightning, thermodynamic and AVHRR satellite observations are examined to shed light on the roles of updraft and aerosol in providing departures from the green ocean regime toward continental behavior. Extreme case studies are identified in which the updraft control is dominant and in which the aerosol control is dominant. The tentative conclusion gives importance to both updrafts and aerosol in shaping the electrification of tropical convection.

  19. Does Electrification Spur the Fertility Transition? Evidence From Indonesia.

    PubMed

    Grimm, Michael; Sparrow, Robert; Tasciotti, Luca

    2015-10-01

    We analyze various pathways through which access to electricity affects fertility in Indonesia, using a district difference-in-difference approach. The electrification rate increased by 65 % over the study period, and our results suggest that the subsequent effects on fertility account for about 18 % to 24 % of the overall decline in fertility. A key channel is increased exposure to television. Using in addition several waves of Demographic and Health Surveys, we find suggestive evidence that increased exposure to TV affects, in particular, fertility preferences and increases the effective use of contraception. Reduced child mortality seems to be another important pathway.

  20. Bolivia: rural electrification. Project impact evaluation report No. 16

    SciTech Connect

    Butler, E.; Poe, K.M.; Tendler, J.

    1980-12-01

    Two rural electrification systems initiated in Bolivia in 1973 and 1974 are the subject of this report. By 1979, all distribution networks were completed, except in the La Paz region. Power was supplied to 42,000 consumers and was used primarily for residential lighting. Although demand outpaced supply, consumption per household was lower than projected, and irrigation and industrial use was negligible. The preponderant positive impact of the projects was social. Household lighting improved the physical quality of life for 7% of Bolivia's rural population.

  1. Shorepower Truck Electrification Project (STEP) - 1Q - 2Q 2013

    SciTech Connect

    2014-02-01

    The Fleet Test and Evaluation Team at the U.S. Department of Energy's National Renewable Energy Laboratory is evaluating and documenting the use of shorepower at 50 planned American Recovery and Reinvestment Act (ARRA)-funded truck stop electrification (TSE) sites across the nation. Trucks participating in the study have idle-reduction equipment installed that was purchased with rebates through the ARRA. A total of 5,000 rebates will be approved. the ARRA. A total of 5,000 rebates will be approved.

  2. User-owned utility models for rural electrification

    SciTech Connect

    Waddle, D.

    1997-12-01

    The author discusses the history of rural electric cooperatives (REC) in the United States, and the broader question of whether such organizations can serve as a model for rural electrification in other countries. The author points out the features of such cooperatives which have given them stability and strength, and emphasizes that for success of such programs, many of these same features must be present. He definitely feels the cooperative models are not outdated, but they need strong local support, and a governmental structure which is supportive, and in particular not negative.

  3. Vertical coupling of the stratocumulus boundary layer by penetrating cumulus

    SciTech Connect

    Wang, Q.; Lenschow, D.H.

    1994-12-31

    During the Atlantic Stratocumulus Transition Experiment (ASTEX), small cumulus clouds that penetrate through the stratocumulus sheets were observed frequently. Radar observations show that the reflectivity cores in the penetrating cumuli are generally 1--2 km in diameter with a much larger enhanced patch of stratocumulus approximately 15--20 km across, whereas visual estimates of the diameter of the cumuli are generally in the neighborhood of several kilometers. In this study, the authors analyze measurements made on 10 June 1992 from the NCAR Electra aircraft. They are particularly interested in the role penetrating cumuli play in transporting moisture and other scalar between the sea surface and the top of the boundary layer, which is directly related to the important practical question of whether or not the penetrating cumuli tend to break up or dissipate the overlying stratocumulus cloud and aid the transition from a stratocumulus to a cumulus boundary layer. Large variations in temperature, specific humidity, and ozone are observed on both in-cloud legs. The differences between the maximum and minimum values of potential temperature, specific humidity, and ozone on these legs are around 1.1 deg, 1.4 g kg{sup {minus}1}, and 7 ppbv, respectively. To the authors` knowledge, such substantial horizontal variations of scalar variables have never been reported before in stratocumulus-topped boundary layers over the ocean. Close inspections of the time series indicate that the highest temperature and moisture and the lowest ozone concentration are found in the Cu region on both legs.

  4. Nearest neighbor spacing of fair weather cumulus clouds

    NASA Technical Reports Server (NTRS)

    Joseph, Joachim H.; Cahalan, Robert F.

    1990-01-01

    Histograms of nearest neighbor spacings of fair weather cumulus at 15 locations over the world's oceans are presented based on the analysis of high resolution Landsat 3 Multispectral Scanner images for amounts of cloud cover ranging from 0.6 to 37.6 percent. These histograms are found to be essentially the same at all locations analyzed, similarly to previous findings on the size distributions and the fractal dimensions of the perimeters for this cloud type. The nearest neighbor spacings are linearly dependent on the effective cloud radii, with a proportionality factor ranging from five to twenty. The histograms peak at about 0.5 km. Nearest-neighbor spacings smaller than about a kilometer, associated with cumulus clouds with an effective radius less than a few hundred meters, have a distribution of cloud centers that is almost indepedent in the horizontal plane and show a tendency for the formation of clumps. Larger spacings of up to thirty kilometers occur and are associated with the larger clouds. These latter spacings are not independent.

  5. Towards Realistic Cumulus Cloud Resolving Simulations at Supersites

    NASA Astrophysics Data System (ADS)

    van Laar, T.; Schemann, V.; Neggers, R.

    2015-12-01

    Realistic fine-scale shallow cumulus cloud resolving simulations are performed to improve our understanding of the interactions between surface heterogeneity and boundary-layer cloud fields. For this purpose we apply the ICON (ICOsahedral Non-hydrostatic) model on a regional domain. ICON has been partly developed by the ongoing project HD(CP)2 (High Definition Clouds and Precipitation for Climate Prediction), which has the aim of getting a better grip on cloud and precipitation processes and their implication for climate prediction. The model domain is centred around JOYCE, an observational supersite in Jülich (Germany). To optimize the realism of the simulation, use is made of heterogeneous surface forcings and non-periodic boundary conditions. A number of prototype cumulus days is simulated, the results of which are evaluated against observations. The focus lies on bulk cloud properties and the vertical structure of the boundary layer. The ICON results are intercompared with available idealized LES results. Sensitivity of the results to the model set-up (e.g. resolution) is assessed.

  6. 76 FR 56797 - United States v. Cumulus Media Inc., et al.; Proposed Final Judgment and Competitive Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... Antitrust Division United States v. Cumulus Media Inc., et al.; Proposed Final Judgment and Competitive... United States District Court for the District of Columbia in United States of America v. Cumulus Media... Complaint alleging that Cumulus Media Inc.'s proposed acquisition of Citadel Broadcasting Corporation...

  7. Photovoltaics for rural electrification in the Dominican Republic

    SciTech Connect

    Hansen, R.D.; Martin, J.G.

    1987-08-21

    Enersol Associates, Inc., has begun to structure a program for the introduction of photovoltaics in rural areas, and started to refer to this as the SOBASEC (SOlar-BASed Rural Electrification Concept) program. Throughout the report we have used the acronym SOBASEC to refer to the specific approach to electrification in rural areas with photovoltaics, as developed by Enersol Associates, Inc. This report documents the efforts to date and describes SOBASEC so that a variety of readers may benefit. This report provides an overall background on the Dominican Republic and a history of the project developed by Enersol in the Puerto Plata region. It describes the electric grid system that is owned and operated by the Dominican Government, and which serves urban dwellers and approximately 30% of the rural population. This paper is dedicated to describing the technical and institutional details of SOBASEC as developed by experience in implementing the program and installing the first 100 PV systems. Also discussed is the logical expansion that can take place with adequate financing and institutional support. This is done by describing a reasonable investment scenario. A key catalytic role of this financing is placed in the hands of the organizations that aim toward economic and social development in less developed countries. Recommendations and concluding comments on where this all may lead in the years to come is finally discussed. 61 refs., 59 figs.

  8. Influence of particle wall adhesion on particle electrification in mixers.

    PubMed

    Zhu, Kewu; Tan, Reginald B H; Chen, Fengxi; Ong, Kunn Hadinoto; Heng, Paul W S

    2007-01-01

    In this work, particle electrification in the Turbula and horizontally oscillating mixers were investigated for adipic acid, microcrystalline cellulose (MCC), and glycine particles. MCC and glycine particles acquired positive electrostatic charges, while adipic acid particles attained negative charges in both mixers. Adipic acid (of sieved size larger than 500 microm), MCC, and glycine particles were monotonically charged to saturated values, and had negligible wall adhesion. On the contrary, the adipic acid particles, both unsieved and sieved but of smaller sieved size fraction, exhibited very different charging kinetics in the horizontally oscillating mixer. These adipic acid particles firstly acquired charges up to a maximum value, and then the charges slowly reduced to a lower saturated value with increasing mixing time. Furthermore, these particles were found to adhere to the inner wall of the mixer, and the adhesion increased with mixing time. Surface specific charge densities for adipic acid particles were estimated based on particle size distribution, and were found to increase with particle mean diameters under the conditions investigated. The results obtained from the current work suggested that electrostatic force enhanced particle-wall adhesion, and the adhered particles can have a significant impact on particle electrification. PMID:16930881

  9. Effects of selected endocrine disruptors on meiotic maturation, cumulus expansion, synthesis of hyaluronan and progesterone by porcine oocyte-cumulus complexes.

    PubMed

    Mlynarcíková, Alzbeta; Nagyová, Eva; Ficková, Mária; Scsuková, Sona

    2009-04-01

    In most mammals, before ovulation, cumulus cells synthesize a large amount of hyaluronan (HA) that is organized into an extracellular matrix (ECM), which provides an essential microenvironment for in vivo oocyte fertilization. This process is called cumulus expansion. The present study assessed effects of selected endocrine disruptors (bisphenol A, BPA; 4-chloro-3-methyl phenol, CMP; di(2-ethylhexyl) phthalate, DEHP; and benzyl butyl phthalate, BBP) in a range of 100pM-100microM, on follicle-stimulating hormone (FSH)-induced meiotic maturation and cumulus expansion of porcine oocyte-cumulus complexes (OCC) cultured in vitro. Moreover, FSH-stimulated production of hyaluronic acid (HA) and progesterone by cumulus cells was measured. Both phenols, BPA and CMP (100microM), significantly affected meiotic maturation of oocytes. The number of oocytes that underwent germinal vesicle breakdown (GVBD) (78.7% and 72.4%, respectively) as well as the rate of oocytes that reached metaphase II stage (MII) (50% and 53.6%, respectively) after 44h culture were decreased compared to control (89.6% for GVBD and 81.5% for MII). FSH-stimulated expansion of cumulus was altered by the highest concentration of BPA and CMP (70% and 64%, respectively vs. 80.3% in control). Although BPA did not alter FSH-stimulated HA synthesis by cumulus cells, its incorporation within the complex was reduced to a half of control value. Progesterone production by OCC was significantly changed in the presence of BPA or DEHP. Finally, our results provide valuable information that oocyte meiotic progression was adversely affected during in vitro culture with endocrine disruptors. PMID:19162163

  10. Rhesus Monkey Cumulus Cells Revert to a Mural Granulosa Cell State After an Ovulatory Stimulus

    PubMed Central

    Chaffin, Charles L.; Lee, Young S.; Patel, Bela G.; Latham, Keith E.

    2012-01-01

    Follicular somatic cells (mural granulosa cells and cumulus cells) and the oocyte communicate through paracrine interactions and through direct gap junctions between oocyte and cumulus cells. Considering that mural and cumulus cells arise through a common developmental pathway and that their differentiation is essential to reproductive success, understanding how these cells differ is a key aspect to understanding their critical functions. Changes in global gene expression before and after an ovulatory stimulus were compared between cumulus and mural granulosa cells to test the hypothesis that mural and cumulus cells are highly differentiated at the time of an ovulatory stimulus and further differentiate during the periovulatory interval. The transcriptomes of the two cell types were markedly different (>1500 genes) before an ovulatory hCG bolus but converged after ovulation to become completely overlapping. The predominant transition was for the cumulus cells to become more like mural cells after hCG. This indicates that the differentiated phenotype of the cumulus cell is not stable and irreversibly established but may rather be an ongoing physiological response to the oocyte. PMID:23008515

  11. Rhesus monkey cumulus cells revert to a mural granulosa cell state after an ovulatory stimulus.

    PubMed

    Chaffin, Charles L; Lee, Young S; VandeVoort, Catherine A; Patel, Bela G; Latham, Keith E

    2012-11-01

    Follicular somatic cells (mural granulosa cells and cumulus cells) and the oocyte communicate through paracrine interactions and through direct gap junctions between oocyte and cumulus cells. Considering that mural and cumulus cells arise through a common developmental pathway and that their differentiation is essential to reproductive success, understanding how these cells differ is a key aspect to understanding their critical functions. Changes in global gene expression before and after an ovulatory stimulus were compared between cumulus and mural granulosa cells to test the hypothesis that mural and cumulus cells are highly differentiated at the time of an ovulatory stimulus and further differentiate during the periovulatory interval. The transcriptomes of the two cell types were markedly different (>1500 genes) before an ovulatory hCG bolus but converged after ovulation to become completely overlapping. The predominant transition was for the cumulus cells to become more like mural cells after hCG. This indicates that the differentiated phenotype of the cumulus cell is not stable and irreversibly established but may rather be an ongoing physiological response to the oocyte.

  12. Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: effect of denuded oocytes on cumulus expansion and oocyte maturation.

    PubMed

    Appeltant, R; Somfai, T; Nakai, M; Bodó, S; Maes, D; Kikuchi, K; Van Soom, A

    2015-03-01

    The aim of the present study was to clarify interactions between oocytes and cumulus cells (CCs) on the level of cumulus expansion and oocyte maturation during IVM of cumulus-oocyte complexes (COCs) in a chemically defined medium using a system that allows individual tracking of oocytes. Especially, the influence of oocyte-secreted factors was investigated by the aid of addition of denuded oocytes (DOs) as a possible approach to improve the IVM system. The basic maturation medium was porcine oocyte medium with addition of gonadotropins only during the first 20 hours of IVM. During IVM, COCs were kept fixed to the bottom of culture dish by adhesive Cell-Tak coating, which enabled individual tracking of COCs during IVM. Size changes in COCs during IVM were measured by digital image analysis. Cumulus expansion in a porcine oocyte medium of intact COCs increased in a typical manner until 20 hours and decreased in size subsequently until 48 hours of IVM (P < 0.05). Removal of oocytes from COCs by oocytectomy allowed the expansion of CCs to some extent, although their expansion ability was lower than that of COCs (P < 0.05). Addition of DOs (COCs to DOs ratio of 9:16) did not improve cumulus expansion and oocyte maturation rates of intact COCs (P > 0.05) but did enhance cumulus expansion of oocytectomized complexes (P < 0.05). Furthermore, removal of CCs before IVM increased oocyte maturation rates compared with COCs (52.3% and 32.9%, respectively) (P < 0.05) and a similar effect was observed in COCs when the gap junction inhibitor carbenoxolone was added to the IVM medium: carbenoxolone repressed the expansion of COCs at 20 hours of IVM. In conclusion, the porcine oocyte enhances cumulus expansion both by gap junctional communications and presumably by oocyte-secreted factor production. Nevertheless, the presence of oocytes is not a prerequisite for this process. In return, CCs maintain meiotic arrest in cumulus-enclosed oocytes during the initial culture

  13. Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: effect of denuded oocytes on cumulus expansion and oocyte maturation.

    PubMed

    Appeltant, R; Somfai, T; Nakai, M; Bodó, S; Maes, D; Kikuchi, K; Van Soom, A

    2015-03-01

    The aim of the present study was to clarify interactions between oocytes and cumulus cells (CCs) on the level of cumulus expansion and oocyte maturation during IVM of cumulus-oocyte complexes (COCs) in a chemically defined medium using a system that allows individual tracking of oocytes. Especially, the influence of oocyte-secreted factors was investigated by the aid of addition of denuded oocytes (DOs) as a possible approach to improve the IVM system. The basic maturation medium was porcine oocyte medium with addition of gonadotropins only during the first 20 hours of IVM. During IVM, COCs were kept fixed to the bottom of culture dish by adhesive Cell-Tak coating, which enabled individual tracking of COCs during IVM. Size changes in COCs during IVM were measured by digital image analysis. Cumulus expansion in a porcine oocyte medium of intact COCs increased in a typical manner until 20 hours and decreased in size subsequently until 48 hours of IVM (P < 0.05). Removal of oocytes from COCs by oocytectomy allowed the expansion of CCs to some extent, although their expansion ability was lower than that of COCs (P < 0.05). Addition of DOs (COCs to DOs ratio of 9:16) did not improve cumulus expansion and oocyte maturation rates of intact COCs (P > 0.05) but did enhance cumulus expansion of oocytectomized complexes (P < 0.05). Furthermore, removal of CCs before IVM increased oocyte maturation rates compared with COCs (52.3% and 32.9%, respectively) (P < 0.05) and a similar effect was observed in COCs when the gap junction inhibitor carbenoxolone was added to the IVM medium: carbenoxolone repressed the expansion of COCs at 20 hours of IVM. In conclusion, the porcine oocyte enhances cumulus expansion both by gap junctional communications and presumably by oocyte-secreted factor production. Nevertheless, the presence of oocytes is not a prerequisite for this process. In return, CCs maintain meiotic arrest in cumulus-enclosed oocytes during the initial culture

  14. An intracloud lightning parameterization scheme for a storm electrification model

    NASA Technical Reports Server (NTRS)

    Helsdon, John H., Jr.; Wu, Gang; Farley, Richard D.

    1992-01-01

    The parameterization of an intracloud lightning discharge has been implemented in the present storm electrification model. The initiation, propagation direction, and termination of the discharge are computed using the magnitude and direction of the electric field vector as the determining criteria. The charge redistribution due to the lightning is approximated assuming the channel to be an isolated conductor with zero net charge over its entire length. Various simulations involving differing amounts of charge transferred and distribution of charges have been done. Values of charge transfer, dipole moment change, and electrical energy dissipation computed in the model are consistent with observations. The effects of the lightning-produced ions on the hydrometeor charges and electric field components depend strongly on the amount of charge transferred. A comparison between the measured electric field change of an actual intracloud flash and the field change due to the simulated discharge shows favorable agreement. Limitations of the parameterization scheme are discussed.

  15. Indonesia solar home systems project for rural electrification

    SciTech Connect

    Sanghvi, A.P.

    1997-12-01

    This paper presents, from a financing aspect the broad issues involved in a plan to provide solar home systems (SHS) to provide rural electrification in several areas of rural Indonesia. The paper discusses the approaches being used to provide funding, develop awareness of the technology, and assure the success of the project. The plan involves the use of grant money to help with some of the initial costs of such systems, and thereby to encourage local financing on a terms rather than cash basis. There are needs for market development, and development of a business structure in the country to support this type of technology. Provided this plan can succeed, it may serve as a model for further efforts.

  16. Runaway electrification of friable self-replicating granular matter.

    PubMed

    Cartwright, Julyan H E; Escribano, Bruno; Grothe, Hinrich; Piro, Oreste; Sainz Díaz, C Ignacio; Tuval, Idan

    2013-10-15

    We establish that the nonlinear dynamics of collisions between particles favors the charging of an insulating, friable, self-replicating granular material that undergoes nucleation, growth, and fission processes; we demonstrate with a minimal dynamical model that secondary nucleation produces a positive feedback in an electrification mechanism that leads to runaway charging. We discuss ice as an example of such a self-replicating granular material: We confirm with laboratory experiments in which we grow ice from the vapor phase in situ within an environmental scanning electron microscope that charging causes fast-growing and easily breakable palmlike structures to form, which when broken off may form secondary nuclei. We propose that thunderstorms, both terrestrial and on other planets, and lightning in the solar nebula are instances of such runaway charging arising from this nonlinear dynamics in self-replicating granular matter. PMID:24041221

  17. Runaway Electrification of Friable Self-Replicating Granular Matter

    PubMed Central

    2013-01-01

    We establish that the nonlinear dynamics of collisions between particles favors the charging of an insulating, friable, self-replicating granular material that undergoes nucleation, growth, and fission processes; we demonstrate with a minimal dynamical model that secondary nucleation produces a positive feedback in an electrification mechanism that leads to runaway charging. We discuss ice as an example of such a self-replicating granular material: We confirm with laboratory experiments in which we grow ice from the vapor phase in situ within an environmental scanning electron microscope that charging causes fast-growing and easily breakable palmlike structures to form, which when broken off may form secondary nuclei. We propose that thunderstorms, both terrestrial and on other planets, and lightning in the solar nebula are instances of such runaway charging arising from this nonlinear dynamics in self-replicating granular matter. PMID:24041221

  18. Rural areas electrification (Latin America), Guatemala City, Guatemala, June 4--7, 1989: Foreign trip report

    SciTech Connect

    Katzman, M.T.

    1989-01-01

    ORNL serves the function of monitoring the Central American Rural Electrification Support Program (CARES) of US Agency for International Development (USAID), which is administered by NRECA. The results of the Demand Assessment Model, presented at the conference, were reviewed, and a paper on the use of marginal cost analysis for rural electrification was delivered for presentation by NRECA staff. Discussions on the acceptability of the model were discussed with utility representatives.

  19. The Effects of Ice on the Frictional Electrification of Plumes

    NASA Astrophysics Data System (ADS)

    Méndez Harper, J.; Courtland, L. M.; Dufek, J.

    2015-12-01

    Studies of the Redoubt (2009), Eyjafjallajökull (2010), and the Cordón Caulle (2011) eruptions and associated electrical activity suggest that ice is a catalyst for the generation of plume lightning [Behnke et al., 2012; Arason et al., 2011; Nicora et al., 2013]. Indeed, the number lightning flashes in the umbrella and convective regions of the plume seems to correlate with lower, ice-forming temperatures. As in conventional thunderstorms, electric charge accumulation and separation in cold plumes may arise from the interplay between ice grains and graupel. However, charging may also be driven by triboelectrification (frictional charging), resulting from collisions between ice and ash grains. Decades of research have shown that fluidized granular materials comprising species of distinct composition often produce more efficient electrification than the interaction of chemically identical particles under similar hydrodynamic regime [e.g. Forward et al., 2009]. Thus, tribocharging in a combined ice and silicate granular flow is likely to yield grains with higher charges than those encountered in a flow composed solely of silicate grains, facilitating the generation of lightning [Méndez Harper and Dufek, 2015, submitted]. To indagate this hypothesis, we have developed a novel methodology to measure the time-dependent charging of individual micron-sized particles in both dry, silicate flows and silicate plus ice flows. Pure ash runs are conducted in a dry (<1 % humidity) environment with a temperature variation of -40o to 25o C. Runs involving ice are performed between -40o and 2o C, permitting us to quantify charging in the mixture as water transmogrifies from solid ice to a more mush-like substance. Additionally, we report on how collisional energy and rates influence electrification in these granular materials. We show that, although the variations in ash composition (basalt to rhyolite) tend to be of little consequence for charging, the presence of a water phase

  20. Comparison of Irrigation Water Use Estimates Calculated from Remotely Sensed Irrigated Acres and State Reported Irrigated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

    USGS Publications Warehouse

    Masoner, J.R.; Mladinich, C.S.; Konduris, A.M.; Smith, S. Jerrod

    2003-01-01

    Increased demand for water in the Lake Altus drainage basin requires more accurate estimates of water use for irrigation. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation, is investigating new techniques to improve water-use estimates for irrigation purposes in the Lake Altus drainage basin. Empirical estimates of reference evapotranspiration, crop evapotranspiration, and crop irrigation water requirements for nine major crops were calculated from September 1999 to October 2000 using a solar radiation-based evapotranspiration model. Estimates of irrigation water use were calculated using remotely sensed irrigated crop acres derived from Landsat 7 Enhanced Thematic Mapper Plus imagery and were compared with irrigation water-use estimates calculated from irrigated crop acres reported by the Oklahoma Water Resources Board and the Texas Water Development Board for the 2000 growing season. The techniques presented will help manage water resources in the Lake Altus drainage basin and may be transferable to other areas with similar water management needs. Irrigation water use calculated from the remotely sensed irrigated acres was estimated at 154,920 acre-feet; whereas, irrigation water use calculated from state reported irrigated crop acres was 196,026 acre-feet, a 23 percent difference. The greatest difference in irrigation water use was in Carson County, Texas. Irrigation water use for Carson County, Texas, calculated from the remotely sensed irrigated acres was 58,555 acrefeet; whereas, irrigation water use calculated from state reported irrigated acres was 138,180 acre-feet, an 81 percent difference. The second greatest difference in irrigation water use occurred in Beckham County, Oklahoma. Differences between the two irrigation water use estimates are due to the differences of irrigated crop acres derived from the mapping process and those reported by the Oklahoma Water Resources Board and Texas Water Development Board.

  1. Growth hormone pathway gene expression varies in porcine cumulus-oocyte complexes during in vitro maturation.

    PubMed

    Zhu, Guiyu; Liu, Shujuan; Jiang, Yunliang; Yang, Honghua; Li, Jinlian

    2008-01-01

    Growth hormone (GH) plays important roles in oocyte development and facilitates the successful production of competent oocytes in many species both in vivo and in vitro. However, the mechanism of GH action on oocyte maturation is not well known. In this paper, the temporospatial messenger ribonucleic acid expression patterns of GH and several other GH-related factors were quantitatively analyzed in porcine cumulus-oocytes complex throughout in vitro maturation (IVM). GH expression was decreased in oocytes during IVM while absent in cumulus cells. GH receptor, insulin-like growth factor-1 (IGF-1), and IGF-1 receptor expressions were also downregulated in oocytes. In cumulus cells, the expression of IGF-1 decreased significantly while IGF-1 receptor expression remained constant. The transcripts of Janus kinase 2 increased in both oocytes and cumulus cells during IVM. The current precise gene expression information provides further evidence to explain the complex network of GH signaling involved in IVM of porcine oocyte.

  2. The radiative impact of cumulus cloudiness in a general circulation model

    NASA Technical Reports Server (NTRS)

    Moeng, C. H.; Randall, D. A.

    1982-01-01

    The effect of cumulus cloudiness on the radiational heating and, on other aspects of the climate were simulated by the GLAS Climate Model. An experiment in which the cumulus cloudiness is neglected completely for purposes of the solar and terrestrial radiation parameterizations was performed. The results are compared with those of a control run, in which 100% cumulus cloud cover is assumed. The net solar radiation input into the Earth atmosphere system is more realistic in the experiment, and the model's underprediction of the global mean outgoing thermal radiation at the top of the atmosphere is reduced. The results suggest that there is a positive feedback between cumulus convection and the radiation field. The upper troposphere is warmer in the experiment, the surface air temperature increases over land, and the thermal lows over the continents intensity.

  3. Effects of cumulus cells on rabbit oocyte in vitro maturation.

    PubMed

    Tao, Y; Cao, C; Zhang, M; Fang, F; Liu, Y; Zhang, Y; Ding, J; Zhang, X

    2008-08-01

    Cumulus cells (CCs) are of great importance in oocyte development and maturation in many species, but detailed influence of CCs has not been extensively examined, especially on rabbit. The present study was designed to investigate the effects of CCs and the elongation of in vitro maturation (IVM) time on rabbit oocyte nuclear and ooplasmic maturation and survival. Cumulus oocyte complexes (COCs) and naked oocytes (NOs) were recovered directly from rabbits super-ovulated with eCG. Corona-enclosed oocytes (COs) and denuded oocytes (DOs) were obtained from COCs after removing a part or whole of CCs. The oocytes were cultured in the following seven groups. (i) Cumulus cell enclosed oocytes (CEOs) were cultured alone (CEOs); (ii) COs were cultured alone (COs); (iii) DOs were cultured alone (DOs); (iv) NOs were cultured alone; (v) DOs were co-cultured with COCs [DOs(COCs)]; (vi) DOs were co-cultured with CCs [DOs(CCs)]; (vii) NOs were co-cultured with CCs [NOs(CCs)]. After the oocytes were cultured for 24 and 30 h, the nuclear maturation was evaluated by first polar body (PB1) extrusion while the ooplasmic maturation was evaluated by the cleavage rate after parthenogenetic activation. The results showed that the nuclear maturation rate of CEOs, COs, DOs(COCs) and DOs(CCs) after 24 h incubation were significantly different from each other (p < or = 0.05), the rate of DOs(CCs) was similar to that of DOs (p > or = 0.05). The cleavage rates in the first two groups were significantly higher than those of the others (p < 0.05). For oocytes cultured for 30 h, the nuclear maturation rates were significantly different for each culture model (p < 0.05). The cleavage rates in first two groups were significantly higher than those of others (p < 0.05). Both the nuclear and cleavage rates significantly increased when the culture time of DOs(COCs) was prolonged from 24 to 30 h. DOs(CCs) nuclear maturation was significantly improved when the culture time was prolonged from 24 to 30 h

  4. Cleavage capability of water buffalo follicular oocytes classified by cumulus cells and fertilized in vitro.

    PubMed

    Suzuki, T; Singla, S K; Sujata, J; Madan, M L

    1991-06-01

    Water buffalo (Murrah) oocytes were collected from ovaries obtained from the slaughter house. They were classified according to the character of the cumulus cells under a stereomicroscope, and cultured in 25 mM Hepes buffered Tissue Culture Medium-199 (TCM-199) supplemented with 5% estrous water buffalo serum in an atmosphere containing 5% CO2 in air at 39 degrees C. After 20-24 hr of in vitro maturation, the oocytes were fertilized using capacitated sperm obtained from 4 different bulls. For cleavage the oocytes were cultured at 39 degrees C in TCM-199 supplemented with 1% estrous water buffalo serum and in an atmosphere containing 5% CO2 in air. The good oocytes, with compact and dense cumulus cells cleaved significantly higher (p less than 0.01, 67.3%), than those of fair. partially naked oocytes with thin cumulus layers (27.5%, 25/91) or small remnants of cumulus cells and poor naked oocytes (3/100). A substantial variation cumulus layers (27.5% 25/91) or small remnants of cumulus cells and poor naked oocytes (3/100). A substantial variation in fertilization and developmental rates (16.0% to 43.8%) was observed among 4 different bulls. Late non-surgically into 14 buffalo recipients on day 6 or 7 of their estrous cycle. One recipient was diagnosed to be pregnant by rectal palpation on day 60 and confirmed to be so on day 90 post-estrus.

  5. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. Using special equipment aboard the Altus II, scientists in ACES will gather electric, magnetic, and optical measurements of the thunderstorms, gauging elements such as lightning activity and the electrical environment in and around the storms. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  6. Rainfall results, 1970-1975: Florida area cumulus experiment.

    PubMed

    Woodley, W L; Simpson, J; Biondini, R; Berkeley, J

    1977-02-25

    The latest rainfall results of the Florida Area Cumulus Experiment (FACE) are discussed after a review of the background, design, and early results of this experiment. Analysis without the benefit of data stratification and appropriate covariates of the 48 random experimentation days obtained through 1975 provided no evidence that dynamic seeding appreciably altered the rainfall over the fixed target area (1.3 x 10(4) square kilometers). Partitioning of the experimentation days according to whether the convective echoes moved across the Florida peninsula or developed in situ was more informative. Use of this echo motion covariate with five meaningful predictor models of natural rainfall in a stepwise regression program produced persuasive evidence for an effect of seeding in both echo motion categories. For days with moving echoes, there is evidence for a positive, statistically significant treatment effect on the rainfall from the subject clouds (the floating target) and in the overall target area. The results for days with stationary echoes, although considerably more tentative, suggest that seeding produces more rainfall in the floating target but with no net change of the precipitation in the overall target area. The ramifications of this result and a possible explanation are discussed. Corroborative statistical analyses and discussion are presented, including a discussion of the physical bases and history of the echo motion covariate and the meteorological predictors, analysis that is supportive of the rain-gage-adjusted radar measurements of precipitation in FACE and results of relevant cloud physics measurements in Florida.

  7. Aerosol Impacts on the Growth of Cumulus Congestus Clouds

    NASA Astrophysics Data System (ADS)

    Sheffield, A. M.; van den Heever, S. C.; Saleeby, S. M.

    2012-12-01

    Tropical convection has been observed to contain three modes of convection, the middle mode of which is cumulus congestus clouds. This study investigates the impacts of aerosol, specifically those aerosols that can serve as cloud condensation nuclei, on the growth and development of congestus clouds observed within idealized cloud-resolving model (CRM) simulations conducted under a state of radiative-convective equilibrium (RCE). The model employed here is the Regional Atmospheric Modeling System (RAMS). RAMS CRM simulations were completed using a large two-dimensional domain (7200 km) at fine resolution (1 km) and long duration (100 days). Results indicate that congestus in more polluted conditions extend to greater heights more frequently than those developing in clean cases. Greater cloud water mass and ice mass forms in more polluted conditions, though ice forms at a fraction of the rate of the cloud mass. The importance of vapor diffusional growth of cloud droplets in the more polluted conditions is highlighted as one such process contributing to congestus development through latent heat release.

  8. Aerosol-induced mechanisms for cumulus congestus growth

    NASA Astrophysics Data System (ADS)

    Sheffield, Amanda M.; Saleeby, Stephen M.; Heever, Susan C.

    2015-09-01

    Tropical convection has been observed to contain three cloud modes, the middle of which is cumulus congestus clouds. Congestus clouds act to moisten the tropical atmosphere, may be mixed-phase, and on occasion surpass the freezing level inversion from where they may develop into deeper convection. This study investigates the impacts of enhanced aerosol concentrations on the growth of congestus clouds produced in idealized cloud-resolving model simulations run under a state of radiative convective equilibrium (RCE). High-resolution, long-duration simulations were completed using the Regional Atmospheric Modeling System (RAMS). Aerosol concentrations between 2 and 4 km above ground level were varied from clean to polluted conditions in order to represent the advection of Saharan dust over the Atlantic Ocean. The congestus populations within each aerosol simulation are statistically analyzed using 10 days of model output after the simulation reaches RCE. Results indicate that congestus in more polluted conditions produce greater amounts of cloud water and ice mass, enhanced updraft strengths, and an increase in the number of congestus cloud tops that extend above the freezing level. Enhanced vapor depositional growth on the populations of more numerous, smaller cloud droplets in the polluted conditions, and the subsequent increase in latent heat release in the warm phase regions of the cloud, is found to be important factors in convective invigoration of these cloud systems. Aerosol feedbacks associated with cold pools and condensate loading also influence the updraft strength and act in opposition to the warm phase invigoration processes.

  9. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

    DOE PAGESBeta

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasingmore » scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.« less

  10. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

    SciTech Connect

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasing scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.

  11. A numerical study of thunderstorm electrification: Model development and case study

    SciTech Connect

    Norville, K.; Baker, M. ); Latham, J. )

    1991-04-20

    The authors have developed a numerical model for examining the thunderstorm electrification process in which they assume the electrification is entirely due to noinductive charge transfer between colliding ice crystals and hail. Since this ice-hail charge mechanism is very independent on particle sizes and distributions, they use an explicit microphysical framework. To maintain simplicity, the electrification model is kinematic; thus the temperature and velocity fields are input into the electrification model. These fields can be either calculated by a background model or retrieved from observations. For this study, they have used the cloud model of Taylor (1989) to generate the temperature and velocity fields to examine the July 19, 1981, CCOPE thundercloud. Using these fields, the electrification model produced time-dependent ice particle concentrations, radar reflectives, charge and vertical electric field distributions in good general agreement with those observed. The model produced a maximum electric field strength of 1.27 kV/cm, which is on the order of that needed for lightning initiation, and this maximum occured very close to the time of the observed discharge (as inferred by the sailplane measurements). Thus the ice-hail charge mechanism appears to have played an important role in the electrical development of the July 19 cloud. The details of the electrification depended on the liquid water content and the glaciation processes, and particularly on the ice crystal characteristics. Rapid growth of the crystals to riming sizes (>400{mu}) yielded the most efficient charging. The electrification was also sensitive to the ice-ice sticking efficiency but not to the characteristics of the large riming ice.

  12. Transcriptomic Diversification of Developing Cumulus and Mural Granulosa Cells in Mouse Ovarian Follicles1

    PubMed Central

    Wigglesworth, Karen; Lee, Kyung-Bon; Emori, Chihiro; Sugiura, Koji; Eppig, John J.

    2014-01-01

    ABSTRACT Cumulus cells and mural granulosa cells (MGCs) have functionally distinct roles in antral follicles, and comparison of their transcriptomes at a global and systems level can propel future studies on mechanisms underlying their functional diversity. These cells were isolated from small and large antral follicles before and after stimulation of immature mice with gonadotropins, respectively. Both cell types underwent dramatic transcriptomic changes, and differences between them increased with follicular growth. Although cumulus cells of both stages of follicular development are competent to undergo expansion in vitro, they were otherwise remarkably dissimilar with transcriptomic changes quantitatively equivalent to those of MGCs. Gene ontology analysis revealed that cumulus cells of small follicles were enriched in transcripts generally associated with catalytic components of metabolic processes, while those from large follicles were involved in regulation of metabolism, cell differentiation, and adhesion. Contrast of cumulus cells versus MGCs revealed that cumulus cells were enriched in transcripts associated with metabolism and cell proliferation while MGCs were enriched for transcripts involved in cell signaling and differentiation. In vitro and in vivo models were used to test the hypothesis that higher levels of transcripts in cumulus cells versus MGCs is the result of stimulation by oocyte-derived paracrine factors (ODPFs). Surprisingly ∼48% of transcripts higher in cumulus cells than MGCs were not stimulated by ODPFs. Those stimulated by ODPFs were mainly associated with cell division, mRNA processing, or the catalytic pathways of metabolism, while those not stimulated by ODPFs were associated with regulatory processes such as signaling, transcription, phosphorylation, or the regulation of metabolism. PMID:25376232

  13. Transcriptomic diversification of developing cumulus and mural granulosa cells in mouse ovarian follicles.

    PubMed

    Wigglesworth, Karen; Lee, Kyung-Bon; Emori, Chihiro; Sugiura, Koji; Eppig, John J

    2015-01-01

    Cumulus cells and mural granulosa cells (MGCs) have functionally distinct roles in antral follicles, and comparison of their transcriptomes at a global and systems level can propel future studies on mechanisms underlying their functional diversity. These cells were isolated from small and large antral follicles before and after stimulation of immature mice with gonadotropins, respectively. Both cell types underwent dramatic transcriptomic changes, and differences between them increased with follicular growth. Although cumulus cells of both stages of follicular development are competent to undergo expansion in vitro, they were otherwise remarkably dissimilar with transcriptomic changes quantitatively equivalent to those of MGCs. Gene ontology analysis revealed that cumulus cells of small follicles were enriched in transcripts generally associated with catalytic components of metabolic processes, while those from large follicles were involved in regulation of metabolism, cell differentiation, and adhesion. Contrast of cumulus cells versus MGCs revealed that cumulus cells were enriched in transcripts associated with metabolism and cell proliferation while MGCs were enriched for transcripts involved in cell signaling and differentiation. In vitro and in vivo models were used to test the hypothesis that higher levels of transcripts in cumulus cells versus MGCs is the result of stimulation by oocyte-derived paracrine factors (ODPFs). Surprisingly ∼48% of transcripts higher in cumulus cells than MGCs were not stimulated by ODPFs. Those stimulated by ODPFs were mainly associated with cell division, mRNA processing, or the catalytic pathways of metabolism, while those not stimulated by ODPFs were associated with regulatory processes such as signaling, transcription, phosphorylation, or the regulation of metabolism.

  14. Influence of oil flow quadrupling on electrification phenomena in a shell type transformer

    SciTech Connect

    Boisdon, C.I.; Peyraque, L.

    1995-05-01

    A shell type auto transformer 500 kV/230 kV/35 kV has been equipped with an exceptional set of oil pumps to make possible a test at an oil flow reaching 4.8 times the rated value. On this transformer, electrification tests have been achieved in unenergized and energized conditions to determine the electrification phenomena at this level of oil flow and to measure the safety margin available for the normal transformer operation. During the tests, temperature and dielectric contraints have been adjusted at a value inducing a maximum electrification level. The dielectric strength of the transformer has not been reduced in spite of the increase of leakage currents due to static electrification. No partial discharges could be detected acoustically and the level of electrically measured partial discharges has remained low. Test datas and results of measurement are given in the document. The established very large margin on oil velocity without certainty of reaching a dielectric limit is analysed. It shows that shell type technology of transformers has no particular sensitiveness to electrification phenomena.

  15. Pyro-electrification of polymer membranes for cell patterning

    NASA Astrophysics Data System (ADS)

    Rega, R.; Gennari, O.; Mecozzia, L.; Grilli, S.; Pagliarulo, V.; Ferraro, P.

    2016-05-01

    In the recent years, much attention has been devoted to the possibility of charging polymer-based materials, due to their potential in developing large-scale and inexpensive flexible thin-film technology. The availability of localized electrostatic fields is in of great interest for a huge amount of applications such as distribution of biomolecules and cells from the liquid phase. Here we report a voltage-free pyro-electrification (PE) process able to induce permanent dipoles into polymer layers; the lithium niobate (LN) crystal is the key component that plays the multi-purpose role of sustaining, heating and poling the polymer layer that is then peeled-off easily in order to have a free-standing charged membrane. The results show the fascinating application for the living cell patterning. It well known that cell behaviour is affected by chemical and topographical cues of substrate. In fact, polymers, such as polystyrene (PS) and poly(methyl methacrylate) (PMMA), are naturally cytophobic and require specific functionalization treatments in order to promote cell adhesion. Through our proposal technique, it's possible to obtain spontaneous organization and a driven growth of SH-SY5Y cells that is solely dictated by the nature of the charge polymer surface, opening, in this way, the innovative chance to manipulate and transfer biological samples on a free-standing polymer layer [1].

  16. Radial-arrayed rotary electrification for high performance triboelectric generator.

    PubMed

    Zhu, Guang; Chen, Jun; Zhang, Tiejun; Jing, Qingshen; Wang, Zhong Lin

    2014-01-01

    Harvesting mechanical energy is an important route in obtaining cost-effective, clean and sustainable electric energy. Here we report a two-dimensional planar-structured triboelectric generator on the basis of contact electrification. The radial arrays of micro-sized sectors on the contact surfaces enable a high output power of 1.5 W (area power density of 19 mW cm(-2)) at an efficiency of 24%. The triboelectric generator can effectively harness various ambient motions, including light wind, tap water flow and normal body movement. Through a power management circuit, a triboelectric-generator-based power-supplying system can provide a constant direct-current source for sustainably driving and charging commercial electronics, immediately demonstrating the feasibility of the triboelectric generator as a practical power source. Given exceptional power density, extremely low cost and unique applicability resulting from distinctive mechanism and structure, the triboelectric generator can be applied not only to self-powered electronics but also possibly to power generation at a large scale. PMID:24594501

  17. Role of contact electrification and electrostatic interactions in gecko adhesion.

    PubMed

    Izadi, Hadi; Stewart, Katherine M E; Penlidis, Alexander

    2014-09-01

    Geckos, which are capable of walking on walls and hanging from ceilings with the help of micro-/nano-scale hierarchical fibrils (setae) on their toe pads, have become the main prototype in the design and fabrication of fibrillar dry adhesives. As the unique fibrillar feature of the toe pads of geckos allows them to develop an intimate contact with the substrate the animal is walking on or clinging to, it is expected that the toe setae exchange significant numbers of electric charges with the contacted substrate via the contact electrification (CE) phenomenon. Even so, the possibility of the occurrence of CE and the contribution of the resulting electrostatic interactions to the dry adhesion of geckos have been overlooked for several decades. In this study, by measuring the magnitude of the electric charges, together with the adhesion forces, that gecko foot pads develop in contact with different materials, we have clarified for the first time that CE does contribute effectively to gecko adhesion. More importantly, we have demonstrated that it is the CE-driven electrostatic interactions which dictate the strength of gecko adhesion, and not the van der Waals or capillary forces which are conventionally considered as the main source of gecko adhesion.

  18. Electricity distribution industry restructuring, electrification, and competition in South Africa

    SciTech Connect

    Galen, P S

    1997-07-01

    This paper reviews the status of the South African electricity supply industry (ESI) and proposals for reorienting and restructuring it. South Africa has been intensely examining its ESI for more than 4 years in an effort to determine whether and how it should be restructured to best support the country`s new economic development and social upliftment goals. The debate has been spirited and inclusive of most ESI stakeholders. The demands on and expectations for the ESI are many and varied. The debate has reflected this diversity of interests and views. In essence, however, there is a consensus on what is expected of the industry, namely, to extend provision of adequate, reliable, and affordable electricity service to all citizens and segments of the economy. This means a large-scale electrification program to reach as many of the nearly 50% of households currently without electricity service as soon as possible, tariff reform to promote equity and efficiency, and the upgrading of service quality now being provided by some of the newly consolidated municipal authorities. The issues involved are how best to achieve these results within the context of the national Reconstruction and Development Program, while accounting for time and resource constraints and balancing the interests of the various parties.

  19. Radial-arrayed rotary electrification for high performance triboelectric generator.

    PubMed

    Zhu, Guang; Chen, Jun; Zhang, Tiejun; Jing, Qingshen; Wang, Zhong Lin

    2014-03-04

    Harvesting mechanical energy is an important route in obtaining cost-effective, clean and sustainable electric energy. Here we report a two-dimensional planar-structured triboelectric generator on the basis of contact electrification. The radial arrays of micro-sized sectors on the contact surfaces enable a high output power of 1.5 W (area power density of 19 mW cm(-2)) at an efficiency of 24%. The triboelectric generator can effectively harness various ambient motions, including light wind, tap water flow and normal body movement. Through a power management circuit, a triboelectric-generator-based power-supplying system can provide a constant direct-current source for sustainably driving and charging commercial electronics, immediately demonstrating the feasibility of the triboelectric generator as a practical power source. Given exceptional power density, extremely low cost and unique applicability resulting from distinctive mechanism and structure, the triboelectric generator can be applied not only to self-powered electronics but also possibly to power generation at a large scale.

  20. Technical Support for China's Village Electrification Program: Cooperative Research and Development Final Report, CRADA number CRD-07-00235

    SciTech Connect

    Kline, D.

    2010-07-01

    This work has two main goals: First, it provides for the analysis of data collected from systems developed in the previous phase of China's rural power program, the Township Electrification Program Second, it will comprise joint IEE-NREL work in support of the upcoming phase, 'Electrification of Unelectrified Areas'.

  1. Production of Cloned Mice by Nuclear Transfer of Cumulus Cells

    PubMed Central

    Kurd, Soleiman; Zarei, Mohammad Ali; Fathi, Fardin; Ghadimi, Tayyeb; Hakhamaneshi, Mohammad Saeed; Jalili, Ali

    2013-01-01

    Background Over the past several years, mammals have been successfully cloned by either the splitting of an early stage embryo or nuclear transfer of adult somatic cells (NT) into oocytes. Although it has been 15 years since the generation of the first cloned mammals from somatic cells by NT, the success rate for producing live offspring by this technique is low regardless of the cell type and animal species used. However, these techniques have the potential to be important tools for future research in basic biology. In the present study, we described our experiences in producing successfully cloned mouse using NT method and piezo-actuated micromanipulator. Methods B6D2F1 mice, 8-12 weeks old, were superovulated with injections of 5 IU of pregnant mare serum gonadotropin and 5 IU of human chorionic gonadotropin administered 48 hr apart. Enucleation and donor nuclei cumulus cell injection were performed with a piezo-actuated micromanipulator after which activation and trichostatin A treatment were used for reconstructed oocytes. Two-cell stage cloned embryos that developed in the mWM medium were transferred into the oviducts of pseudopregnant NMRI mice. Results Of 367 oocytes collected, 131 (69%) developed into 2-cell stage embryos. Of these, 5 (1%) live pups were successfully delivered. We used NMRI foster mother to raise the pups by lactation. One adult cloned mouse was mated, after which she delivered and raised normal offspring. Conclusion For mouse cloning, the present study also successfully tested the capability of somatic cell nuclear transfer SCNT using a piezo unit. PMID:23919122

  2. Embryo quality predictive models based on cumulus cells gene expression

    PubMed Central

    Burnik Papler, T; Verdenik, I; Fon Tacer, K; Vrtačnik Bokal, E

    2016-01-01

    Abstract Since the introduction of in vitro fertilization (IVF) in clinical practice of infertility treatment, the indicators for high quality embryos were investigated. Cumulus cells (CC) have a specific gene expression profile according to the developmental potential of the oocyte they are surrounding, and therefore, specific gene expression could be used as a biomarker. The aim of our study was to combine more than one biomarker to observe improvement in prediction value of embryo development. In this study, 58 CC samples from 17 IVF patients were analyzed. This study was approved by the Republic of Slovenia National Medical Ethics Committee. Gene expression analysis [quantitative real time polymerase chain reaction (qPCR)] for five genes, analyzed according to embryo quality level, was performed. Two prediction models were tested for embryo quality prediction: a binary logistic and a decision tree model. As the main outcome, gene expression levels for five genes were taken and the area under the curve (AUC) for two prediction models were calculated. Among tested genes, AMHR2 and LIF showed significant expression difference between high quality and low quality embryos. These two genes were used for the construction of two prediction models: the binary logistic model yielded an AUC of 0.72 ± 0.08 and the decision tree model yielded an AUC of 0.73 ± 0.03. Two different prediction models yielded similar predictive power to differentiate high and low quality embryos. In terms of eventual clinical decision making, the decision tree model resulted in easy-to-interpret rules that are highly applicable in clinical practice. PMID:27785402

  3. Analysis of cumulus solar irradiance reflectance (CSIR) events

    NASA Astrophysics Data System (ADS)

    Laird, John L.; Harshvardhan

    Clouds are extremely important with regard to the transfer of solar radiation at Earth's surface. This study investigates Cumulus Solar Irradiance Reflection (CSIR) using ground-based pyranometers. CSIR events are short-term increases in solar radiation observed at the surface as a result of reflection off the sides of convective clouds. When Sun-cloud observer geometry is favorable, these occurrences produce characteristic spikes in the pyranometer traces and solar irradiance values may exceed expected clear-sky values. Ultraviolet CSIR events were investigated during the summer of 1995 using UVA and UVB pyranometers. Observed data were compared to clear-sky curves which were generated using a third degree polynomial best-fit line technique. Periods during which the observed data exceeded this clear-sky curve were identified as CSIR events. The magnitude of a CSIR event was determined by two different quantitative calculations. The MAC (magnitude above clear-sky) is an absolute measure of the difference between the observed and clear-sky irradiances. Maximum MAC values of 3.4 Win -2 and 0.0169 Wm -2 were observed at the UV-A and UV-B wavelengths, respectively. The second calculation determined the percentage above clear-sky (PAC) which indicated the relative magnitude of a CSIR event. Maximum UV-A and UV-B PAC magnitudes of 10.1% and 7.8%, respectively, were observed during the study. Also of interest was the duration of the CSIR events which is a function of Sun-cloud-sensor geometry and the speed of cloud propagation over the measuring site. In both the UV-A and UV-B wavelengths, significant CSIR durations of up to 30 minutes were observed. C 1997 Elsevier Science B.V.

  4. Analysis of Cumulus Solar Irradiance Reflectance (CSIR) Events

    NASA Technical Reports Server (NTRS)

    Laird, John L.; Harshvardham

    1996-01-01

    Clouds are extremely important with regard to the transfer of solar radiation at the earth's surface. This study investigates Cumulus Solar Irradiance Reflection (CSIR) using ground-based pyranometers. CSIR events are short-term increases in solar radiation observed at the surface as a result of reflection off the sides of convective clouds. When sun-cloud observer geometry is favorable, these occurrences produce characteristic spikes in the pyranometer traces and solar irradiance values may exceed expected clear-sky values. Ultraviolet CSIR events were investigated during the summer of 1995 using Yankee Environmental Systems UVA-1 and UVB-1 pyranometers. Observed data were compared to clear-sky curves which were generated using a third degree polynomial best-fit line technique. Periods during which the observed data exceeded this clear-sky curve were identified as CSIR events. The magnitude of a CSIR event was determined by two different quantitative calculations. The MAC (magnitude above clear-sky) is an absolute measure of the difference between the observed and clear-sky irradiances. Maximum MAC values of 3.4 Wm(exp -2) and 0.069 Wm(exp -2) were observed at the UV-A and UV-B wavelengths, respectively. The second calculation determined the percentage above clear-sky (PAC) which indicated the relative magnitude of a CSIR event. Maximum UV-A and UV-B PAC magnitudes of 10.1% and 7.8%, respectively, were observed during the study. Also of interest was the duration of the CSIR events which is a function of sun-cloud-sensor geometry and the speed of cloud propagation over the measuring site. In both the UV-A and UV-B wavelengths, significant CSIR durations of up to 30 minutes were observed.

  5. Impact of Prunus Cerasus on PGR and HAS2 in Cumulus Cells and Fertility Outcome

    PubMed Central

    Namvar Vansofla, Fatemeh; Roshangar, Leila; Montaseri, Azadeh; Soleimani Rad, Jafar

    2016-01-01

    Purpose: Cumulus cells have a critical role in normal oocyte development and fertilization. Prunus cerasus is an anthocyanin rich berry and performs strong antioxidant activity. The present study set to determine if Prunus cerasus can affect expression of HAS2 (hyaluronan synthase 2) and progesterone receptor in Cumulus cells and its consequences outcome of the in vitro fertilization. Methods: 60 female and 15 male adult mice were used for mating and IVF (in vitro fertilization). Prunus cerasus extraction was added to the diet of female mice for 30 days. Ovulation induction and oocytes collection were done as routine. The cumulus cells were dissected apart, and the expression of progesterone receptor and HAS2 was detected using RT-PCR (real-time polymerase chain reaction). Fertilization rate was evaluated by IVF. All data were analyzed using t-test. Results: Data was showed that expression of progesterone receptor and HAS2 in cumulus cells of mice that received prunus cerasus increased. Moreover, oocyte fertilization rate also increased significantly. Conclusion: Prunus cerasus as an antioxidant natural can become an important medication for improving oocyte quality and opening new opportunities for infertility treatment. It is concluded that Prunus cerasus consumption could improve fertility rate by increasing progesterone receptor and HAS2 activity in cumulus cells. PMID:27123419

  6. The fine structure of the cumulus oophorus during follicular development in sheep.

    PubMed

    Cran, D G; Hay, M F; Moor, R M

    1979-11-01

    The cumulus and membrana granulosa of non-atretic ovarian follicles from primordial up to a stage shortly before ovulation were studied by electron microscopy. The follicular cells of primordial follicles were undifferentiated and rested on a thick basal lamina. In secondary follicles the endoplasmic reticulum had proliferated forming an anastomosing network. In early antral and antral follicles (0.5--2.0 mm dia.) the ER was composed of short cisternae, the mitochondria had elongated and gap junctions were first observed. In late antral follicles (3.0--5.9 mm dia.) gap junctions were frequent. In the cumulus the glycogen was associated with electron lucent areas whereas in the granulosa it was invariably associated with membranes. In large antral follicles large membrane bound bodies were present in the basal cells of the cumulus. At early oestrus a distinctive mitochondrial morphology was noted in the granulosa but not elsewhere in the follicles. At mid oestrus numerous annular nexuses were present in the granulosa but not in the cumulus. At late oestrus numerous lipid droplets were formed in both cumulus and granulosa, the boundary with theca interna became indistinct and the basal lamina became incomplete. PMID:574800

  7. Greenhouse gas implications of fleet electrification based on big data-informed individual travel patterns.

    PubMed

    Cai, Hua; Xu, Ming

    2013-08-20

    Environmental implications of fleet electrification highly depend on the adoption and utilization of electric vehicles at the individual level. Past research has been constrained by using aggregated data to assume all vehicles with the same travel pattern as the aggregated average. This neglects the inherent heterogeneity of individual travel behaviors and may lead to unrealistic estimation of environmental impacts of fleet electrification. Using "big data" mining techniques, this research examines real-time vehicle trajectory data for 10,375 taxis in Beijing in one week to characterize the travel patterns of individual taxis. We then evaluate the impact of adopting plug-in hybrid electric vehicles (PHEV) in the taxi fleet on life cycle greenhouse gas emissions based on the characterized individual travel patterns. The results indicate that 1) the largest gasoline displacement (1.1 million gallons per year) can be achieved by adopting PHEVs with modest electric range (approximately 80 miles) with current battery cost, limited public charging infrastructure, and no government subsidy; 2) reducing battery cost has the largest impact on increasing the electrification rate of vehicle mileage traveled (VMT), thus increasing gasoline displacement, followed by diversified charging opportunities; 3) government subsidies can be more effective to increase the VMT electrification rate and gasoline displacement if targeted to PHEVs with modest electric ranges (80 to 120 miles); and 4) while taxi fleet electrification can increase greenhouse gas emissions by up to 115 kiloton CO2-eq per year with the current grid in Beijing, emission reduction of up to 36.5 kiloton CO2-eq per year can be achieved if the fuel cycle emission factor of electricity can be reduced to 168.7 g/km. Although the results are based on a specific public fleet, this study demonstrates the benefit of using large-scale individual-based trajectory data (big data) to better understand environmental implications

  8. Greenhouse gas implications of fleet electrification based on big data-informed individual travel patterns.

    PubMed

    Cai, Hua; Xu, Ming

    2013-08-20

    Environmental implications of fleet electrification highly depend on the adoption and utilization of electric vehicles at the individual level. Past research has been constrained by using aggregated data to assume all vehicles with the same travel pattern as the aggregated average. This neglects the inherent heterogeneity of individual travel behaviors and may lead to unrealistic estimation of environmental impacts of fleet electrification. Using "big data" mining techniques, this research examines real-time vehicle trajectory data for 10,375 taxis in Beijing in one week to characterize the travel patterns of individual taxis. We then evaluate the impact of adopting plug-in hybrid electric vehicles (PHEV) in the taxi fleet on life cycle greenhouse gas emissions based on the characterized individual travel patterns. The results indicate that 1) the largest gasoline displacement (1.1 million gallons per year) can be achieved by adopting PHEVs with modest electric range (approximately 80 miles) with current battery cost, limited public charging infrastructure, and no government subsidy; 2) reducing battery cost has the largest impact on increasing the electrification rate of vehicle mileage traveled (VMT), thus increasing gasoline displacement, followed by diversified charging opportunities; 3) government subsidies can be more effective to increase the VMT electrification rate and gasoline displacement if targeted to PHEVs with modest electric ranges (80 to 120 miles); and 4) while taxi fleet electrification can increase greenhouse gas emissions by up to 115 kiloton CO2-eq per year with the current grid in Beijing, emission reduction of up to 36.5 kiloton CO2-eq per year can be achieved if the fuel cycle emission factor of electricity can be reduced to 168.7 g/km. Although the results are based on a specific public fleet, this study demonstrates the benefit of using large-scale individual-based trajectory data (big data) to better understand environmental implications

  9. Specific antibody against the Aujeszky's disease virus in the complex cumulus oophorus-oocyte of sows.

    PubMed

    Jerábek, J; Horký, D; Trávník, P; Rodák, L

    1989-01-01

    Oocytes collected from sows vaccinated and revaccinated with an inactivated vaccine against Aujeszky's disease (AD) were examined for the presence of specific antibodies of the IgG class against AD virus in the complex cumulus oophorus-oocyte by means of immunocytochemical methods. No specific antibody of the IgG class was detected in the cumulus-oocyte complexes collected from sows before vaccination. On the other hand, the specific IgG antibody was found in all immunocytochemically examined complexes cumulus-oocyte collected from revaccinated sows. The specific antibody of the IgG class against AD virus and the porcine IgG were immunocytochemically visualized under both light and electron microscopes as a fine granular product disseminated in oocytes and follicular cells.

  10. Energy harvester using contact-electrification of magnetic fluid droplets under oscillating magnetic field

    NASA Astrophysics Data System (ADS)

    Kim, D.; Yun, K.-S.

    2015-12-01

    This paper reports a fluidic-based energy harvester generating electric power through contact-electrification of ferrofluid droplets, which will allow the power generation using oscillating magnetic field without vibration of any mechanical structure such as membrane or cantilever. The proposed device consists of top and bottom plates with a conducting electrode coated with a hydrophobic layer and water-based ferrofluid droplet. The contact area between the ferrofluid and the solid surface is changed according to the magnetic field applied by a magnet, which generates AC output power by contact electrification at the ferrofluid-solid interface.

  11. Transportation Electrification Load Development For a Renewable Future Analysis

    SciTech Connect

    Markel, Tony; Mai, Trieu; Kintner-Meyer, Michael CW

    2010-09-30

    Electrification of the transportation sector offers the opportunity to significantly reduce petroleum consumption. The transportation sector accounts for 70% of US petroleum consumption. The transition to electricity as a transportation fuel will create a new load for electricity generation. In support of a recent US Department of Energy funded activity that analyzed a future generation scenario with high renewable energy technology contributions, a set of regional hourly load profiles for electrified vehicles were developed for the 2010 to 2050 timeframe. These load profiles with their underlying assumptions will be presented in this paper. The transportation electrical energy was determined using regional population forecast data, historical vehicle per capita data, and market penetration growth functions to determine the number of plug-in electric vehicles (PEVs) in each analysis region. Two market saturation scenarios of 30% of sales and 50% of sales of PEVs consuming on average {approx}6 kWh per day were considered. Results were generated for 3109 counties and were consolidated to 134 Power Control Areas (PCA) for the use NREL's's regional generation planning analysis tool ReEDS. PEV aggregate load profiles from previous work were combined with vehicle population data to generate hourly loads on a regional basis. A transition from consumer-controlled charging toward utility-controlled charging was assumed such that by 2050 approximately 45% of the transportation energy demands could be delivered across 4 daily time slices under optimal control from the utility perspective. No other literature has addressed the potential flexibility in energy delivery to electric vehicles in connection with a regional power generation study. This electrified transportation analysis resulted in an estimate for both the flexible load and fixed load shapes on a regional basis that may evolve under two PEV market penetration scenarios. EVS25 Copyright.

  12. Importance of the GDF9 signaling pathway on cumulus cell expansion and oocyte competency in sheep.

    PubMed

    Varnosfaderani, Sh Rouhollahi; Ostadhosseini, S; Hajian, M; Hosseini, S M; Khashouei, E Asadi; Abbasi, H; Hosseinnia, P; Nasr-Esfahani, M H

    2013-09-15

    Acquisition of developmental competency in cumulus oocyte complexes (COCs) is derived from endocrine hormones and oocyte secreted factors. The contribution of these factors in oocyte maturation and development is an active area of research. The objective of this research was to investigate whether growth differentiation factor 9 (GDF9) that is secreted by oocyte affects cumulus expansion and oocyte development in sheep. Immature ovine COCs were cultured in the presence of recombinant human GDF9 (rhGDF9), denuded oocytes, SB-431542, a specific inhibitor of activin-like kinase 4/5/7; or a combination of these factors. Routine in vitro maturation of COCs and denuded oocytes were used as external control samples. Cultured COCs were used for assessment of (1) cumulus expansion; (2) expression of cumulus-related transcripts including pentraxin 3, hyaluronan synthase 2 (HAS2), tumor necrosis factor alpha-induced protein 6, prostaglandin synthase 2, B-cell lymphoma 2 (BCL2), and Bcl2-associated X (BAX); and (3) yield and quality of embryo development. It was observed that cumulus expansion was not affected by any of these treatments. HAS2 mRNA expression confirmed this observation. In the presence of exogenous GDF9, cleavage rate was reduced, blastocyst rate did not differ from other groups, and trophectoderm cell number significantly increased. This suggests that exogenous GDF9 could improve embryo quality. It was also observed that oocyte secreted factors reduced proapoptotic BAX mRNA, and BCL2 mRNA expression was not significantly different from other groups. This study provides evidence that GDF9 signaling might have a minor influence on ovine cumulus expansion and oocyte development and that other signaling pathway(s) might have a dominant role.

  13. Effects of aerosols and relative humidity on cumulus clouds

    NASA Astrophysics Data System (ADS)

    Fan, Jiwen; Zhang, Renyi; Li, Guohui; Tao, Wei-Kuo

    2007-07-01

    The influences of the aerosol type and concentration and relative humidity (RH) on cumulus clouds have been investigated using a two-dimensional spectral-bin cloud model. Three simulations are conducted to represent the polluted continental, clean continental, and marine aerosol types. Under the same initial dynamic and thermodynamic conditions, the maritime aerosol case results in more intensive radar reflectivity in both developing and mature stages than the continental aerosol cases, because of enhanced warm rain by collisions and ice processes by deposition growth due to larger droplet sizes and higher supersaturation, respectively. The considerable delay in convective development due to reduced droplet condensation is responsible for the longer cloud lifetime in the marine aerosol case. For the continental case, the most noticeable effects of increasing aerosol number concentrations (with 15 different initial values) are the increases of the cloud droplet number concentration and cloud water content but a decrease in the effective droplet radius. More latent heat release from increasing condensation results in stronger convection and more melting precipitation at the higher aerosol concentrations. Melting precipitation and secondary clouds primarily contribute to enhanced precipitation with increasing aerosols. The precipitation, however, decreases with increasing aerosol in the extremely high aerosol cases (over 5 × 104 cm-3) due to suppression of convection from depleted water vapor and inefficient coalescence. When the initial aerosol concentration exceeds a critical level, most of the cloud properties become less sensitive to aerosols, implying that the aerosol effect on deep convection is more pronounced in relatively clean air than in heavily polluted air. The aerosol effect on the cloud properties is strongly dependent on RH. As the surface RH increases from 40 to 70%, the cloud changes from shallow warm to deep convective types due to a significant

  14. Harvesting water drop energy by a sequential contact-electrification and electrostatic-induction process.

    PubMed

    Lin, Zong-Hong; Cheng, Gang; Lee, Sangmin; Pradel, Ken C; Wang, Zhong Lin

    2014-07-16

    A new prototype triboelectric nanogenerator with superhydrophobic and self-cleaning features is invented to harvest water drop energy based on a sequential contact electrification and electrostatic induction process. Because of the easy-fabrication, cost-effectiveness, and robust properties, the developed triboelectric nanogenerator expands the potential applications to harvesting energy from household wastewater and raindrops.

  15. Direct probing of contact electrification by using optical second harmonic generation technique.

    PubMed

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa; Wang, Zhong Lin

    2015-08-14

    Contact electrification between two different materials is one of the oldest fields of study in solid-state physics. Here, we introduced an innovative system based on optical electric-field-induced second harmonic generation (EFI-SHG) technique that can directly monitor the dynamic performance of the contact electrification on the surface of polyimide film. After the contact, the EFI-SHG system visualized briefly three relaxations of the tribo-induced charges on the surface of a polyimide film, a fast relaxation within 3 min followed by two much slower relaxations, which were possibly related to different charge diffusion routes. The contact electrification under several special experimental conditions (wind, water and steam) was studied to demonstrate the high flexibility and material selectivity of the EFI-SHG. The EFI-SHG studies confirmed the motion of the water can remove the surface charge, while the appearance and the evaporation of a thin water layer cannot enhance the charge diffusion. We anticipate that this experimental technique will find a variety of applications in the field of contact electrification and the development of the recently invented triboelectric nano generator.

  16. Lighting up the World The first global application of the open source, spatial electrification toolkit (ONSSET)

    NASA Astrophysics Data System (ADS)

    Mentis, Dimitrios; Howells, Mark; Rogner, Holger; Korkovelos, Alexandros; Siyal, Shahid; Broad, Oliver; Zepeda, Eduardo; Bazilian, Morgan

    2016-04-01

    In September 2015, the international community has adopted a new set of targets, following and expanding on the millennium development goals (MDGs), the Sustainable Development Goals (SDGs). Ensuring access to affordable, reliable, sustainable and modern energy for all is one of the 17 set goals that each country should work towards realizing. According to the latest Global Tracking Framework, 15% of the global population live without access to electricity. The majority of those (87%) reside in rural areas. Countries can reach universal access through various electrification options, depending on different levels of energy intensity and local characteristics of the studied areas, such as renewable resources availability, spatially differentiated costs of diesel-fuelled electricity generation, distance from power network and major cities, population density and others, data which are usually inadequate in national databases. This general paucity of reliable energy-related information in developing countries calls for the utilization of geospatial data. This paper presents a Geographic Information Systems (GIS) based electrification analysis for all countries that have not yet reached full access to electricity (Sub-Saharan Africa, Developing Asia, Latin America and Middle East). The cost optimal mix of electrification options ranges from grid extensions to mini-grid and stand-alone applications and is identified for all relevant countries. It is illustrated how this mix is influenced by scrolling through various electrification levels and different oil prices. Such an analysis helps direct donors and investors and inform multinational actions with regards to investments related to energy access.

  17. Direct probing of contact electrification by using optical second harmonic generation technique

    NASA Astrophysics Data System (ADS)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa; Wang, Zhong Lin

    2015-08-01

    Contact electrification between two different materials is one of the oldest fields of study in solid-state physics. Here, we introduced an innovative system based on optical electric-field-induced second harmonic generation (EFI-SHG) technique that can directly monitor the dynamic performance of the contact electrification on the surface of polyimide film. After the contact, the EFI-SHG system visualized briefly three relaxations of the tribo-induced charges on the surface of a polyimide film, a fast relaxation within 3 min followed by two much slower relaxations, which were possibly related to different charge diffusion routes. The contact electrification under several special experimental conditions (wind, water and steam) was studied to demonstrate the high flexibility and material selectivity of the EFI-SHG. The EFI-SHG studies confirmed the motion of the water can remove the surface charge, while the appearance and the evaporation of a thin water layer cannot enhance the charge diffusion. We anticipate that this experimental technique will find a variety of applications in the field of contact electrification and the development of the recently invented triboelectric nano generator.

  18. Direct probing of contact electrification by using optical second harmonic generation technique.

    PubMed

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa; Wang, Zhong Lin

    2015-01-01

    Contact electrification between two different materials is one of the oldest fields of study in solid-state physics. Here, we introduced an innovative system based on optical electric-field-induced second harmonic generation (EFI-SHG) technique that can directly monitor the dynamic performance of the contact electrification on the surface of polyimide film. After the contact, the EFI-SHG system visualized briefly three relaxations of the tribo-induced charges on the surface of a polyimide film, a fast relaxation within 3 min followed by two much slower relaxations, which were possibly related to different charge diffusion routes. The contact electrification under several special experimental conditions (wind, water and steam) was studied to demonstrate the high flexibility and material selectivity of the EFI-SHG. The EFI-SHG studies confirmed the motion of the water can remove the surface charge, while the appearance and the evaporation of a thin water layer cannot enhance the charge diffusion. We anticipate that this experimental technique will find a variety of applications in the field of contact electrification and the development of the recently invented triboelectric nano generator. PMID:26272162

  19. Direct probing of contact electrification by using optical second harmonic generation technique

    PubMed Central

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa; Wang, Zhong Lin

    2015-01-01

    Contact electrification between two different materials is one of the oldest fields of study in solid-state physics. Here, we introduced an innovative system based on optical electric-field-induced second harmonic generation (EFI-SHG) technique that can directly monitor the dynamic performance of the contact electrification on the surface of polyimide film. After the contact, the EFI-SHG system visualized briefly three relaxations of the tribo-induced charges on the surface of a polyimide film, a fast relaxation within 3 min followed by two much slower relaxations, which were possibly related to different charge diffusion routes. The contact electrification under several special experimental conditions (wind, water and steam) was studied to demonstrate the high flexibility and material selectivity of the EFI-SHG. The EFI-SHG studies confirmed the motion of the water can remove the surface charge, while the appearance and the evaporation of a thin water layer cannot enhance the charge diffusion. We anticipate that this experimental technique will find a variety of applications in the field of contact electrification and the development of the recently invented triboelectric nano generator. PMID:26272162

  20. SELCO: A model for solar rural electrification in India

    NASA Astrophysics Data System (ADS)

    Hande, H. Harish

    1999-11-01

    The following thesis presents the concept of a Rural Energy Service Company in India, known as SELCO. The model is being set up as a sustainable proposition for the implementation of solar photovoltaics as a viable alternative to provide reliable home lighting in the rural areas of India. The SELCO approach has already achieved noteworthy social and commercial results. Institutional, policy and operational problems have long plagued the rural electrification programs in India, resulting in thousands of villages without access to electricity. SELCO is a solar energy service company operating in Southern India since 1995, focusing on the enormous untapped market for home lighting where thousands of households have no access to electricity and severe power shortages face those already connected to the electric grid. The Company has installed nearly 2,000 solar home lighting systems. From a modest two employees company in 1995, it has grown to 35 in 1997 and from one office to eight. The hypothesis to be tested in this study is that in rural India, in a market not subsidized by the government, a solar service company with available loans from local banks and cooperatives and with sales, installation, and maintenance personnel in the villages can be successful in introducing photovoltaic systems to provide basic amenities such as lighting and water pumping for the improvement of the quality of life, public health, and the environment. The initial success of SELCO lends considerable evidence to the acceptance of the hypothesis. To accomplish its mission, SELCO works with commercial, retail, and rural development banks with large rural branch networks to stimulate loans to SELCO's customers based on a standard set of attractive financing terms. SELCO through its successful model has convinced the policy makers that a way to increase rural families' access to consumer financing for solar home lighting systems is through the existing financial network available in the

  1. Wind-blown Sand Electrification Inspired Triboelectric Energy Harvesting Based on Homogeneous Inorganic Materials Contact: A Theoretical Study and Prediction

    PubMed Central

    Hu, Wenwen; Wu, Weiwei; Zhou, Hao-miao

    2016-01-01

    Triboelectric nanogenerator (TENG) based on contact electrification between heterogeneous materials has been widely studied. Inspired from wind-blown sand electrification, we design a novel kind of TENG based on size dependent electrification using homogeneous inorganic materials. Based on the asymmetric contact theory between homogeneous material surfaces, a calculation of surface charge density has been carried out. Furthermore, the theoretical output of homogeneous material based TENG has been simulated. Therefore, this work may pave the way of fabricating TENG without the limitation of static sequence. PMID:26817411

  2. Effect of Acrylamide on Oocyte Nuclear Maturation and Cumulus Cells Apoptosis in Mouse In Vitro

    PubMed Central

    Liu, Shuzhen; Jiang, Ligang; Zhong, Tao; Kong, Shuhui; Zheng, Rongbin; Kong, Fengyun; Zhang, Cong; Zhang, Lei; An, Liguo

    2015-01-01

    Acrylamide (ACR) is a chemical compound with severe neurotoxicity, genotoxicity, carcinogenicity and reproductive toxicity. Recent studies showed that ACR impairs the function of reproductive organs, e.g., epididymis and testes. In vitro maturation of mouse oocyte is a sensitive assay to identify potential chemical hazard to female fertility. The aim of this study was to evaluate the adverse effects of ACR on the nuclear maturation and cumulus cells apoptosis of mouse oocytes in vitro. Cumulus–oocyte complexes were incubated in a maturation medium containing 0, 5, 10 and 20 μM of ACR. Chromosome alignment and spindle morphology of oocytes was determined by immunofluorescence and confocal microscopy. Our results showed that oocytes exposed to different doses of ACR in vitro were associated with a significant decrease of oocyte maturation, significant increase of chromosome misalignment rate, occurrence of abnormal spindle configurations, and the inhibition of oocyte parthenogenetic activation. Furthermore, apoptosis of cumulus cells was determined by TUNEL and CASPASE-3 assay. Results showed that apoptosis in cumulus cells was enhanced and the expression of CASPASE-3 was increased after cumulus–oocyte complexes were exposed to ACR. Therefore, ACR may affect the nuclear maturation of oocytes via the apoptosis of cumulus cells in vitro. PMID:26275143

  3. Interaction of a cumulus cloud ensemble with the large-scale environment

    NASA Technical Reports Server (NTRS)

    Arakawa, A.; Schubert, W.

    1973-01-01

    Large-scale modification of the environment by cumulus clouds is discussed in terms of entrainment, detrainment, evaporation, and subsidence. Drying, warming, and condensation by vertical displacement of air are considered as well as budget equations for mass, static energy, water vapor, and liquid water.

  4. Effect of oil overlay on inhibition potential of roscovitine in sheep cumulus-oocyte complexes.

    PubMed

    Crocomo, L F; Marques Filho, W C; Ulian, C M V; Branchini, N S; Silva, D T; Ackermann, C L; Landim-Alvarenga, F C; Bicudo, S D

    2015-06-01

    Inhibitors of cyclin-dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus-oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor-free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (-) at 38.5°C and 5% CO2 . At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/-) exhibited total expansion while in both Rosco groups (+/-) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/-). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression.

  5. Sub-grid Parameterization of Cumulus Vertical Velocities for Climate and Numerical Weather Prediction Models

    NASA Astrophysics Data System (ADS)

    Cooke, William; Donner, Leo

    2015-04-01

    Microphysical and aerosol processes determine the magnitude of climate forcing by aerosol-cloud interactions, are central aspects of cloud-climate feedback, and are important elements in weather systems for which accurate forecasting is a major goal of numerical weather prediction. Realistic simulation of these processes demands not only accurate microphysical and aerosol process representations but also realistic simulation of the vertical motions in which the aerosols and microphysics act. Aerosol activation, for example, is a strong function of vertical velocity. Cumulus parameterizations for climate and numerical weather prediction models have recently begun to include vertical velocities among the statistics they predict. These vertical velocities have been subject to only limited evaluation using observed vertical velocities. Deployments of multi-Doppler radars and dual-frequency profilers in recent field campaigns have substantially increased the observational base of cumulus vertical velocities, which for decades had been restricted mostly to GATE observations. Observations from TWP-ICE (Darwin, Australia) and MC3E (central United States) provide previously unavailable information on the vertical structure of cumulus vertical velocities and observations in differing synoptic contexts from those available in the past. They also provide an opportunity to independently evaluate cumulus parameterizations with vertical velocities tuned to earlier GATE observations. This presentation will compare vertical velocities observed in TWP-ICE and MC3E with cumulus vertical velocities using the parameterization in the GFDL CM3 climate model. Single-column results indicate parameterized vertical velocities are frequently greater than observed. Errors in parameterized vertical velocities exhibit similarities to vertical velocities explicitly simulated by cloud-system resolving models, and underlying issues in the treatment of microphysics may be important for both. The

  6. Kinematics of hamster sperm during penetration of the cumulus cell matrix.

    PubMed

    Drobnis, E Z; Yudin, A I; Cherr, G N; Katz, D F

    1988-12-01

    During capacitation, mammalian spermatozoa gain the ability to penetrate the cumulus cell matrix (CCM). The role of hyperactivated motility for this capacity is uncertain. In the present study, hamster sperm were observed during penetration and progression through the CCM, and flagellar beat patterns were quantitated by characterization of the underlying flagellar bends. Small numbers of sperm were added to cumulus masses slightly compressed on a slide (150 micron depth), and penetration was videorecorded using interference contrast optics. During penetration of the cumulus surface, sperm did not generate the large flagellar bends and asymmetric beats that are hallmarks of hyperactivation in low viscosity media. Instead, they entered slowly using high-frequency, low-amplitude sinusoidal flagellar motions. Within the CCM, sperm continued to move slowly, and they exhibited three distinct patterns of motility. The first was sinusoidal, produced by alternating, propagated bends: principal bends (PB) moved the head away from the beat midline, with the convex edge of the head leading, and reverse bends (RB) had the opposite curvature. The second pattern was asymmetric and sinusoidal: an extreme RB developed in the distal flagellum, was propagated distally, and was followed by a PB of less curvature. The third motility pattern was a hatchet-like stroke of the sperm head which resulted when an extreme, nonpropagated PB developed slowly in the proximal midpiece, and was released rapidly. In this mode there were no reverse bends, and sperm did not progress. There were subpopulations of capacitating sperm in free-swimming medium which had these same bend types and motility patterns, suggesting that qualitative flagellar movement may not change during CCM penetration. Sperm velocity in the CCM was not strongly correlated with flagellar beat kinematics, suggesting local heterogeneity in cumulus mechanical resistance and/or differences in interaction of the matrix with the

  7. Estrogen promotes the development of mouse cumulus cells in coordination with oocyte-derived GDF9 and BMP15.

    PubMed

    Sugiura, Koji; Su, You-Qiang; Li, Qinglei; Wigglesworth, Karen; Matzuk, Martin M; Eppig, John J

    2010-12-01

    The differentiation and function of cumulus cells depend upon oocyte-derived paracrine factors, but studies on the estrogen receptor knockout mice suggested that estrogen also participates in these processes. This study investigates the possible coordination of estrogen and oocytes in the development and function of cumulus cells using cumulus expansion and the expression of transcripts required for expansion as functional endpoints. Preantral granulosa cell-oocyte complexes developed in vitro with 17β-estradiol (E2) exhibited increased levels of cumulus expansion and Has2 transcripts, encoding hyaluronan synthase 2, compared with those developed without E2. Moreover, cumulus cell-oocyte complexes (COCs) isolated from antral follicles and maintained in culture without E2 exhibited reduced cumulus expansion and Has2 mRNA levels compared with freshly isolated COCs. Exogenous E2, provided during the maintenance culture, alleviated these deficiencies. However, when oocytes were removed from COCs, E2 supplementation did not maintain competence to undergo expansion; the presence in culture of either fully grown oocytes or recombinant growth differentiation factor 9 (GDF9) was required. Recombinant bone morphogenetic protein 15, but not fibroblast growth factor 8, augmented the GDF9 effect. Oocytes or GDF9 suppressed cumulus cell levels of Nrip1 transcripts encoding nuclear receptor-interacting protein 1, a potential inhibitor of estrogen receptor signals. Therefore, E2 and oocyte-derived paracrine factors GDF9 and bone morphogenetic protein 15 coordinate to promote the development of cumulus cells and maintain their competence to undergo expansion. Furthermore, suppression of Nrip1 expression in cumulus cells by oocyte may be one mechanism mediating cross talk between oocyte and E2 signals that promotes follicular development.

  8. Overview of the Cumulus Humilis Aerosol Processing Study.

    SciTech Connect

    Berg, L. K.; Berkowitz, C. M.; Ogren, J. A.; Hostetler, C. A.; Ferrare, R. A.; Dubey, M.; Andrews, E.; Coulter, R. L.; Hair, J. W.; Hubbe, J. M.Lee, Y. N.; Mazzoleni, C; Olfert, J; Springston, SR; Environmental Science Division; PNNL; NOAA Earth System Research Lab.; NASA Langley Research Center; LANL; BNL; Univ.of Alberta; Univ. of Colorado

    2009-11-01

    Aerosols influence climate directly by scattering and absorbing radiation and indirectly through their influence on cloud microphysical and dynamical properties. The Intergovernmental Panel on Climate Change (IPCC) concluded that the global radiative forcing due to aerosols is large and in general cools the planet. But the uncertainties in these estimates are also large due to our poor understanding of many of the important processes related to aerosols and clouds. To address this uncertainty an integrated strategy for addressing issues related to aerosols and aerosol processes was proposed. Using this conceptual framework, the Cumulus Humilis Aerosol Processing Study (CHAPS) is a stage 1 activity, that is, a detailed process study. The specific focus of CHAPS was to provide concurrent observations of the chemical composition of the activated [particles that are currently serving as cloud condensation nuclei (CCN)] and nonactivated aerosols, the scattering and extinction profiles, and detailed aerosol and droplet size spectra in the vicinity of Oklahoma City, Oklahoma, during June 2007. Numerous campaigns have examined aerosol properties downwind from large pollution sources, including the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign and the two of the three Aerosol Characterization Experiments, ACE-2 and ACE-Asia. Other studies conducted near cities have examined changes in both aerosols and clouds downwind of urban areas. For example wintertime stratiform clouds associated with the urban plumes of Denver, Colorado, and Kansas City, Missouri, have a larger number concentration and smaller median volume diameter of droplets than clouds that had not been affected by the urban plume. Likewise, a decrease in precipitation in polluted regions along the Front Range of the Rocky Mountains was discovered. In a modeling study, it was found that precipitation downwind of urban areas may be influenced by changes in aerosols as well as the

  9. NASA Earth Science Research and Applications Using UAVs

    NASA Technical Reports Server (NTRS)

    Guillory, Anthony R.

    2003-01-01

    The NASA Earth Science Enterprise sponsored the UAV Science Demonstration Project, which funded two projects: the Altus Cumulus Electrification Study (ACES) and the UAV Coffee Harvest Optimization experiment. These projects were intended to begin a process of integrating UAVs into the mainstream of NASA s airborne Earth Science Research and Applications programs. The Earth Science Enterprise is moving forward given the positive science results of these demonstration projects to incorporate more platforms with additional scientific utility into the program and to look toward a horizon where the current piloted aircraft may not be able to carry out the science objectives of a mission. Longer duration, extended range, slower aircraft speed, etc. all have scientific advantages in many of the disciplines within Earth Science. The challenge we now face are identifying those capabilities that exist and exploiting them while identifying the gaps. This challenge has two facets: the engineering aspects of redesigning or modifying sensors and a paradigm shift by the scientists.

  10. Transportation Electrification Education Partnership for Green Jobs and Sustainable Mobility

    SciTech Connect

    Peng, Huei; Mi, Chris; Gover, James

    2013-06-28

    This collaborative educational project between the University of Michigan—Ann Arbor, University of Michigan—Dearborn and the Kettering University successfully executed almost all the elements we proposed to do. In the original proposal, we proposed to develop four graduate courses, six undergraduate courses, four professional short courses, a K-12 electric vehicle education kit, a Saturday morning seminar series, and a set of consumer education material to support the advancement of transportation electrification. The first four deliverables were all successfully developed and offered. When we held the kick-off meeting in NETL in Morgantown back in early 2010 with all the ten ARRA education teams, however, it quickly became clear that among the ten ARRA education grantee teams, our proposed “consume education” activities are not better or with the potential to create bigger impact than some of activities proposed in other teams. For example, the Odyssey 2010 event held by the West Virginia University team had planned and successfully reached to more than 230,000 attendees, which is way more than what our proposed 100k event could ever reach. It was under the suggestion of Joseph Quaranta, the ARRA education Program Director at that time, that we should coordinate and eliminate redundancy. The resources should then be focused on activities that have less overlap. Therefore, the originally proposed activities: Saturday morning seminar series, and a set of consumer education material were dropped from our scope. We expanded the scope of our “education kit” activity to include some educational materials, mainly in the form of videos. The target audience also changed from general public to K-12 students. The majority of the project cost (~70%) goes toward the establishment of three undergraduate laboratories, which provides critically needed hands-on learning experience for next-generation green mobility engineers. We are very proud that the ARRA money

  11. Best practices for photovoltaic household electrification programs: Lessons from experiences in selected countries. World Bank Technical Paper No. 324

    SciTech Connect

    Cabraal, A.; Cosgrove-Davies, M.; Schaeffer, L.

    1996-09-01

    The report draws on case studies of recent experiences in the Dominican Republic, Indonesia, the Philippines, and Sri Lanka to the identify key ingredients of successful residential photovoltaic (PV) electrification programs and ways of overcoming financial and institutional barriers to the use of PV systems. The report concludes that PV systems are a viable complement to grid-based energy services delivery and that these systems have a cost-effective niche and market potential within the rural electrification framework.

  12. Individual bovine in vitro embryo production and cumulus cell transcriptomic analysis to distinguish cumulus-oocyte complexes with high or low developmental potential.

    PubMed

    Bunel, A; Jorssen, E P; Merckx, E; Leroy, J L; Bols, P E; Sirard, M A

    2015-01-15

    Studying cumulus cell (CC) transcriptome is of great interest as it could provide a noninvasive method to assess oocyte quality. In cattle, the search for quality markers has not been done with cumulus-oocyte complexes (COCs) cultured individually from maturation to blastocyst stage. Here, differences between high- and low-potential COCs were examined by transcriptomic analysis of CC biopsies obtained from COCs of 2 to 6 mm follicles (n = 249; eight replicates) before individual in vitro maturation, fertilization, and culture until Day 8 after fertilization. Each COC was individually tracked and categorized based on his fate: embryo at blastocyst stage (CC-Blast) or embryo arrested at 2- to 8-cell stage (CC-2-8-cells). Average blastocyst rates were 27.7% for individual culture and 31.2% for group control (not significantly different). For transcriptomic analysis, five cumulus biopsies per replicate were pooled for each fate. Three CC replicates underwent transcriptomic analysis using RNA microarray assay. Some clear differences in gene expression between the CC-Blast and the CC-2-8-cell groups were identified. Considering a 1.5-fold change (P < 0.05), 68 genes were differentially expressed between the CC-Blast and CC-2-8-cells. Quantitative reverse transcription-polymerase chain reaction validations were performed for 12 selected genes: six upregulated genes for each COC fate. Higher expression of 1-acylglycerol-3-phosphate O-acyltransferase 9 (AGPAT9) (lipid metabolism), Chloride intracellular channel 3 (CLIC3), Keratin 8 (KRT8), and Lumican (LUM) (molecular transport) was observed in CC-2-8-cells (P < 0.05). The CC-Blast fate analysis revealed a significantly higher expression of Glycine amidinotransferase (L-arginine:glycine amidinotransferase) (GATM) (posttranslational modification, amino acid metabolism, and free radical scavenging). This newly identified set of genes could provide new markers to distinguish COCs associated with good quality embryos from COCs

  13. Assessing the Impacts of Rural Electrification in Sub-Saharan Africa: The Case of Ethiopia

    NASA Astrophysics Data System (ADS)

    Aragaw, Mekonnen Lulie

    This study links rural electrification and the transition to modern energy services with poverty reduction and rural development in Ethiopia. Benefits of rural electrification in reducing poverty and accelerating rural development in low-income developing countries have been insufficiently researched. This study analyses available empirical evidence at a local level and examines how electricity access translates into productive use beyond powering radios and lighting. A survey of 336 households was conducted in Northern Ethiopia on impacts of electrification on four rural towns with varying number of years of access to electricity. Evidence at household and community levels shows that access to electricity was followed by an increase in household connectivity rate, and slow transition to modern energy services based on level of household income and number of years of a household's connection to electricity services. The pace of transition to modern energy services was slow, and household energy poverty and dependence on biomass fuels continued in most rural towns, having little impact on improved environmental management practices. Improvement in rural livelihood, poverty reduction, and delivery of public services was highest for those with more years of access to electricity, and higher income households. The fact that impacts of RE depend on number of years of a household's electricity connection implies gradual improvements rather than immediate benefits after connection. In the short-term, households improved their quality of life through better lighting and reduced indoor-air pollution. In the medium and longer-term, households and communities diversified their income and received improved public services such as education, health, and potable water. Further benefits were wider off-farm and non-farm employment, increased rural markets, and improved environment for rural development. Very poor households benefited least, while those better-off utilized

  14. The Macroscopic Entrainment Processes of Simulated Cumulus Ensemble. Part II: Testing the Entraining-Plume Model.

    NASA Astrophysics Data System (ADS)

    Lin, Chichung; Arakawa, Akio

    1997-04-01

    According to Part I of this paper, it seems that ignoring the contribution from descendent cloud air in a cloud model for cumulus parameterization (CMCP), such as the spectral cumulus ensemble model in the Arakawa-Schubert parameterization, is an acceptable simplification for tropical deep convection. Since each subensemble in the spectral cumulus ensemble model is formally analogous to an entraining plume, the latter is examined using the simulated data from a cloud-resolving model (CRM). The authors first follow the analysis procedure of Warner. With the data from a nonprecipitating experiment, the authors show that the entraining-plume model cannot simultaneously predict the mean liquid water profile and cloud top height of the clouds simulated by the CRM. However, the mean properties of active elements of clouds, which are characterized by strong updrafts, can be described by an entraining plume of similar top height.With the data from a precipitating experiment, the authors examine the spectral cumulus ensemble model using the Paluch diagram. It is found that the spectral cumulus ensemble model appears adequate if different types of clouds in the spectrum are interpreted as subcloud elements with different entrainment characteristics. The resolved internal structure of clouds can thus be viewed as a manifestation of a cloud spectrum. To further investigate whether the fractional rate of entrainment is an appropriate parameter for characterizing cloud types in the spectral cumulus ensemble model, the authors stratify the simulated saturated updrafts (subcloud elements) into different types according to their eventual heights and calculate the cloud mass flux and mean moist static energy for each type. Entrainment characteristics are then inferred through the cloud mass flux and in-cloud moist static energy. It is found that different types of subcloud elements have distinguishable thermodynamic properties and entrainment characteristics. However, for each cloud

  15. Electrification of Shaken Granular Flows as a Model of Natural Storm Charging

    NASA Astrophysics Data System (ADS)

    Kara, O.; Nordsiek, F.; Lathrop, D. P.

    2015-12-01

    The charging of particulates in nature is widespread and observed in thunderstorms, volcanic ash clouds, thunder-snow, and dust storms. However the mechanism of charge separation at large (> 1km) scale is poorly understood. We perform simple laboratory experiments to better understand the collective phenomena involved in granular electrification. We confine granular particles in an oscillating cylindrical chamber which is enclosed and sealed by two conducting plates. The primary measurement is the voltage difference between the two plates. We find that collective effects occurring in the bulk of the material play a significant role in the electrification process. We extend that by addition of photodetection capabilities to the experimental chamber to detect electrical discharges between the particles and each other and the plates. We present measurements of electrical discharges in addition to the slower dynamics of voltage variation in the system.

  16. Impact of a scale-aware cumulus parameterization in an operational NWP system modeling system

    NASA Astrophysics Data System (ADS)

    Chen, Baode; Yang, Yuhua; Wang, Xiaofeng

    2014-05-01

    To better understand the behavior of convective schemes across the grey zone, we carried out one-month (July of 2013) realtime-like experiment with an operational NWP system modeling system which includes the ADAS data assimilation scheme and WRF forecast model. The Grell-Freitas cumulus parameterization scheme, which is a scale-aware convective parameterization scheme and has been developed to better handle the transition in behavior of the sub-grid scale convective processes through the grey zone, was used in different resolution (15km, 9km and 3km) model set-up. Subjective and quantitative evaluations of the forecasts were conducted and the skills of the different experimental forecasts relatively to existing forecasting guidance were compared. A summary of the preliminary findings about the proportion of resolved vs unresolved physical processes in the gray zone will be presented along with a discussion of the potential operational impacts of the cumulus parameterization.

  17. A cumulus parameterization scheme designed for nested grid meso-{beta} scale models

    SciTech Connect

    Weissbluth, M.J.; Cotton, W.R.

    1991-12-31

    A generalized cumulus parameterization based upon higher order turbulence closure has been incorporated into one dimensional simulations. The scheme consists of a level 2.5w turbulence closure scheme mated with a convective adjustment scheme. The convective adjustment scheme includes a gradient term which can be interpreted as either a subsidence term when the scheme is used in large scale models or a mesoscale compensation term when the scheme is used in mesoscale models. The scheme also includes a convective adjustment term which is interpreted as a detrainment term in large scale models. In mesoscale models, the mesoscale compensation term and the advection by the mean vertical motions combine to yield no net advection which is desirable since the convective moistening and heating is now wholly accomplished by the convective adjustment term; double counting is then explicitly eliminated. One dimensional simulations indicate satisfactory performance of the cumulus parameterization scheme for a non-entraining updraft.

  18. A cumulus parameterization scheme designed for nested grid meso-. beta. scale models

    SciTech Connect

    Weissbluth, M.J.; Cotton, W.R.

    1991-01-01

    A generalized cumulus parameterization based upon higher order turbulence closure has been incorporated into one dimensional simulations. The scheme consists of a level 2.5w turbulence closure scheme mated with a convective adjustment scheme. The convective adjustment scheme includes a gradient term which can be interpreted as either a subsidence term when the scheme is used in large scale models or a mesoscale compensation term when the scheme is used in mesoscale models. The scheme also includes a convective adjustment term which is interpreted as a detrainment term in large scale models. In mesoscale models, the mesoscale compensation term and the advection by the mean vertical motions combine to yield no net advection which is desirable since the convective moistening and heating is now wholly accomplished by the convective adjustment term; double counting is then explicitly eliminated. One dimensional simulations indicate satisfactory performance of the cumulus parameterization scheme for a non-entraining updraft.

  19. Measured and modeled cloud-aerosol radiative effects in polluted cumulus clouds

    NASA Astrophysics Data System (ADS)

    Schmidt, K. S.; Feingold, G.; Pilewskie, P.; Jiang, H.; Coddington, O.

    2009-04-01

    Recent studies have emphasized the need to consider aerosol particles and clouds as an entity rather than artificially separating aerosol and cloud radiative forcing. A particularly difficult situation is that of cumulus clouds in a polluted background where radiative effects from heterogeneous clouds, aerosol particles, and surface albedo can only be distinguished by their spectral signature. We have used spectral irradiance measurements from the Gulf of Mexico Atmospheric Composition and Climate Study, and extensive three-dimensional radiative transfer calculations applied to the output of large eddy simulations, to show that measurements below clouds or cloud gaps are only reproduced when including aerosol particles in the calculations. Our technique enables the derivation of measurement-based spectral forcing and absorption of the cloud-aerosol-system. Furthermore, we present a new spectral effect caused by a combination of molecular scattering and cumulus cloud effects that is also relevant to cloud remote sensing.

  20. Dependence of entrainment in shallow cumulus convection on vertical velocity and distance to cloud edge

    NASA Astrophysics Data System (ADS)

    Tian, Yang; Kuang, Zhiming

    2016-04-01

    The dependence of entrainment rate on environmental conditions and cloud characteristics is investigated using large eddy simulations (LES) of the response of shallow cumulus convection to a small-amplitude temperature perturbation that is horizontally uniform and localized in height. The simulated cumulus fields are analyzed in the framework of an ensemble of entraining plumes by tracking a large number of Lagrangian parcels embedded in the LES and grouping them into different plumes based on their detrainment heights. The results show that fractional entrainment rate per unit height of a plume is inversely proportional to the plume's vertical velocity and its distance to the cloud edge, while changes in environmental stratification and relative humidity, the plume's buoyancy, or the vertical gradient of its buoyancy due to the temperature perturbation have little effect on the plume's entrainment rate.

  1. Annihilating time and space: The electrification of the United States Army, 1875--1920

    NASA Astrophysics Data System (ADS)

    Brown, Shannon Allen

    2000-10-01

    The United States Army embraced electrical technology in the 1870s as part of a wider initiative to meet the challenge of the coastal defense mission. As commercial power storage, generation, and transmission technology improved and the army came to recognize the value of the energy source as a means and method of improving command and control, localized electrical networks were integrated into the active service of the military. New vulnerabilities emerged as the army became ever more reliant upon electric power, however, and electrification---the institutional adoption and adaptation of electrical technologies---emerged as a very expensive and contentious process guided by technical, political, and economic pressures, and influenced by conflicting personalities within the service. This study considers the institutional evolution of the U.S. Army before and during World War I with respect to the adoption and application of electrical technology. The changing relationships between the military and electrical manufacturing and utilities industries during the period 1875--1920 are also explored. Using a combination of military archival sources and published primary materials, this study traces the effects of electrification on the army. In the end, this study proves that electrification was, at first, a symptom of, and later, a partial solution to the army's struggle to modernize and centralize during the period under consideration. Electrification produced a set of conditions that encouraged a new maturity within the ranks of the army, in technical, doctrinal, and administrative terms. This growth eventually led to the development of new capabilities, new forms of military organization, new missions, and new approaches to warfare.

  2. Excluding Contact Electrification in Surface Potential Measurement Using Kelvin Probe Force Microscopy.

    PubMed

    Li, Shengming; Zhou, Yusheng; Zi, Yunlong; Zhang, Gong; Wang, Zhong Lin

    2016-02-23

    Kelvin probe force microscopy (KPFM), a characterization method that could image surface potentials of materials at the nanoscale, has extensive applications in characterizing the electric and electronic properties of metal, semiconductor, and insulator materials. However, it requires deep understanding of the physics of the measuring process and being able to rule out factors that may cause artifacts to obtain accurate results. In the most commonly used dual-pass KPFM, the probe works in tapping mode to obtain surface topography information in a first pass before lifting to a certain height to measure the surface potential. In this paper, we have demonstrated that the tapping-mode topography scan pass during the typical dual-pass KPFM measurement may trigger contact electrification between the probe and the sample, which leads to a charged sample surface and thus can introduce a significant error to the surface potential measurement. Contact electrification will happen when the probe enters into the repulsive force regime of a tip-sample interaction, and this can be detected by the phase shift of the probe vibration. In addition, the influences of scanning parameters, sample properties, and the probe's attributes have also been examined, in which lower free cantilever vibration amplitude, larger adhesion between the probe tip and the sample, and lower cantilever spring constant of the probe are less likely to trigger contact electrification. Finally, we have put forward a guideline to rationally decouple contact electrification from the surface potential measurement. They are decreasing the free amplitude, increasing the set-point amplitude, and using probes with a lower spring constant.

  3. The product is progress: rural electrification in Costa Rica. Project impact evaluation No. 22

    SciTech Connect

    Hoover, G.; Goddard, P.O.; Gomez, G.; Harrison, P.

    1981-10-01

    Because Costa Rica had abundant hydroelectric potential and a government which was strongly committed to equitable growth, a considerable return was reaped from a relatively small investment in rural electrification (RE). This report details this success and A.I.D.'s contribution (1965-69). Aiming to diversify agriculture, increase income, expand agroindustry, and develop replicable RE cooperatives (REC's), the project produced positive but not wholly anticipated results.

  4. Modification of cumulus convection and planetary boundary layer schemes in the GRAPES global model

    NASA Astrophysics Data System (ADS)

    Liu, Kun; Chen, Qiying; Sun, Jian

    2015-10-01

    Cumulus convection is a key linkage between hydrological cycle and large-scale atmospheric circulation. Cumulus parameterization scheme is an important component in numerical weather and climate modeling studies. In the Global/Regional Assimilation and Prediction Enhanced System (GRAPES), turbulent mixing and diffusion approach is applied in its shallow convection scheme. This method overestimates the vertical transport of heat and moisture fluxes but underestimates cloud water mixing ratio over the region of stratocumulus clouds. As a result, the simulated low stratocumulus clouds are less than observations. To overcome this problem, a mass flux method is employed in the shallow convection scheme to replace the original one. Meanwhile, the deep convection scheme is adjusted correspondingly. This modification is similar to that in the US NCEP Global Forecast System (GFS), which uses the simplified Arakawa Schubert Scheme (SAS). The planetary boundary layer scheme (PBL) is also revised by considering the coupling between the PBL and stratocumulus clouds. With the modification of both the cumulus and PBL schemes, the GRAPES simulation of shallow convective heating rate becomes more reasonable; total amounts of stratocumulus clouds simulated over the eastern Pacific and their vertical structure are more consistent with observations; the underestimation of stratocumulus clouds simulated by original schemes is less severe with the revised schemes. Precipitation distribution in the tropics becomes more reasonable and spurious precipitation is effectively suppressed. The westward extension and northward movement of the western Pacific subtropical high simulated with the revised schemes are more consistent with Final Operational Global Analysis (FNL) than that simulated with the original schemes. The statistical scores for the global GRAPES forecast are generally improved with the revised schemes, especially for the simulation of geopotential height in the Northern

  5. Cumulus Cell Transcripts Transit to the Bovine Oocyte in Preparation for Maturation.

    PubMed

    Macaulay, Angus D; Gilbert, Isabelle; Scantland, Sara; Fournier, Eric; Ashkar, Fazl; Bastien, Alexandre; Saadi, Habib A Shojaei; Gagné, Dominic; Sirard, Marc-André; Khandjian, Édouard W; Richard, François J; Hyttel, Poul; Robert, Claude

    2016-01-01

    So far, the characteristics of a good quality egg have been elusive, similar to the nature of the physiological, cellular, and molecular cues leading to its production both in vivo and in vitro. Current understanding highlights a strong and complex interdependence between the follicular cells and the gamete. Secreted factors induce cellular responses in the follicular cells, and direct exchange of small molecules from the cumulus cells to the oocyte through gap junctions controls meiotic arrest. Studying the interconnection between the cumulus cells and the oocyte, we previously demonstrated that the somatic cells also contribute transcripts to the gamete. Here, we show that these transcripts can be visualized moving down the transzonal projections (TZPs) to the oocyte, and that a time course analysis revealed progressive RNA accumulation in the TZPs, indicating that RNA transfer occurs before the initiation of meiosis resumption under a timetable fitting with the acquisition of developmental competence. A comparison of the identity of the nascent transcripts trafficking in the TZPs, with those in the oocyte increasing in abundance during maturation, and that are present on the oocyte's polyribosomes, revealed transcripts common to all three fractions, suggesting the use of transferred transcripts for translation. Furthermore, the removal of potential RNA trafficking by stripping the cumulus cells caused a significant reduction in maturation rates, indicating the need for the cumulus cell RNA transfer to the oocyte. These results offer a new perspective to the determinants of oocyte quality and female fertility, as well as provide insight that may eventually be used to improve in vitro maturation conditions.

  6. Cumulus Cell Transcripts Transit to the Bovine Oocyte in Preparation for Maturation.

    PubMed

    Macaulay, Angus D; Gilbert, Isabelle; Scantland, Sara; Fournier, Eric; Ashkar, Fazl; Bastien, Alexandre; Saadi, Habib A Shojaei; Gagné, Dominic; Sirard, Marc-André; Khandjian, Édouard W; Richard, François J; Hyttel, Poul; Robert, Claude

    2016-01-01

    So far, the characteristics of a good quality egg have been elusive, similar to the nature of the physiological, cellular, and molecular cues leading to its production both in vivo and in vitro. Current understanding highlights a strong and complex interdependence between the follicular cells and the gamete. Secreted factors induce cellular responses in the follicular cells, and direct exchange of small molecules from the cumulus cells to the oocyte through gap junctions controls meiotic arrest. Studying the interconnection between the cumulus cells and the oocyte, we previously demonstrated that the somatic cells also contribute transcripts to the gamete. Here, we show that these transcripts can be visualized moving down the transzonal projections (TZPs) to the oocyte, and that a time course analysis revealed progressive RNA accumulation in the TZPs, indicating that RNA transfer occurs before the initiation of meiosis resumption under a timetable fitting with the acquisition of developmental competence. A comparison of the identity of the nascent transcripts trafficking in the TZPs, with those in the oocyte increasing in abundance during maturation, and that are present on the oocyte's polyribosomes, revealed transcripts common to all three fractions, suggesting the use of transferred transcripts for translation. Furthermore, the removal of potential RNA trafficking by stripping the cumulus cells caused a significant reduction in maturation rates, indicating the need for the cumulus cell RNA transfer to the oocyte. These results offer a new perspective to the determinants of oocyte quality and female fertility, as well as provide insight that may eventually be used to improve in vitro maturation conditions. PMID:26586844

  7. Comparisons of air quality impacts of fleet electrification and increased use of biofuels

    NASA Astrophysics Data System (ADS)

    Alhajeri, Nawaf S.; McDonald-Buller, Elena C.; Allen, David T.

    2011-04-01

    The air quality impacts of the partial electrification of the transportation fleet and the use of biofuels (E85) were modeled for the Austin Metropolitan Statistical Area, based on a 2030 vision of regional development. Changes in ozone precursor emissions and predicted ozone, carbon monoxide and aldehyde concentrations were estimated for multiple electrification and biofuel scenarios. Maximum changes in hourly ozone concentration from the use of plug-in hybrid electric vehicles (PHEVs) for 17% of the vehicle miles traveled ranged from - 8.5 to 2.2 ppb, relative to a base case with no electrification and minimal biofuel use, depending on time of day and location. Differences in daily maximum 1 h ozone concentration ranged from - 2.3 to 0.004 ppb. Replacement of all gasoline fuels with E85 had a smaller effect than PHEVs on maximum daily ozone concentrations. Maximum ozone changes for this scenario ranged from - 2.1 to 2.8 ppb and the difference in daily maximum 1 h ozone concentrations ranged from - 1.53 to 0 ppb relative to the base case. The smaller improvements in maximum ozone concentrations associated with extensive (100%) use of biofuels, compared to a smaller (17%) penetration of PHEVs, suggests that higher levels of PHEV penetration may lead to even greater improvements; however, the higher penetration would require expansion of the electrical grid capacity. The air quality impacts of the PHEVs would then depend on the emissions associated with the added generation.

  8. Railroad electrification in America's future: an assessment of prospects and impacts. Final report

    SciTech Connect

    White, R.K.; Yabroff, I.W.; Dickson, E.M.; Zink, R.A.; Gray, M.E.; Moon, A.E.

    1980-01-01

    Such considerations as the level of traffic, the relative financial health of individual railroads, the capacity of the associated supply and engineering/construction industries, and the logical connecting points at classifying yards, as well as the national interest value of creating a continuous system, continental in scope, were used to construct a scenario for railroad electrification that closely approximates how an electrification program might be implemented. For the economic reasons cited, much of the US railroad system would remain conventionally powered. This scenario provides for an electrified network involving 14 mainlines operated by 10 companies that could transport much of the nation's rail-borne freight. Five years of planning and engineering work would be required for each link before construction could begin. With 1000 miles or less of electrified route per year, 14 years would be needed to construct the 9000-mile network of our scenario. (The scenario constructed runs from 1980 to 1998.) The analysis was aided with the construction of the SRI Railroad Industry Model. Basically a model of industry operations and finances, the model produces income statements and balance sheets at yearly intervals. Railroad energy costs, railroad freight levels, maintenance costs, purchases and leases of rooling stock, electrification facility investments, future inflation, rate setting practices, annual depreciation, taxes, and profits were calculated.

  9. Cumulus cell gene expression associated with pre-ovulatory acquisition of developmental competence in bovine oocytes.

    PubMed

    Bunel, A; Nivet, A L; Blondin, P; Vigneault, C; Richard, F J; Sirard, M A

    2014-01-01

    The final days before ovulation impact significantly on follicular function and oocyte quality. This study investigated the cumulus cell (CC) transcriptomic changes during the oocyte developmental competence acquisition period. Six dairy cows were used for 24 oocyte collections and received FSH twice daily over 3 days, followed by FSH withdrawal for 20, 44, 68 and 92 h in four different oestrous cycles for each of the six cows. Half of the cumulus-oocyte complexes were subjected to in vitro maturation, fertilisation and culture to assess blastocyst rate. The other half of the CC underwent microarray analysis (n=3 cows, 12 oocyte collections) and qRT-PCR (n=3 other cows, 12 oocyte collections). According to blastocyst rates, 20 h of FSH withdrawal led to under-differentiated follicles (49%), 44 and 68 h to the most competent follicles (71% and 61%) and 92 h to over-differentiated ones (51%). Ten genes, from the gene lists corresponding to the three different follicular states, were subjected to qRT-PCR. Interestingly, CYP11A1 and NSDHL gene expression profiles reflected the blastocyst rate. However most genes were associated with the over-differentiated status: GATM, MAN1A1, VNN1 and NRP1. The early period of FSH withdrawal has a minimal effect on cumulus gene expression, whereas the longest period has a very significant one and indicates the beginning of the atresia process.

  10. On testing two major cumulus parameterization schemes using the CSU Regional Atmospheric Modeling System

    SciTech Connect

    Kao, C.Y.J.; Bossert, J.E.; Winterkamp, J.; Lai, C.C.

    1993-10-01

    One of the objectives of the DOE ARM Program is to improve the parameterization of clouds in general circulation models (GCMs). The approach taken in this research is two fold. We first examine the behavior of cumulus parameterization schemes by comparing their performance against the results from explicit cloud simulations with state-of-the-art microphysics. This is conducted in a two-dimensional (2-D) configuration of an idealized convective system. We then apply the cumulus parameterization schemes to realistic three-dimensional (3-D) simulations over the western US for a case with an enormous amount of convection in an extended period of five days. In the 2-D idealized tests, cloud effects are parameterized in the ``parameterization cases`` with a coarse resolution, whereas each cloud is explicitly resolved by the ``microphysics cases`` with a much finer resolution. Thus, the capability of the parameterization schemes in reproducing the growth and life cycle of a convective system can then be evaluated. These 2-D tests will form the basis for further 3-D realistic simulations which have the model resolution equivalent to that of the next generation of GCMs. Two cumulus parameterizations are used in this research: the Arakawa-Schubert (A-S) scheme (Arakawa and Schubert, 1974) used in Kao and Ogura (1987) and the Kuo scheme (Kuo, 1974) used in Tremback (1990). The numerical model used in this research is the Regional Atmospheric Modeling System (RAMS) developed at Colorado State University (CSU).

  11. FSH in vitro versus LH in vivo: similar genomic effects on the cumulus.

    PubMed

    Assidi, Mourad; Richard, François J; Sirard, Marc-André

    2013-01-01

    The use of gonadotropins to trigger oocyte maturation both in vivo and in vitro has provided precious and powerful knowledge that has significantly increased our understanding of the ovarian function. Moreover, the efficacy of most assisted reproductive technologies (ART) used in both humans and livestock species relies on gonadotropin input, mainly FSH and LH. Despite the significant progress achieved and the huge impact of gonadotropins, the exact molecular pathways of the two pituitary hormones, FSH and LH, still remain poorly understood. Moreover, these pathways may not be the same when moving from the in vivo to the in vitro context. This misunderstanding of the intricate synergy between these two hormones leads to a lack of consensus about their use mainly in vitro or in ovulation induction schedules in vivo. In order to optimize their use, additional work is thus required with a special focus on comparing the in vitro versus the in vivo effects. In this context, this overview will briefly summarize the downstream gene expression pathways induced by both FSH in vitro and LH in vivo in the cumulus compartment. Based on recent microarray comparative analysis, we are reporting that in vitro FSH stimulation on cumulus cells appears to achieve at least part of the gene expression activity after in vivo LH stimulation. We are then proposing that the in vitro FSH-response of cumulus cells have similitudes with the in vivo LH-response. PMID:24066945

  12. Cumulus Moistening, the Diurnal Cycle, and Initiation of the Madden-Julian Oscillation during DYNAMO

    NASA Astrophysics Data System (ADS)

    Ruppert, J. H.; Johnson, R. H.

    2014-12-01

    Atmospheric soundings, cloud radar, and air-sea flux measurements collected during DYNAMO (Dynamics of the MJO) are employed to study the initiation of the Madden-Julian Oscillation (MJO) over the tropical Indian Ocean. Findings indicate that moistening of the troposphere during MJO initiation occurs in two stages: low-to-midlevel moistening in the suppressed phase (i.e., prior to the onset of deep convection), followed by deep-column moistening during the early active phase. The first stage of moistening occurs as the drying by large-scale subsidence and horizontal advection wane and convective clouds increase in areal coverage and deepen from shallow to congestus. Analysis of the suppressed phase reveals the striking degree to which the moistening characteristic of this period is accomplished by the diurnal cycle of cumulus clouds. This diurnal cycle is driven by the cycle in sea surface temperature and air-sea fluxes linked to shallow oceanic diurnal warm layers. This coupled diurnal cycle, and the associated afternoon peak in convective cloud depth, cloud areal coverage, and cumulus moistening, likely drives more vigorous overall moistening than would occur without this diurnal cycle. A conspicuous finding pertaining to the suppressed phase convection is the prominence of mesoscale cloud organization (i.e., open cells and horizontal convective rolls), which is hypothesized to enhance convective instability in localized patches, thereby promoting deeper, more vigorous cumulus moistening than would otherwise occur.

  13. Repeated superovulation may affect mitochondrial functions of cumulus cells in mice

    PubMed Central

    Xie, Juan-Ke; Wang, Qian; Zhang, Ting-Ting; Yin, Shen; Zhang, Cui-Lian; Ge, Zhao-Jia

    2016-01-01

    Controlled ovarian stimulation by exogenous gonadotrophins is a key procedure during the in vitro fertilization cycle to obtain a sufficient number of oocytes in humans. Previous studies demonstrated that repeated superovulation had deleterious effects on the ovaries. However, whether repeated superovulation adversely affects the mitochondrial functions of cumulus cells remains unclear. In this study, mice were divided into three groups: superovulation once (R1); superovulation three times (R3), and superovulation five times (R5). We evaluated the effects of repeated superovulation on mitochondrial DNA copies (mtDNA) and observed decreased mtDNA copies per cell with increasing number of superovulation cycles. Further, we investigated the DNA methylation status in exon 2 and the mRNA expression level of nuclear-encoded DNA polymerase gamma A (PolgA). The results showed that the DNA methylation levels of PolgA in R1 and R5 were slightly lower than in R3. Additionally, the altered DNA methylation in PolgA coincided with the changes in PolgA expression in cumulus cells. We also found that the mRNA expression of COX1, CYTB, ND2, and ND4 was altered by repeated superovulation in cumulus cells. Thus, repeated superovulation had adverse effects on mitochondrial function. PMID:27698360

  14. Direct entrainment and detrainment rate distributions of individual shallow cumulus clouds in an LES

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2013-02-01

    Probability distribution functions of shallow cumulus cloud core entrainment and detrainment rates are calculated using 4362 individual cumulus clouds isolated from LES using a cloud tracking algorithm. Calculation of the mutual information between fractional entrainment/detrainment and a variety of mean cloud core properties suggests that fractional entrainment rate is best predicted by the mean cloud buoyancy B and the environmental buoyancy lapse rate dθρdz at that level, while fractional detrainment is best predicted by the mean vertical velocity w and the critical mixing fraction χc. Fractional entrainment and detrainment rates are relatively insensitive to cloud core horizontal area, and the circumference of horizontal cloud core sections display an a0.69 dependence. This implies that cloud core mass entrainment flux E is proportional to cloud core cross-sectional area instead of cloud core surface area, as is generally assumed. Empirical best-fit relations for ε(B, dθρdz and δ(w, χc) are found for both individual shallow cumulus clouds and cloud ensembles. It is found that clouds with high buoyancy in strong stratification experience low entrainment rates, while clouds with high vertical velocities and critical mixing fractions experience low detrainment rates.

  15. Direct entrainment and detrainment rate distributions of individual shallow cumulus clouds in an LES

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2013-08-01

    Probability distribution functions of shallow cumulus cloud core entrainment and detrainment rates are calculated using 4362 individual cumulus clouds isolated from LES (large eddy simulation) using a cloud tracking algorithm. Calculation of the mutual information between fractional entrainment/detrainment and a variety of mean cloud core properties suggests that fractional entrainment rate is best predicted by the mean cloud buoyancy B and the environmental buoyancy lapse rate dθρ/dz at that level, while fractional detrainment is best predicted by the mean vertical velocity w and the critical mixing fraction χc. Fractional entrainment and detrainment rates are relatively insensitive to cloud core horizontal area, and the perimeter of horizontal cloud core sections display an a0.73 dependence. This implies that cloud core mass entrainment flux E is proportional to cloud core cross-sectional area instead of cloud core surface area, as is generally assumed. Empirical best-fit relations for ɛ(B, dθρ/dz and δ(w, χc) are found for both individual shallow cumulus clouds and cloud ensembles. It is found that clouds with high buoyancy in strong stratification experience low entrainment rates, while clouds with high vertical velocities and critical mixing fractions experience low detrainment rates.

  16. Statistical analysis of an LES shallow cumulus cloud ensemble using a cloud tracking algorithm

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2012-01-01

    A technique for the tracking of individual clouds in a Large Eddy Simulation (LES) is presented. We use this technique on an LES of a shallow cumulus cloud field based upon the Barbados Oceanographic and Meteorological Experiment (BOMEX) to calculate statistics of cloud height, lifetime, and other physical properties for individual clouds in the model. We also examine the question of nature versus nurture in shallow cumulus clouds: do properties at cloud base determine the upper-level properties of the clouds (nature), or are cloud properties determined by the environmental conditions they encounter (nurture). We find that clouds which ascend through an environment that has been pre-moistened by previous cloud activity are no more likely to reach the inversion than clouds that ascend through a drier environment. Cloud base thermodynamic properties are uncorrelated with upper-level cloud properties, while mean fractional entrainment and detrainment rates display moderate correlations with cloud properties up to the inversion. Conversely, cloud base area correlates well with upper-level cloud area and maximum cloud height. We conclude that cloud thermodynamic properties are primarily influenced by entrainment and detrainment processes, cloud area and height are primarily influenced by cloud base area, and thus nature and nurture both play roles in the dynamics of BOMEX shallow cumulus clouds.

  17. Statistical analysis of a LES shallow cumulus cloud ensemble using a cloud tracking algorithm

    NASA Astrophysics Data System (ADS)

    Dawe, J. T.; Austin, P. H.

    2011-08-01

    A technique for the tracking of individual clouds in a Large Eddy Simulation (LES) is presented. We use this technique on a LES of a shallow cumulus cloud field based upon the Barbados Oceanographic and Meteorological Experiment (BOMEX) to calculate statistics of cloud height, lifetime, and other physical properties for individual clouds in the model. We also examine the question of nature versus nurture in shallow cumulus clouds: do properties at cloud base determine the upper-level properties of the clouds (nature), or are cloud properties determined by the environmental conditions they encounter (nurture). We find that clouds which ascend through an environment that has been pre-moistened by previous cloud activity are no more likely to reach the inversion than clouds that ascend through a drier environment. Cloud base thermodynamic properties are uncorrelated with upper-level cloud properties, while mean fractional entrainment and detrainment rate displays moderate correlations with cloud properties up to the inversion. Conversely, cloud base area correlates well with upper-level cloud area and maximum cloud height. We conclude that cloud thermodynamic properties are primarily influenced by entrainment and detrainment processes, cloud area and height are primarily influenced by cloud base area, and thus nature and nurture both play roles in the dynamics of BOMEX shallow cumulus clouds.

  18. Cloud Condensation Nuclei in Cumulus Humilis — selected Case Study During the CHAPS Campaign

    SciTech Connect

    Yu, X.; Lee, Y.; Berg, L.; Berkowitz, C.; Alexander, L.; Laskin, A.; Ogren, J.; Andrews, E.

    2010-03-15

    The Cumulus Humilis Aerosol Processing Study (CHAPS) provided a unique opportunity to study aerosol and cloud processing. Clouds play an active role in the processing and cycling of atmospheric constituents. Gases and particles can partition to cloud droplets by absorption and condensation as well as activation and impact scavenging. The U.S. Department of Energy (DOE) G-1 aircraft was used as one of the main platforms in CHAPS. Flight tracks were designed and implemented to characterize freshly emitted aerosols at cloud top and cloud base as well as within the cloud, i.e., cumulus humilis (or fair-weather cumulus), in the vicinity of Oklahoma City. Measurements of interstitial aerosols and residuals of activated condensation cloud nuclei were conducted simultaneously. The interstitial aerosols were measured downstream of an isokinetic inlet, and the activated particles downstream of a counter-flow virtual impactor (CVI). The sampling line to the Aerodyne Aerosol Mass Spectrometer (AMS) was switched between the isokinetic inlet and the CVI to allow characterization of non-activated interstitial particles outside of clouds in contrast to particles activated in clouds. Trace gases including ozone, carbon monoxide, sulfur dioxide, and a series of volatile organic compounds (VOCs) were also measured, as were key meteorological state parameters including liquid water content, cloud drop size, and dew point. We will report on the CCN properties in cumulus humilis. Several approaches will be taken. The first is single-particle analysis of particles collected by the Time-Resolved Aerosol Sampler (TRAC) by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) coupled with energy disperse X-ray spectroscopy (EDX). Specifically, we examine differences between activated and interstitial ones, such as differences in chemical composition and morphology. The second analysis will link in situ measurements by AMS and PTRMS with the observations by TRAC. For

  19. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely-piloted aircraft to study thunderstorms in the Atlantic Ocean off Key West and the west of the Everglades. Data obtained through sensors mounted to the aircraft will allow researchers in ACES to gauge elements such as lightning activity and the electrical environment in and around storms. By learning more about individual storms, scientists hope to better understand the global water and energy cycle, as well as climate variability. Contained in one portion of the aircraft is a three-axis magnetic search coil, which measures the AC magnetic field; a three-axis electric field change sensor; an accelerometer; and a three-axis magnetometer, which measures the DC magnetic field. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the Marshall Space Flight Center, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  20. NASA Studies Lightning Storms Using High-Flying, Uninhabited Vehicle

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A NASA team studying the causes of electrical storms and their effects on our home planet achieved a milestone on August 21, 2002, completing the study's longest-duration research flight and monitoring four thunderstorms in succession. Radio news media can talk with Dr. Richard Blakeslee, the project's principal investigator, and Tony Kim, project manager at the Marshall Space Flight Center (MSFC), about their results and how their work will help improve future weather forecasting ability. Based at the Naval Air Station Key West, Florida, researchers with the Altus Cumulus Electrification Study (ACES) used the Altus II remotely- piloted aircraft to study a thunderstorm in the Atlantic Ocean off Key West, two storms at the western edge of the Everglades, and a large storm over the northwestern corner of the Everglades. This photograph shows Tony Kim And Dr. Richard Blakeslee of MSFC testing aircraft sensors that would be used to measure the electric fields produced by thunderstorm as part of NASA's ACES. With dual goals of gathering weather data safely and testing the adaptability of the uninhabited aircraft, the ACES study is a collaboration among the MSFC, the University of Alabama in Huntsville, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Pernsylvania State University in University Park, and General Atomics Aeronautical Systems, Inc.

  1. Regulation of gap-junctional communication between cumulus cells during in vitro maturation in swine, a gap-FRAP study.

    PubMed

    Santiquet, Nicolas W; Develle, Yann; Laroche, Anthony; Robert, Claude; Richard, François J

    2012-08-01

    Intercellular gap-junctional communication (GJC) plays an important role in ovarian cell physiology. Closure of GJC has been proposed to be involved in oocyte maturation, particularly in the resumption of meiosis, both in vivo and in vitro, by controlling the flow of meiosis inhibitors, such as cAMP and cGMP. Understanding how GJC dynamics are regulated during in vitro maturation (IVM) could provide a powerful tool for controlling meiotic resumption and oocyte maturation in vitro. Since little is known about the GJC dynamic regulation between cumulus cells, we have developed an assay based on recovery of calcein fluorescence in photobleached cumulus cells, a gap-FRAP assay. The GJC profile has been characterized during the first hours of porcine IVM. We showed that equine chorionic gonadotropin (eCG) and epidermal growth factor (EGF) down-regulated GJC effectiveness between cumulus cells. However, human chorionic gonadotropin was not down-regulating GJC effectiveness. We also showed that the GJC network expanded during this period and that this effect was not regulated by gonadotropins. Porcine follicular fluid present in the maturation medium also had an impact on GJC regulation, increasing GJC network establishment and the effectiveness of calcein transfer rate between cumulus cells. These results show that both eCG and EGF are regulating the decrease in GJC effectiveness after 4.5 h of IVM, while the network extension is gonadotropin independent. Regulation of GJC between cumulus cells would then be specifically regulated during in vitro IVM.

  2. Identification of hyaluronic acid-binding proteins and their expressions in porcine cumulus-oocyte complexes during in vitro maturation.

    PubMed

    Yokoo, Masaki; Miyahayashi, Yasunori; Naganuma, Takako; Kimura, Naoko; Sasada, Hiroshi; Sato, Eimei

    2002-10-01

    Hyaluronic acid-binding proteins (HABPs) are necessary for expansion of the cumulus-oocyte complex (COC) during oocyte maturation. In this study, to obtain the detailed information of HABPs during cumulus expansion, we examined the expression of HABPs in porcine COCs during in vitro maturation (IVM). After maturation culture, proteins were extracted from porcine COCs and separated by SDS-PAGE and then transferred to polyvinylidene fluoride membranes. After transfer, the membranes were subjected to ligand blotting with biotinylated hyaluronic acid (bHA) or fluorescein isothiocyanate-labeled hyaluronic acid (FITC-HA). Furthermore, the extracted proteins were subjected to immunoprecipitation, Western blotting, and immunofluorescence analysis to dissect the HABPs. Ligand blotting with FITC-HA could detect HABPs. Using this ligand-blotting method, 13 and 14 bands of HABPs were detected in porcine COCs after 0 and 48 h in culture, respectively. Of these, the level of expression of 85-kDa HABP increased with cumulus expansion during IVM and was newly detected after culture. Immunoprecipitation, Western blotting, and immunofluorescent analysis confirmed that the 85-kDa HABP corresponded to CD44 and that it existed on/in the membrane of cumulus cells. The present results indicated that HABP expressed in porcine COCs during IVM, particularly CD44, may form a network of the matrices in the extracellular space of the oocyte with cumulus expansion during IVM.

  3. The microstructure of selected, small, isolated, cumulus clouds near Red Deer, Alberta

    NASA Astrophysics Data System (ADS)

    Kochtubajda, B.

    Physical experiments designed to explore the potential of rain augmentation through airborne glaciogenic seeding on small, isolated non-precipitating cumuliform clouds near Red Deer, Alberta were carried out during the period 1982-1985. The microstructure of 90 cumulus congestus clouds have been documented through repeated in-situ sampling using a cloud physics instrumented aircraft platform. Observations from the inspection passes of 57 clouds seeded with either dry ice pellets or silver iodide pyrotechnics, and all the passes of 33 natural clouds are presented. Measurements of the cloud droplet concentration indicate that Alberta cumulus clouds are typically continental in nature, with an average droplet concentration of 535 cm -3 and an average droplet diameter of 10.6 μm. Alberta clouds have average liquid water contents of 0.57 g m -3, with a peak 1-sec value of 3.17 g m -3. The 1-km average liquid water contents are 0.83 g m -3, with a peak value of 2.81 g m -3. Cloud lifetimes vary between 11 and 20 minutes. Concentrations of naturally occurring ice crystals are found to be low. The average maximum 1-km ice concentration was 31 -1, and the peak 1-km concentration was 73.11 -1 in the natural cloud dataset. Evidence of precipitation-sized particles was detected in 21% (7 of 33) of the clouds, and precipitation below cloud base was detected in 6% (2 of 33) of the clouds. A comparison of the Alberta cloud characteristics to the cumulus clouds from different locations showed that there are some distinct differences between Alberta clouds and the clouds from the other regions.

  4. New airborne retrieval approach for trade wind cumulus properties under overlying cirrus

    NASA Astrophysics Data System (ADS)

    Werner, F.; Siebert, H.; Pilewskie, P.; Schmeissner, T.; Shaw, R. A.; Wendisch, M.

    2013-05-01

    A new retrieval method is presented to derive the optical thickness τ and effective droplet radius reff of shallow cumulus in the presence of overlying thin cirrus. This new approach allows for a retrieval without a priori knowledge of the microphysical and optical properties of the overlying cirrus. The retrieval is applied to helicopter-borne solar spectral reflectivity measurements gathered by the Spectral Modular Airborne Radiation measurements sysTem (SMART-HELIOS) above trade wind cumuli near Barbados. Collocated microphysical cumulus properties (liquid water content, effective droplet radius, droplet number concentration) were measured by in situ instruments installed on the Airborne Cloud Turbulence Observation System (ACTOS). Cloud inhomogeneities lead to an underestimation of retrieved τ of up to 114%, while reff is biased by up to 27%. Moreover, misrepresentation of the overlying cirrus may cause an overestimation of the classically retrieved cumulus reff of up to 50% and an underestimation of τof up to 6%. The new retrieval, effectively correcting for the influence of overlying cirrus, enables reliable estimates of τ of the cumuli for optically thin, overcast cirrus conditions and reduces the retrieval error for reff of the cumuli by almost 50%. Agreement between in situ measured and retrieved reff is in the range of ±1 μm. The retrieval can also reproduce the wide range of in situ measured mean reff (7-18 μm), which is a result of different aerosol load and cloud top heights on the different flight days. The observed τ ranges between 5 and 36.

  5. Observational estimates of detrainment and entrainment in non-precipitating shallow cumulus

    NASA Astrophysics Data System (ADS)

    Norgren, M. S.; Small, J. D.; Jonsson, H. H.; Chuang, P. Y.

    2014-08-01

    Vertical transport associated with cumulus clouds is important to the redistribution of gases, particles and energy, with subsequent consequences for many aspects of the climate system. Previous studies have suggested that detrainment from clouds can be comparable to the updraft mass flux, and thus represents an important contribution to vertical transport. In this study, we describe a new method to deduce the amounts of gross detrainment and entrainment experienced by non-precipitating cumulus clouds using aircraft observations. The method utilizes equations for three conserved variables: cloud mass, total water and moist static energy. Optimizing these three equations leads to estimates of the mass fractions of adiabatic mixed-layer air, entrained air and detrained air that the sampled cloud has experienced. The method is applied to six flights of the CIRPAS Twin Otter during the Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) which took place in the Houston, Texas region during the summer of 2006 during which 176 small, non-precipitating cumulus were sampled. Our analysis suggests that, on average, these clouds were comprised of 30 to 70% mixed-layer air, with entrained air comprising most of the remainder. The mass fraction of detrained air was less than 2% for a majority of the clouds, although 15% of them did exhibit detrained air fractions larger than 10%. Entrained and detrained air mass fractions both increased with altitude, and the largest detrainment events were almost all associated with air that was at their level of neutral buoyancy, findings that are consistent with previous studies.

  6. Effects of cumulus parameterization closures on simulations of summer precipitation over the continental United States

    NASA Astrophysics Data System (ADS)

    Qiao, Fengxue; Liang, Xin-Zhong

    2016-09-01

    This study examines the effects of five cumulus closure assumptions on simulations of summer precipitation in the continental U.S. by utilizing an ensemble cumulus parameterization (ECP) that incorporates multiple alternate closure schemes into a single cloud model formulation. Results demonstrate that closure algorithms significantly affect the summer mean, daily frequency and intensity, and diurnal variation of precipitation, with strong regional dependence. Overall, the vertical velocity (W) closure produces the smallest summer mean biases, while the moisture convergence (MC) closure most realistically reproduces daily variability. Both closures have advantages over others in simulating U.S. daily rainfall frequency distribution, though both slightly overestimate intense rain events. The MC closure is superior at capturing summer rainfall amount, daily variability, and heavy rainfall frequency over the Central U.S., but systematically produces wet biases over the North American Monsoon (NAM) region and Southeast U.S., which can be reduced by using the W closure. The instability tendency (TD) and the total instability adjustment (KF) closures are better at capturing observed diurnal signals over the Central U.S. and the NAM, respectively. The results reasonably explain the systematic behaviors of several major cumulus parameterizations. A preliminary experiment combining two optimal closures (averaged moisture convergence and vertical velocity) in the ECP scheme significantly reduced the wet (dry) biases over the Southeast U.S. in the summer of 1993 (2003), and greatly improved daily rainfall correlations over the NAM. Further improved model simulation skills may be achieved in the future if optimal closures and their appropriate weights can be derived at different time scales based on specific climate regimes.

  7. Initial electrification to the first lightning flash in New Mexico thunderstorms

    NASA Astrophysics Data System (ADS)

    Stolzenburg, Maribeth; Marshall, Thomas C.; Krehbiel, Paul R.

    2015-11-01

    The initial electrification of three New Mexico thunderstorms is examined using in situ and remote measurements. The earliest deflection of electric field (E) measured at the surface was 5-8.6 min before the first flash and coincident with the development of substantial radar reflectivity (40 dBZ) above -5°C. Rapid growth of surface E (>5 V/m/s) started 2.4-3.1 min before the first flash, when 40 dBZ reflectivities reached above the -15°C level. In two cases with clear surface E records, radar reflectivity indicators (40 dBZ echo through -10°C and echo top through -15°C) would yield longer warning times before the first flash than the E record. The first flash in each storm initiated at altitudes between 7.4 and 8.8 km; hence, the temperatures where the largest (negative) E for normal intracloud lightning initiation had developed during the initial electrification were -10°C to -20°C. Negative and positive charge regions associated with the first flash in each cell were centered at -8°C to -16°C (6.9-8.0 km) and -20°C to -24°C (9.0-9.2 km), respectively. In two cases, balloon data indicate the only substantial charge regions present before the first flash were those involved in the flash. Another case shows an initial period of opposite polarity E deflection at the surface coincident with substantial low-level positive charge within the cloud, although this charge was not involved in the first 8 min (first 17 flashes) of lightning activity. The findings support the notion that the initial electrification resulted from charging via the noninductive ice-ice collisional mechanism.

  8. Detection of RUNX2 gene expression in cumulus cells in women undergoing controlled ovarian stimulation

    PubMed Central

    2012-01-01

    Background RUNX2 is a transcription factor, whose expression has been recently identified in the mouse ovary. Regulation of RUNX2 expression and its function in the human ovary have not been determined yet. The aim of the present study is the investigation of the possible correlation between RUNX2 gene expression in cumulus cells and controlled ovarian stimulation and pregnancy outcomes after ART treatment. Methods A total of 41 patients undergoing ICSI treatment for male factor infertility were enrolled into a specific ART program, during which cumulus cells were collected. The expression of RUNX2 gene in cumulus cells was examined by real-time PCR. Results Concerning RUNX2 gene expression, 12 out of 41 women were detected with RUNX2 expression, with ratios ranging from 0.84 to 1.00, while 28 out of 41 women had no expression (ratio = 0). Only 1 woman presented a weak RUNX2 gene expression (ratio = 0.52). From 8 women that proceeded to pregnancy, 7 of them did not express RUNX2 gene in cumulus cells, while one was the woman with weak gene expression that also achieved pregnancy. The group of women without RUNX2 expression presented higher number of follicles (p = 0.013), higher number of retrieved oocytes (p = 0.016), higher basal LH serum levels (p = 0.016) and higher peak estradiol levels (p = 0.013), while the number of fertilized oocytes differed marginally between the two groups (p = 0.089). Moreover, RUNX2 expression was negatively associated with LH levels (OR = 0.22, p = 0.021) and E2 levels (OR = 0.25, p = 0.026). Conclusions Consequently, based on the preliminary findings of the present pilot study a potential inhibitory mechanism of RUNX2 gene is observed in the ovary when high mRNA levels are detected, suggesting that RUNX2 could possibly be used as a candidate genetic marker in the monitoring of the outcome of an ART treatment. PMID:23186169

  9. Cumulus cloud base height estimation from high spatial resolution Landsat data - A Hough transform approach

    NASA Technical Reports Server (NTRS)

    Berendes, Todd; Sengupta, Sailes K.; Welch, Ron M.; Wielicki, Bruce A.; Navar, Murgesh

    1992-01-01

    A semiautomated methodology is developed for estimating cumulus cloud base heights on the basis of high spatial resolution Landsat MSS data, using various image-processing techniques to match cloud edges with their corresponding shadow edges. The cloud base height is then estimated by computing the separation distance between the corresponding generalized Hough transform reference points. The differences between the cloud base heights computed by these means and a manual verification technique are of the order of 100 m or less; accuracies of 50-70 m may soon be possible via EOS instruments.

  10. A microphysical connection among biomass burning, cumulus clouds, and stratospheric moisture.

    PubMed

    Sherwood, Steven

    2002-02-15

    A likely causal chain is established here that connects humidity in the stratosphere, relative humidity near the tropical tropopause, ice crystal size in towering cumulus clouds, and aerosols associated with tropical biomass burning. The connections are revealed in satellite-observed fluctuations of each quantity on monthly to yearly time scales. More aerosols lead to smaller ice crystals and more water vapor entering the stratosphere. The connections are consistent with physical reasoning, probably hold on longer time scales, and may help to explain why stratospheric water vapor appears to have been increasing for the past five decades. PMID:11847336

  11. A microphysical connection among biomass burning, cumulus clouds, and stratospheric moisture.

    PubMed

    Sherwood, Steven

    2002-02-15

    A likely causal chain is established here that connects humidity in the stratosphere, relative humidity near the tropical tropopause, ice crystal size in towering cumulus clouds, and aerosols associated with tropical biomass burning. The connections are revealed in satellite-observed fluctuations of each quantity on monthly to yearly time scales. More aerosols lead to smaller ice crystals and more water vapor entering the stratosphere. The connections are consistent with physical reasoning, probably hold on longer time scales, and may help to explain why stratospheric water vapor appears to have been increasing for the past five decades.

  12. Boundary-layer cumulus over land: Some observations and conceptual models

    SciTech Connect

    Stull, R.B.

    1993-09-01

    Starting in 1980, the Boundary Layer Research Team at the University of Wisconsin has been systematically studying the formation and evolution of nonprecipitating boundary-layer cumulus clouds (BLCu) in regions of fair weather (anticyclones) over land (Stull, 1980). Our approach is to quantify the average statistical characteristics of the surface, thermals, boundary layer, and clouds over horizontal regions of roughly 20 km in diameter. Within such a region over land, there is typically quite a variation in land use, and associated variations in surface albedo and moisture.

  13. Sensitivity of PBL and Cumulus schemes for Thunderstorm prediction over an Indian Region

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Charan Mohanty, Uma; Kumar, Krishan

    2015-04-01

    The cloud processes play an important role in all forms of precipitation. Its proper representation is one of the challenging tasks in mesoscale numerical simulation. Studies have revealed that mesoscale feature require proper initialization which may likely to improve the convective system rainfall forecasts. Understanding the precipitation process, model initial condition accuracy and resolved/sub grid-scale precipitation processes representation, are the important areas which needed to improve in order to represent the mesoscale features properly. Various attempts have been done in order to improve the model performance through grid resolution, physical parameterizations, etc. But it is the physical parameterizations which provide a convective atmosphere for the development and intensification of convective events. Further, physical parameterizations consist of cumulus convection, surface fluxes of heat, moisture, momentum, and vertical mixing in the planetary boundary layer (PBL). How PBL and Cumulus schemes capture the evolution of thunderstorm have been analysed by taking thunderstorm cases occurred over Kolkata, India in the year 2011. PBL and cumulus schemes were customized for WSM-6 microphysics because WSM series has been widely used in operational forecast. Results have shown that KF (PBL scheme) and WSM-6 (Cumulus Scheme) have reproduced the evolution of surface variable such as CAPE, temperature and rainfall very much like observation. Further, KF and WSM-6 scheme also provided the increased moisture availability in the lower atmosphere which was taken to higher level by strong vertical velocities providing a platform to initiate a thunderstorm much better. Overestimation of rain in WSM-6 occurs primarily because of occurrence of melting and freezing process within a deeper layer in WSM-6 scheme. These Schemes have reproduced the spatial pattern and peak rainfall coverage closer to TRMM observation. It is the the combination of WSM-6, and KF schemes

  14. A concept of wind-diesel hybrid systems for the electrification of small rural communities in Brazil

    SciTech Connect

    Pinho, J.T.; Bezerra, U.H.

    1997-12-31

    This work presents the concept of a wind-diesel hybrid system for the electrification of a small rural community in the Northern Region of Brazil, which can be used in many other places with similar characteristics. The system consists of two small diesel units and two wind turbines, one of which was designed and developed as a prototype with the purpose of gaining some insight in the field of wind turbine technology. Some considerations about small communities of the Northern Region of Brazil, and about electrification concepts are also made.

  15. Transport in Rayleigh-stable experimental Taylor-Couette flow and granular electrification in a shaking experiment

    NASA Astrophysics Data System (ADS)

    Nordsiek, Freja

    This dissertation consists of two projects: Rayleigh-stable Taylor-Couette flow and granular electrification. Taylor-Couette flow is the fluid flow in the gap between two cylinders rotating at different rates. Azimuthal velocity profiles, dye visualization, and inner cylinder torques were measured on two geometrically similar Taylor-Couettes with axial boundaries attached to the outer cylinder, the Maryland and Twente T3C experiments. This was done in the Rayleigh stable regime, where the specific angular momentum increases radially, which is relevant to astrophysical and geophysical flows and in particular, stellar and planetary accretion disks. The flow substantially deviates from laminar Taylor-Couette flow beginning at moderate Reynolds number. Angular momentum is primarily transported to the axial boundaries instead of the outer cylinder due to Ekman pumping when the inner cylinder is rotating faster than the outer cylinder. A phase diagram was constructed from the transitions identified from torque measurements taken over four decades of the Reynolds number. Flow angular velocities larger and smaller than both cylinders were found. Together, these results indicate that experimental Taylor-Couette with axial boundaries attached to the outer cylinder is an imperfect model for accretion disk flows. Thunderstorms, thunder-snow, volcanic ash clouds, and dust storms all display lightning, which results from electrification of droplets and particles in the atmosphere. While lightning is fairly well understood (plasma discharge), the mechanisms that result in million-volt differences across the storm are not. A novel granular electrification experiment was upgraded and used to study some of these mechanisms in the lab. The relative importance of collective interactions between particles versus particle properties (material, size, etc.) on collisional electrification was investigated. While particle properties have an order of magnitude effect on the strength of

  16. Les cooperatives et l'electrification rurale du Quebec, 1945--1964

    NASA Astrophysics Data System (ADS)

    Dorion, Marie-Josee

    Cette these est consacree a l'histoire de l'electrification rurale du Quebec, et, plus particulierement, a l'histoire des cooperatives d'electricite. Fondees par vagues successives a partir de 1945, les cooperatives rurales d'electricite ont ete actives dans plusieurs regions du Quebec et elles ont electrifie une partie significative des zones rurales. Afin de comprendre le contexte de la creation des cooperatives d'electricite, notre these debute (premiere partie) par une analyse du climat sociopolitique des annees precedant la naissance du systeme cooperatif d'electrification rurale. Nous y voyons de quelle facon l'electrification rurale devient progressivement, a partir de la fin des annees 1920, une question d'actualite a laquelle les divers gouvernements qui se succedent tentent de trouver une solution, sans engager---ou si peu---les fonds de l'Etat. En ce sens, la premiere etatisation et la mise sur pied d'Hydro-Quebec, en 1944, marquent une rupture quant au mode d'action privilegie jusque-la. La nouvelle societe d'Etat se voit cependant retirer son mandat d'electrifier le monde rural un an apres sa fondation, car le gouvernement Duplessis, de retour au pouvoir, prefere mettre en place son propre modele d'electrification rurale. Ce systeme repose sur des cooperatives d'electricite, soutenues par un organisme public, l'Office de l'electrification rurale (OER). L'OER suscite de grandes attentes de la part des ruraux et c'est par centaines qu'ils se manifestent. Cet engouement pour les cooperatives complique la tache de l'OER, qui doit superviser de nouvelles societes tout en assurant sa propre organisation. Malgre des hesitations et quelques delais introduits par un manque de connaissances techniques et de personnel qualifie, les commissaires de l'OER se revelent perspicaces et parviennent a mettre sur pied un systeme cooperatif d'electrification rurale qui produit des resultats rapides. Il leur faudra cependant compter sur l'aide des autres acteurs engages

  17. Contact Electrification of Regolith Particles and Chloride Electrolysis: Synthesis of Perchlorates on Mars

    NASA Astrophysics Data System (ADS)

    Tennakone, K.

    2016-10-01

    Contact electrification of chloride-impregnated martian regolith particles due to eolian agitation and moisture condensation on coalesced oppositely charged grains may lead to spontaneous electrolysis that generates hypochlorite, chlorite, chlorate, and perchlorate with a concomitant reduction of water to hydrogen. This process is not curtailed even if moisture condenses as ice because chloride ionizes on the surface of ice. Limitations dictated by potentials needed for electrolysis and breakdown electric fields enable estimation of the required regolith grain size. The estimated dimension turns out to be of the same order of magnitude as the expected median size of martian regolith, and a simple calculation yields the optimum rate of perchlorate production.

  18. Rural electrification in multiethnic Arizona: A study of power, urbanization and change

    NASA Astrophysics Data System (ADS)

    Glaser, Leah Suzanne

    2002-01-01

    From as early as the 1880s until as late as the 1970s, electrical power served as a critical tool for bringing America's diverse western communities into an urban industrial era. This study examines the process of electrification in three demographically diverse rural regions of Eastern Arizona. These three regions include the valleys of the Southeast, the White Mountains, and the Navajo Reservation to the north. While federal programs aided rural residents, local and regional factors determined the timing and nature of electrification and its impact. Access to electricity depended upon economics and technological advances, as well as a combination of local community and regional characteristics such as location, landscape, demographics, politics, and culture. At the turn of the century, electricity, with its elaborate and extensive infrastructure of wires, towers, and poles, emerged across America's cultural landscapes as the industrial era's most prominent symbol of progress, power, and a modern, urban lifestyle. Technological innovations and mechanization flourished, but primarily in the urban areas of the Northeast. People living outside concentrated settlements, of all ethnic backgrounds, had few hopes for delivery due to the cost of building power lines to a limited market. Arizona's rural population has historically been ethnically diverse, and its landscape varies from desert valleys to mountains of alpine forest. The federal government owns much of the land. Aided by federal guidance and funding sources like the New Deal's Rural Electrification Administration (REA), the existing rural communities took the initiative and constructed electrical systems specific to their local and regional needs. While products of the communities that built them, these systems symbolized and defined newly urbanized regions within the context of old rural landscapes, lifestyles, and traditions. In some ways the rural electrification process urbanized rural Arizona. The

  19. A case study of cumulus formation beneath a stratocumulus sheet: Its structure and effect on boundary layer budgets

    NASA Technical Reports Server (NTRS)

    Barlow, Roy W.; Nicholls, S.

    1990-01-01

    On several occasions during the FIRE Marine Stratocumulus IFO off the California coast, small cumulus were observed to form during the morning beneath the main stratocumulus (Sc) deck. This occurs in the type of situation described by Turton and Nicholls (1987) in which there is insufficient generation of turbulent kinetic energy (TKE) from the cloudtop or the surface to sustain mixing throughout the layer, and a separation of the surface and cloud layers occurs. The build up of humidity in the surface layer allows cumuli to form, and the more energetic of these may penetrate back into the Sc deck, reconnecting the layers. The results presented were collected by the UKMO C-130 aircraft flying in a region where these small cumulus had grown to the extent that they had penetrated into the main Sc deck above. The structure of these penetrative cumulus are examined and their implications on the layer flux and radiation budget discussed.

  20. Non-invasive assessment of porcine oocyte quality by supravital staining of cumulus-oocyte complexes with lissamine green B.

    PubMed

    Dutta, Rahul; Li, Shun; Fischer, Konrad; Kind, Alexander; Flisikowska, Tatiana; Flisikowski, Krzysztof; Rottmann, Oswald; Schnieke, Angelika

    2016-06-01

    We evaluated the usefulness of lissamine green B (LB) staining of cumulus-oocyte complexes (COC) as a non-invasive method of predicting maturational and developmental competence of slaughterhouse-derived porcine oocytes cultured in vitro. Cumulus cells of freshly aspirated COCs were evaluated either morphologically on the basis of thickness of cumulus cell layers, or stained with LB, which penetrates only non-viable cells. The extent of cumulus cell staining was taken as an inverse indicator of membrane integrity. The two methods of COC grading were then examined as predictors of nuclear maturation and development after parthenogenetic activation. In both cases LB staining proved a more reliable indicator than morphological assessment (P < 0.05). The relationship between LB staining and cumulus cell apoptosis was also examined. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for DNA fragmentation revealed that oocytes within COCs graded as low quality by either LB staining or visual morphology showed significantly greater DNA fragmentation (P < 0.05) than higher grades, and that LB and visual grading were of similar predictive value. Expression of the stress response gene TP53 showed significantly higher expression in COCs graded as low quality by LB staining. However expression of the apoptosis-associated genes BAK and CASP3 was not significantly different between high or low grade COCs, suggesting that mRNA expression of BAK and CASP3 is not a reliable method of detecting apoptosis in porcine COCs. Evaluation of cumulus cell membrane integrity by lissamine green B staining thus provides a useful new tool to gain information about the maturational and developmental competence of porcine oocytes. PMID:27172057

  1. The four cumulus cloud modes and their progression during rainfall events: A C-band polarimetric radar perspective

    NASA Astrophysics Data System (ADS)

    Kumar, Vickal V.; Jakob, Christian; Protat, Alain; May, Peter T.; Davies, Laura

    2013-08-01

    There is no objective definition to separate cumulus congestus clouds from the shallow cumulus and deep clouds. This has generated misinterpretation about the role of congestus clouds to promote deep convection through the potential of moistening the middle troposphere. In this study, an objective identification for the different tropical cumulus modes is found by examining the occurrence frequency of the cloud cell top heights (CTHs) and near-ground (at 2.5 km height) rainfall properties of these cells using a three-season database of the Darwin C-band polarimetric radar. Four cumulus modes were identified, namely a shallow cumulus mode with CTH in the trade inversion layer (1-3 km), a congestus mode with tops in the highly stable middle troposphere (3-6.5 km), a deep convective mode with tops in the region of free convection (6.5-15 km), and an overshooting convection mode with tops in the tropical tropopause layer (CTH >15 km). The study also investigates the connections between these cumulus modes during heavy rainfall events. The congestus mode occurs predominantly from ~10 h prior to the peak rainfall event to ~2 h past the event. The deep cloud populations (Modes 3 and 4) have their maxima at and shortly after the time of the rainfall peak, with maximum occurrence just below the tropical tropopause layer. A comparison of the heavy rainfall events occurring in morning (oceanic) conditions against the afternoon (continental) conditions revealed a higher ratio of the shallow to the deep cloud population and a shorter transition time from the shallow to the onset of deep population in the morning-oceanic conditions than the afternoon-land conditions. It is also found through the analysis of the large-scale moisture budget data set that for both the morning and afternoon events, the moistening peaked before the peak in the congestus populations.

  2. Implication of the oligomeric state of the N-terminal PTX3 domain in cumulus matrix assembly

    PubMed Central

    Ievoli, Elena; Lindstedt, Ragnar; Inforzato, Antonio; Camaioni, Antonella; Palone, Francesca; Day, Anthony J.; Mantovani, Alberto; Salvatori, Giovanni; Salustri, Antonietta

    2011-01-01

    Pentraxin 3 (PTX3) plays a key role in the formation of the hyaluronan-rich matrix of the cumulus oophorus surrounding ovulated eggs that is required for successful fertilization and female fertility. PTX3 is a multimeric protein consisting of eight identical protomers held together by a combination of non-covalent interactions and disulfide bonds. Recent findings suggest that the oligomeric status of PTX3 is important for stabilizing the cumulus matrix. Because the role of PTX3 in the cumulus resides in the unique N-terminal sequence of the protomer, we investigated further this issue by testing the ability of distinct Cys/Ser mutants of recombinant N-terminal region of PTX3 (N_PTX3) with different oligomeric arrangement to promote in vitro normal expansion in cumuli from Ptx3-null mice. Here we report that the dimer of the N_PTX3 is unable to rescue cumulus matrix organization, and that the tetrameric assembly of the protein is the minimal oligomeric state required for accomplishing this function. We have previously demonstrated that PTX3 binds to HCs of IαI and TSG-6, which are essential for cumulus matrix formation and able to interact with hyaluronan. Interestingly, here we show by solid-phase binding experiments that the dimer of the N_PTX3 retains the ability to bind to both IαI and TSG-6, suggesting that the octameric structure of PTX3 provides multiple binding sites for each of these ligands. These findings support the hypothesis that PTX3 contributes to cumulus matrix organization by cross-linking HA polymers through interactions with multiple HCs of IαI and/or TSG-6. The N-terminal PTX3 tetrameric oligomerization was recently reported to be also required for recognition and inhibition of FGF2. Given that this growth factor has been detected in the mammalian preovulatory follicle, we wondered whether FGF2 negatively influences cumulus expansion and PTX3 may also serve in vivo to antagonize its activity. We found that a molar excess of FGF2, above PTX3

  3. Microphysics, Radiation and Surface Processes in the Goddard Cumulus Ensemble (GCE) Model

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Simpson, J.; Baker, D.; Braun, S.; Chou, M.-D.; Ferrier, B.; Johnson, D.; Khain, A.; Lang, S.; Lynn, B.

    2001-01-01

    The response of cloud systems to their environment is an important link in a chain of processes responsible for monsoons, frontal depression, El Nino Southern Oscillation (ENSO) episodes and other climate variations (e.g., 30-60 day intra-seasonal oscillations). Numerical models of cloud properties provide essential insights into the interactions of clouds with each other, with their surroundings, and with land and ocean surfaces. Significant advances are currently being made in the modeling of rainfall and rain-related cloud processes, ranging in scales from the very small up to the simulation of an extensive population of raining cumulus clouds in a tropical- or midlatitude-storm environment. The Goddard Cumulus Ensemble (GCE) model is a multi-dimensional nonhydrostatic dynamic/microphysical cloud resolving model. It has been used to simulate many different mesoscale convective systems that occurred in various geographic locations. In this paper, recent GCE model improvements (microphysics, radiation and surface processes) will be described as well as their impact on the development of precipitation events from various geographic locations. The performance of these new physical processes will be examined by comparing the model results with observations. In addition, the explicit interactive processes between cloud, radiation and surface processes will be discussed.

  4. Aerosol and gas re-distribution by shallow cumulus clouds: An investigation using airborne measurements

    NASA Astrophysics Data System (ADS)

    Wonaschuetz, Anna; Sorooshian, Armin; Ervens, Barbara; Chuang, Patrick Y.; Feingold, Graham; Murphy, Shane M.; de Gouw, Joost; Warneke, Carsten; Jonsson, Haflidi H.

    2012-09-01

    Aircraft measurements during the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) are used to examine the influence of shallow cumulus clouds on vertical profiles of aerosol chemical composition, size distributions, and secondary aerosol precursor gases. The data show signatures of convective transport of particles, gases and moisture from near the surface to higher altitudes, and of aqueous-phase production of aerosol mass (sulfate and organics) in cloud droplets and aerosol water. In cloudy conditions, the average aerosol volume concentration at an altitude of 2850 m, above typical cloud top levels, was found to be 34% of that at 450 m; for clear conditions, the same ratio was 13%. Both organic and sulfate mass fractions were on average constant with altitude (around 50%); however, the ratio of oxalate to organic mass increased with altitude (from 1% at 450 m to almost 9% at 3450 m), indicative of the influence of in-cloud production on the vertical abundance and characteristics of secondary organic aerosol (SOA) mass. A new metric termed "residual cloud fraction" is introduced as a way of quantifying the "cloud processing history" of an air parcel. Results of a parcel model simulating aqueous phase production of sulfate and organics reproduce observed trends and point at a potentially important role of SOA production, especially oligomers, in deliquesced aerosols. The observations emphasize the importance of shallow cumulus clouds in altering the vertical distribution of aerosol properties that influence both their direct and indirect effect on climate.

  5. What does nature tell us about aerosol effects in a trade cumulus regime?

    NASA Astrophysics Data System (ADS)

    Yuan, T.; Remer, L. A.; Yu, H.; Wang, H.

    2011-12-01

    Detecting aerosol effect on cloud amount has been elusive to both observations and modeling due to potential buffering mechanisms and convolution of meteorology. Here through a natural experiment provided by long-term degassing of a low-lying volcano and use of A-Train satellite observations, we show modifications of trade cumulus cloud fields including decreased droplet size, decreased precipitation efficiency and increased cloud amount are associated with volcanic aerosols. In addition we find significantly higher cloud tops for polluted clouds. We demonstrate that the observed microphysical and macrophysical changes cannot be explained by synoptic meteorology or the orographic effect of the Hawaiian Islands. Idealized large eddy simulations reproduce some key observed features of the cloud response to aerosol perturbations, which helps us further understand the underlying mechanisms. The "total shortwave aerosol forcing", resulting from direct and indirect forcings including both cloud albedo and cloud amount, is almost an order of magnitude higher than aerosol direct forcing alone. Furthermore, the precipitation reduction associated with enhanced aerosol leads to large changes in the energetics of air-sea exchange and trade wind boundary layer. Our results represent the first observational evidence of large-scale increase of cloud amount due to aerosols in a trade cumulus regime, which can be used to constrain the representation of aerosol-cloud interactions in climate models. The findings also have implications for volcano-climate interactions and climate mitigation research.

  6. Laboratory simulations show diabatic heating drives cumulus-cloud evolution and entrainment.

    PubMed

    Narasimha, Roddam; Diwan, Sourabh Suhas; Duvvuri, Subrahmanyam; Sreenivas, K R; Bhat, G S

    2011-09-27

    Clouds are the largest source of uncertainty in climate science, and remain a weak link in modeling tropical circulation. A major challenge is to establish connections between particulate microphysics and macroscale turbulent dynamics in cumulus clouds. Here we address the issue from the latter standpoint. First we show how to create bench-scale flows that reproduce a variety of cumulus-cloud forms (including two genera and three species), and track complete cloud life cycles--e.g., from a "cauliflower" congestus to a dissipating fractus. The flow model used is a transient plume with volumetric diabatic heating scaled dynamically to simulate latent-heat release from phase changes in clouds. Laser-based diagnostics of steady plumes reveal Riehl-Malkus type protected cores. They also show that, unlike the constancy implied by early self-similar plume models, the diabatic heating raises the Taylor entrainment coefficient just above cloud base, depressing it at higher levels. This behavior is consistent with cloud-dilution rates found in recent numerical simulations of steady deep convection, and with aircraft-based observations of homogeneous mixing in clouds. In-cloud diabatic heating thus emerges as the key driver in cloud development, and could well provide a major link between microphysics and cloud-scale dynamics.

  7. Project Overview: Cumulus Humilis Aerosol Processing Study (CHAPS): Proposed Summer 2007 ASP Field Campaign

    SciTech Connect

    Berkowitz, Carl M.; Berg, Larry K.; Ogren, J. A.; Hostetler, Chris A.; Ferrare, Richard

    2006-05-18

    This white paper presents the scientific motivation and preliminary logistical plans for a proposed ASP field campaign to be carried out in the summer of 2007. The primary objective of this campaign is to use the DOE Gulfstream-1 aircraft to make measurements characterizing the chemical, physical and optical properties of aerosols below, within and above large fields of fair weather cumulus and to use the NASA Langley Research Center’s High Spectral Resolution Lidar (HSRL) to make independent measurements of aerosol backscatter and extinction profiles in the vicinity of these fields. Separate from the science questions to be addressed by these observations will be information to add in the development of a parameterized cumulus scheme capable of including multiple cloud fields within a regional or global scale model. We will also be able to compare and contrast the cloud and aerosol properties within and outside the Oklahoma City plume to study aerosol processes within individual clouds. Preliminary discussions with the Cloud and Land Surface Interaction Campaign (CLASIC) science team have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign, suggesting collaboration would benefit both teams.

  8. Multi-summer Cumulus-Radiation-Aerosol Climatology at SGP site

    NASA Astrophysics Data System (ADS)

    Kassianov, E.; Berg, L. K.; Flynn, C.; Long, C.; Barnard, J.

    2010-12-01

    Compared to other cloud types, shallow cumulus clouds are relatively small in size and have large variations over time/space that are poorly captured by current large-scale models of the atmosphere. Since these small-scale variations are very difficult to monitor and accurately describe, models improvement is hampered, in part, by the lack of appropriate observational constraints, including cloud and aerosol properties, surface parameters and radiative fluxes. To address this issue, a multi-summer (2000-2007) cumulus-radiation-aerosol climatology has been developed for the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Site. In particular, this climatology is applied to illustrate that positive values of shortwave cloud radiative forcing occur frequently and are characterized by fluctuations with a small temporal scale; the duration for the majority of events with positive radiative forcing is less than 5 minutes. In this presentation, the developed climatology will be described and several important applications will be shown.

  9. Impact of Anthropogenic Aerosol on the Properties of Shallow Maritime Cumulus Clouds

    NASA Astrophysics Data System (ADS)

    Gao, L.; Wilcox, E. M.; Shan, Y.

    2015-12-01

    The northern Indian Ocean region is frequently covered by cumulus clouds that are responsible for moistening the boundary layer and contribute to tropical deep convection. Because this region is uniquely located close to the highly polluted Indian plateau, air mass with high aerosol concentration can be easily transported to this area. These small cumulus clouds, coupled with the effects of aerosol, have a large potential to affect the regional and global albedo. The aerosol effects on cloud properties and atmospheric structures are examined in this work, using the UAV (Unmanned Aerial Vehicle) data that are observed from CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) and MAC (Maldives Autonomous unmanned aerial vehicle Campaign). On average, the high polluted cases show warmer temperature through the entire atmospheric column and higher relative humidity in boundary layer. The maximum temperature difference between high and low polluted cases can be found around the cloud layer altitude. In addition, the height of sub-cloud mixed layer is higher in low polluted cases. Clouds in high polluted cases are generally becoming narrower and taller than those in low polluted cases, and are associated with greater cloud water content and higher cloud droplet number concentrations, especially in small droplet range (diameters less than 10 micrometers). Meanwhile, the effective radius of cloud droplets decreases as the aerosol concentration increases. These facts indicate that the high polluted clouds are on average brighter with higher albedo.

  10. Rhythm Pattern of Sole through Electrification of the Human Body When Walking

    NASA Astrophysics Data System (ADS)

    Takiguchi, Kiyoaki; Wada, Takayuki; Tohyama, Shigeki

    The rhythm of automatic cyclic movements such as walking is known to be generated by a rhythm generator called CPG in the spinal cord. The measurement of rhythm characteristics in walking is considered to be important for analyzing human bipedal walking and adaptive walking on irregular terrain. In particular, the soles that contact the terrain surface perform flexible movements similar to the movement of the fins of a lungfish, which is considered to be the predecessor of land animals. The sole movements are believed to be a basic movement acquired during prehistoric times. The detailed rhythm pattern of sole motion is considered to be important. We developed a method for measuring electrification without installing device on a subject's body and footwear for stabilizing the electrification of the human body. We measured the rhythm pattern of 20 subjects including 4 infants when walking by using this system and the corresponding equipment. Therefore, we confirmed the commonality of the correlative rhythm patterns of 20 subjects. Further, with regard to an individual subject, the reproducibility of a rhythm pattern with strong correlation coefficient > 0.93 ± 0.5 (mean ± SD) concerning rhythms of trials that are differently conducted on adult subjects could be confirmed.

  11. Investigation of contact electrification based broadband energy harvesting mechanism using elastic PDMS microstructures

    NASA Astrophysics Data System (ADS)

    Dhakar, Lokesh; Tay, F. E. H.; Lee, Chengkuo

    2014-10-01

    Triboelectric energy harvesting has recently garnered a lot of interest because of its easy fabrication and high power output. Contact electrification depends on the chemical properties of contacting materials. Another important factor in contact electrification mechanism is surfaces’ elastic and topographical characteristics. One of the biggest limitations of resonant mechanism based devices is their narrow operating bandwidth. This paper presents a broadband mechanism which utilizes stiffness induced in the cantilever motion due to contact between two triboelectric surfaces. We have conducted experiments using polydimethylsiloxane (PDMS) micropad patterns to study the effect of micropad array configuration on the performance of triboelectric energy harvesting devices. The maximum power output measured from the device was observed to be 0.69 μW at an acceleration of 1 g. Due to the non-linearity introduced by contact separation mechanism, the bandwidth of the triboelectric energy harvester was observed to be increased by 63% at an acceleration level of 1 g. A hybrid energy harvesting mechanism has also been demonstrated by compounding the triboelectric energy harvester with a piezoelectric bimorph.

  12. Patronage power: Rural electrification, river development, and Lyndon Johnson (1937--1939)

    NASA Astrophysics Data System (ADS)

    Dusek, Paul-Michael Mays

    Few historians document Lyndon Johnson's efforts to construct a state-wide political machine at the local level early in his congressional career. The literature glorifies Johnson for hydroelectric river development and rural electrification. This thesis acknowledges the transformative nature of rural electrification in Central Texas through the efforts of Johnson but, more importantly, reveals how extensively Johnson sought to capitalize on the tail-end of the New Deal to utilize government-funded relief projects to establish a state-wide political machine. An analysis of the correspondence between Johnson, his local political operators, members of his state-wide network, and rural constituents reveals another layer to the complexity of Johnson and further exposes his ambitious, calculating nature. Johnson used rural electrification to first create a community of supporters in his congressional district then used rural electrification and multipurpose river development programs to cultivate political contacts across the state of Texas. This thesis explores the first time that Lyndon Johnson used patronage to develop a political community as a publicly elected official. Johnson pushed for constant expansion of operations to ensure a steady supply of new jobs while displaying a cavalier attitude about specific regulations regarding the allocation of funds. His machine manipulated and massaged congressional appropriations restrictions and utilized multiple congressional revenue streams to stretch finances further and lower overhead costs to increase the scope of operations thus further improving the lives of his constituents. Johnson also used this movement to efficiently and effectively construct a foundation for his political machine. This thesis also clarifies an early moment in Johnson's beliefs about civil rights. Instead of standing on principle, Johnson relied on extortion and threats to fight racism at this early juncture in his political career because of

  13. Patronage power: Rural electrification, river development, and Lyndon Johnson (1937--1939)

    NASA Astrophysics Data System (ADS)

    Dusek, Paul-Michael Mays

    Few historians document Lyndon Johnson's efforts to construct a state-wide political machine at the local level early in his congressional career. The literature glorifies Johnson for hydroelectric river development and rural electrification. This thesis acknowledges the transformative nature of rural electrification in Central Texas through the efforts of Johnson but, more importantly, reveals how extensively Johnson sought to capitalize on the tail-end of the New Deal to utilize government-funded relief projects to establish a state-wide political machine. An analysis of the correspondence between Johnson, his local political operators, members of his state-wide network, and rural constituents reveals another layer to the complexity of Johnson and further exposes his ambitious, calculating nature. Johnson used rural electrification to first create a community of supporters in his congressional district then used rural electrification and multipurpose river development programs to cultivate political contacts across the state of Texas. This thesis explores the first time that Lyndon Johnson used patronage to develop a political community as a publicly elected official. Johnson pushed for constant expansion of operations to ensure a steady supply of new jobs while displaying a cavalier attitude about specific regulations regarding the allocation of funds. His machine manipulated and massaged congressional appropriations restrictions and utilized multiple congressional revenue streams to stretch finances further and lower overhead costs to increase the scope of operations thus further improving the lives of his constituents. Johnson also used this movement to efficiently and effectively construct a foundation for his political machine. This thesis also clarifies an early moment in Johnson's beliefs about civil rights. Instead of standing on principle, Johnson relied on extortion and threats to fight racism at this early juncture in his political career because of

  14. The NCEP-NCAR Stratocumulus-to-Cumulus Transition Climate Process Team

    NASA Astrophysics Data System (ADS)

    Bretherton, C. S.; Teixeira, J.; Blossey, P. N.; Caldwell, P.; Fletcher, J. K.; Han, J.; Jones, C. R.; Klein, S. A.; Mechoso, C. R.; Pan, H.; Park, S.; Sun, R.; Suselj, K.; Witek, M. L.; Xiao, H.

    2012-12-01

    The NCEP-NCAR Stratocumulus-to-Cumulus Transition Climate Process Team (Sc-Cu CPT) is a NOAA-funded collaboration started in 2010 between two universities, two climate modeling centers, and two other national labs to improve the representation of low clouds in the NCEP Global Forecast System (GFS) and the NCAR Community Atmosphere Model (CAM5). Highlights of CPT activities will be presented. The GFS is not only the U.S. operational global weather forecast model, it is also periodically used as a starting point for the Climate Forecast System (CFS), NCEP's operational coupled seasonal-to-interannual forecast model. As strategic preparation for developing version 3 of the CFS, two CPT goals were (1) to evaluate the free-running climate of GFS coupled to an ocean model using customary metrics for climate modeling, and (2) to reduce model biases in subtropical low cloud cover. The AMWG diagnostics package used for evaluating CAM5 was adapted to 50-year coupled GFS simulations, as well as to version 2 of the CFS. Both models had low overall circulation, precipitation and temperature biases, but had serious global energy conservation errors and cloud radiative forcing 40-50% too small in global mean. Using short coupled runs, the first issue was addressed by adding missing heating due to dissipation of turbulent kinetic energy, and the second issue has been partly addressed through a suite of minor changes to the moist physics parameterizations. Improvements to the boundary-layer scheme are also under development. CPT members also have refined the moist physics parameterizations in the CAM5, including unification of shallow and deep cumulus convection, improvement of cloud fraction and microphysics schemes, and diagnosis of systematic biases in the simulation of aerosol indirect effects in precipitating boundary-layer clouds. Lastly, CPT members have performed LES simulations of boundary-layer cloud sensitivities and of the stratocumulus-to-cumulus transition that help

  15. Stochastic and scale-adaptive shallow cumulus parameterization (EDMF-DualM-S in ICON)

    NASA Astrophysics Data System (ADS)

    Sakradzija, M.; Seifert, A.; Heus, T.; Dipankar, A.

    2014-12-01

    Numerical cloud-resolving studies of cumulus clouds reveal the small-scale variability of convection that is not fully controlled by the large scale environment. From the parameterization point of view, this means that there is a whole distribution of the sub-grid convective states that can correspond to the same large scale forcing. Moreover, the stochastic variability becomes higher with the increasing model resolution. As the cloud sample within a model grid box becomes smaller, the most probable realization of the sub-grid convection deviates further away from the convective ensemble mean. Therefore, as the atmospheric models approach higher and higher resolution, it becomes more important to develop stochastic schemes that sub-sample the convective cloud ensemble and adapt to the model resolution. We propose an approach to represent the stochastic variability of the unresolved shallow-convective states, and the dependence of the distribution of sub-grid states on the model horizontal resolution. We combine the theory of fluctuations in a convective ensemble based on a statistical mechanics approach and Large-Eddy Simulation (LES) of shallow cumulus clouds of an idealized case over the ocean. Based on the empirical and theoretical findings, a stochastic cloud generator is developed and coupled to the EDMF-DualM cloud scheme in the ICON model as a stochastic process that runs simultaneously with the EDMF scheme. The stochastic scheme adds more complexity to the cloud parameterization in EDMF, but on the other side, the cloud mass flux profiles are locally sampled instead of using the buoyancy sorting closure for the bulk vertical profile. The scheme also relaxes the statistical equilibrium assumption by applying it only at the scale at which it is appropriate and by including the memory component. Preliminary results show that the variability is well reproduced and that the scheme is scale-adaptive. Impact on the mean profiles is small, except for a significant

  16. Scale-Dependence of the Response of Tropopause Height to Deep Cumulus Convection

    NASA Astrophysics Data System (ADS)

    Fishbein, E.; Wong, S.

    2014-12-01

    Deep cumulus convection can influence the height of the tropopause either through plumes which penetration into the tropical tropopause layer (TTL) or by forcing broad-scale vertical motion. This study uses the unique capabilities of satellite-based cross-track sounders to provide three-dimensional images of temperature in the TTL. These are used to derive thermal tropopause height and to study the scale-dependence of tropopause height variability and its relation to distance and intensity of deep convection. The data used in this study are 10 years of tropical Atmospheric Infrared Sounder (AIRS) swath (level 2) temperature profile data. Localized spatial power spectra are derived from swaths of tropopause height, which are ordered relative to the timing of deep convective clouds. The relative contributions of small-scale and large-scale power are use to characterize the influence of the scale of the vertical motion in the TTL. The highest spatial scales sampled by the AIRS temperature field are mesoscale systems of deep cumulus convection approximately 200 to 400 km across because the horizontal spatial resolution of the AIRS temperature profile product is approximately 50 km. AIRS temperature profiles have state-dependent errors correlated with cloud amount, but are more useful than temperature profiles from microwave sounders because of their higher vertical resolution. TTL temperature has less sampling error then mid and lower troposphere temperature, and the time binning is used to characterize and reduce these errors. The intensity of cumulus convection is inferred from the derived cloud properties, specifically cloud-top height, cloud-ice effective diameter and their power. The height difference between tropopause and cloud-top is used to characterize the likelihood that vertical motions extend to the tropopause, while the cloud-ice effective diameter provides a measure of the intensity of the convective vertical velocity and its ability to lift larger ice

  17. Embryonic Poly(A)-Binding Protein (EPAB) Is Required for Granulosa Cell EGF Signaling and Cumulus Expansion in Female Mice.

    PubMed

    Yang, Cai-Rong; Lowther, Katie M; Lalioti, Maria D; Seli, Emre

    2016-01-01

    Embryonic poly(A)-binding protein (EPAB) is the predominant poly(A)-binding protein in Xenopus, mouse, and human oocytes and early embryos before zygotic genome activation. EPAB is required for translational activation of maternally stored mRNAs in the oocyte and Epab(-/-) female mice are infertile due to impaired oocyte maturation, cumulus expansion, and ovulation. The aim of this study was to characterize the mechanism of follicular somatic cell dysfunction in Epab(-/-) mice. Using a coculture system of oocytectomized cumulus oophorus complexes (OOXs) with denuded oocytes, we found that when wild-type OOXs were cocultured with Epab(-/-) oocytes, or when Epab(-/-) OOXs were cocultured with WT oocytes, cumulus expansion failed to occur in response to epidermal growth factor (EGF). This finding suggests that oocytes and cumulus cells (CCs) from Epab(-/-) mice fail to send and receive the necessary signals required for cumulus expansion. The abnormalities in Epab(-/-) CCs are not due to lower expression of the oocyte-derived factors growth differentiation factor 9 or bone morphogenetic protein 15, because Epab(-/-) oocytes express these proteins at comparable levels with WT. Epab(-/-) granulosa cells (GCs) exhibit decreased levels of phosphorylated MEK1/2, ERK1/2, and p90 ribosomal S6 kinase in response to lutenizing hormone and EGF treatment, as well as decreased phosphorylation of the EGF receptor. In conclusion, EPAB, which is oocyte specific, is required for the ability of CCs and GCs to become responsive to LH and EGF signaling. These results emphasize the importance of oocyte-somatic communication for GC and CC function.

  18. Mean and Turbulence Structure of the Shallow Cumulus-topped Boundary Layers in the DYNAMO Measurement Domain

    NASA Astrophysics Data System (ADS)

    Alappattu, D. P.; Wang, Q.; Khelif, D.

    2013-12-01

    Abstract: Extensive measurements were collected using NOAA's WP-3D Orion aircraft (P3) on 19 November 2011 over the Topical Indian Ocean (TIO; 8E-EQ and 72E-81E) as a part of DYNAMO (Dynamics of Madden Julian Oscillation) field campaign. On this mission P3 conducted five vertically stacked level legs each having 4-5 levels of measurements. Boundary layer profiling also performed after each vertically stacked leg. A total of 6 hour 18 minutes of high frequency (25 Hz) data of temperature, humidity and three components of wind were collected. Sea surface temperature (SST) and liquid water content also were measured. Average sampling levels of the vertically stacked legs were at 60 m, 120 m, 350 m, 475 m and 650 m. The lowest three levels were well inside the boundary layer while the next two levels were at the cloud base and within the cloud respectively. Aircraft penetrated through a minimum of one trade wind cumulus in each vertically stacked leg. A few of the observed trade wind cumuli were precipitating during the measurements. The case to be presented is the only flight were shallow precipitating cumulus clouds were sampled intensively before the active phase of the November MJO event. We will discuss the mean vertical structure and the horizontal variability of this cumulus-topped boundary layer. Fluxes of momentum, sensible heat and latent heat estimated using the eddy correlation method will be presented to illustrate the energy and water vapor transport in this type of boundary layer in the DYNAMO domain. Variation of drag coefficient and heat exchange coefficients with wind speed is also presented. Spectral analysis performed on the data will reveal the dominant turbulent eddy size in the presence of cumulus clouds. Finally, we will discuss the observed differences in vertical velocity, buoyancy and entrainment/detrainment eddy fluxes in the precipitating and non-precipitating cumulus clouds.

  19. 3'5'-cyclic adenosine monophosphate-dependent up-regulation of phosphodiesterase type 3A in porcine cumulus cells.

    PubMed

    Sasseville, Maxime; Côté, Nancy; Vigneault, Christian; Guillemette, Christine; Richard, François J

    2007-04-01

    The means by which cumulus cells react to gonadotropin stimulation and regulate the subsequent production and degradation of cAMP are largely unknown. In this article, we report that cyclic nucleotide phosphodiesterase (PDE) type 3A (Pde3a) is transcriptionally regulated in porcine cumulus cells by a cAMP-dependent pathway during in vitro maturation (IVM). cAMP-PDE activity was increased in the cumulus-oocyte complex (COC) after 10 h of IVM, and 78% of this increase was sensitive to a Pde3-specific inhibitor, cilostamide. Although no variation was observed in the oocyte, cilostamide-sensitive cAMP-PDE activity increased in the cumulus cells after IVM. This was supported by Western blotting, which showed that the intensity of a 135-kDa anti-Pde3a immunoreactive band was increased in COC after IVM. The Pde3a mRNA level was up-regulated 28-fold in the COC after 4 h of IVM and remained high up to 12 h. The mRNA up-regulation and increased activity were inhibited by an RNA synthesis inhibitor, alpha-amanitin. The cilostamide-sensitive increase in PDE activity was inhibited by a protein synthesis inhibitor, cycloheximide. Pregnant mare serum gonadotropin (PMSG) caused dose-dependent activation of Pde3. The PMSG-dependent increase in Pde3 activity and Pde3a mRNA were mimicked by the adenylyl cyclase activator forskolin or prostaglandin E2. PMSG-dependent Pde3 activation was inhibited by the protein kinase A-specific inhibitor H89. Collectively, our results show for the first time that degradation of the intracellular cyclic nucleotide by Pde3a is transcriptionally up-regulated via a cAMP-dependent pathway in cumulus cells, suggesting that it has a functional role during the ovulatory gonadotropin surge.

  20. Precipitation susceptibility in marine stratocumulus and shallow cumulus from airborne measurements

    NASA Astrophysics Data System (ADS)

    Jung, Eunsil; Albrecht, Bruce A.; Sorooshian, Armin; Zuidema, Paquita; Jonsson, Haflidi H.

    2016-09-01

    Precipitation tends to decrease as aerosol concentration increases in warm marine boundary layer clouds at fixed liquid water path (LWP). The quantitative nature of this relationship is captured using the precipitation susceptibility (So) metric. Previously published works disagree on the qualitative behavior of So in marine low clouds: So decreases monotonically with increasing LWP or cloud depth (H) in stratocumulus clouds (Sc), while it increases and then decreases in shallow cumulus clouds (Cu). This study uses airborne measurements from four field campaigns on Cu and Sc with similar instrument packages and flight maneuvers to examine if and why So behavior varies as a function of cloud type. The findings show that So increases with H and then decreases in both Sc and Cu. Possible reasons for why these results differ from those in previous studies of Sc are discussed.

  1. Optical properties of continental haze and cumulus and orographic clouds based on Space Shuttle polarimetric observations.

    PubMed

    Egan, W G; Israel, S; Sidran, M; Hindman, E E; Johnson, W R; Whitehead, V S

    1993-11-20

    Digitized Space Shuttle imagery in the red, green, and blue spectral regions (0.600, 0.540, and 0.435 µm, respectively) is used to characterize the mean radius and the index of refraction of droplets in cumulus and orographic clouds. The clouds are shown to consist concurrently of submicrometer and supermicrometer droplets, with the percent polarization indicative of the dominant sizes. Cloud development from haze as well as inhomogeneities in the cloud decks can be traced remotely. The absorption properties of clouds can also be determined remotely. An optical depth of continental haze in the same three spectral regions as the clouds is computed from the polarimetric and photometric contributions. Both Mie and Rayleigh scattering are included in the model.

  2. Three-dimensional simulations of cumulus congestus clouds on GATE day 261

    NASA Technical Reports Server (NTRS)

    Simpson, J.; Van Helvoirt, G.; Mccumber, M.

    1982-01-01

    Schlesinger's (1978) three-dimensional cumulus model is applied to showering congestus clouds on day 261 of GATE. Model results are compared with each other and with observations to analyze the effects of varying shear and altered sounding. Relationships between shear, mesovortices and dynamic entrainment are examined, as well as the model clouds' impact on the environment as a function of shear. The simulations appear to resemble reality in many important aspects. Altostratus layers observed on day 261 are found to be a by-product of convection in three-dimensional shear. Rapid erosion of cloud base to 3.6 km is related to the ambient thermal structure, with wind shear and initial perturbation playing a secondary role. Some of the apparent conflict regarding lateral versus cloud-top entrainment is clarified, as well as some factors governing convective downdraft structure and intensity.

  3. A unified view of convective transports by stratocumulus clouds, shallow cumulus clouds, and deep convection

    NASA Technical Reports Server (NTRS)

    Randall, David A.

    1990-01-01

    A bulk planetary boundary layer (PBL) model was developed with a simple internal vertical structure and a simple second-order closure, designed for use as a PBL parameterization in a large-scale model. The model allows the mean fields to vary with height within the PBL, and so must address the vertical profiles of the turbulent fluxes, going beyond the usual mixed-layer assumption that the fluxes of conservative variables are linear with height. This is accomplished using the same convective mass flux approach that has also been used in cumulus parameterizations. The purpose is to show that such a mass flux model can include, in a single framework, the compensating subsidence concept, downgradient mixing, and well-mixed layers.

  4. Observational evidence for aerosol invigoration in shallow cumulus downstream of Mount Kilauea

    NASA Astrophysics Data System (ADS)

    Mace, G. G.; Abernathy, A. C.

    2016-03-01

    Knowledge of how marine boundary layer (MBL) shallow cumulus clouds respond to changes in aerosol is central to understanding how MBL clouds modulate the climate system. Mount Kilauea on the island of Hawaii began erupting in 2008 injecting substantial SO2 into the marine boundary layer creating a unique natural laboratory. Examining data from approximately 600 passes of the A-Train downstream of Mount Kilauea over a 3 year period and separating data into aerosol optical depth quartiles, we find an unambiguous increase in marine boundary cloud top height and an increase in surface wind speed as aerosol increases while the radar reflectivity does not change substantially. We conclude that increased aerosols may have caused invigoration of the MBL clouds. Additionally, we find that increases in sub 1 km cloud fraction combined with increasing aerosol explain the increased visible reflectance suggesting that evidence for the so-called first aerosol indirect effect should be reexamined.

  5. Patterns of intercellular connectivity in the mammalian cumulus-oocyte complex.

    PubMed

    Albertini, D F; Rider, V

    1994-02-01

    Electron and fluorescence microscopic techniques have been used in a complementary fashion to study the patterns of follicle cell-oocyte interactions within cumulus-oocyte-complexes of various mammals. The principal findings are: (1) two distinct types of transzonal processes exist that are distinguishable on the basis of cytoskeletal composition; (2) in some of the species examined (pig, goat, primate), corkscrew-shaped processes rich in tubulin, traverse the zona pellucida and are invaginated into the oocyte cortex; (3) actin-rich processes either ramify as a network at the outer surface of the zona pellucida or penetrate the zona and make contact with the oolemma in a species specific manner. These results are discussed with respect both to the need to employ complementary optical methods in assessing connectivity patterns within COC and to the possible role that extracellular matrix-cell interactions play in the homeostatic control of oocyte growth and maturation.

  6. Derivation of Cumulus Cloud Dimensions and Shape from the Airborne Measurements by the Research Scanning Polarimeter

    NASA Technical Reports Server (NTRS)

    Alexandrov, Mikhail D.; Cairns, Brian; Emde, Claudia; Ackerman, Andrew S.; Ottaviani, Matteo; Wasilewski, Andrzej P.

    2016-01-01

    The Research Scanning Polarimeter (RSP) is an airborne instrument, whose measurements have been extensively used for retrievals of microphysical properties of clouds. In this study we show that for cumulus clouds the information content of the RSP data can be extended by adding the macroscopic parameters of the cloud, such as its geometric shape, dimensions, and height above the ground. This extension is possible by virtue of the high angular resolution and high frequency of the RSP measurements, which allow for geometric constraint of the cloud's 2D cross section between a number of tangent lines of view. The retrieval method is tested on realistic 3D radiative transfer simulations and applied to actual RSP data.

  7. Interactions between a tropical mixed boundary layer and cumulus convection in a radiative-convective model

    SciTech Connect

    Dean, C.L.

    1993-05-01

    This report details a radiative-convective model, combining previously developed cumulus, stable cloud and radiation parameterizations with a boundary layer scheme, which was developed in the current study. The cloud model was modified to incorporate the effects of both small and large clouds. The boundary layer model was adapted from a mixed layer model was only slightly modified to couple it with the more sophisticated cloud model. The model was tested for a variety of imposed divergence profiles, which simulate the regions of the tropical ocean from approximately the intertropical Convergence Zone (ITCZ) to the subtropical high region. The sounding used to initialize the model for most of the runs is from the trade wind region of ATEX. For each experiment, the model was run with a timestep of 300 seconds for a period of 7 days.

  8. Active immunization of rats with cumulus-free mouse ova: induction of infertility and antibody titers.

    PubMed

    Aitken, R J; Richardson, D W

    1981-04-01

    Active immunization of rats with cross-reacting zona pellucida antigens derived from cumulus-free mouse ova resulted in the induction in fertility without adverse side effects. Half of the immunized animals never regained their fertility despite repeated matings with fertile males. Two of the remaining animals conceived when antibody titers fell to basal levels and gave birth to litters of normal healthy young. Post mortem examination of immunized animals 24 hours after finding sperm in the vaginal smears resulted in the recovery of tubal ova exhibiting the presence of a precipitate on the outer surface of the zona pellucida. Some of these ova appeared to have been fertilized, suggesting that anti-zona antibodies may also inhibit fertility through a post-fertilization mechanism of action. PMID:7288384

  9. Direct Numerical Simulation of Evaporative Cooling at the Lateral Boundary of Shallow Cumulus Clouds

    NASA Astrophysics Data System (ADS)

    Heus, T.; Abma, D.; Mellado, J.

    2012-12-01

    This study investigates the dynamics of a narrow region of subsiding air at the lateral boundary of cumulus clouds, focusing on the role of evaporative cooling. Previous observational and large-eddy simulations showed the relevance of this subsiding shell in cloud dynamics, but have also showed that the size of this shell is well below what large-eddy simulations can resolve. Therefore, we have performed direct numerical simulations of an idealized subsiding shell to investigate accurately the complete turbulent field. The system develops a self-similar, Reynolds number independent flow which allows for the determination of explicit scaling laws relating the characteristic length, time and velocity scales of the shell. In particular, it is found that the shell width grows quadratically in time, and linearly with decreasing height. The magnitude of these growth rates confirm the importance of the subsiding shell because of the relatively fast development of entrainment-determining scales: for typical thermodynamic conditions in cumulus clouds, a velocity of the order of 1~m~s-1 and a thickness of the order of 10 meters are established in about 2 minutes. This fits well within the typical cloud life time, suggesting that our idealization is an adequate framework for the analysis of relevant aspects in the subsiding shell associated with buoyancy reversal. It also indicates that the scaling laws derived here can be used to estimate the potential strength of a subsiding shell and the mean lateral entrainment associated with it, provided an estimate of the local thermodynamical state of the cloud boundary. It is shown that the dominant parameter of this system is the saturation buoyancy, whereas the effect of the saturation mixing fraction is minor.uoyancy field in the subsiding shell. Blue colors are low values, red colors are high values.

  10. Fatty acid synthesis and oxidation in cumulus cells support oocyte maturation in bovine.

    PubMed

    Sanchez-Lazo, Laura; Brisard, Daphné; Elis, Sébastien; Maillard, Virginie; Uzbekov, Rustem; Labas, Valérie; Desmarchais, Alice; Papillier, Pascal; Monget, Philippe; Uzbekova, Svetlana

    2014-09-01

    Oocyte meiotic maturation requires energy from various substrates including glucose, amino acids, and lipids. Mitochondrial fatty acid (FA) β-oxidation (FAO) in the oocyte is required for meiotic maturation, which is accompanied by differential expression of numerous genes involved in FAs metabolism in surrounding cumulus cells (CCs) in vivo. The objective was to elucidate components involved in FAs metabolism in CCs during oocyte maturation. Twenty-seven genes related to lipogenesis, lipolysis, FA transport, and FAO were chosen from comparative transcriptome analysis of bovine CCs before and after maturation in vivo. Using real-time PCR, 22 were significantly upregulated at different times of in vitro maturation (IVM) in relation to oocyte meiosis progression from germinal vesicle breakdown to metaphase-II. Proteins FA synthase, acetyl-coenzyme-A carboxylase, carnitine palmitoyltransferase, perilipin 2, and FA binding protein 3 were detected by Western blot and immunolocalized to CCs and oocyte cytoplasm, with FA binding protein 3 concentrated around oocyte chromatin. By mass spectrometry, CCs lipid profiling was shown to be different before and after IVM. FAO inhibitors etomoxir and mildronate dose-dependently decreased the oocyte maturation rate in vitro. In terms of viability, cumulus enclosed oocytes were more sensitive to etomoxir than denuded oocytes. In CCs, etomoxir (150 μM) led to downregulation of lipogenesis genes and upregulated lipolysis and FAO genes. Moreover, the number of lipid droplets decreased, whereas several lipid species were more abundant compared with nontreated CCs after IVM. In conclusion, FAs metabolism in CCs is important to maintain metabolic homeostasis and may influence meiosis progression and survival of enclosed oocytes. PMID:25058602

  11. Absence of cumulus cells during in vitro maturation affects lipid metabolism in bovine oocytes.

    PubMed

    Auclair, Sylvain; Uzbekov, Rustem; Elis, Sébastien; Sanchez, Laura; Kireev, Igor; Lardic, Lionel; Dalbies-Tran, Rozenn; Uzbekova, Svetlana

    2013-03-15

    Cumulus cells (CC) surround the oocyte and are coupled metabolically through regulation of nutrient intake. CC removal before in vitro maturation (IVM) decreases bovine oocyte developmental competence without affecting nuclear meiotic maturation. The objective was to investigate the influence of CC on oocyte cytoplasmic maturation in relation to energy metabolism. IVM with either cumulus-enclosed (CEO) or -denuded (DO) oocytes was performed in serum-free metabolically optimized medium. Transmission electron microscopy revealed different distribution of membrane-bound vesicles and lipid droplets between metaphase II DO and CEO. By Nile Red staining, a significant reduction in total lipid level was evidenced in DO. Global transcriptomic analysis revealed differential expression of genes regulating energy metabolism, transcription, and translation between CEO and DO. By Western blot, fatty acid synthase (FAS) and hormone-sensitive phospholipase (HSL) proteins were detected in oocytes and in CC, indicating a local lipogenesis and lypolysis. FAS protein was significantly less abundant in DO that in CEO and more highly expressed in CC than in the oocytes. On the contrary, HSL protein was more abundant in oocytes than in CC. In addition, active Ser⁵⁶³-phosphorylated HSL was detected in the oocytes only after IVM, and its level was similar in CEO and DO. In conclusion, absence of CC during IVM affected lipid metabolism in the oocyte and led to suboptimal cytoplasmic maturation. Thus, CC may influence the oocyte by orienting the consumption of nutritive storage via regulation of local fatty acid synthesis and lipolysis to provide energy for maturation. PMID:23321473

  12. Improving Forecasts of Cumulus: An Intersection of the Renewable Energy and Climate Science Communities

    NASA Astrophysics Data System (ADS)

    Berg, L. K.; Gustafson, W. I., Jr.; Kassianov, E.; Long, C. N.

    2015-12-01

    Accurate forecasts of broken cloud fields and their associated impact on the downwelling solar irradiance has remained a challenge to the renewable energy industry. Likewise, shallow cumulus play an important role in the Earth's radiation budget and hydrologic cycle and are of interest to the weather forecasting and climate science communities. The main challenge associated with predicting these clouds are their relatively small size (on the order of a kilometer or less) relative to the model grid spacing. Recently, however, there have been significant efforts put into improving forecasts of shallow clouds and the associated temporal and spatial variability of the solar irradiance that they induce. As an example of these efforts, we will describe recent modifications to the standard Kain-Fritsch parameterization as applied within the Weather Research and Forecasting (WRF) model that are designed to improve predictions of the macroscale and microscale structure of shallow cumulus. These modifications are shown to lead to a realistic increase in the simulated cloud fraction and associated decrease in the solar irradiance. We will evaluate our results using data collected at the Department of Energy's Atmospheric Radiation Measurement (ARM) Southern Great Plains site, which is located in north-central Oklahoma. Our team has analyzed over 5 years of data collected at this site to document the macroscale structure of the clouds (including cloud fraction, cloud-base and cloud-top height) as well as their impact on the downwelling shortwave and longwave irradiance. One particularly interesting impact of shallow cumuli is the enhancement of the diffuse radiation, such that during periods in which the sun is not blocked, the observed irradiance can be significantly larger than the corresponding clear sky case. To date, this feature is not accurately represented by models that apply the plane-parallel assumption applied in the standard radiation parameterizations.

  13. Distribution of cortical granules in bovine oocytes classified by cumulus complex.

    PubMed

    Hosoe, M; Shioya, Y

    1997-11-01

    The present study was conducted to examine distributional changes of cortical granules (CGs) during meiotic maturation and fertilisation in vitro and the developmental ability in bovine oocytes classified by cumulus cells. The oocytes were classified by the morphology of their cumulus cell layers as follows: class A, compact and thick; class B, compact but thin; class C, naked; and class D, expanded. Some of the oocytes were stained with Lens curinalis agglutinin (LCA) before and after maturation in vitro and after insemination, and then stained with orcein to observe their nuclear stages. The others were left in culture. Distributional patterns of the CGs were classified into four types: type I, CGs distributed in clusters; type II, CGs dispersed and partly clustered; type III, all CGs dispersed; and type IV, no CGs. Most of the oocytes before culture showed a type I pattern, but this decreased after maturation culture, whereas type III increased in class A. The oocytes of class B showed similar changes while the oocytes of class C did not. In class C, many oocytes showed type I after culture, indicating that cytoplasmic maturation was not completed. In class D, 80.4% of the oocytes exhibited type III before maturation culture, indicating that their cytoplasmic maturation was different from classes A-C. And about 70% of the class D oocytes were at the nuclear stage of germinal vesicle breakdown (GVBD) before culture. The developmental rates to blastocysts in classes A-D were 28.7%, 23.1%, 0.5% and 3.4% respectively. PMID:9563685

  14. A Fractal Dimensional Analysis on the Cloud Shape Parameters of Cumulus over Land.

    NASA Astrophysics Data System (ADS)

    Gotoh, Kazuo; Fujii, Yasuhiko

    1998-10-01

    High-resolution Landsat thematic mapper image data were employed in the present study to estimate the influence of regional wind systems on the macrophysical properties of cumulus clouds, such as perimeter fractal dimension, orientation angle, and cloud-base height. As a case study, an image of cumulus clouds was chosen in which small- and large-sized clouds prevail over the land in the presence of local winds. Cloud extraction from backgrounds becomes difficult when the background comprises various brightnesses. Furthermore, the surface brightness of a cloud is not uniform when shadows appear on the surface. These effects contribute to errors in cloud extraction only using a simple threshold. To address these problems, technical improvements in processing, including the combination of clustering, dynamic threshold, and edge detection, are presented and shown to produce more accurate cloud outlines seen from the zenith direction.The clouds' statistical area-perimeter relation was shown to confirm that the fractal dimension of the cumuli follows the double power law: two different perimeter fractal dimensions exist for larger clouds and for smaller clouds. Correspondence of the bending point (around 0.7 km2) in the area-perimeter relation with the bending point in the area-major axis relation was also demonstrated. Analysis of cloud orientation showed that larger clouds (>0.7 km2) indicate the approximate direction of the local wind, whereas smaller clouds do not show clear tendencies in their directions, suggesting that there is a difference in formation between larger and smaller clouds. These findings suggest that in the presence of horizontal local wind, larger clouds are likely to be formed by aggregation of smaller cloud cells (unicellular clouds) during the process of alignment to become long- and roll-shaped clouds (multicellular clouds).Uneven distribution of cloud-base height was also demonstrated in this study. Clouds with higher base levels are found to

  15. Observational estimates of detrainment and entrainment in non-precipitating shallow cumulus

    NASA Astrophysics Data System (ADS)

    Norgren, M. S.; Small, J. D.; Jonsson, H. H.; Chuang, P. Y.

    2016-01-01

    Vertical transport associated with cumulus clouds is important to the redistribution of gases, particles, and energy, with subsequent consequences for many aspects of the climate system. Previous studies have suggested that detrainment from clouds can be comparable to the updraft mass flux, and thus represents an important contribution to vertical transport. In this study, we describe a new method to deduce the amounts of gross detrainment and entrainment experienced by non-precipitating cumulus clouds using aircraft observations. The method utilizes equations for three conserved variables: cloud mass, total water, and moist static energy. Optimizing these three equations leads to estimates of the mass fractions of adiabatic mixed-layer air, entrained air and detrained air that the sampled cloud has experienced. The method is applied to six flights of the CIRPAS Twin Otter during the Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) which took place in the Houston, Texas region during the summer of 2006 during which 176 small, non-precipitating cumuli were sampled. Using our novel method, we find that, on average, these clouds were comprised of 30 to 70 % mixed-layer air, with entrained air comprising most of the remainder. The mass fraction of detrained air was usually very small, less than 2 %, although values larger than 10 % were found in 15 % of clouds. Entrained and detrained air mass fractions both increased with altitude, consistent with some previous observational studies. The largest detrainment events were almost all associated with air that was at their level of neutral buoyancy, which has been hypothesized in previous modeling studies. This new method could be readily used with data from other previous aircraft campaigns to expand our understanding of detrainment for a variety of cloud systems.

  16. Safety of brilliant cresyl blue staining protocols on human granulosa and cumulus cells.

    PubMed

    Alcoba, Diego Duarte; Conzatti, Maiara; Ferreira, Gustavo Dias; Pimentel, Anita Mylius; Kussler, Ana Paula; Capp, Edison; von Eye Corleta, Helena; Brum, Ilma Simoni

    2016-02-01

    The selection of human immature oocytes destined for in vitro maturation (IVM) is performed according to their cumulus-oocyte complex (COC) morphology. In animal models, oocyte pre-selection with brilliant cresyl blue (BCB) staining improves fertilization and blastocyst rates and even increases the number of calves born. As the granulosa cells and cumulus cells (GCs and CCs) have a close relationship with the oocyte and are available in in vitro fertilization (IVF) programs, applying BCB staining to these cells may help to elucidate whether BCB shows toxicity to human oocytes and to determine the safest protocol for this dye. GCs and CCs were isolated from 24 patients who underwent controlled ovarian stimulation. After 48 h, cells were exposed to: Dulbecco's Modified Eagle Medium (DMEM) with or without phenol red, DPBS and mDPBS for 60 min; 13, 20 and 26 μM BCB for 60 min; and 60, 90 or 120 min to 13 μM BCB. Cellular viability was tested using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) and trypan blue assays. The 20 and 26 μM BCB exposures resulted in lower cell viability, similar to when cells were exposed to BCB for 90 or 120 min. GCs and CCs viabilities were equal among control group and 13 μM BCB group after 60 min. BCB staining was not toxic to GCs and CCs when the regime of 13 μM BCB for 60 min was used. Due to the close molecular/biochemical relationship between these cells and the gamete, we propose that it is unlikely that the use of BCB could interfere with the viability/health of human oocytes. PMID:25921213

  17. Entrainment rates at the tops of laboratory analogs of cumulus and stratocumulus clouds

    NASA Astrophysics Data System (ADS)

    Górska, Anna; Malinowski, Szymon P.; Fugal, Jacob

    2015-04-01

    We investigate entrainment at tops of laboratory analogs of convective clouds: cumulus and stratocumulus. Cloudy saturated moist air (T ~22 °C) containing droplets of diameters of ~3-10 μm, is introduced into a laboratory cloud chamber of dimensions of 1.0×1.0×1.8 through an opening in the bottom wall. Initialy cloudy air fills ~60 cm thick layer at the bottom. Mixing between the cloud and unsaturated air above (T ~22 °C, RH ~35 %) results in evaporative cooling triggering convection which, in turn, leads to formation of a well mixed layer capperd with a temperature inversion. The temperature jump is about 2 °C within ~30 cm deep layer. Then updrafts are forced through a 30cm high tube extending from the bottom of the chamber. "Strong' updrafts which penetrate the whole inversion layer mimic overshooting cumulus clouds while "weak' updrafts diverging under the inversion simulate stratocumulus clouds. We use a laser sheet technique to image two-dimensional cross sections through the clouds. A specially developed mutiscale Particle Image Velicimetry (PIV) algorithm allows to retrieve 2D velocity fields. Suitable image processing allows to determine cloud-clear air interface in the images. Extracting velocities of cloudy (ui) and environmental (ua) air on both sides of the interface allows us calculate entrainment / detrainment rates: E = -ρa(ua - ui) - entrainment rate D = ρa(ua - ui) - detrainment rate. On the poster we will present fine structures of entraimnet/dertaiment process and discuss similarities and differences in both investigated types of clouds.

  18. Safety of brilliant cresyl blue staining protocols on human granulosa and cumulus cells.

    PubMed

    Alcoba, Diego Duarte; Conzatti, Maiara; Ferreira, Gustavo Dias; Pimentel, Anita Mylius; Kussler, Ana Paula; Capp, Edison; von Eye Corleta, Helena; Brum, Ilma Simoni

    2016-02-01

    The selection of human immature oocytes destined for in vitro maturation (IVM) is performed according to their cumulus-oocyte complex (COC) morphology. In animal models, oocyte pre-selection with brilliant cresyl blue (BCB) staining improves fertilization and blastocyst rates and even increases the number of calves born. As the granulosa cells and cumulus cells (GCs and CCs) have a close relationship with the oocyte and are available in in vitro fertilization (IVF) programs, applying BCB staining to these cells may help to elucidate whether BCB shows toxicity to human oocytes and to determine the safest protocol for this dye. GCs and CCs were isolated from 24 patients who underwent controlled ovarian stimulation. After 48 h, cells were exposed to: Dulbecco's Modified Eagle Medium (DMEM) with or without phenol red, DPBS and mDPBS for 60 min; 13, 20 and 26 μM BCB for 60 min; and 60, 90 or 120 min to 13 μM BCB. Cellular viability was tested using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) and trypan blue assays. The 20 and 26 μM BCB exposures resulted in lower cell viability, similar to when cells were exposed to BCB for 90 or 120 min. GCs and CCs viabilities were equal among control group and 13 μM BCB group after 60 min. BCB staining was not toxic to GCs and CCs when the regime of 13 μM BCB for 60 min was used. Due to the close molecular/biochemical relationship between these cells and the gamete, we propose that it is unlikely that the use of BCB could interfere with the viability/health of human oocytes.

  19. Small RNA profile of the cumulus-oocyte complex and early embryos in the pig.

    PubMed

    Yang, Cai-Xia; Du, Zhi-Qiang; Wright, Elane C; Rothschild, Max F; Prather, Randall S; Ross, Jason W

    2012-11-01

    Small RNA represent several unique noncoding RNA classes that have important function in the development of germ cells and early embryonic development. Deep sequencing was performed on small RNA from cumulus cells (recovered from germinal vesicle [GV] and metaphase II-arrested [MII] oocytes), GV and MII oocytes, in vitro fertilization-derived embryos at 60 h postfertilization (4- to 8-cell stage), and Day 6 blastocysts. Additionally, a heterologous miRNA microarray method was also used to identify miRNA expressed in the oocyte during in vitro maturation. Similar to the results of expression analysis of other species, these data demonstrate dynamic expression regulation of multiple classes of noncoding RNA during oocyte maturation and development to the blastocyst stage. Mapping small RNA to the pig genome indicates dynamic distribution of small RNA organization across the genome. Additionally, a cluster of miRNA and Piwi-interacting RNA (piRNA) was discovered on chromosome 6. Many of the small RNA mapped to annotated repetitive elements in the pig genome, of which the SINE/tRNA-Glu and LINE/L1 elements represented a large proportion. Two piRNA (piR84651 and piR16993) and seven miRNA (MIR574, MIR24, LET7E, MIR23B, MIR30D, MIR320, and MIR30C) were further characterized using quantitative RT-PCR. Secretory carrier membrane protein 4 (SCAMP4) was predicted to be subject to posttranscriptional gene regulation mediated by small RNA, by annotating small RNA reads mapped to exonic regions in the pig genome. Consistent with the prediction results, SCAMP4 was further confirmed to be differentially expressed at both transcriptional and translational levels. These data establish a small RNA expression profile of the pig cumulus-oocyte complex and early embryos and demonstrate their potential capacity to be utilized for predictions of functional posttranscriptional regulatory events.

  20. Measurements of cloud condensation nuclei spectra within maritime cumulus cloud droplets: Implications for mixing processes

    NASA Technical Reports Server (NTRS)

    Twohy, Cynthia H.; Hudson, James G.

    1995-01-01

    In a cloud formed during adiabatic expansion, the droplet size distribution will be systematically related to the critical supersaturation of the cloud condensation nuclei (CNN), but this relationship can be complicated in entraining clouds. Useful information about cloud processes, such as mixing, can be obtained from direct measurements of the CNN involved in droplet nucleation. This was accomplished by interfacing two instruments for a series of flights in maritime cumulus clouds. One instrument, the counterflow virtual impactor, collected cloud droplets, and the nonvolatile residual nuclei of the droplets was then passed to a CCN spectrometer, which measured the critical supersaturation (S(sub c)) spectrum of the droplet nuclei. The measured S(sub c) spectra of the droplet nuclei were compared with the S(sub c) spectra of ambient aerosol particles in order to identify which CCN were actually incorporated into droplets and to determine when mixing processes were active at different cloud levels. The droplet nuclei nearly always exhibited lower median S(sub c)'s than the ambient aerosol, as expected since droplets nucleate perferentially on particles with lower critical supersaturations. Critical supersaturation spectra from nuclei of droplets near cloud base were similar to those predicted for cloud regions formed adiabatically, but spectra of droplet nuclei from middle cloud levels showed some evidence that mixing had occurred. Near cloud top, the greatest variation in the spectra of the droplet nuclei was observed, and nuclei with high S(sub c)'s were sometimes present even within relatively large droplets. This suggests that the extent of mixing increases with height in cumulus clouds and that inhomogeneous mixing may be important near cloud top. These promising initial results suggest improvements to the experimental technique that will permit more quantitative results in future experiments.

  1. Theoretical modeling of relative humidity on contact electrification of sand particles

    PubMed Central

    Zheng, XiaoJing; Zhang, Rui; Huang, HaoJie

    2014-01-01

    Contact electrification of identical insulating particles has crucial significance for industrial and environmental science, especially in wind-blown granular systems. At the same time, the experimental phenomena of charge transfer first increased and then decreased with the increase of relative humidity has attracted the interest of many researchers. Humidity can affect the charge transfer has been early observed in the experiment, but the reason always puzzles researchers. In this study, based on trapped high-energy electron transfer mechanism, we introduce the effect of the water film in the charge transfer model and consider the actual situations of the sand particles in the collision process. Furthermore, charge transfer between sand particles in a single collision under different humidity conditions is investigated. The predicted results agree well with the law obtained in existing experiments qualitatively and thereby a possible explanation why humidity can affect the charge transfer is given. PMID:24637964

  2. Final environmental impact statement/report and 4(f) statement. Volume 1. Northeast corridor improvement project electrification: New Haven, CT to Boston, MA. Final report

    SciTech Connect

    1994-10-31

    This document is the final environmental impact statement and final environmental impact report (FEIS/R) on the proposal by the National Railroad Passenger Corporation (Amtrak) to complete the electrification of the Northeast Corridor main line by extending electric traction from New Haven, CT, to Boston, MA. This document (Volume I) is the main body of the FEIS/R and includes a 4(f) Statement on the proposed location of an electrification facility in the Great Swamp Wildlife Management Area.

  3. Cloud electrification and lightning activity in a tropical cyclone-like vortex

    NASA Astrophysics Data System (ADS)

    Barthe, C.; Hoarau, T.; Bovalo, C.

    2016-11-01

    In this study, a high resolution simulation of an electrified tropical cyclone-like vortex was performed with the French mesoscale model Meso-NH coupled to an explicit electrical scheme. The objective was to analyze how graupel characteristics could influence the occurrence of lightning flashes in tropical cyclones. Two simulations were run: a control simulation using a 1-moment mixed phase bulk microphysical scheme, and a second simulation in which the parameters used to describe the graupel mass-diameter and fall speed-diameter relationships were modified to obtain smaller graupel fall speeds. Decreasing the graupel fall speed (vg) resulted in a weaker storm with a larger radius of maximum winds. For both simulated tropical cyclones, a deep mixed phase layer conducive to cloud electrification was observed. However, in the simulation where vg was decreased, the flash rate was almost zero throughout the simulation, whereas it reached a few flashes per minute in the control simulation. Several reasons that can explain this difference in the total flash rate are highlighted. Decreasing vg resulted in graupel being spread horizontally over a broader area by the secondary circulation. The more pronounced tilting observed with slower vg meant that poles of charges were not vertically aligned and thus the vertical electric field was reduced. In this study, the difference in the total flash rate mainly arose from changes in the mass and charge transfer rates due to changes in the parameters used to define the mass-diameter and particle-diameter relationships. Cloud electrification and lightning flashes being threshold-processes, a small change in the model physics can have a dramatic impact on the total flash rate.

  4. Transportation Electrification

    SciTech Connect

    Schwendeman, Lawrence; Crouch, Alan

    2013-12-17

    This project has accomplished the following objectives: to address the critical need for technician training in new and emerging propulsion technologies by developing new courses, including information and training on electric vehicles, plug-in hybrid electric vehicles, and fuel cell vehicles; to integrate the new certificate with the existing Associate of Applied Science Degree and Certificate automotive degrees; to disseminate these leading edge courses throughout the Commonwealth of Virginia and neighboring Mid-Atlantic States; and to provide training opportunities for displaced workers and underrepresented populations seeking careers in the automotive industry.

  5. Energy solutions in rural Africa: mapping electrification costs of distributed solar and diesel generation versus grid extension

    NASA Astrophysics Data System (ADS)

    Szabó, S.; Bódis, K.; Huld, T.; Moner-Girona, M.

    2011-07-01

    Three rural electrification options are analysed showing the cost optimal conditions for a sustainable energy development applying renewable energy sources in Africa. A spatial electricity cost model has been designed to point out whether diesel generators, photovoltaic systems or extension of the grid are the least-cost option in off-grid areas. The resulting mapping application offers support to decide in which regions the communities could be electrified either within the grid or in an isolated mini-grid. Donor programs and National Rural Electrification Agencies (or equivalent governmental departments) could use this type of delineation for their program boundaries and then could use the local optimization tools adapted to the prevailing parameters. The views expressed in this paper are those of the authors and do not necessarily represent European Commission and UNEP policy.

  6. Design and Implementation of Improved Electronic Load Controller for Self-Excited Induction Generator for Rural Electrification.

    PubMed

    Kathirvel, C; Porkumaran, K; Jaganathan, S

    2015-01-01

    This paper offers an alternative technique, namely, Improved Electronic Load Controller (IELC), which is proposal to improve power quality, maintaining voltage at frequency desired level for rural electrification. The design and development of IELC are considered as microhydroenergy system. The proposed work aims to concentrate on the new schemes for rural electrification with the help of different kinds of hybrid energy systems. The objective of the proposed scheme is to maintain the speed of generation against fluctuating rural demand. The Electronic Load Controller (ELC) is used to connect and disconnect the dump load during the operation of the system, and which absorbs the load when consumer are not in active will enhance the lifestyle of the rural population and improve the living standards. Hydroelectricity is a promising option for electrification of remote villages in India. The conventional methods are not suitable to act as standalone system. Hence, the designing of a proper ELC is essential. The improved electronic load control performance tested with simulation at validated through hardware setup. PMID:26783553

  7. Design and Implementation of Improved Electronic Load Controller for Self-Excited Induction Generator for Rural Electrification

    PubMed Central

    Kathirvel, C.; Porkumaran, K.; Jaganathan, S.

    2015-01-01

    This paper offers an alternative technique, namely, Improved Electronic Load Controller (IELC), which is proposal to improve power quality, maintaining voltage at frequency desired level for rural electrification. The design and development of IELC are considered as microhydroenergy system. The proposed work aims to concentrate on the new schemes for rural electrification with the help of different kinds of hybrid energy systems. The objective of the proposed scheme is to maintain the speed of generation against fluctuating rural demand. The Electronic Load Controller (ELC) is used to connect and disconnect the dump load during the operation of the system, and which absorbs the load when consumer are not in active will enhance the lifestyle of the rural population and improve the living standards. Hydroelectricity is a promising option for electrification of remote villages in India. The conventional methods are not suitable to act as standalone system. Hence, the designing of a proper ELC is essential. The improved electronic load control performance tested with simulation at validated through hardware setup. PMID:26783553

  8. Aerosol-Cloud microphysical closure in warm tropical cumulus during CRYSTAL-FACE

    NASA Astrophysics Data System (ADS)

    Conant, W. C.; Lu, M.; Vanreken, T.; Rissman, T.; Varutbangkul, V.; Jonsson, H. H.; Nenes, A.; Jimenez, J. L.; Delia, A. E.; Bahreini, R.; Roberts, G. C.; Flagan, R. C.; Seinfeld, J. H.

    2002-12-01

    We present a closure study between aerosol and warm-cloud microphysics using field data collected during the NASA CRYSTAL-FACE campaign. CRYSTAL-FACE was conducted in continental and marine environments near southern Florida in July, 2002. Detailed profiles of thirteen cumulus clouds were made by the CIRPAS Twin Otter aircraft, which was equipped with four aerosol sizing systems, two CCN counters operated at 0.4% and 0.7% supersaturation, an Aerodyne aerosol mass spectrometer, a MOUDI filter sampler system, two cloud drop sizing probes, and two turbulence probes. A wide range of CCN (300 to >3500 cm-3) and cloud drop concentrations (200 to >1600 cm-3) provides an ideal case study for aerosol-cloud interactions and the first and second indirect effects. Vertical characterization of the young and mature cumulus clouds are obtained from multiple horizontal passes from below cloud base to cloud top. A detailed adiabatic cloud activation model accurately predicts the cloud drop concentration 100 m above cloud base. The model is constrained by observed updraft velocity and below-cloud aerosol properties (i.e. concentration, size distribution, composition, and supersaturation spectrum). Each cloud contains a core often exceeding 500 m in height in which the equivalent potential temperature follows a moist-adiabatic vertical profile. Effective radius most often follows an adiabatic profile, even in regions where liquid water content and/or equivalent potential temperature are sub-adiabatic. Large cloud-to-cloud variations in the vertical profile of effective radius are primarily driven by below-cloud aerosol concentration and to a lesser degree by cloud dynamics (i.e. vertical velocity). Six of the thirteen clouds are simulated using the RAMS large-eddy-simulation model. RAMS is integrated with bulk and bin microphysical models and is coupled to an offline 3-D radiative transfer model to study the aerosol effects on cloud microphysics and radiative properties. More

  9. Tropical Cumulus Convection and Upward Propagating Waves in Middle Atmospheric GCMs

    NASA Technical Reports Server (NTRS)

    Horinouchi, T.; Pawson, S.; Shibata, K.; Langematz, U.; Manzini, E.; Giorgetta, M. A.; Sassi, F.; Wilson, R. J.; Hamilton, K. P.; deGranpre, J.; Atlas, Robert (Technical Monitor)

    2002-01-01

    It is recognized that the resolved tropical wave spectrum can vary considerably between general circulation models (GCMs) and that these differences can have an important impact on the simulated climate. A comprehensive comparison of the waves is presented for the December-January-February period using high-frequency (three-hourly) data archives from eight GCMs and one simple model participating in the GCM Reality Intercomparison Project for SPARC (GRIPS). Quantitative measures of the structure and causes of the wavenumber-frequency structure of resolved waves and their impacts on the climate are given. Space-time spectral analysis reveals that the wave spectrum throughout the middle atmosphere is linked to variability of convective precipitation, which is determined by the parameterized convection. The variability of the precipitation spectrum differs by more than an order of magnitude between the models, with additional changes in the spectral distribution (especially the frequency). These differences can be explained primarily by the choice of different, cumulus par amet erizations: quasi-equilibrium mass-flux schemes tend to produce small variability, while the moist-convective adjustment scheme is most active. Comparison with observational estimates of precipitation variability suggests that the model values are scattered around the truth. This result indicates that a significant portion of the forcing of the equatorial quasi-biennial oscillation (QBO) is provided by waves with scales that are not resolved in present-day GCMs, since only the moist convective adjustment scheme (which has the largest transient variability) can force a QBO in models that have no parameterization of non-stationary gravity waves. Parameterized cumulus convection also impacts the nonmigrating tides in the equatorial region. In most of the models, momentum transport by diurnal nonmigrating tides in the mesosphere is larger than that by Kelvin waves, being more significant than has

  10. Competence Classification of Cumulus and Granulosa Cell Transcriptome in Embryos Matched by Morphology and Female Age

    PubMed Central

    Thuesen, Lea Langhoff; Andersen, Claus Yding; Nyboe-Andersen, Anders; Ziebe, Søren; Winther, Ole; Grøndahl, Marie Louise

    2016-01-01

    Objective By focussing on differences in the mural granulosa cell (MGC) and cumulus cell (CC) transcriptomes from follicles resulting in competent (live birth) and non-competent (no pregnancy) oocytes the study aims on defining a competence classifier expression profile in the two cellular compartments. Design: A case-control study. Setting: University based facilities for clinical services and research. Patients: MGC and CC samples from 60 women undergoing IVF treatment following the long GnRH-agonist protocol were collected. Samples from 16 oocytes where live birth was achieved and 16 age- and embryo morphology matched incompetent oocytes were included in the study. Methods MGC and CC were isolated immediately after oocyte retrieval. From the 16 competent and non-competent follicles, mRNA was extracted and expression profile generated on the Human Gene 1.0 ST Affymetrix array. Live birth prediction analysis using machine learning algorithms (support vector machines) with performance estimation by leave-one-out cross validation and independent validation on an external data set. Results We defined a signature of 30 genes expressed in CC predictive of live birth. This live birth prediction model had an accuracy of 81%, a sensitivity of 0.83, a specificity of 0.80, a positive predictive value of 0.77, and a negative predictive value of 0.86. Receiver operating characteristic analysis found an area under the curve of 0.86, significantly greater than random chance. When applied on 3 external data sets with the end-point outcome measure of blastocyst formation, the signature resulted in 62%, 75% and 88% accuracy, respectively. The genes in the classifier are primarily connected to apoptosis and involvement in formation of extracellular matrix. We were not able to define a robust MGC classifier signature that could classify live birth with accuracy above random chance level. Conclusion We have developed a cumulus cell classifier, which showed a promising performance on

  11. Effects of needle tip bevel and aspiration procedure on the morphology and developmental capacity of bovine compact cumulus oocyte complexes.

    PubMed

    Bols, P E; Ysebaert, M T; Van Soom, A; de Kruif, A

    1997-04-15

    Effects of the needle tip bevel and the aspiration procedure on the morphology of cumulusoocyte-complexes (COCs) and the developmental capacity of the oocytes after IVF were studied in 2 in vitro oocyte pick-up (OPU) simulations using a disposable ovum pick-up needle guidance system. In Experiment 1, the influence of the length of the needle bevel was investigated using a short and a long bevelled 20-g disposable needle. After being aspirated from slaughterhouse ovaries, the retrieved COCs were divided into 3 categories: 1) oocytes surrounded by a compact cumulus, 2) oocytes with an expanded cumulus, 3) partially naked oocytes. In Experiment 2, the influence of 5 different levels of aspiration vacuum for 3 different needle diameters (18-g, 19-g, 20-g) and 2 different needle bevels (long, short) was tested on the recovery and on the morphology of the cumulus investment of a fixed number of previously scored compact cumulus oocytes complexes (CCOCs), retrieved after slicing slaughterhouse ovaries. The re-retrieved COCs were allocated to Categories 1 and 3. The results show that the length of the needle bevel has a significant effect on oocyte recovery, in favor of the long-bevelled needle. As soon as higher aspiration vacua are used, a decrease of the number of CCOCs can be observed, which is less prominent for the short-bevelled needle compared to the long-bevelled one. The final number of blastocysts is similar for both needle types. In Experiment 2, the disposable needle system proved to be highly effective since nearly 80% of the CCOCs were retrieved. At low aspiration vacuum, up to 90% of the CCOCs withstand the aspiration procedure undamaged. Increasing the aspiration vacuum results in a decrease of the number of CCOCs, which is less pronounced using thinner needles. Averaged over all needle types, the prevalence of blastocysts expressed relative to the number of recovered oocytes decreases with higher aspiration vacuum. PMID:16728071

  12. The Effect of Cumulus Cloud Field Anisotropy on Domain-Averaged Solar Fluxes and Atmospheric Heating Rates

    NASA Technical Reports Server (NTRS)

    Hinkelman, Laura M.; Evans, K. Franklin; Clothiaux, Eugene E.; Ackerman, Thomas P.; Stackhouse, Paul W., Jr.

    2006-01-01

    Cumulus clouds can become tilted or elongated in the presence of wind shear. Nevertheless, most studies of the interaction of cumulus clouds and radiation have assumed these clouds to be isotropic. This paper describes an investigation of the effect of fair-weather cumulus cloud field anisotropy on domain-averaged solar fluxes and atmospheric heating rate profiles. A stochastic field generation algorithm was used to produce twenty three-dimensional liquid water content fields based on the statistical properties of cloud scenes from a large eddy simulation. Progressively greater degrees of x-z plane tilting and horizontal stretching were imposed on each of these scenes, so that an ensemble of scenes was produced for each level of distortion. The resulting scenes were used as input to a three-dimensional Monte Carlo radiative transfer model. Domain-average transmission, reflection, and absorption of broadband solar radiation were computed for each scene along with the average heating rate profile. Both tilt and horizontal stretching were found to significantly affect calculated fluxes, with the amount and sign of flux differences depending strongly on sun position relative to cloud distortion geometry. The mechanisms by which anisotropy interacts with solar fluxes were investigated by comparisons to independent pixel approximation and tilted independent pixel approximation computations for the same scenes. Cumulus anisotropy was found to most strongly impact solar radiative transfer by changing the effective cloud fraction, i.e., the cloud fraction when the field is projected on a surface perpendicular to the direction of the incident solar beam.

  13. Expression of bone morphogenetic proteins and receptors in porcine cumulus-oocyte complexes during in vitro maturation.

    PubMed

    Zhu, Guiyu; Guo, Bingran; Pan, Dengke; Mu, Yulian; Feng, Shutang

    2008-03-01

    In vitro oocyte growth is the essential technology which enables oocytes to achieve maturation and acquire the competence for subsequent manipulation. There is increasing evidence that members of the transforming growth factor-beta (TGF-beta) superfamily are expressed in a variety of cell types within the ovary in a developmental stage-related manner and function as crucial factors in oocyte growth and follicular development. However, the expression of TGF-beta family members has been studied extensively in follicular compartment cells in the ovaries while poorly explored in the cumulus-oocytes complex (COC) within culture systems. Using semi-quantitative RT-PCR, we investigated the temporal and spatial expression patterns of several bone morphogenetic proteins (BMP-4, BMP-6, BMP-15 and GDF-9), as well as BMP receptors (BMPRIA, BMPRIB, BMPRII and ActRII), in porcine COCs throughout in vitro maturation (IVM). In oocytes, the transcription of BMP-6, BMP-15, GDF-9 and BMPRII were down-regulated, while BMP-4, BMPRIA and BMPRIB remained unchanged during IVM. In cumulus cells, BMP-4 mRNA expression increased significantly, while BMP-6 and ActRII was down-regulated during IVM. Nevertheless, mRNAs of BMPRIA, BMPRIB and BMPRII were constantly expressed in cumulus cells in the process. However, BMP-15 was absent in cumulus cells and ActRII was not detected in oocytes. In addition, hardly any transcription of BMP-2, BMP-5, BMP-7, ActRIA was found in porcine COCs throughout IVM. These data demonstrate a complex BMP-signaling system for member gene expression within porcine COCs during IVM and indicate the need for further functional characterization of these factors during oocyte maturation.

  14. Simulation of the Summer Monsoon Rainfall over East Asia using the NCEP GFS Cumulus Parameterization at Different Horizontal Resolutions

    SciTech Connect

    Lim, Kyo-Sun; Hong, Song You; Yoon, Jin-Ho; Han, Jongil

    2014-10-01

    The most recent version of Simplified Arakawa-Schubert (SAS) cumulus scheme in National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) (GFS SAS) has been implemented into the Weather and Research Forecasting (WRF) model with a modification of triggering condition and convective mass flux to become depending on model’s horizontal grid spacing. East Asian Summer Monsoon of 2006 from June to August is selected to evaluate the performance of the modified GFS SAS scheme. Simulated monsoon rainfall with the modified GFS SAS scheme shows better agreement with observation compared to the original GFS SAS scheme. The original GFS SAS scheme simulates the similar ratio of subgrid-scale precipitation, which is calculated from a cumulus scheme, against total precipitation regardless of model’s horizontal grid spacing. This is counter-intuitive because the portion of resolved clouds in a grid box should be increased as the model grid spacing decreases. This counter-intuitive behavior of the original GFS SAS scheme is alleviated by the modified GFS SAS scheme. Further, three different cumulus schemes (Grell and Freitas, Kain and Fritsch, and Betts-Miller-Janjic) are chosen to investigate the role of a horizontal resolution on simulated monsoon rainfall. The performance of high-resolution modeling is not always enhanced as the spatial resolution becomes higher. Even though improvement of probability density function of rain rate and long wave fluxes by the higher-resolution simulation is robust regardless of a choice of cumulus parameterization scheme, the overall skill score of surface rainfall is not monotonically increasing with spatial resolution.

  15. Prolactin and growth hormone affect metaphase-II chromosomes in aging oocytes via cumulus cells using similar signaling pathways

    PubMed Central

    Lebedeva, Irina Y.; Singina, Galina N.; Lopukhov, Alexander V.; Shedova, Ekaterina N.; Zinovieva, Natalia A.

    2015-01-01

    General senescence of the adult organism is closely connected with reproductive one. Meanwhile, the age-related reduction in the female fertility is primarily associated with a decline in the gamete quality. Molecular and cellular changes in oocytes of old mammalian females are very similar to those occurring during aging of matured ova of their young counterparts, suggesting similarities in underlying mechanisms. The aim of the present work was to study actions of two related pituitary hormones, prolactin (PRL) and growth hormone (GH), on age-associated modifications of metaphase-II (M-II) chromosomes in bovine oocytes using a model of the prolonged culture. We analyzed: (1) effects of PRL and GH on abnormal changes in the chromosome morphology in aging matured oocytes and the role of cumulus cells in these effects and (2) signaling pathways involved in the hormone actions. During the prolonged culture of oocytes, a gradual rise in the frequency of destructive modifications of M-II chromosomes was revealed. In the case of cumulus-enclosed oocytes (CEOs), PRL and GH exerted dose-dependent biphasic effects on the frequency of these modifications. Both PRL (50 ng/ml) and GH (10 ng/ml) decelerated the abnormal chromosome changes in CEOs, but did not affect the chromosome configuration in denuded oocytes. Concurrently, the presence of PRL and GH receptors in cumulus cells surrounding matured oocytes was demonstrated. Attenuating effects of both hormones on the chromosome modifications in aging CEOs were abolished by PP2 (an inhibitor of Src-family tyrosine kinases), triciribine (an inhibitor of Akt kinase), and calphostin C (a protein kinase C inhibitor). Our findings indicate that PRL and GH can exert the similar decelerating action on age-associated alterations in the M-II chromosome morphology in bovine ova, which is mediated by cumulus cells and may be related to activation of Src-family tyrosine kinases as well as Akt- and protein kinase C-dependent signal

  16. Daily differential expression of melatonin-related genes and clock genes in rat cumulus-oocyte complex: changes after pinealectomy.

    PubMed

    Coelho, L A; Peres, R; Amaral, F G; Reiter, R J; Cipolla-Neto, J

    2015-05-01

    This study investigated the maturational stage (immature and mature ovaries) differences of mRNA expression of melatonin-forming enzymes (Aanat and Asmt), melatonin membrane receptors (Mt1 and Mt2) and putative nuclear (Rorα) receptors, and clock genes (Clock, Bmal1, Per1, Per2, Cry1, Cry2) in cumulus-oocyte complexes (COC) from weaning Wistar rats. We also examined the effects of pinealectomy and of melatonin pharmacological replacement on the daily expression of these genes in COC. qRT-PCR analysis revealed that in oocytes, the mRNA expression of Asmt, Mt2, Clock, Bmal1, Per2, and Cry1 were higher (P < 0.05) in immature ovaries than in the mature ones. In cumulus cells, the same pattern of mRNA expression for Asmt, Aanat, Rorα, Clock, Per1, Cry1, and Cry2 genes was observed. In oocytes, pinealectomy altered the daily mRNA expression profiles of Asmt, Mt1, Mt2, Clock, Per1, Cry1, and Cry2 genes. In cumulus cells, removal of the pineal altered the mRNA expression profiles of Mt1, Mt2, Rorα, Aanat, Asmt, Clock, Bmal1, Per2, Cry1, and Cry2 genes. Melatonin treatment partially or completely re-established the daily mRNA expression profiles of most genes studied. The mRNA expression of melatonin-related genes and clock genes in rat COC varies with the maturational stage of the meiotic cellular cycle in addition to the hour of the day. This suggests that melatonin might act differentially in accordance with the maturational stage of cumulus/oocyte complex. In addition, it seems that circulating pineal melatonin is very important in the design of the daily profile of mRNA expression of COC clock genes and genes related to melatonin synthesis and action.

  17. Bone morphogenetic protein 15 and fibroblast growth factor 10 enhance cumulus expansion, glucose uptake, and expression of genes in the ovulatory cascade during in vitro maturation of bovine cumulus-oocyte complexes.

    PubMed

    Caixeta, Ester S; Sutton-McDowall, Melanie L; Gilchrist, Robert B; Thompson, Jeremy G; Price, Christopher A; Machado, Mariana F; Lima, Paula F; Buratini, José

    2013-07-01

    Oocyte-secreted factors (OSFs) regulate differentiation of cumulus cells and are of pivotal relevance for fertility. Bone morphogenetic protein 15 (BMP15) and fibroblast growth factor 10 (FGF10) are OSFs and enhance oocyte competence by unknown mechanisms. We tested the hypothesis that BMP15 and FGF10, alone or combined in the maturation medium, enhance cumulus expansion and expression of genes in the preovulatory cascade and regulate glucose metabolism favouring hyaluronic acid production in bovine cumulus-oocyte complexes (COCs). BMP15 or FGF10 increased the percentage of fully expanded COCs, but the combination did not further stimulate it. BMP15 increased cumulus cell levels of mRNA encoding a disintegrin and metalloprotease 10 (ADAM10), ADAM17, amphiregulin (AREG), and epiregulin (EREG) at 12 h of culture and of prostaglandin (PG)-endoperoxide synthase 2 (PTGS2), pentraxin 3 (PTX3) and tumor necrosis factor alpha-induced protein 6 (TNFAIP6 (TSG6)) at 22 h of culture. FGF10 did not alter the expression of epidermal growth factor-like factors but enhanced the mRNA expression of PTGS2 at 4 h, PTX3 at 12 h, and TNFAIP6 at 22 h. FGF10 and BMP15 stimulated glucose consumption by cumulus cells but did not affect lactate production or levels of mRNA encoding glycolytic enzymes phosphofructokinase and lactate dehydrogenase A. Each growth factor increased mRNA encoding glucosamine:fructose-6-PO4 transaminases, key enzymes in the hexosamine pathway leading to hyaluronic acid production, and BMP15 also stimulated hyaluronan synthase 2 (HAS2) mRNA expression. This study provides evidence that BMP15 and FGF10 stimulate expansion of in vitro-matured bovine COCs by driving glucose metabolism toward hyaluronic acid production and controlling the expression of genes in the ovulatory cascade, the first acting upon ADAM10, ADAM17, AREG, and EREG and the second on downstream genes, particularly PTGS2.

  18. The electrification of Nova Scotia, 1884--1973: Technological modernization as a response to regional disparity

    NASA Astrophysics Data System (ADS)

    King, Lionel Bradley

    This dissertation investigates local attempts to use technology as a force for regional rehabilitation in the economically-depressed Maritime region of Canada. At the time of Confederation in 1867, the Maritime province of Nova Scotia was prosperous, progressive, and cultured. By the end of the 1910s, the province had entered a long period of economic and social decline. Recent historiography has shown that, far from passively accepting their fate, Nova Scotians and other Maritimers, actively resisted marginalization with political, cultural, or social action. The thesis expands upon that literature by exploring technology-based strategies of provincial rehabilitation using Thomas P. Hughes's systems perspective and David E. Nye's semiotic approach. In doing so, it applies methods from the social constructivist school of the history of technology to the larger concerns of Maritime Canadian historiography. In large part, the North American culture of technology determined the ways in which Nova Scotians applied technological solutions to provincial concerns. Technology has long been central to the Western idea of progress. As the "high technology" of the late nineteenth and early twentieth centuries, electricity reinforced that view: its ephemeral nature and silent efficiency led people to endow it with transformative, even mystical, powers. As a result, Nova Scotians, adopted a program of electrical modernization in the late 1910s as a remedy for regional disparity. The Nova Scotia government's first step was the creation of an Ontario-style hydroelectric commission designed to bring order to the province's fragmented and inefficient electrical network. Over the next few decades, the Nova Scotia Power Commission implemented rural electrification, home modernization, and regional system-building models that had already proven successful in Ontario and the United States. The system-building philosophies behind these programs were adapted to local conditions and

  19. Long-term Statistics of Continental Cumuli: Does Aerosol Trigger Cumulus Variability?

    SciTech Connect

    Kassianov, Evgueni I.; Berg, Larry K.; McFarlane, Sally A.; Flynn, Connor J.; Turner, David D.

    2009-02-01

    Atmospheric aerosols may control the formation, maintenance, and dissipation of cumuli by changing their microphysics. Recent observational and modeling results exist both in support and against strong potential impacts of aerosol [1-3]. Typically, the aerosol impact on water clouds has been investigated for regions with high aerosol loading and/or large atmospheric moisture [4]. Can we provide observational evidence of the aerosol-cloud relationship for a relatively dry continental region with low/moderate aerosol burden? To address this question, we revisit the aerosol-cloud relationship at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. In comparison with highly polluted regions, the SGP site is characterized by relatively small-to-moderate aerosol loading. Also, moisture content is small-to-moderate (compared to marine and coastal regions) for the SGP site. Because cumulus clouds have important impacts on climate forcing estimations [5] and are susceptible to aerosol effects [6], we focus on fair-weather cumuli (FWC) and their association with aerosol concentration and other potentially important factors. This association is investigated using a new 8-year aerosol and cloud climatology (2000-2007) developed with collocated and coincident surface and satellite observations.

  20. On the sensitivity of droplet size relative dispersion to warm cumulus cloud evolution

    NASA Astrophysics Data System (ADS)

    Tas, E.; Koren, I.; Altaratz, O.

    2012-07-01

    Relative dispersion (ɛ), defined as the ratio between cloud droplet size distribution width (σ) and cloud droplet average radius (), is a key factor used to parameterize various cloud processes in global circulation models (GCMs) and bulk microphysical scheme models (BSMs). Recent studies indicate that the impact of aerosol loading (N) and atmospheric thermodynamic conditions on ɛ are far from fully understood. Currently, a fixed value per hydrometeor type is used in most BSMs and GCMs, which imposes significant limitations on our ability to model and predict cloud processes and their impact on the environment, on regional to global scales. In this study, we use a detailed bin microphysics single cloud model to investigate the combined impact of atmospheric thermodynamic conditions and N on ɛ, in warm cumulus clouds. As initial conditions, we used different lapse-rates combined with 8 scenarios of aerosol loading, representing very clean (N = 25 cm-3) to heavily polluted (N = 1600 cm-3) conditions. Moreover, the results are analyzed per cloud evolutionary stage according to the dominance of microphysical processes. The use of this method indicated a different pattern of ɛ at each stage. Specifically, during the mature stage fitting of ɛ to rv is relatively resilient to changes in the environmental conditions. Such findings suggest a new view of the effect of aerosols on clouds, via changes in the cloud evolution patterns and a new approach to parameterization of ɛ based on rv, which can significantly improve the prediction of cloud processes by GCMs and BSMs.

  1. Quantifying the transport of subcloud layer reactants by shallow cumulus clouds over the Amazon

    NASA Astrophysics Data System (ADS)

    Ouwersloot, H. G.; Vilà-Guerau de Arellano, J.; van Stratum, B. J. H.; Krol, M. C.; Lelieveld, J.

    2013-12-01

    We investigate the vertical transport of atmospheric chemical reactants from the subcloud layer to the cumulus cloud layer driven by shallow convection over the Amazon during the dry season. The dynamical and chemical assumptions needed for mesoscale and global chemistry transport model parametrizations are systematically analyzed using a Large Eddy Simulation model. We quantify the mass flux transport contribution to the temporal evolution of reactants. Isoprene, a key atmospheric compound over the tropical rain forest, decreases by 8.5% h-1 on average and 15% h-1 at maximum due to mass‒flux‒induced removal. We apply mass flux parametrizations for the transport of chemical reactants and obtain satisfactory agreement with numerically resolved transport, except for some reactants like O3, NO, and NO2. The latter is caused by the local partitioning of reactants, influenced by UV radiation extinction by clouds and small‒scale variability of ambient atmospheric compounds. By considering the longer‒lived NOx (NO + NO2), the transport is well represented by the parametrization. Finally, by considering heterogeneous surface exchange conditions, it is demonstrated that the parametrizations are sensitive to boundary conditions due to changes in the boundary layer dynamics.

  2. From large-eddy simulation to multi-UAVs sampling of shallow cumulus clouds

    NASA Astrophysics Data System (ADS)

    Lamraoui, Fayçal; Roberts, Greg; Burnet, Frédéric

    2016-04-01

    In-situ sampling of clouds that can provide simultaneous measurements at satisfying spatio-temporal resolutions to capture 3D small scale physical processes continues to present challenges. This project (SKYSCANNER) aims at bringing together cloud sampling strategies using a swarm of unmanned aerial vehicles (UAVs) based on Large-eddy simulation (LES). The multi-UAV-based field campaigns with a personalized sampling strategy for individual clouds and cloud fields will significantly improve the understanding of the unresolved cloud physical processes. An extensive set of LES experiments for case studies from ARM-SGP site have been performed using MesoNH model at high resolutions down to 10 m. The carried out simulations led to establishing a macroscopic model that quantifies the interrelationship between micro- and macrophysical properties of shallow convective clouds. Both the geometry and evolution of individual clouds are critical to multi-UAV cloud sampling and path planning. The preliminary findings of the current project reveal several linear relationships that associate many cloud geometric parameters to cloud related meteorological variables. In addition, the horizontal wind speed indicates a proportional impact on cloud number concentration as well as triggering and prolonging the occurrence of cumulus clouds. In the framework of the joint collaboration that involves a Multidisciplinary Team (including institutes specializing in aviation, robotics and atmospheric science), this model will be a reference point for multi-UAVs sampling strategies and path planning.

  3. A model of the effect of cumulus clouds on the redistribution and transformation of pollutants

    NASA Astrophysics Data System (ADS)

    Cho, H. R.; Niewiadomski, M.; Iribarne, J. V.; Melo, O.

    1989-01-01

    A one-dimensional time-dependent cumulus model was developed to study the effects of convective clouds on air pollutants. The model contains two drafts, core and periphery, surrounded by a stagnant environment. There are exchanges between the two drafts and between cloud and environment, both by dynamic entrainment/detrainment and by turbulence. Application to a "base case" with given initial conditions and producing a cloud 7 km thick is analyzed. Microphysical exchanges involved mainly cloud water, rain, and graupel. The warm rain mechanism seems to dominate, including a frozen drop stage. At lower temperatures the ice mechanism is also effective. Only a minor fraction of the SO2 entering the cloud becomes oxidized and is partly rained out to the ground as sulfate. Although H2O2 is the main and faster oxidant, O3 also contributes in a rather large proportion. Oxidation of NOx with subsequent dissolution of the acids is negligible, unless the OH radical concentration in the air is very high. Production and deposition of acidity depends on SO2 concentration in a very nonlinear way, but approximately linearly on H2O2 concentration. The acidity concentration of precipitation varies substantially under different regions of the cloud. Consideration of solutes in solid phase is shown to appreciably influence the results. The model was also applied to small, 2-km-thick cumuli, and the results compared with those of a three-dimensional model and with observations, with reasonable agreement.

  4. Aging of recipient oocytes reduces the development of cloned embryos receiving cumulus cells.

    PubMed

    Liu, Guohui; Kato, Yoko; Tsunoda, Yukio

    2007-08-01

    Parthenogenetic activation is an important factor in successful production of cloned mammals. Because it has been reported that aged oocytes are more sensitive to parthenogenetic activation than young oocytes, the present study examined the effects of oocyte aging on the in vitro and in vivo developmental potential of nuclear-transferred (NT) mouse oocytes receiving cumulus cells. The potentials of young NT oocytes (14 h after human chorionic gonadotrophin [hCG] injection) to develop into blastocysts was, however, significantly higher than that of aged oocytes (20 h after hCG injection; 16% vs 6%). When the nuclei of NT oocytes at the 2-cell stage were fused with enucleated fertilized 2-cell embryos, the potentials of the serial NT embryos to develop into blastocysts were no different for both young and aged oocytes (74% vs 74%). Live young, however, were obtained only after transfer of serial NT blastocysts developed from young NT oocytes (2%). In contrast to a report using embryonic nuclei as the nuclear donors, the results of the present study indicate that young oocytes are superior to aged oocytes as a source of recipient cytoplasm for mouse somatic cell cloning. PMID:17389775

  5. Integrated cumulus ensemble and turbulence (ICET): An integrated parameterization system for general circulation models (GCMs)

    SciTech Connect

    Evans, J.L.; Frank, W.M.; Young, G.S.

    1996-04-01

    Successful simulations of the global circulation and climate require accurate representation of the properties of shallow and deep convective clouds, stable-layer clouds, and the interactions between various cloud types, the boundary layer, and the radiative fluxes. Each of these phenomena play an important role in the global energy balance, and each must be parameterized in a global climate model. These processes are highly interactive. One major problem limiting the accuracy of parameterizations of clouds and other processes in general circulation models (GCMs) is that most of the parameterization packages are not linked with a common physical basis. Further, these schemes have not, in general, been rigorously verified against observations adequate to the task of resolving subgrid-scale effects. To address these problems, we are designing a new Integrated Cumulus Ensemble and Turbulence (ICET) parameterization scheme, installing it in a climate model (CCM2), and evaluating the performance of the new scheme using data from Atmospheric Radiation Measurement (ARM) Program Cloud and Radiation Testbed (CART) sites.

  6. Transcriptomic Analysis and Meta-Analysis of Human Granulosa and Cumulus Cells

    PubMed Central

    Burnik Papler, Tanja; Vrtacnik Bokal, Eda; Maver, Ales; Kopitar, Andreja Natasa; Lovrečić, Luca

    2015-01-01

    Specific gene expression in oocytes and its surrounding cumulus (CC) and granulosa (GC) cells is needed for successful folliculogenesis and oocyte maturation. The aim of the present study was to compare genome-wide gene expression and biological functions of human GC and CC. Individual GC and CC were derived from 37 women undergoing IVF procedures. Gene expression analysis was performed using microarrays, followed by a meta-analysis. Results were validated using quantitative real-time PCR. There were 6029 differentially expressed genes (q < 10−4); of which 650 genes had a log2 FC ≥ 2. After the meta-analysis there were 3156 genes differentially expressed. Among these there were genes that have previously not been reported in human somatic follicular cells, like prokineticin 2 (PROK2), higher expressed in GC, and pregnancy up-regulated nonubiquitous CaM kinase (PNCK), higher expressed in CC. Pathways like inflammatory response and angiogenesis were enriched in GC, whereas in CC, cell differentiation and multicellular organismal development were among enriched pathways. In conclusion, transcriptomes of GC and CC as well as biological functions, are distinctive for each cell subpopulation. By describing novel genes like PROK2 and PNCK, expressed in GC and CC, we upgraded the existing data on human follicular biology. PMID:26313571

  7. Stratocumulus to Cumulus Transition Capped by a Light-Absorbing Smoke Layer

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Feingold, G.; Kazil, J.; McComiskey, A. C.

    2015-12-01

    Biomass burning aerosol emitted from Africa seasonally advects over the eastern Atlantic and forms a layer of light-absorbing smoke above stratocumulus clouds, which influences heating profiles, dynamics, and cloud microphysics. In this study, large-eddy simulation is used to investigate the effect of the absorbing smoke layer on the stratocumulus to cumulus transition (SCT). A prognostic absorbing smoke model incorporates humidity effects on optical properties, and is coupled with a two-moment bulk microphysics scheme and an interactive radiation code. Smoke both absorbs shortwave radiation and acts as cloud condensation nuclei (CCN). Simulations are of three day duration. The simulations assess sensitivity of the SCT to distance of the smoke layer from the cloud top, aerosol optical thickness and single scattering albedo, and precipitation. Our simulations show that 1) As a shortwave absorber, the smoke stabilizes the free atmosphere and strengthens the temperature jump at the boundary layer top, which limits entrainment; 2) Smoke helps evaporate cloud during daytime, which amplifies the diurnal cycle of cloud cover; 3) As a source of CCN, the entrained smoke suppresses rain formation, which inhibits precipitation-generated cloud breakup. The net effect of smoke is modification of heating profiles to limit the deepening of the planetary boundary layer, and suppression of precipitation. This leads to enhancement of the diurnal cycle of cloudiness but a delay in the SCT.

  8. Growth factors and extracellular matrix proteins in interactions of cumulus-oocyte complex, spermatozoa and oviduct.

    PubMed

    Einspanier, R; Gabler, C; Bieser, B; Einspanier, A; Berisha, B; Kosmann, M; Wollenhaupt, K; Schams, D

    1999-01-01

    The expression and localization of selected growth factor systems and extracellular matrix (ECM) components that may influence oocyte maturation and fertilization within the mammalian oviduct are reported. Fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) systems could be detected by use of RT-PCR, RNase protection assay (RPA) and immunohistochemistry in bovine follicles, bovine cumulus-oocyte complexes (COC) and bovine and marmoset oviducts. Two different subtypes of the FGF receptor (FGFR-1 and -2) were identified in distinct cell types, indicating a functional difference. A complete epidermal growth factor (EGF) system was found in the porcine, but not in the bovine, oviduct. There were additional differences between bovine and primate oviducts: FGF-1/2 and FGFR were increased in the marmoset around ovulation, in contrast to an increase in FGF-1 in the cow. Immunohistochemistry revealed accumulation and storage of FGF and VEGF on the surface of the epithelium, possibly due to their binding property on heparanglycoproteins. Other ECM components, matrix metalloproteinase 1 (MMP-1) and tissue inhibitor of metalloproteinase 1 (TIMP-1), were found to be modulated in the ovarian follicle, COC and oviduct during the cycle. An oviduct-mediated depletion of sperm surface proteins (BSP1-3) was discovered as well as a sperm-induced novel oviductal mRNA related to an anti-oxidant protein family. Associated systems of growth factors and ECM components can be suggested as paracrine or autocrine mediators during fertilization in a species-, cycle- and tissue-dependent manner.

  9. Higher SOD1 Gene Expression in Cumulus Cells From Infertile Women With Moderate and Severe Endometriosis.

    PubMed

    Donabela, Flávia Cappello; Meola, Juliana; Padovan, Cristiana Carolina; de Paz, Cláudia Cristina Paro; Navarro, Paula Andrea

    2015-11-01

    It is questioned whether worsening of oocyte quality and oxidative stress (OS) are involved in the pathogenesis of infertility related to endometriosis and in compromised intracytoplasmic sperm injection (ICSI) outcomes. Cumulus cells (CCs) protect oocytes from entering apoptosis induced by OS. Thus, we carried out a case-control study comparing expression of superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and glutathione peroxidase 4 (GPX4; genes encoding for the main antioxidant enzymes) in CCs from mature oocytes of 26 infertile patients with minimal/mild endometriosis, 14 patients with moderate/severe endometriosis, and 41 controls undergoing controlled ovarian stimulation for ICSI, using real-time polymerase chain reaction. As a secondary objective, we investigated the interaction between the expression of these genes and clinical pregnancy (CP) by a statistical model. Only infertile women with moderate/severe endometriosis showed increased expression of the SOD1 in CCs compared to women with minimal/mild endometriosis and controls, with a positive interaction between increased expression and the occurrence of CP, suggesting that SOD1 might be a potential biomarker of CP following ICSI.

  10. Comparative gene expression profiling in human cumulus cells according to ovarian gonadotropin treatments.

    PubMed

    Assou, Said; Haouzi, Delphine; Dechaud, Hervé; Gala, Anna; Ferrières, Alice; Hamamah, Samir

    2013-01-01

    In in vitro fertilization cycles, both HP-hMG and rFSH gonadotropin treatments are widely used to control human follicle development. The objectives of this study are (i) to characterize and compare gene expression profiles in cumulus cells (CCs) of periovulatory follicles obtained from patients stimulated with HP-hMG or rFSH in a GnRH antagonist cycle and (ii) to examine their relationship with in vitro embryo development, using Human Genome U133 Plus 2.0 microarrays. Genes that were upregulated in HP-hMG-treated CCs are involved in lipid metabolism (GM2A) and cell-to-cell interactions (GJA5). Conversely, genes upregulated in rFSH-treated CCs are implicated in cell assembly and organization (COL1A1 and COL3A1). Interestingly, some genes specific to each gonadotropin treatment (NPY1R and GM2A for HP-hMG; GREM1 and OSBPL6 for rFSH) were associated with day 3 embryo quality and blastocyst grade at day 5, while others (STC2 and PTX3) were related to in vitro embryo quality in both gonadotropin treatments. These genes may prove valuable as biomarkers of in vitro embryo quality. PMID:24151596

  11. The effect of cumulus cloud field anisotropy on solar radiative fluxes and atmospheric heating rates

    NASA Astrophysics Data System (ADS)

    Hinkelman, Laura M.

    The effect of fair-weather cumulus cloud field anisotropy on domain average surface fluxes and atmospheric heating profiles was studied. Causes of anisotropy were investigated using a large-eddy simulation (LES) model. Cloud formation under a variety of environmental conditions was simulated and the degree of anisotropy in the output fields was calculated. Wind shear was found to be the single greatest factor in the development of both vertically tilted and horizontally stretched cloud structures. A stochastic field generation algorithm was used to produce twenty three-dimensional liquid water content fields based on the statistical properties of the LES cloud scenes. Progressively greater degrees of tilt and stretching were imposed on each of these scenes, so that an ensemble of scenes were produced for each level of distortion. The resulting scenes were used as input to a three-dimensional Monte Carlo model. Domain-average transmission, reflection, and absorption of broadband solar radiation were computed for each scene along with the average heating rate profile. Both tilt and horizontal stretching were found to significantly affect calculated fluxes, with the amount and sign of flux differences depending strongly on sun position relative to cloud distortion geometry. For nearly all solar geometries, domain-averaged fluxes and atmospheric heating rate profiles calculated using the Independent Pixel Approximation differed substantially from the corresponding three-dimensional Monte Carlo results.

  12. Optimizing the Betts-Miller-Janjic cumulus parameterization with Intel Many Integrated Core (MIC) architecture

    NASA Astrophysics Data System (ADS)

    Huang, Melin; Huang, Bormin; Huang, Allen H.-L.

    2015-10-01

    The schemes of cumulus parameterization are responsible for the sub-grid-scale effects of convective and/or shallow clouds, and intended to represent vertical fluxes due to unresolved updrafts and downdrafts and compensating motion outside the clouds. Some schemes additionally provide cloud and precipitation field tendencies in the convective column, and momentum tendencies due to convective transport of momentum. The schemes all provide the convective component of surface rainfall. Betts-Miller-Janjic (BMJ) is one scheme to fulfill such purposes in the weather research and forecast (WRF) model. National Centers for Environmental Prediction (NCEP) has tried to optimize the BMJ scheme for operational application. As there are no interactions among horizontal grid points, this scheme is very suitable for parallel computation. With the advantage of Intel Xeon Phi Many Integrated Core (MIC) architecture, efficient parallelization and vectorization essentials, it allows us to optimize the BMJ scheme. If compared to the original code respectively running on one CPU socket (eight cores) and on one CPU core with Intel Xeon E5-2670, the MIC-based optimization of this scheme running on Xeon Phi coprocessor 7120P improves the performance by 2.4x and 17.0x, respectively.

  13. Electrification in winter storms and the analysis of thunderstorm overflight data

    NASA Technical Reports Server (NTRS)

    Brook, Marx

    1993-01-01

    We have been focusing our study of electrification in winter storms on the lightning initiation process, making inferences about the magnitude of the electric fields from the initial pulses associated with breakdown, i.e., with the formation of the initial streamers. The essence of the most significant finding is as follows: (1) initial breakdown radiation pulses from stepped leaders prior to the first return stroke are very large, reaching values of 20-30 Volts/meter, comparable to return stroke radiation; and (2) the duration of the stepped leader, from the initial detectable radiation pulse to the return stroke onset, is very-short-ranging from a minimum 1.5 ms to a maximum of 4.5 ms. This past summer (June-August of 1991) we participated in the CAPE program at the Kennedy Space Center in order to acquire data on stepped leaders in summer storms with the same equipment used to get the winter storm data. We discovered that the vigorous leaders seen in winter so frequently were present in summer storms, although not as large in amplitude and certainly not as frequent.

  14. Electrification of the transportation sector offers limited country-wide greenhouse gas reductions

    NASA Astrophysics Data System (ADS)

    Meinrenken, Christoph J.; Lackner, Klaus S.

    2014-03-01

    Compared with conventional propulsion, plugin and hybrid vehicles may offer reductions in greenhouse gas (GHG) emissions, regional air/noise pollution, petroleum dependence, and ownership cost. Comparing only plugins and hybrids amongst themselves, and focusing on GHG, relative merits of different options have been shown to be more nuanced, depending on grid-carbon-intensity, range and thus battery manufacturing and weight, and trip patterns. We present a life-cycle framework to compare GHG emissions for three drivetrains (plugin-electricity-only, gasoline-only-hybrid, and plugin-hybrid) across driving ranges and grid-carbon-intensities, for passenger cars, vans, buses, or trucks (well-to-wheel plus storage manufacturing). Parameter and model uncertainties are quantified via sensitivity analyses. We find that owing to the interplay of range, GHG/km, and portions of country-wide kms accessible to electrification, GHG reductions achievable from plugins (whether electricity-only or hybrids) are limited even when assuming low-carbon future grids. Furthermore, for policy makers considering GHG from electricity and transportation sectors combined, plugin technology may in fact increase GHG compared to gasoline-only-hybrids, regardless of grid-carbon-intensity.

  15. A study of wayside energy storage systems (WESS) for railway electrification

    SciTech Connect

    Turner, A.B.

    1984-05-01

    Results of a 1982 study of wayside energy storage systems (WESS) for railway electrification are summarized. The study was performed by SNC Inc. for the Transportation Development Center of Transport Canada (TDC). WESS introduces savings in the overall costs of the electric energy supplied to the catenary, by reducing the peak load seen by the utility and, if locomotive regeneration is available, the total energy demand. A number of energy storage systems were evaluated for near-term WESS applications. Two were found to be practicable: lead-acid batteries and steel flywheels. The required battery technology already exists and installations, existing or planned, approach the required levels of stored energy and power. For steel flywheels existing systems have available stored energy levels of less than one thirtieth of that required for WESS. Detailed engineering studies would be necessary to demonstrate that single wheel systems of the capacity required could be manufactured at reasonable cost. Budget estimates were derived for the combined installation and operating costs of battery and flywheel WESS. These were compared with the potential savings in the costs of electricity supply for a 20-year operating life, using average Canadian Utility rates and typical WESS parameters.

  16. Atmospheric Electrification in Dusty, Reactive Gases in the Solar System and Beyond

    NASA Astrophysics Data System (ADS)

    Helling, Christiane; Harrison, R. Giles; Honary, Farideh; Diver, Declan A.; Aplin, Karen; Dobbs-Dixon, Ian; Ebert, Ute; Inutsuka, Shu-ichiro; Gordillo-Vazquez, Francisco J.; Littlefair, Stuart

    2016-07-01

    Detailed observations of the solar system planets reveal a wide variety of local atmospheric conditions. Astronomical observations have revealed a variety of extrasolar planets none of which resembles any of the solar system planets in full. Instead, the most massive amongst the extrasolar planets, the gas giants, appear very similar to the class of (young) brown dwarfs which are amongst the oldest objects in the Universe. Despite this diversity, solar system planets, extrasolar planets and brown dwarfs have broadly similar global temperatures between 300 and 2500 K. In consequence, clouds of different chemical species form in their atmospheres. While the details of these clouds differ, the fundamental physical processes are the same. Further to this, all these objects were observed to produce radio and X-ray emissions. While both kinds of radiation are well studied on Earth and to a lesser extent on the solar system planets, the occurrence of emissions that potentially originate from accelerated electrons on brown dwarfs, extrasolar planets and protoplanetary disks is not well understood yet. This paper offers an interdisciplinary view on electrification processes and their feedback on their hosting environment in meteorology, volcanology, planetology and research on extrasolar planets and planet formation.

  17. Potential for widespread electrification of personal vehicle travel in the United States

    NASA Astrophysics Data System (ADS)

    Needell, Zachary A.; McNerney, James; Chang, Michael T.; Trancik, Jessika E.

    2016-09-01

    Electric vehicles can contribute to climate change mitigation if coupled with decarbonized electricity, but only if vehicle range matches travellers’ needs. Evaluating electric vehicle range against a population’s needs is challenging because detailed driving behaviour must be taken into account. Here we develop a model to combine information from coarse-grained but expansive travel surveys with high-resolution GPS data to estimate the energy requirements of personal vehicle trips across the US. We find that the energy requirements of 87% of vehicle-days could be met by an existing, affordable electric vehicle. This percentage is markedly similar across diverse cities, even when per capita gasoline consumption differs significantly. We also find that for the highest-energy days, other vehicle technologies are likely to be needed even as batteries improve and charging infrastructure expands. Car sharing or other means to serve this small number of high-energy days could play an important role in the electrification and decarbonization of transportation.

  18. Solar-Based Rural Electrification and Micro-Enterprise Development in Latin America: A Gender Analysis

    SciTech Connect

    Smith, J.

    2000-11-16

    Worldwide, an estimated 1.5 to 2 billion people do not have access to electricity, including 100 million in the Latin America region. Depending on the country, 30 to 90% of this unelectrified Latin American population lives in rural areas where geographic remoteness and low energy consumption patterns may preclude the extension of the conventional electricity grid. Women are heavily impacted by the energy scarcity given their role as primary energy procurers and users for the household, agricultural and small industrial subsectors in developing countries. As a result, women spend disproportionately more time engaged in energy-related activities like carrying water and searching for cooking fuel. This paper describes the use of decentralized renewable energy systems as one approach to meet the energy needs of rural areas in Latin America. It outlines the advantages of a decentralized energy paradigm to achieve international development goals, especially as they relate to women. The paper studies Enersol Associates, Inc.'s Solar-Based Rural Electrification model as an example of a decentralized energy program which has merged energy and development needs through the local involvement of energy entrepreneurs, non-governmental organizations and community members.

  19. Robust thin-film generator based on segmented contact-electrification for harvesting wind energy.

    PubMed

    Meng, Xian Song; Zhu, Guang; Wang, Zhong Lin

    2014-06-11

    Collecting and converting energy from ambient air flow promise to be a viable approach in developing self-powered autonomous electronics. Here, we report an effective and robust triboelectric generator that consists of an undulating thin-film membrane and an array of segmented fine-sized electrode pairs on a single substrate. Sequential processes of contact electrification and electrostatic induction generate alternating flows of free electrons when the membrane interacts with ambient air flow. Based on an optimum rational design, the segmented electrodes play an essential role in boosting the output current, leading to an enhancement of over 500% compared to the structure without the segmentation. The thin-film based generator can simultaneously and continuously light up tens of commercial light-emitting diodes. Moreover, it possesses exceptional durability, providing constant electric output after millions of operation cycles. This work offers a truly practical solution that opens the avenue to take advantage of wind energy by using the triboelectric effect. PMID:24824071

  20. Assessment of the Electrification of the Road Transport Sector on Net System Emissions

    NASA Astrophysics Data System (ADS)

    Miller, James

    As worldwide environmental consciousness grows, electric vehicles (EVs) are becoming more common and despite the incredible potential for emissions reduction, the net emissions of the power system supply side plus the transportation system are dependent on the generation matrix. Current EV charging patterns tend to correspond directly with the peak consumption hours and have the potential to increase demand sharply allowing for only a small penetration of Electric Vehicles. Using the National Household Travel Survey (NHTS) data a model is created for vehicle travel patterns using trip chaining. Charging schemes are modeled to include uncontrolled residential, uncontrolled residential/industrial charging, optimized charging and optimized charging with vehicle to grid discharging. A charging profile is then determined based upon the assumption that electric vehicles would directly replace a percentage of standard petroleum-fueled vehicles in a known system. Using the generation profile for the specified region, a unit commitment model is created to establish not only the generation dispatch, but also the net CO2 profile for variable EV penetrations and charging profiles. This model is then used to assess the impact of the electrification of the road transport sector on the system net emissions.

  1. Stress Induced Mechano-electrical Writing-Reading of Polymer Film Powered by Contact Electrification Mechanism.

    PubMed

    Goswami, Sumita; Nandy, Suman; Calmeiro, Tomás R; Igreja, Rui; Martins, Rodrigo; Fortunato, Elvira

    2016-01-01

    Mechano-electrical writing and reading in polyaniline (PANI) thin film are demonstrated via metal-polymer contact electrification mechanism (CEM). An innovative conception for a non-destructive self-powered writable-readable data sheet is presented which can pave the way towards new type of stress induced current harvesting devices. A localized forced deformation of the interface has been enacted by pressing the atomic force microscopic probe against the polymer surface, allowing charge transfer between materials interfaces. The process yields a well-defined charge pattern by transmuting mechanical stress in to readable information. The average of output current increment has been influenced from 0.5 nA to 15 nA for the applied force of 2 nN to 14 nN instead of electrical bias. These results underscore the importance of stress-induced current harvesting mechanism and could be scaled up for charge patterning of polymer surface to writable-readable data sheet. Time evolutional current distribution (TECD) study of the stress-induced patterned PANI surface shows the response of readability of the recorded data with time.

  2. Stress Induced Mechano-electrical Writing-Reading of Polymer Film Powered by Contact Electrification Mechanism

    NASA Astrophysics Data System (ADS)

    Goswami, Sumita; Nandy, Suman; Calmeiro, Tomás R.; Igreja, Rui; Martins, Rodrigo; Fortunato, Elvira

    2016-01-01

    Mechano-electrical writing and reading in polyaniline (PANI) thin film are demonstrated via metal-polymer contact electrification mechanism (CEM). An innovative conception for a non-destructive self-powered writable-readable data sheet is presented which can pave the way towards new type of stress induced current harvesting devices. A localized forced deformation of the interface has been enacted by pressing the atomic force microscopic probe against the polymer surface, allowing charge transfer between materials interfaces. The process yields a well-defined charge pattern by transmuting mechanical stress in to readable information. The average of output current increment has been influenced from 0.5 nA to 15 nA for the applied force of 2 nN to 14 nN instead of electrical bias. These results underscore the importance of stress-induced current harvesting mechanism and could be scaled up for charge patterning of polymer surface to writable-readable data sheet. Time evolutional current distribution (TECD) study of the stress-induced patterned PANI surface shows the response of readability of the recorded data with time.

  3. Stress Induced Mechano-electrical Writing-Reading of Polymer Film Powered by Contact Electrification Mechanism

    PubMed Central

    Goswami, Sumita; Nandy, Suman; Calmeiro, Tomás R.; Igreja, Rui; Martins, Rodrigo; Fortunato, Elvira

    2016-01-01

    Mechano-electrical writing and reading in polyaniline (PANI) thin film are demonstrated via metal-polymer contact electrification mechanism (CEM). An innovative conception for a non-destructive self-powered writable-readable data sheet is presented which can pave the way towards new type of stress induced current harvesting devices. A localized forced deformation of the interface has been enacted by pressing the atomic force microscopic probe against the polymer surface, allowing charge transfer between materials interfaces. The process yields a well-defined charge pattern by transmuting mechanical stress in to readable information. The average of output current increment has been influenced from 0.5 nA to 15 nA for the applied force of 2 nN to 14 nN instead of electrical bias. These results underscore the importance of stress-induced current harvesting mechanism and could be scaled up for charge patterning of polymer surface to writable-readable data sheet. Time evolutional current distribution (TECD) study of the stress-induced patterned PANI surface shows the response of readability of the recorded data with time. PMID:26786701

  4. Relations of kinematics, microphysics and electrification in an isolated mountain thunderstorm

    SciTech Connect

    Ziegler, C.L.; Ray, P.S.; MacGorman, D.R.

    1986-10-01

    This paper addresses aspects of the airflow, microphysics, and electrification in a mountain thunderstorm which occurred on 7 August 1979 over the Langmuir Laboratory near Socorro, New Mexico, site of the Thunderst Research International Program (TRIP). Single Doppler observations are used to form a conceptual model of the essentially one-dimensional storm nematic numerical cloud model is employed with the analytic updraft profile to diagnose the evolution of temperature, water substance, radar reflectivity, space charge density and axial electric field in the main updraft region. Retrieved thermal, microphysical, and electrical variabiles are verified with in situ aircraft and balloon observations and measured radar reflectivity. The calculated ing graupel particles is in a direct proportion to cloud and precipitation content, and attains a peak value of about 10 C km/sup -3/ min/sup -1/ between -30/sup 0/ and -40/sup 0/C. and vertical electric field imply that the noninductive graupel-ice charge separation mechanism accounts for a substantial portion of the storm's total separated charge. The peak noninductive charging rate appears to balance the discharge rate implied by the observed flash rate.

  5. Activation of 5' adenosine monophosphate-activated protein kinase blocks cumulus cell expansion through inhibition of protein synthesis during in vitro maturation in Swine.

    PubMed

    Santiquet, Nicolas; Sasseville, Maxime; Laforest, Martin; Guillemette, Christine; Gilchrist, Robert B; Richard, François J

    2014-08-01

    The serine/threonine kinase 5' adenosine monophosphate-activated protein kinase (AMPK), a heterotrimeric protein known as a metabolic switch, is involved in oocyte nuclear maturation in mice, cattle, and swine. The present study analyzed AMPK activation in cumulus cell expansion during in vitro maturation (IVM) of porcine cumulus-oocyte complexes (COC). 5-Aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) is a well-known activator of AMPK. It inhibited oocyte meiotic resumption in COC. Moreover, cumulus cell expansion did not occur in the presence of AICAR, demonstrating its marked impact on cumulus cells. Activation of AMPK was supported by AICAR-mediated phosphorylation of alpha AMPK subunits. Furthermore, the presence of AICAR increased glucose uptake, a classical response to activation of this metabolic switch in response to depleted cellular energy levels. Neither nuclear maturation nor cumulus expansion was reversed by glucosamine, an alternative substrate in hyaluronic acid synthesis, through the hexosamine biosynthetic pathway, which ruled out possible depletion of substrates. Both increased gap junction communication and phosphodiesterase activity in COC are dependent on protein synthesis during the initial hours of IVM; however, both were inhibited in the presence of AICAR, which supports the finding that activation of AMPK by AICAR mediated inhibition of protein synthesis. Moreover, this protein synthesis inhibition was equivalent to that of the well-known protein synthesis inhibitor cycloheximide, as observed on cumulus expansion and protein concentration. Finally, the phosphorylation level of selected kinases was investigated. The pattern of raptor phosphorylation is supportive of activation of AMPK-mediated inhibition of protein synthesis. In conclusion, AICAR-mediated AMPK activation in porcine COC inhibited cumulus cell expansion and protein synthesis. These results bring new considerations to the importance of this kinase in ovarian

  6. Fibroblast growth factor 17 and bone morphogenetic protein 15 enhance cumulus expansion and improve quality of in vitro-produced embryos in cattle.

    PubMed

    Machado, Mariana Fernandes; Caixeta, Ester Siqueira; Sudiman, Jaqueline; Gilchrist, Robert B; Thompson, Jeremy G; Lima, Paula Fernanda; Price, Christopher A; Buratini, José

    2015-08-01

    Bone morphogenetic protein 15 (BMP15) and members of the fibroblast growth factor (FGF) family are expressed by the oocyte and are involved in the control of cumulus cell function. We tested the hypothesis that FGF17, alone or combined with BMP15 in the maturation medium, enhances cumulus expansion, meiosis progression, embryonic development, and expression of mRNA encoding key genes regulating expansion (prostaglandin-endoperoxide synthase 2 [PTGS2], hyaluronan synthase 2 [HAS2], tumor necrosis factor-stimulated gene 6 [TNFAIP6], and pentraxin 3 [PTX3]) and markers of oocyte developmental competence (phosphofructokinase [PFKP], gremlin [GREM1], versican [VCAN], and the genomic progesterone receptor [nPR]) in cumulus cells. Fibroblast growth factor 17 and BMP15 increased the percentage of fully expanded cumulus-oocyte complexes (COCs), but there was no additive effect when both were combined. Neither FGF17 nor BMP15 altered the percentage of oocytes reaching meiosis II at the end of COC culture or cleavage and blastocyst rates after IVF. However, embryo quality, as assessed by the number of cells in the inner cell mass, was improved by the combination of FGF17 with BMP15. Fibroblast growth factor 17 alone did not alter gene expression in cumulus cells at the end of IVM, whereas BMP15 increased PTGS2 and PTX3 mRNA levels. The combination of FGF17 and BMP15 increased nPR mRNA abundance in cumulus cells but did not change the expression of other markers of developmental competence. This study provides novel evidence that FGF17 enhances cumulus expansion in bovine COCs submitted to IVM and that the supplementation of the IVM medium with FGF17 and BMP15 may improve embryo quality.

  7. Dynamic secretion during meiotic reentry integrates the function of the oocyte and cumulus cells.

    PubMed

    Cakmak, Hakan; Franciosi, Federica; Zamah, A Musa; Cedars, Marcelle I; Conti, Marco

    2016-03-01

    The differentiation of the female gamete into a developmentally competent oocyte relies on the protected environment of the ovarian follicle. The oocyte plays a key role in establishing this microenvironment by releasing paracrine factors that control the functions of surrounding somatic cells. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are secreted during follicle growth and play pivotal roles in this local regulation. The current view is that the function of these secreted factors declines in the periovulatory period when the oocyte reenters the meiotic cell cycle. Here, we provide evidence that oocyte reentry into meiosis is instead associated with a shift in the pattern of secretion with a new set of bioactive molecules synthesized before ovulation. Using interleukin 7 (IL7) as a prototypic secreted factor, we show that its secretion is dependent on activation of mRNA translation in synchrony with the cell cycle and that its translation is under the control of somatic cells. IL7 is part of a local feedback loop with the soma because it regulates cumulus cell replication. Similar conclusions are reached when IL7 secretion is measured in human follicular fluid during in vitro fertilization cycles. IL7 concentration in the follicular fluid correlates with the oocyte ability to reach the MII stage of maturation. These findings are consistent with the hypothesis that a new set of local factors is secreted by the oocyte during ovulation. These dynamic secretions are likely critical for promoting the final stages of maturation and oocyte developmental competence. PMID:26864200

  8. Towards an Understanding of Aerosol Redistribution by Shallow Cumulus Clouds with a Focus on Organics

    NASA Astrophysics Data System (ADS)

    Wonaschuetz, A.; Sorooshian, A.; Murphy, S. M.; Ervens, B.; Chuang, P. Y.; Feingold, G.; Jonsson, H. H.; Flagan, R. C.; Seinfeld, J.

    2010-12-01

    The extent to which clouds alter the vertical distribution of aerosols and concentrations of various inorganic and organic species has important implications for gas phase chemistry, air quality, and radiative forcing of climate. Models have been shown to inaccurately predict the vertical concentrations of organic aerosol mass and its oxidation state, especially in the free troposphere, where measurements usually exceed predictions of mass and underestimate O:C ratios. This work uses an airborne data set from the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) to address the convective redistribution of aerosols by small cumulus clouds, and also to quantify the contribution of aqueous chemistry to the vertical profiles of inorganic and organic particle species. There is evidence for convective pumping of aerosols in regions above cloud tops, where enhanced particle concentrations are observed in addition to high levels of sulfate and organics. Pre-conditioned areas in clear air that were recently processed by clouds exhibit enhanced levels of sulfate and organic acids as compared to other clear air regions. There is a trend towards enrichment of water-soluble organic aerosols (relative to both total organic and inorganic mass) as a function of both altitude (up to 4 km) and relative humidity. The most plausible explanation is that these species are produced by multi-phase chemistry. Modeling analysis will be presented to constrain the chemical aging processes in clouds and aqueous particles in the summertime southeastern Texas atmosphere. The usefulness of utilizing aerosol tracers for estimating the vertical profile of convective mass flux due to clouds is also explored.

  9. LH-Receptor Gene Expression in Human Granulosa and Cumulus Cells from Antral and Preovulatory Follicles

    PubMed Central

    Jeppesen, Janni Vikkelsø; Kristensen, Stine Gry; Nielsen, Maria Eilsø; Humaidan, Peter; Dal Canto, Maria; Fadini, Rubens; Schmidt, Kirsten T.; Ernst, Erik

    2012-01-01

    Context: Human granulosa cells (GC) acquire LH receptor (LHR) expression during the follicular phase of the menstrual cycle. Currently, the precise follicular stage is unknown, and specific roles of LH in the follicular development are not fully understood. Objective: Our objective was to measure LHR gene expression on GC and cumulus cells (CC) from normal human follicles with diameters form 3–20 mm. Design, Setting, and Patients: At a university hospital, GC, CC, and the corresponding follicular fluid (FF) were collected from patients undergoing fertility preservation by having one ovary frozen and patients undergoing infertility treatment. Interventions: Cells and fluids were isolated from surgically excised ovaries or from aspirated preovulatory follicles. Main Outcome Measures: We evaluated gene expression of LHR, FSHR, androgen receptor (AR), aromatase (CYP19a1), and AMHR2 normalized to the GAPDH expression and associated with FF levels of anti-Mullerian hormone, inhibin-B, and steroids. Results: LHR expression was maximal in GC from preovulatory follicles before ovulation induction. A majority of 150 antral follicles (3–10 mm in diameter) showed LHR expression at approximately 10% of the maximum, and LHR expression showed significant associations with FSHR, AR, CYP19a1, and AMHR2 and with FF estradiol and progesterone. Levels of FSHR continued to decline in GC as the follicular diameter increased. Conclusions: The LHR gene is expressed in GC of human antral follicles throughout the follicular phase and is significantly associated with expression of the CYP19a1 gene and with the corresponding FF concentrations of estradiol and progesterone. LH appears to affect human follicular development during most the follicular phase in normal women. PMID:22659248

  10. Dynamic secretion during meiotic reentry integrates the function of the oocyte and cumulus cells

    PubMed Central

    Cakmak, Hakan; Franciosi, Federica; Zamah, A. Musa; Cedars, Marcelle I.; Conti, Marco

    2016-01-01

    The differentiation of the female gamete into a developmentally competent oocyte relies on the protected environment of the ovarian follicle. The oocyte plays a key role in establishing this microenvironment by releasing paracrine factors that control the functions of surrounding somatic cells. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are secreted during follicle growth and play pivotal roles in this local regulation. The current view is that the function of these secreted factors declines in the periovulatory period when the oocyte reenters the meiotic cell cycle. Here, we provide evidence that oocyte reentry into meiosis is instead associated with a shift in the pattern of secretion with a new set of bioactive molecules synthesized before ovulation. Using interleukin 7 (IL7) as a prototypic secreted factor, we show that its secretion is dependent on activation of mRNA translation in synchrony with the cell cycle and that its translation is under the control of somatic cells. IL7 is part of a local feedback loop with the soma because it regulates cumulus cell replication. Similar conclusions are reached when IL7 secretion is measured in human follicular fluid during in vitro fertilization cycles. IL7 concentration in the follicular fluid correlates with the oocyte ability to reach the MII stage of maturation. These findings are consistent with the hypothesis that a new set of local factors is secreted by the oocyte during ovulation. These dynamic secretions are likely critical for promoting the final stages of maturation and oocyte developmental competence. PMID:26864200

  11. Impact of Cumulus Cloud Spacing on Landsat Atmospheric Correction and Aerosol Retrieval

    NASA Technical Reports Server (NTRS)

    Wen, Guoyong; Cahalan, Robert F.; Tsay, Si-Chee; Oreopoulos, Lazaros

    2001-01-01

    A Landsat-7 ETM+ image acquired over the Southern Great Plains DoE/ARM site during the ARESE II experiment is used to study the effect of clouds on reflected radiation in clear patches of a cumulus cloud field. The result shows that the apparent path radiance in the clear patches is enhanced by nearby clouds in both band 1 (blue) and band 3 (red) of ETM+. More importantly, the magnitude of the enhancement depends on the mean cloud-free distance in the clear patches. For cloud-free distance less than 0.5 km, the enhancement of apparent path radiance is more than 0.025 and 0.015 (reflectance units) in band 1 and band 3 respectively, which corresponds to an enhancement of apparent aerosol optical thickness of approximately 0.25 and approximately 0.15. Neglecting of the 3-D cloud effect would lead to underestimates of surface reflectance of approximately 0.025 and approximately 0.015 in the blue and red band respectively, if the true aerosol optical thickness is 0.2 and the surface reflectance is 0.05. The enhancement decreases exponentially with mean cloud-free distance, reaching asymptotic values of 0.09 for band 1 and 0.027 for band 3 at a mean cloud-free distance about 2 km. The asymptotic values are slightly larger than the mean path radiances retrieved from a completely clear region -- 0.086 and 0.024 for the blue and red band respectively.

  12. Multi-Scale Interaction between Cumulus Convection and its Environment in the Tropical Indian Ocean during CINDY/DYNAMO as Revealed by High-Resolution Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Takemi, T.

    2013-12-01

    The activity of cumulus convection in the tropical oceanic regions is strongly regulated by the larger-scale environmental atmosphere, while at the same time cumulus convection influences the larger-scale atmosphere. It is recognized that the spatial and temporal variability of moisture content play an important role in determining such multi-scale interaction processes: the down-scale regulation and up-scale influence. This study investigates the interaction between tropical cumulus convection and its environment in the tropical Indian Ocean during the active and in-active phases of Madden-Julian Oscillation (MJO) by conducting 100-m-mesh numerical simulations intended to sufficiently resolve mixing processes between cumulus clouds and their environments. The cases from the Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011 (CINDY2012)/Dynamics of MJO (DYNAMO) are examined. Numerical simulations are conducted with the use of the Weather Research and Forecasting (WRF) model with the nesting capability to resolve the area of interest at high resolutions. The nested computational domains cover the area of 2500 km by 2250 km, 1200 km by 1000 km, 300 km by 300 km, and 100 km by 60 km at 12.5-km, 2.5-km, 500-m, and 100-m horizontal grid spacing, respectively. The computational domains at the 500-m and 100-m grids are centered at the R/V Mirai observation site. The relationship among the tropospheric moisture variation, the diurnal variation of the atmospheric boundary layer, and the development and evolution of cumulus convection is specifically focused. Downscale regulation of environmental conditions on cumulus convection and upscale organization from boundary-layer disturbances to mesoscale convective systems are investigated. The vertical development of cumulus clouds are closely related to the relative humidity of the environment at levels lower than the cloud-top height. It is shown that the development and organization of cumulus

  13. Pregnancies established from water buffalo (Bubalus bubalis) blastocysts derived from in vitro matured, in vitro fertilized oocytes and co-cultured with cumulus and oviductal cells.

    PubMed

    Madan, M L; Chauhan, M S; Singla, S K; Manik, R S

    1994-09-01

    Buffalo ovaries were collected immediately after slaughter and were transported to laboratory in sterile saline at 37 degrees C. Follicular oocytes with the cumulus mass aspirated from 2 to 6 mm in diameter follicles were cultured in TCM-199 medium supplemented with 10% buffalo estrus serum (BES) in 5% CO(2) at 38.5 degrees C. After 20 to 24 h of incubation, the oocytes were inseminated with precapacitated frozen thawed spermatozoa for 6 h. The fertilization rate was 78.15% of the matured oocytes. Over an in vitro culture period of 3 to 9 d, 4.02% of the inseminated oocytes developed to the morula stage when cultured with cumulus cells alone and 17.83% when cumulus cells plus oviductal epithelial cells were used. The percentage of developed blastocysts was very low (0.57%) when the oocytes were co-cultured with cumulus cells from the original oocytes. However, 8% of the inseminated oocytes that were denuded 3 d after insemination developed to the blastocyst stage when they were co-cultured with cumulus and oviductal epithelial cells. Sixteen early/expanded blastocysts were transferred non-surgically to 16 recipients. Four of the 16 recipients became pregnant, of which 2 delivered normal buffalo male calves.

  14. Effects of stratocumulus, cumulus, and cirrus clouds on the UV-B diffuse to global ratio: Experimental and modeling results

    NASA Astrophysics Data System (ADS)

    López, María Laura; Palancar, Gustavo G.; Toselli, Beatriz M.

    2012-04-01

    Broadband measurements of global and diffuse UV-B irradiance (280-315 nm) together with modeled and measured diffuse to global ratios (DGR) have been used to characterize the influence of different types of clouds on irradiance at the surface. Measurements were carried out during 2000-2001 in Córdoba City, Argentina. The Tropospheric Ultraviolet Visible (TUV) model was used to analyze the behavior of the modeled DGRs for different cloud optical depths and at different altitudes and solar zenith angles (SZA). Different cloud altitudes were also tested, although only the results for a cloud placed at 1.5-2.5 km of altitude are shown. A total of 16 day with stratocumulus, 12 with cumulus, and 16 with cirrus have been studied and compared among them and also against 21 clear sky days. Different behaviors were clearly detected and also differentiated through the analysis of the averages and the standard deviations of the DGRs: 1.02±0.06 for stratocumulus, 0.74±0.18 for cumulus, 0.63±0.12 for cirrus, and 0.60±0.13 for the clear sky days, respectively. Stratocumulus clouds showed a low variability in the DGR values, which were concentrated close to one at all SZAs. DGR values for cumulus clouds presented a large variability at all SZAs, mostly associated with the different optical depths. Finally, the closeness between the DGR values for cirrus clouds and the DGR values for clear days showed that these clouds generally do not strongly affect the UV-B irradiance at the surface at any SZA. In the opposite side, stratocumulus clouds were identified as those with the largest effects, at all SZAs, on the UV-B irradiance at the surface.

  15. Metal Ion-dependent Heavy Chain Transfer Activity of TSG-6 Mediates Assembly of the Cumulus-Oocyte Matrix*

    PubMed Central

    Briggs, David C.; Birchenough, Holly L.; Ali, Tariq; Rugg, Marilyn S.; Waltho, Jon P.; Ievoli, Elena; Jowitt, Thomas A.; Enghild, Jan J.; Richter, Ralf P.; Salustri, Antonietta; Milner, Caroline M.; Day, Anthony J.

    2015-01-01

    The matrix polysaccharide hyaluronan (HA) has a critical role in the expansion of the cumulus cell-oocyte complex (COC), a process that is necessary for ovulation and fertilization in most mammals. Hyaluronan is organized into a cross-linked network by the cooperative action of three proteins, inter-α-inhibitor (IαI), pentraxin-3, and TNF-stimulated gene-6 (TSG-6), driving the expansion of the COC and providing the cumulus matrix with its required viscoelastic properties. Although it is known that matrix stabilization involves the TSG-6-mediated transfer of IαI heavy chains (HCs) onto hyaluronan (to form covalent HC·HA complexes that are cross-linked by pentraxin-3) and that this occurs via the formation of covalent HC·TSG-6 intermediates, the underlying molecular mechanisms are not well understood. Here, we have determined the tertiary structure of the CUB module from human TSG-6, identifying a calcium ion-binding site and chelating glutamic acid residue that mediate the formation of HC·TSG-6. This occurs via an initial metal ion-dependent, non-covalent, interaction between TSG-6 and HCs that also requires the presence of an HC-associated magnesium ion. In addition, we have found that the well characterized hyaluronan-binding site in the TSG-6 Link module is not used for recognition during transfer of HCs onto HA. Analysis of TSG-6 mutants (with impaired transferase and/or hyaluronan-binding functions) revealed that although the TSG-6-mediated formation of HC·HA complexes is essential for the expansion of mouse COCs in vitro, the hyaluronan-binding function of TSG-6 does not play a major role in the stabilization of the murine cumulus matrix. PMID:26468290

  16. Metal Ion-dependent Heavy Chain Transfer Activity of TSG-6 Mediates Assembly of the Cumulus-Oocyte Matrix.

    PubMed

    Briggs, David C; Birchenough, Holly L; Ali, Tariq; Rugg, Marilyn S; Waltho, Jon P; Ievoli, Elena; Jowitt, Thomas A; Enghild, Jan J; Richter, Ralf P; Salustri, Antonietta; Milner, Caroline M; Day, Anthony J

    2015-11-27

    The matrix polysaccharide hyaluronan (HA) has a critical role in the expansion of the cumulus cell-oocyte complex (COC), a process that is necessary for ovulation and fertilization in most mammals. Hyaluronan is organized into a cross-linked network by the cooperative action of three proteins, inter-α-inhibitor (IαI), pentraxin-3, and TNF-stimulated gene-6 (TSG-6), driving the expansion of the COC and providing the cumulus matrix with its required viscoelastic properties. Although it is known that matrix stabilization involves the TSG-6-mediated transfer of IαI heavy chains (HCs) onto hyaluronan (to form covalent HC·HA complexes that are cross-linked by pentraxin-3) and that this occurs via the formation of covalent HC·TSG-6 intermediates, the underlying molecular mechanisms are not well understood. Here, we have determined the tertiary structure of the CUB module from human TSG-6, identifying a calcium ion-binding site and chelating glutamic acid residue that mediate the formation of HC·TSG-6. This occurs via an initial metal ion-dependent, non-covalent, interaction between TSG-6 and HCs that also requires the presence of an HC-associated magnesium ion. In addition, we have found that the well characterized hyaluronan-binding site in the TSG-6 Link module is not used for recognition during transfer of HCs onto HA. Analysis of TSG-6 mutants (with impaired transferase and/or hyaluronan-binding functions) revealed that although the TSG-6-mediated formation of HC·HA complexes is essential for the expansion of mouse COCs in vitro, the hyaluronan-binding function of TSG-6 does not play a major role in the stabilization of the murine cumulus matrix.

  17. Improved solar irradiance forecast with Weather Research and Forecasting model: A Sensitivity test of shallow cumulus clouds to the turbulence process

    NASA Astrophysics Data System (ADS)

    Kim, C. K.; Betterton, E. A.; Leuthold, M.; Holmgren, W.; Cronin, A.

    2014-12-01

    Accurate forecasts of solar irradiance are required for electric utilities to economically integrate substantial amounts of solar power into their power generation portfolios. A common failing of numerical weather models is the prediction of shallow cumulus clouds which are generally difficult to be resolved due to complicated processes in the planetary boundary layer. The present study carried out the sensitivity test of turbulence parameterization for better predicting solar irradiance during the shallow cumulus events near the state of Arizona by using the Weather Research and Forecasting model. The results from the simulations show that increasing the exchange coefficient leads to enhanced vertical mixing and a deeper mixed layer. At the top of mixed layer, an adiabatically ascending air parcel achieved the water vapour saturation and finally shallow cumulus is generated. A detailed analysis will be discussed in the upcoming conference.

  18. Oocyte-secreted growth differentiation factor 9 inhibits BCL-2-interacting mediator of cell death-extra long expression in porcine cumulus cell.

    PubMed

    Wang, Xian-Long; Wang, Kun; Zhao, Shuan; Wu, Yi; Gao, Hui; Zeng, Shen-Ming

    2013-09-01

    Oocyte-secreted factors (OSFs) maintain the low incidence of cumulus cell apoptosis. In this report, we described that the presence of oocytes suppressed the expression of proapoptotic protein BCL-2-interacting mediator of cell death-extra long (BIMEL) in porcine cumulus cells. Atretic (terminal deoxynucleotidyl transferase dUTP nick end labeling-positive) cumulus cells strongly expressed BIMEL protein. The healthy cumulus- oocyte complex exhibited a low BIMEL expression in cumulus cell while the removal of oocyte led to an about 2.5-fold (P < 0.5) increased expression in oocytectomized complex (OOX). Coculturing OOXs with denuded oocytes decreased BIMEL expression to the normal level. The similar expression pattern could also be achieved in OOXs treated with exogenous recombinant mouse growth differentiation factor 9 (GDF9), a well-characterized OSF. This inhibitory action of GDF9 was prevented by the addition of a phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. Luciferase assay further demonstrated that BIM gene expression was forkhead box O3a (FOXO3a)-dependent because mutation of FOXO3a-binding site on the BIM promoter inhibited luciferase activities. Moreover, the activity of BIM promoter encompassing the FOXO3a-binding site could be regulated by GDF9. Additionally, we found that GDF9 elevated the levels of phosphorylated AKT and FOXO3a, and this process was independent of the SMAD signal pathway. Taken together, we concluded that OSFs, particularly GDF9, maintained the low level of BIMEL expression in cumulus cell through activation of the PI3K/FOXO3a pathway.

  19. Characterization of the effects of metformin on porcine oocyte meiosis and on AMP-activated protein kinase activation in oocytes and cumulus cells.

    PubMed

    Bilodeau-Goeseels, Sylvie; Magyara, Nora; Collignon, Coralie

    2014-05-01

    The adenosine monophosphate-activated protein kinase (AMPK) activators 5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside (AICAR) and metformin (MET) inhibit resumption of meiosis in porcine cumulus-enclosed oocytes. The objective of this study was to characterize the inhibitory effect of MET on porcine oocyte meiosis by: (1) determining the effects of an AMPK inhibitor and of inhibitors of signalling pathways involved in MET-induced AMPK activation in other cell types on MET-mediated meiotic arrest in porcine cumulus-enclosed oocytes; (2) determining whether MET and AICAR treatments lead to increased activation of porcine oocyte and/or cumulus cell AMPK as measured by phosphorylation of its substrate acetyl-CoA carboxylase; and (3) determining the effects of inhibition of the AMPK kinase, Ca2+/calmodulin-dependent protein kinase kinase (CaMKK), and Ca2+ chelation on oocyte meiotic maturation and AMPK activation in porcine oocytes and cumulus cells. The AMPK inhibitor compound C (CC; 1 μM) did not reverse the inhibitory effect of AICAR (1 mM) and MET (2 mM) on porcine oocyte meiosis. Additionally, CC had a significant inhibitory effect on its own. eNOS, c-Src and PI-3 kinase pathway inhibitors did not reverse the effect of metformin on porcine oocyte meiosis. The level of acetyl-CoA carboxylase (ACC) phosphorylation in oocytes and cumulus cells did not change in response to culture in the presence of MET, AICAR, CC, the CaMKK inhibitor STO-609 or the Ca2+ chelator BAPTA-AM for 3 h, but STO-609 increased the percentage of porcine cumulus-enclosed oocytes (CEO) that remained at the germinal vesicle (GV) stage after 24 h of culture. These results indicate that the inhibitory effect of MET and AICAR on porcine oocyte meiosis was probably not mediated through activation of AMPK.

  20. Observations and Model Simulations of Transport and Precipitation Development in a Seeded Cumulus Congestus Cloud.

    NASA Astrophysics Data System (ADS)

    Huston, Michael W.; Detwiler, Andrew G.; Kopp, Fred J.; Stith, Jeffrey L.

    1991-10-01

    Observations made by three instrumented aircraft, a Doppler radar, and other data sources were used to follow the initiation and development of precipitation in a small cumulus congestus cloud. The cloud was seeded at its base using an airborne silver iodide solution burner. Sulfur hexafluoride tracer gas was released along with the seeding material. Analyzers on two instrumented aircraft detected the tracer gas during subsequent cloud penetrations as it was carried up into the cloud along with the seeding agent. Ice developed initially in the upper regions of the cloud near the 10°C level 15 min after the commencement of seeding. This is consistent with primary nucleation by the seeding agent. The cloud developed millimeter-size graupel within the following few minutes. A radar echo approaching 40 dBZ subsequently developed. The echo was observed to descend through the cloud as the cloud dissipated.One-dimensional, steady-state and two-dimensional, time-dependent bulk water models were used to simulate this cloud. The one-dimensional model produced realistic values for updraft speeds allowing credible estimates of time required for transport from cloud base to upper regions of the cloud. The development of precipitation in the two-dimensional simulation resembled that in the observed cloud. Precipitation developed through riming of snow to graupel. In both the observed and simulated clouds, precipitation development was limited by cloud lifetime. Both clouds collapsed at a time when they were still generating ample supercooled water in their updrafts. Total precipitation on the ground from the seeded cloud simulations was 5 times the radar estimated rainfall total of 0.5 mm from the observed seeded cloud. This occurred despite the fact that the simulated cloud went through an accelerated life cycle compared to the observed cloud. A comparison between simulations with a natural ice process and with cloud base release of silver iodide shows that seeding accelerated

  1. Observed correlations between aerosol and cloud properties in an Indian Ocean trade cumulus regime

    DOE PAGESBeta

    Pistone, Kristina; Praveen, Puppala S.; Thomas, Rick M.; Ramanathan, Veerabhadran; Wilcox, Eric M.; Bender, Frida A.-M.

    2016-04-27

    There are many contributing factors which determine the micro- and macrophysical properties of clouds, including atmospheric vertical structure, dominant meteorological conditions, and aerosol concentration, all of which may be coupled to one another. In the quest to determine aerosol effects on clouds, these potential relationships must be understood. Here we describe several observed correlations between aerosol conditions and cloud and atmospheric properties in the Indian Ocean winter monsoon season.In the CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) field campaign conducted in February and March 2012 in the northern Indian Ocean, continuous measurements were made of atmospheric precipitable water vapor (PWV)more » and the liquid water path (LWP) of trade cumulus clouds, concurrent with measurements of water vapor flux, cloud and aerosol vertical profiles, meteorological data, and surface and total-column aerosol from instrumentation at a ground observatory and on small unmanned aircraft. We present observations which indicate a positive correlation between aerosol and cloud LWP only when considering cases with low atmospheric water vapor (PWV < 40 kg m–2), a criterion which acts to filter the data to control for the natural meteorological variability in the region.We then use the aircraft and ground-based measurements to explore possible mechanisms behind this observed aerosol–LWP correlation. The increase in cloud liquid water is found to coincide with a lowering of the cloud base, which is itself attributable to increased boundary layer humidity in polluted conditions. High pollution is found to correlate with both higher temperatures and higher humidity measured throughout the boundary layer. A large-scale analysis, using satellite observations and meteorological reanalysis, corroborates these covariations: high-pollution cases are shown to originate as a highly polluted boundary layer air mass approaching the observatory from a

  2. Ice formation and development in aged, wintertime cumulus over the UK: observations and modelling

    NASA Astrophysics Data System (ADS)

    Crawford, I.; Bower, K. N.; Choularton, T. W.; Dearden, C.; Crosier, J.; Westbrook, C.; Capes, G.; Coe, H.; Connolly, P. J.; Dorsey, J. R.; Gallagher, M. W.; Williams, P.; Trembath, J.; Cui, Z.; Blyth, A.

    2012-06-01

    In situ high resolution aircraft measurements of cloud microphysical properties were made in coordination with ground based remote sensing observations of a line of small cumulus clouds, using Radar and Lidar, as part of the Aerosol Properties, PRocesses And InfluenceS on the Earth's climate (APPRAISE) project. A narrow but extensive line (~100 km long) of shallow convective clouds over the southern UK was studied. Cloud top temperatures were observed to be higher than -8 °C, but the clouds were seen to consist of supercooled droplets and varying concentrations of ice particles. No ice particles were observed to be falling into the cloud tops from above. Current parameterisations of ice nuclei (IN) numbers predict too few particles will be active as ice nuclei to account for ice particle concentrations at the observed, near cloud top, temperatures (-7.5 °C). The role of mineral dust particles, consistent with concentrations observed near the surface, acting as high temperature IN is considered important in this case. It was found that very high concentrations of ice particles (up to 100 L-1) could be produced by secondary ice particle production providing the observed small amount of primary ice (about 0.01 L-1) was present to initiate it. This emphasises the need to understand primary ice formation in slightly supercooled clouds. It is shown using simple calculations that the Hallett-Mossop process (HM) is the likely source of the secondary ice. Model simulations of the case study were performed with the Aerosol Cloud and Precipitation Interactions Model (ACPIM). These parcel model investigations confirmed the HM process to be a very important mechanism for producing the observed high ice concentrations. A key step in generating the high concentrations was the process of collision and coalescence of rain drops, which once formed fell rapidly through the cloud, collecting ice particles which caused them to freeze and form instant large riming particles. The

  3. The tropical water and energy cycles in a cumulus ensemble model. Part 1: Equilibrium climate

    NASA Technical Reports Server (NTRS)

    Sui, C. H.; Lau, K. M.; Tao, W. K.; Simpson, J.

    1994-01-01

    A cumulus ensemble model is used to study the tropical water and energy cycles and their role in the climate system. The model includes cloud dynamics, radiative processes, and microphysics that incorporate all important production and conversion processes among water vapor and five species of hydrometeors. Radiative transfer in clouds is parameterized based on cloud contents and size distributions of each bulk hydrometeor. Several model integrations have been carried out under a variety of imposed boundary and large-scale conditions. In Part 1 of this paper, the primary focus is on the water and heat budgets of the control experiment, which is designed to simulate the convective - radiative equilibrium response of the model to an imposed vertical velocity and a fixed sea surface temperature at 28 C. The simulated atmosphere is conditionally unstable below the freezing level and close to neutral above the freezing level. The equilibrium water budget shows that the total moisture source, M(sub s), which is contributed by surface evaporation (0.24 M(sub s)) and the large-scale advection (0.76 M(sub s)), all converts to mean surface precipitation bar-P(sub s). Most of M(sub s) is transported verticaly in convective regions where much of the condensate is generated and falls to surface (0.68 bar-P(sub s)). The remaining condensate detrains at a rate of 0.48 bar-P(sub s) and constitutes 65% of the source for stratiform clouds above the melting level. The upper-level stratiform cloud dissipates into clear environment at a rate of 0.14 bar-P(sub s), which is a significant moisture source comparable to the detrained water vapor (0.15 bar-P(sub s)) to the upper troposphere from convective clouds. In the lower troposphere, stratiform clouds evaporate at a rate of 0.41 bar-P(sub s), which is a more dominant moisture source than surface evaporation (0.22 bar-P(sub s)). The precipitation falling to the surface in the stratiform region is about 0.32 bar-P(sub s). The associated

  4. Microphysics, Radiation and Surface Processes in the Goddard Cumulus Ensemble (GCE) Model

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Starr, David (Technical Monitor)

    2002-01-01

    One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with Cloud Resolving Models (CRMs). The CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (size about 2-200 km). The CRMs also allow explicit interaction between out-going longwave (cooling) and in-coming solar (heating) radiation with clouds. Observations can provide the initial conditions and validation for CRM results. The Goddard Cumulus Ensemble (GCE) Model, a CRM, has been developed and improved at NASA/Goddard Space Flight Center over the past two decades. The GCE model has been used to understand the following: 1) water and energy cycles and their roles in the tropical climate system; 2) the vertical redistribution of ozone and trace constituents by individual clouds and well organized convective systems over various spatial scales; 3) the relationship between the vertical distribution of latent heating (phase change of water) and the large-scale (pre-storm) environment; 4) the validity of assumptions used in the representation of cloud processes in climate and global circulation models; and 5) the representation of cloud microphysical processes and their interaction with radiative forcing over tropical and midlatitude regions. Four-dimensional cloud and latent heating fields simulated from the GCE model have been provided to the TRMM Science Data and Information System (TSDIS) to develop and improve algorithms for retrieving rainfall and latent heating rates for TRMM and the NASA Earth Observing System (EOS). More than 90 referred papers using the GCE model have been published in the last two decades. Also, more than 10 national and international universities are currently using the GCE model for research and teaching. In this talk, five specific major GCE improvements: (1

  5. The three-dimensional structure of cumulus clouds over the ocean. 1: Structural analysis

    NASA Technical Reports Server (NTRS)

    Kuo, Kwo-Sen; Welch, Ronald M.; Weger, Ronald C.; Engelstad, Mark A.; Sengupta, S. K.

    1993-01-01

    Thermal channel (channel 6, 10.4-12.5 micrometers) images of five Landsat thematic mapper cumulus scenes over the ocean are examined. These images are thresholded using the standard International Satellite Cloud Climatology Project (ISCCP) thermal threshold algorithm. The individual clouds in the cloud fields are segmented to obtain their structural statistics which include size distribution, orientation angle, horizontal aspect ratio, and perimeter-to-area (PtA) relationship. The cloud size distributions exhibit a double power law with the smaller clouds having a smaller absolute exponent. The cloud orientation angles, horizontal aspect ratios, and PtA exponents are found in good agreement with earlier studies. A technique also is developed to recognize individual cells within a cloud so that statistics of cloud cellular structure can be obtained. Cell structural statistics are computed for each cloud. Unicellular clouds are generally smaller (less than or equal to 1 km) and have smaller PtA exponents, while multicellular clouds are larger (greater than or equal to 1 km) and have larger PtA exponents. Cell structural statistics are similar to those of the smaller clouds. When each cell is approximated as a quadric surface using a linear least squares fit, most cells have the shape of a hyperboloid of one sheet, but about 15% of the cells are best modeled by a hyperboloid of two sheets. Less than 1% of the clouds are ellipsoidal. The number of cells in a cloud increases slightly faster than linearly with increasing cloud size. The mean nearest neighbor distance between cells in a cloud, however, appears to increase linearly with increasing cloud size and to reach a maximum when the cloud effective diameter is about 10 km; then it decreases with increasing cloud size. Sensitivity studies of threshold and lapse rate show that neither has a significant impact upon the results. A goodness-of-fit ratio is used to provide a quantitative measure of the individual cloud

  6. The three-dimensional structure of cumulus clouds over the ocean: 1. Structural analysis

    NASA Astrophysics Data System (ADS)

    Kuo, Kwo-Sen; Welch, Ronald M.; Weger, Ronald C.; Engelstad, Mark A.; Sengupta, S. K.

    1993-11-01

    Thermal channel (channel 6, 10.4-12.5 μm) images of five Landsat thematic mapper cumulus scenes over the ocean are examined. These images are thresholded using the standard International Satellite Cloud Climatology Project thermal threshold algorithm. The individual clouds in the cloud fields are segmented to obtain their structural statistics which include size distribution, orientation angle, horizontal aspect ratio, and perimeter-to-area (PtA) relationship. It is found that the cloud size distributions exhibit a double power law with the smaller clouds having a smaller absolute exponent. The cloud orientation angles, horizontal aspect ratios, and PtA exponents are found in good agreement with earlier studies. A technique also is developed to recognize individual cells within a cloud so that statistics of cloud cellular structure can be obtained. Cell structural statistics are computed for each cloud. Further examination reveals that unicellular clouds are generally smaller (≤ 1 km) and have smaller PtA exponents, while multicellular clouds are larger (≥ 1 km) and have larger PtA exponents. Cell structural statistics are similar to those of the smaller clouds. Each cell is approximated as a quadric surface using a linear least squares fit. Most cells are found to have the shape of a hyperboloid of one sheet. However, about 15% of the cells are best modeled by a hyperboloid of two sheets. Contrary to intuition, less than 1% of the clouds are found to be ellipsoidal. The number of cells in a cloud is found to increase slightly faster than linearly with increasing cloud size. The mean nearest neighbor distance between cells in a cloud, however, appears to increase linearly with increasing cloud size and to reach a maximum when the cloud effective diameter is about 10 km; then it decreases with increasing cloud size. Sensitivity studies of threshold and lapse rate show that neither has a significant impact upon the results. A goodness-of-fit ratio is used to

  7. The Goddard Cumulus Ensemble Model (GCE): Improvements and Applications for Studying Precipitation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lang, Stephen E.; Zeng, Xiping; Li, Xiaowen; Matsui, Toshi; Mohr, Karen; Posselt, Derek; Chern, Jiundar; Peters-Lidard, Christa; Norris, Peter M.; Kang, In-Sik; Choi, Ildae; Hou, Arthur; Lau, K.-M.; Yang, Young-Min

    2014-01-01

    Convection is the primary transport process in the Earth's atmosphere. About two-thirds of the Earth's rainfall and severe floods derive from convection. In addition, two-thirds of the global rain falls in the tropics, while the associated latent heat release accounts for three-fourths of the total heat energy for the Earth's atmosphere. Cloud-resolving models (CRMs) have been used to improve our understanding of cloud and precipitation processes and phenomena from micro-scale to cloud-scale and mesoscale as well as their interactions with radiation and surface processes. CRMs use sophisticated and realistic representations of cloud microphysical processes and can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems. CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. The Goddard Cumulus Ensemble model (GCE) has been developed and improved at NASA/Goddard Space Flight Center over the past three decades. It is amulti-dimensional non-hydrostatic CRM that can simulate clouds and cloud systems in different environments. Early improvements and testing were presented in Tao and Simpson (1993) and Tao et al. (2003a). A review on the application of the GCE to the understanding of precipitation processes can be found in Simpson and Tao (1993) and Tao (2003). In this paper, recent model improvements (microphysics, radiation and land surface processes) are described along with their impact and performance on cloud and precipitation events in different geographic locations via comparisons with observations. In addition, recent advanced applications of the GCE are presented that include understanding the physical processes responsible for diurnal variation, examining the impact of aerosols (cloud condensation nuclei or CCN and ice nuclei or IN) on

  8. Observed correlations between aerosol and cloud properties in an Indian Ocean trade cumulus regime

    NASA Astrophysics Data System (ADS)

    Pistone, Kristina; Praveen, Puppala S.; Thomas, Rick M.; Ramanathan, Veerabhadran; Wilcox, Eric M.; Bender, Frida A.-M.

    2016-04-01

    There are many contributing factors which determine the micro- and macrophysical properties of clouds, including atmospheric vertical structure, dominant meteorological conditions, and aerosol concentration, all of which may be coupled to one another. In the quest to determine aerosol effects on clouds, these potential relationships must be understood. Here we describe several observed correlations between aerosol conditions and cloud and atmospheric properties in the Indian Ocean winter monsoon season.In the CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) field campaign conducted in February and March 2012 in the northern Indian Ocean, continuous measurements were made of atmospheric precipitable water vapor (PWV) and the liquid water path (LWP) of trade cumulus clouds, concurrent with measurements of water vapor flux, cloud and aerosol vertical profiles, meteorological data, and surface and total-column aerosol from instrumentation at a ground observatory and on small unmanned aircraft. We present observations which indicate a positive correlation between aerosol and cloud LWP only when considering cases with low atmospheric water vapor (PWV < 40 kg m-2), a criterion which acts to filter the data to control for the natural meteorological variability in the region.We then use the aircraft and ground-based measurements to explore possible mechanisms behind this observed aerosol-LWP correlation. The increase in cloud liquid water is found to coincide with a lowering of the cloud base, which is itself attributable to increased boundary layer humidity in polluted conditions. High pollution is found to correlate with both higher temperatures and higher humidity measured throughout the boundary layer. A large-scale analysis, using satellite observations and meteorological reanalysis, corroborates these covariations: high-pollution cases are shown to originate as a highly polluted boundary layer air mass approaching the observatory from a northwesterly

  9. Observed correlations between aerosol and cloud properties in an Indian Ocean trade cumulus regime

    NASA Astrophysics Data System (ADS)

    Pistone, K.; Praveen, P. S.; Thomas, R. M.; Ramanathan, V.; Wilcox, E.; Bender, F. A.-M.

    2015-10-01

    There are many contributing factors which determine the micro- and macrophysical properties of clouds, including atmospheric structure, dominant meteorological conditions, and aerosol concentration, all of which may be coupled to one another. In the quest to determine aerosol effects on clouds, these potential relationships must be understood, as changes in atmospheric conditions due to aerosol may change the expected magnitude of indirect effects by altering cloud properties in unexpected ways. Here we describe several observed correlations between aerosol conditions and cloud and atmospheric properties in the Indian Ocean winter monsoon season. In the CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) field campaign conducted in February and March 2012 in the northern Indian Ocean, continuous measurements of atmospheric precipitable water vapor and the liquid water path (LWP) of trade cumulus clouds were made, concurrent with measurements of water vapor flux, cloud and aerosol vertical profiles, meteorological data, and surface and total-column aerosol. Here we present evidence of a positive correlation between aerosol and cloud LWP which becomes clear after the data are filtered to control for the natural meteorological variability in the region. We then use the aircraft and ground observatory measurements to explore the mechanisms behind the observed aerosol-LWP correlation. We determine that increased boundary-layer humidity lowering the cloud base is responsible for the observed increase in cloud liquid water. Large-scale analysis indicates that high pollution cases originate with a highly-polluted boundary layer air mass approaching the observatory from a northwesterly direction. This polluted mass exhibits higher temperatures and humidity than the clean case, the former of which may be attributable to heating due to aerosol absorption of solar radiation over the subcontinent. While high temperature conditions dispersed along with the high

  10. A Regulation of Tropical Climate by Radiative Cooling as Simulated in a Cumulus Ensemble Model

    NASA Technical Reports Server (NTRS)

    Sui, Chung-Hsiung; Lau, K.-M.; Li, X.; Chou, M.-D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Responses of tropical atmosphere to low-boundary forcing are investigated in a 2-D cumulus ensemble model (CEM) with an imposed warm-pool and cold-pool SST contrast (deltaSST). The domain-mean vertical motion is constrained to produce heat sink and moisture source as in the observed tropical climate. In a series of experiments, the warm pool SST is specified at different values while the cold pool SST is specified at 26 C. The strength of the circulation increases with increasing deltaSST until deltaSST reaches 3.5 C, and remains unchanged as deltaSST exceeds 3.5 C. The regulation of tropical convection by zonal SST gradient is constrained by the radiative cooling over the cold pool. For deltaSST less than 3.5 C, an enhanced subsidence warming is balanced by a reduced condensation heating over the cold pool. For deltaSST greater than 3.5 C, the subsidence regime expands over the entire cold pool where no condensation heating exist so that a further enhanced subsidence warming can no longer be sustained. The above regulation mechanism is also evident in the change of energy at the top of the atmosphere (TOA) that is dominated by cloud and water vapor greenhouse effect (c (sub LW)) and G (sub clear). The change in shortwave radiation at TOA is largely cancelled between the warm pool and cold pool, likely due to the same imposed vertical motion in our experiments. For deltaSST less than 3.5 C, an increase of deltaSST is associated with a large increase in c (sub Lw) due to increased total clouds in response to enhanced SST-induced circulation. For deltaSST greater than 3.5 C, clouds over the warm pool decrease with increasing SST, and the change in c (sub LW) is much smaller. In both dSST regimes, the change in CLW is larger than the change in G(sub clear) which is slightly negative. However, in the case of uniform warming (deltaSST=0), DeltaG(sub clear), is positive, approximately 5 W per square meters per degree change of SST.

  11. Microphysical, macrophysical and radiative signatures of volcanic aerosols in trade wind cumulus observed by the A-Train

    NASA Astrophysics Data System (ADS)

    Yuan, T.; Remer, L. A.; Yu, H.

    2011-07-01

    Increased aerosol concentrations can raise planetary albedo not only by reflecting sunlight and increasing cloud albedo, but also by changing cloud amount. However, detecting aerosol effect on cloud amount has been elusive to both observations and modeling due to potential buffering mechanisms and convolution of meteorology. Here through a natural experiment provided by long-term degassing of a low-lying volcano and use of A-Train satellite observations, we show modifications of trade cumulus cloud fields including decreased droplet size, decreased precipitation efficiency and increased cloud amount are associated with volcanic aerosols. In addition we find significantly higher cloud tops for polluted clouds. We demonstrate that the observed microphysical and macrophysical changes cannot be explained by synoptic meteorology or the orographic effect of the Hawaiian Islands. The "total shortwave aerosol forcin", resulting from direct and indirect forcings including both cloud albedo and cloud amount, is almost an order of magnitude higher than aerosol direct forcing alone. Furthermore, the precipitation reduction associated with enhanced aerosol leads to large changes in the energetics of air-sea exchange and trade wind boundary layer. Our results represent the first observational evidence of large-scale increase of cloud amount due to aerosols in a trade cumulus regime, which can be used to constrain the representation of aerosol-cloud interactions in climate models. The findings also have implications for volcano-climate interactions and climate mitigation research.

  12. Microphysical, Macrophysical and Radiative Signatures of Volcanic Aerosols in Trade Wind Cumulus Observed by the A-Train

    NASA Technical Reports Server (NTRS)

    Yuan, T.; Remer, L. A.; Yu, H.

    2011-01-01

    Increased aerosol concentrations can raise planetary albedo not only by reflecting sunlight and increasing cloud albedo, but also by changing cloud amount. However, detecting aerosol effect on cloud amount has been elusive to both observations and modeling due to potential buffering mechanisms and convolution of meteorology. Here through a natural experiment provided by long-tem1 degassing of a low-lying volcano and use of A-Train satellite observations, we show modifications of trade cumulus cloud fields including decreased droplet size, decreased precipitation efficiency and increased cloud amount are associated with volcanic aerosols. In addition we find significantly higher cloud tops for polluted clouds. We demonstrate that the observed microphysical and macrophysical changes cannot be explained by synoptic meteorology or the orographic effect of the Hawaiian Islands. The "total shortwave aerosol forcin", resulting from direct and indirect forcings including both cloud albedo and cloud amount. is almost an order of magnitude higher than aerosol direct forcing alone. Furthermore, the precipitation reduction associated with enhanced aerosol leads to large changes in the energetics of air-sea exchange and trade wind boundary layer. Our results represent the first observational evidence of large-scale increase of cloud amount due to aerosols in a trade cumulus regime, which can be used to constrain the representation of aerosol-cloud interactions in climate models. The findings also have implications for volcano-climate interactions and climate mitigation research.

  13. Insights from modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    DOE PAGESBeta

    Mechem, David B.; Giangrande, Scott E.; Wittman, Carly S.; Borque, Paloma; Toto, Tami; Kollias, Pavlos

    2015-03-13

    A case of shallow cumulus and precipitating cumulus congestus sampled at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) supersite is analyzed using a multi-sensor observational approach and numerical simulation. Observations from a new radar suite surrounding the facility are used to characterize the evolving statistical behavior of the precipitating cloud system. This is accomplished using distributions of different measures of cloud geometry and precipitation properties. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Our emphasis ismore » on assessing the importance of time-varying vs. steady-state large-scale forcing on the model's ability to reproduce the evolutionary behavior of the cloud system. Additional consideration is given to how the characteristic spatial scale and homogeneity of the forcing imposed on the simulation influences the evolution of cloud system properties. Results indicate that several new scanning radar estimates such as distributions of cloud top are useful to differentiate the value of time-varying (or at least temporally well-matched) forcing on LES solution fidelity.« less

  14. Insights from modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    SciTech Connect

    Mechem, David B.; Giangrande, Scott E.; Wittman, Carly S.; Borque, Paloma; Toto, Tami; Kollias, Pavlos

    2015-03-13

    A case of shallow cumulus and precipitating cumulus congestus sampled at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) supersite is analyzed using a multi-sensor observational approach and numerical simulation. Observations from a new radar suite surrounding the facility are used to characterize the evolving statistical behavior of the precipitating cloud system. This is accomplished using distributions of different measures of cloud geometry and precipitation properties. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Our emphasis is on assessing the importance of time-varying vs. steady-state large-scale forcing on the model's ability to reproduce the evolutionary behavior of the cloud system. Additional consideration is given to how the characteristic spatial scale and homogeneity of the forcing imposed on the simulation influences the evolution of cloud system properties. Results indicate that several new scanning radar estimates such as distributions of cloud top are useful to differentiate the value of time-varying (or at least temporally well-matched) forcing on LES solution fidelity.

  15. Synergistic roles of BMP15 and GDF9 in the development and function of the oocyte-cumulus cell complex in mice: genetic evidence for an oocyte-granulosa cell regulatory loop.

    PubMed

    Su, You-Qiang; Wu, Xuemei; O'Brien, Marilyn J; Pendola, Frank L; Denegre, James N; Matzuk, Martin M; Eppig, John J

    2004-12-01

    Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are oocyte-specific growth factors that appear to play key roles in granulosa cell development and fertility in most mammalian species. We have evaluated the role(s) of these paracrine factors in the development and function of both the cumulus cells and oocytes by assessing cumulus expansion, oocyte maturation, fertilization, and preimplantation embryogenesis in Gdf9+/-Bmp15-/- [hereafter, double mutant (DM)] mice. We found that cumulus expansion, as well as the expression of hyaluronon synthase 2 (Has2) mRNA was impaired in DM oocyte-cumulus cell complexes. This aberrant cumulus expansion was not remedied by coculture with normal wild-type (WT) oocytes, indicating that the development and/or differentiation of cumulus cells in the DM, up to the stage of the preovulatory luteinizing hormone (LH) surge, is impaired. In addition, DM oocytes failed to enable FSH to induce cumulus expansion in WT oocytectomized (OOX) cumulus. Moreover, LH-induced oocyte meiotic resumption was significantly delayed in vivo, and this delayed resumption of meiosis was correlated with the reduced activation of mitogen-activated protein kinase (MAPK) in the cumulus cells, thus suggesting that GDF9 and BMP15 also regulate the function of cumulus cells after the preovulatory LH surge. Although spontaneous in vitro oocyte maturation occurred normally, oocyte fertilization and preimplantation embryogenesis were significantly altered in the DM, suggesting that the full complement of both GDF9 and BMP15 are essential for the development and function of oocytes. Because receptors for GDF9 and BMP15 have not yet been identified in mouse oocytes, the effects of the mutations in the Bmp15 and Gdf9 genes on oocyte development and functions must be produced indirectly by first affecting the granulosa cells and then the oocyte. Therefore, this study provides further evidence for the existence and functioning of an oocyte

  16. Electrification of particulate entrained fluid flows-Mechanisms, applications, and numerical methodology

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Gu, Zhaolin

    2015-10-01

    Particulates in natural and industrial flows have two basic forms: liquid (droplet) and solid (particle). Droplets would be charged in the presence of the applied electric field (e.g. electrospray). Similar to the droplet charging, particles can also be charged under the external electric field (e.g. electrostatic precipitator), while in the absence of external electric field, tribo-electrostatic charging is almost unavoidable in gas-solid two-phase flows due to the consecutive particle contacts (e.g. electrostatic in fluidized bed or wind-blown sand). The particle charging may be beneficial, or detrimental. Although electrostatics in particulate entrained fluid flow systems have been so widely used and concerned, the mechanisms of particulate charging are still lack of a thorough understanding. The motivation of this review is to explore a clear understanding of particulate charging and movement of charged particulate in two-phase flows, by summarizing the electrification mechanisms, physical models of particulate charging, and methods of charging/charged particulate entrained fluid flow simulations. Two effective methods can make droplets charged in industrial applications: corona charging and induction charging. The droplet charge to mass ratio by corona charging is more than induction discharge. The particle charging through collisions could be attributed to electron transfer, ion transfer, material transfer, and/or aqueous ion shift on particle surfaces. The charges on charged particulate surface can be measured, nevertheless, the charging process in nature or industry is difficult to monitor. The simulation method might build a bridge of investigating from the charging process to finally charged state on particulate surface in particulate entrained fluid flows. The methodology combining the interface tracking under the action of the applied electric with the fluid flow governing equations is applicable to the study of electrohydrodynamics problems. The charge

  17. Recovery Act - An Interdisciplinary Program for Education and Outreach in Transportation Electrification

    SciTech Connect

    Anderson, Carl; Bohmann, Leonard; Naber, Jeffrey; Beard, John; Passerello, Chris; Worm, Jeremy; Chen, Bo; Allen, Jeffrey; Weaver, Wayne; Hackney, Stephen; Keith, Jason; Meldrum, Jay; Mork, Bruce

    2013-01-30

    1) How the project adds to the education of engineering students in the area of vehicle electrification: This project created and implemented a significant interdisciplinary curriculum in HEV engineering that includes courses focused on the major components (engines, battery cells, e-machines, and power electronics). The new curriculum, rather uniquely, features two new classes and two new labs that emphasize a vehicle level integration of a hybrid electric powertrain that parallels the vehicle development process used by the OEMs - commercial grade software is used to design a hybrid electric vehicle, hardware-in-the-loop testing is performed on each component until the entire powertrain is optimized, the calibration is flashed to a vehicle, ride-and-drives are executed including on board data acquisition. In addition, nine existing courses were modified by adding HEV material to the courses. 2) The educational effectiveness and economic feasibility of the new curriculum: The new courses are offered at both the undergraduate and graduate levels. They are listed across the college in mechanical, chemical, electrical, and materials science and engineering. They are offered both on campus and to distance learning students. Students across the college of engineering and at all degree levels are integrating these courses into their degree programs. Over the three year project the course enrollments on-campus has totaled 1,249. The distance learning enrollments has totaled 315. With such robust enrollments we absolutely expect that these courses will be in the curriculum for the long run. 3) How the project is otherwise of benefit to the public: One outcome of the project is the construction of the Michigan Tech Mobile Lab. Two complete HEV dynamometer test cells, and four work stations are installed in the 16.2 meter Mobile Laboratory and hauled by a class 8 truck. The Mobile Lab is used to teach the university courses. It is also used to deliver short courses to

  18. Transcriptome dynamics and molecular cross-talk between bovine oocyte and its companion cumulus cells

    PubMed Central

    2011-01-01

    Background The bi-directional communication between the oocyte and its companion cumulus cells (CCs) is crucial for development and functions of both cell types. Transcripts that are exclusively expressed either in oocytes or CCs and molecular mechanisms affected due to removal of the communication axis between the two cell types is not investigated at a larger scale. The main objectives of this study were: 1. To identify transcripts exclusively expressed either in oocyte or CCs and 2. To identify those which are differentially expressed when the oocyte is cultured with or without its companion CCs and vice versa. Results We analyzed transcriptome profile of different oocyte and CC samples using Affymetrix GeneChip Bovine Genome array containing 23000 transcripts. Out of 13162 genes detected in germinal vesicle (GV) oocytes and their companion CCs, 1516 and 2727 are exclusively expressed in oocytes and CCs, respectively, while 8919 are expressed in both. Similarly, of 13602 genes detected in metaphase II (MII) oocytes and CCs, 1423 and 3100 are exclusively expressed in oocytes and CCs, respectively, while 9079 are expressed in both. A total of 265 transcripts are differentially expressed between oocytes cultured with (OO + CCs) and without (OO - CCs) CCs, of which 217 and 48 are over expressed in the former and the later groups, respectively. Similarly, 566 transcripts are differentially expressed when CCs mature with (CCs + OO) or without (CCs - OO) their enclosed oocytes. Of these, 320 and 246 are over expressed in CCs + OO and CCs - OO, respectively. While oocyte specific transcripts include those involved in transcription (IRF6, POU5F1, MYF5, MED18), translation (EIF2AK1, EIF4ENIF1) and CCs specific ones include those involved in carbohydrate metabolism (HYAL1, PFKL, PYGL, MPI), protein metabolic processes (IHH, APOA1, PLOD1), steroid biosynthetic process (APOA1, CYP11A1, HSD3B1, HSD3B7). Similarly, while transcripts over expressed in OO + CCs are involved in

  19. Influence of co-culture with denuded oocytes during in vitro maturation on fertilization and developmental competence of cumulus-enclosed porcine oocytes in a defined system.

    PubMed

    Appeltant, Ruth; Somfai, Tamás; Kikuchi, Kazuhiro; Maes, Dominiek; Van Soom, Ann

    2016-04-01

    Co-culture of cumulus-oocyte complexes (COCs) with denuded oocytes (DOs) during in vitro maturation (IVM) was reported to improve the developmental competence of oocytes via oocyte-secreted factors in cattle. The aim of the present study was to investigate if addition of DOs during IVM can improve in vitro fertilization (IVF) and in vitro culture (IVC) results for oocytes in a defined in vitro production system in pigs. The maturation medium was porcine oocyte medium supplemented with gonadotropins, dbcAMP and β-mercaptoethanol. Cumulus-oocyte complexes were matured without DOs or with DOs in different ratios (9 COC, 9 COC+16 DO and 9 COC+36 DO). Consequently; oocytes were subjected to IVF as intact COCs or after denudation to examine if DO addition during IVM would affect cumulus or oocyte properties. After fertilization, penetration and normal fertilization rates of zygotes were not different between all tested groups irrespective of denudation before IVF. When zygotes were cultured for 6 days, no difference could be observed between all treatment groups in cleavage rate, blastocyst rate and cell number per blastocyst. In conclusion, irrespective of the ratio, co-culture with DOs during IVM did not improve fertilization parameters and embryo development of cumulus-enclosed porcine oocytes in a defined system.

  20. RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

    SciTech Connect

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-06-19

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only a relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.

  1. RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

    DOE PAGESBeta

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-06-19

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only amore » relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.« less

  2. Improving High-resolution Weather Forecasts using the Weather Research and Forecasting (WRF) Model with Upgraded Kain-Fritsch Cumulus Scheme

    EPA Science Inventory

    High-resolution weather forecasting is affected by many aspects, i.e. model initial conditions, subgrid-scale cumulus convection and cloud microphysics schemes. Recent 12km grid studies using the Weather Research and Forecasting (WRF) model have identified the importance of inco...

  3. RACORO Continental Boundary Layer Cloud Investigations: 3. Separation of Parameterization Biases in Single-Column Model CAM5 Simulations of Shallow Cumulus

    NASA Technical Reports Server (NTRS)

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-01-01

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) Project has constructed case studies from the Atmospheric Radiation Measurement Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only a relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.

  4. Sensitivity of the GCM driven summer monsoon simulations to cumulus parameterization schemes in nested RegCM3

    NASA Astrophysics Data System (ADS)

    Sinha, P.; Mohanty, U. C.; Kar, S. C.; Dash, S. K.; Kumari, S.

    2013-04-01

    The regional climate model (RegCM3) from the Abdus Salam International Centre for Theoretical Physics has been used to simulate the Indian summer monsoon for three different monsoon seasons such as deficit (1987), excess (1988) and normal (1989). Sensitivity to various cumulus parameterization and closure schemes of RegCM3 driven by the National Centre for Medium Range Weather Forecasting global spectral model products has been tested. The model integration of the nested RegCM3 is conducted using 90 and 30-km horizontal resolutions for outer and inner domains, respectively. The India Meteorological Department gridded rainfall (1° × 1°) and National Centre for Environment Prediction (NCEP)-Department of Energy (DOE) reanalysis-2 of 2.5° × 2.5° horizontal resolution data has been used for verification. The RegCM3 forced by NCEP-DOE reanalysis-2 data simulates monsoon seasons of 1987 and 1988 reasonably well, but the monsoon season of 1989 is not represented well in the model simulations. The RegCM3 runs driven by the global model are able to bring out seasonal mean rainfall and circulations well with the use of the Grell and Anthes-Kuo cumulus scheme at 90-km resolution. While the rainfall intensity and distribution is brought out well with the Anthes-Kuo scheme, upper air circulation features are brought out better by the Grell scheme. The simulated rainfall distribution is better with RegCM3 using the MIT-Emanuel cumulus scheme for 30-km resolution. Several statistical analyses, such as correlation coefficient, root mean square error, equitable threat score, confirm that the performance of MIT-Emanuel scheme at 30-km resolution is better in simulating all-India summer monsoon rainfall. The RegCM3 simulated rainfall amount is more and closer to observations than that from the global model. The RegCM3 has corrected its driven GCM in terms of rainfall distribution and magnitude over some parts of India during extreme years. This study brings out several

  5. Increased expression of pentraxin 3 after in vivo and in vitro stimulation with gonadotropins in porcine oocyte-cumulus complexes and granulosa cells.

    PubMed

    Nagyova, E; Kalous, J; Nemcova, L

    2016-07-01

    It has been previously shown that multimeric pentraxin 3 (PTX3) is a key component of the cumulus oophorus extracellular matrix (ECM) in mice. In response to the ovulatory LH surge, the cumulus cells assemble a unique ECM that envelopes the oocyte and cumulus cell complex. Importantly, cumuli from PTX3(-/-) mice were defective in their ECM organization and their fertility was impaired. It has been demonstrated that tumor necrosis factor alpha-induced protein 6 catalyzes the formation of heavy chains of (inter-alpha-trypsin inhibitor) -hyaluronan complexes and these are then cross-linked via PTX3. This process is tightly regulated and requires the proteins to meet/interact in the correct order. Finally, in this way, the above-listed proteins form the cumulus oophorus ECM. We investigated whether PTX3 is expressed in the porcine preovulatory follicle. Porcine oocyte-cumulus complexes (OCC) and mural granulosa cells (MGC) from gilts were obtained either after stimulation in vivo with eCG/hCG (4, 8, 16, 24, and 32 h) or culture in vitro (4, 24, and 44 h) in FSH/LH-supplemented medium. The methods performed were real-time reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunostaining. The expression of PTX3 transcripts was significantly increased 24 h after either in vivo hCG stimulation or in vitro FSH/LH treatment in both OCC and MGC. Western blot analysis with PTX3 antibody revealed that not only matrix extracts from in vivo-stimulated gilts contain high levels of PTX3 protein but also matrix extracts of FSH/LH-stimulated OCC cultured in medium supplemented either with follicular fluid or with porcine serum. The localization of PTX3 in the cumulus oocyte complex was confirmed by immunostaining. In conclusion, PTX3 is produced by porcine OCC and MGC both in vivo and in vitro with gonadotropin stimuli inducing cumulus expansion.

  6. Static electrification in a 700 MVA 23.7/345 kV generator step up transformer

    SciTech Connect

    Ugo, J.H.; Moore, H.R.

    1995-05-01

    On April 5, 1994, Generator Step-Up Transformer 2E at the Braidwood nuclear station of Commonwealth Edison was tripped off line by protective relays due to a B O high voltage winding failure. At the time of the trip, there were no system disturbances and the unit was at 98% load. Transformer 2E had been in service at Braidwood Station since 1984. Two identical 625/700 MVA, 3 O, 23.7-345 KV transformers (2E and 2W) were in services as the GSU transformers for Braidwood Unit 2. Both are shell form designs furnished to Commonwealth Edison between 1975 and 1980. A teardown inspection of the failed transformer was performed, and this inspection revealed that a turn to turn failure had occurred within the first section of the B O 345 KV winding. The failure appears to have originated strand to strand within conductors of the same turn and later progressed into the turn to turn fault detected on April 5, 1994. During this inspection, evidence of discharges resulting from static electrification were found. These were rather light surface discharges which had not progressed to the dark or worm hole appearing state. It was concluded that the static electrification discharges did not contribute to the failure. Prior to August 1992, the operating policy regarding cooler operation on the Braidwood transformers was to activate all pumps upon closing of the generator field breaker. This operating mode provided conditions conducive to static electrification. Since August 1992, the cooler controls were divided into a group 1 and group 2 operating sequence with group 1 being initiated upon closing of the generator field breaker, and group 2 by top oil temperatures of 60 C. It is assumed that the discharges observed had occurred prior to the group 1 and group 2 cooler control modification. It is also believed that a more serious problem could have resulted from these discharges if the transformer would have continued to be operated without the use of the cooler temperature controls.

  7. Epigenetic modification of long interspersed elements-1 in cumulus cells of mature and immature oocytes from patients with polycystic ovary syndrome

    PubMed Central

    Wasinarom, Artisa; Sereepapong, Wisan; Sirayapiwat, Porntip; Rattanatanyong, Prakasit; Mutirangura, Apiwat

    2016-01-01

    Objective The long interspersed elements (LINE-1, L1s) are a group of genetic elements found in large numbers in the human genome that can translate into phenotype by controlling genes. Growing evidence supports the role of epigenetic in polycystic ovary syndrome (PCOS). The purpose of this study is to evaluate the DNA methylation levels in LINE-1 in a tissue-specific manner using cumulus cells from patients with PCOS compared with normal controls. Methods The study included 19 patients with PCOS and 22 control patients who were undergoing controlled ovarian hyperstimulation. After oocyte retrieval, cumulus cells were extracted. LINE-1 DNA methylation levels were analysed by bisulfite treatment, polymerase chain reaction, and restriction enzyme digestion. The Connection Up- and Down-Regulation Expression Analysis of Microarrays software package was used to compare the gene regulatory functions of intragenic LINE-1. Results The results showed higher LINE-1 DNA methylation levels in the cumulus cells of mature oocytes in PCOS patients, 79.14 (±2.66) vs. 75.40 (±4.92); p=0.004, but no difference in the methylation of cumulus cells in immature oocytes between PCOS and control patients, 70.33 (±4.79) vs. 67.79 (±5.17); p=0.155. However, LINE-1 DNA methylation levels were found to be higher in the cumulus cells of mature oocytes than in those of immature oocytes in both PCOS and control patients. Conclusion These findings suggest that the epigenetic modification of LINE-1 DNA may play a role in regulating multiple gene expression that affects the pathophysiology and development of mature oocytes in PCOS. PMID:27358825

  8. Impact of subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models

    SciTech Connect

    Xiao, Heng; Gustafson, William I.; Wang, Hailong

    2014-04-29

    Subgrid-scale interactions between turbulence and radiation are potentially important for accurately reproducing marine low clouds in climate models. To better understand the impact of these interactions, the Weather Research and Forecasting (WRF) model is configured for large eddy simulation (LES) to study the stratocumulus-to-trade cumulus (Sc-to-Cu) transition. Using the GEWEX Atmospheric System Studies (GASS) composite Lagrangian transition case and the Atlantic Trade Wind Experiment (ATEX) case, it is shown that the lack of subgrid-scale turbulence-radiation interaction, as is the case in current generation climate models, accelerates the Sc-to-Cu transition. Our analysis suggests that in cloud-topped boundary layers subgrid-scale turbulence-radiation interactions contribute to stronger production of temperature variance, which in turn leads to stronger buoyancy production of turbulent kinetic energy and helps to maintain the Sc cover.

  9. A simple parcel method for prediction of cumulus onset and area-averaged cloud amount over heterogeneous land surfaces

    NASA Technical Reports Server (NTRS)

    Wetzel, Peter J.

    1990-01-01

    A set of PBL data selected from the Wangara experiment is used to examine the relationship between cumulus amount and the calculated relative humidity of rising parcels. The Wilde et al. (1985) method is compared to two explicit parcel methods. It is shown that predictions using parcel methods, in which surface air is lifted to its equilibrium level while being diluted by a defined amount of mixed layer air, are superior for cloud amount, especially during periods of rapid cloud onset when the mean boundary layer top is swiftly rising through a near-neutral layer. Pending independent verification, it appears that an rms error in instantaneous cloud amount of + or - 10 percent may be achievable.

  10. Nonesterified Fatty Acid-Induced Endoplasmic Reticulum Stress in Cattle Cumulus Oocyte Complexes Alters Cell Metabolism and Developmental Competence.

    PubMed

    Sutton-McDowall, Melanie L; Wu, Linda L Y; Purdey, Malcolm; Abell, Andrew D; Goldys, Ewa M; MacMillan, Keith L; Thompson, Jeremy G; Robker, Rebecca L

    2016-01-01

    Reduced oocyte quality has been associated with poor fertility of high-performance dairy cows during peak lactation, due to negative energy balance. We examined the role of nonesterified fatty acids (NEFAs), known to accumulate within follicular fluid during under- and overnutrition scenarios, in causing endoplasmic reticulum (ER) stress of in vitro maturated cattle cumulus-oocyte complexes (COCs). NEFA concentrations were: palmitic acid (150 μM), oleic acid (200 μM), and steric acid (75 μM). Abattoir-derived COCs were randomly matured for 24 h in the presence of NEFAs and/or an ER stress inhibitor, salubrinal. Total and hatched blastocyst yields were negatively impacted by NEFA treatment compared with controls, but this was reversed by salubrinal. ER stress markers, activating transcription factor 4 (Atf4) and heat shock protein 5 (Hspa5), but not Atf6, were significantly up-regulated by NEFA treatment within whole COCs but reversed by coincubation with salubrinal. Likewise, glucose uptake and lactate production, measured in spent medium samples, showed a similar pattern, suggesting that cumulus cell metabolism is sensitive to NEFAs via an ER stress-mediated process. In contrast, while mitochondrial DNA copy number was recovered in NEFA-treated oocytes, oocyte autofluorescence of the respiratory chain cofactor, FAD, was lower following NEFA treatment of COCs, and this was not reversed by salubrinal, suggesting the negative impact was via reduced mitochondrial function. These results reveal the significance of NEFA-induced ER stress on bovine COC developmental competence, revealing a potential therapeutic target for improving oocyte quality during peak lactation. PMID:26658709

  11. On impacts of overlying solar-absorbing aerosol layers on the transition of stratocumulus to trade cumulus clouds

    NASA Astrophysics Data System (ADS)

    Fridlind, A. M.; Ackerman, A. S.; Zhou, X.; Wood, R.; Kollias, P.

    2015-12-01

    Early cloud-scale modeling work on effects of solar-absorbing aerosol layers focused on the desiccation of shallow cumulus clouds embedded with such layers, resulting from the reduction in relative humidity induced by solar heating, as well as reduced vertical mixing from stabilization of the boundary layer. Such a cloud response serves as a positive radiative forcing at the top of atmosphere, tending to warm the climate system. Subsequent work has largely targeted the impact of overlying solar-absorbing aerosol layers on stratiform clouds in the marine boundary layer, in which the solar heating increases the strength of the temperature inversion capping the boundary layer, which reduces entrainment of overlying air into the boundary layer. Because entrainment typically (but not always) reduces the average relative humidity of the boundary layer and thereby leads to a thinner cloud layer, a reduction in entrainment induced by an absorbing aerosol layer leads to a thicker cloud layer and a negative radiative forcing at the top of atmosphere, tending to cool the climate system. Here we use large-eddy simulations to assess the effects of overlying solar-absorbing aerosol layers on the transition of stratocumulus to trade cumulus clouds. Beyond the impact on the inversion strength, we also consider the changes induced by microphysical response to entrained aerosol that serve as cloud condensation nuclei, as well as reduction in solar heating of the cloud induced by the overlying aerosol layer. Observationally-based transition cases used in a recent large-eddy simulation intercomparison will be used as a starting point for the model setup, along with idealized aerosol layer properties based on remote sensing and in situ observations. We will also use the same simulation setups to evaluate and compare the response of the single column model version of the GISS climate model (with two-moment microphysics).

  12. Hypothesis: the reversal of the relation between economic growth and health progress in Sweden in the nineteenth and twentieth centuries was caused by electrification.

    PubMed

    Milham, Samuel

    2014-01-01

    The expected decline of health indicators with economic recessions and improvement with economic growth in the nineteenth century Sweden was reversed in the twentieth century, giving the counterintuitive pattern of higher mortality and lower life expectancy in economic expansions and improvement of these indices in recessions. The change or "tipping point" occurred at the end of the nineteenth century or early in the twentieth century when electrification was introduced into Sweden. All 5 of the reversals of annual industrial electric energy use in the US between 1912 and 1970 were accompanied by recessions with lowered GDP, increased unemployment, decreased mortality and increased life expectancy. The health indices were not related to residential electricity use. The mortality improvement between 1931 and 1932 by state in the US strongly favored urban areas over rural areas. Rural unemployment by state in 1930 was significantly positively correlated with residential electrification percentage by state in 1930. The health effects of economic change are mediated by electrical exposure.

  13. Melatonin enhances the in vitro maturation and developmental potential of bovine oocytes denuded of the cumulus oophorus.

    PubMed

    Zhao, Xue-Ming; Min, Jiang-Tao; Du, Wei-Hua; Hao, Hai-Sheng; Liu, Yan; Qin, Tong; Wang, Dong; Zhu, Hua-Bin

    2015-08-01

    This study was designed to determine the effect of melatonin on the in vitro maturation (IVM) and developmental potential of bovine oocytes denuded of the cumulus oophorus (DOs). DOs were cultured alone (DOs) or with 10-9 M melatonin (DOs + MT), cumulus-oocyte complexes (COCs) were cultured without melatonin as the control. After IVM, meiosis II (MII) rates of DOs, and reactive oxygen species (ROS) levels, apoptotic rates and parthenogenetic blastocyst rates of MII oocytes were determined. The relative expression of ATP synthase F0 Subunit 6 and 8 (ATP6 and ATP8), bone morphogenetic protein 15 (BMP-15) and growth differentiation factor 9 (GDF-9) mRNA in MII oocytes and IFN-tau (IFN-τ), Na+/K+-ATPase, catenin-beta like 1 (CTNNBL1) and AQP3 mRNA in parthenogenetic blastocysts were quantified using real-time polymerase chain reaction (PCR). The results showed that: (1) melatonin significantly increased the MII rate of DOs (65.67 ± 3.59 % vs. 82.29 ± 3.92%; P < 0.05), decreased the ROS level (4.83 ± 0.42 counts per second (c.p.s) vs. 3.78 ± 0.29 c.p.s; P < 0.05) and apoptotic rate (36.99 ± 3.62 % vs. 21.88 ± 2.08 %; P < 0.05) and moderated the reduction of relative mRNA levels of ATP6, ATP8, BMP-15 and GDF-9 caused by oocyte denudation; (2) melatonin significantly increased the developmental rate (24.17 ± 3.54 % vs. 35.26 ± 4.87%; P < 0.05), and expression levels of IFN-τ, Na+/K+-ATPase, CTNNBL1 and AQP3 mRNA of blastocyst. These results indicated that melatonin significantly improved the IVM quality of DOs, leading to an increased parthenogenetic blastocyst formation rate and quality. PMID:24869483

  14. Quantifying and Parameterizing the Transport of Sub-Cloud Layer Moisture and Reactants by Shallow Cumulus Clouds over Land

    NASA Astrophysics Data System (ADS)

    Ouwersloot, H. G.; van Stratum, B. J.; Vila-Guerau Arellano, J.; Sikma, M.; Krol, M. C.; Lelieveld, J.

    2013-12-01

    We investigate the vertical transport of moisture and atmospheric chemical reactants from the sub-cloud layer to the cumulus cloud layer related to the kinematic mass flux that is driven by shallow convection over land. The dynamical and chemical assumptions needed for mesoscale and global chemistry-transport model parameterizations are systematically analysed using numerical experiments performed by a Large-Eddy Simulation (LES) model. First, we identify and discuss the four primary feedback mechanisms between sub-cloud layer dynamics and mass-flux transport by shallow cumulus clouds for typical mid-latitude conditions. These feedbacks involve mixed-layer drying and heating, changing the moisture variability at the sub-cloud layer top and adjusting entrainment. Based on this analysis and LES experiments, we design parameterizations for cloud properties and mass-flux transport of air and moisture that can be applied to large-scale models. As an intermediate step, we incorporate the parameterizations in a conceptual mixed-layer model, which enables us to study these interplays in more detail. By comparing the results of this model with LES case studies, we show for a wide range of conditions that the new parameterizations enable the model to reproduce the sub-cloud layer dynamics and the four aforementioned feedbacks. However, by considering heterogeneous sensible and latent heat fluxes at the surface, we demonstrate that the parameterizations are sensitive to specific boundary conditions due to changes in the boundary-layer dynamics. Second, we extend the investigation to determine whether the parameterizations are suitable for tropical conditions and to represent the transport of reactants. The numerical experiments in this analysis are inspired by observations over the Amazon during the dry season. Isoprene, a key atmospheric compound over the tropical rain forest, decreases by 8.5 % hr-1 on average and 15 % hr-1 at maximum due to mass-flux induced removal. The

  15. Gene Expression of Monocarboxylate Transporters and Oocyte-secreted Factors in Bovine Cumulus-oocyte Complexes Selected by Brilliant Cresyl Blue.

    PubMed

    Lopes, E F; Marques, L S; Duranti, R G; de Oliveira, A T D; Lopes, R F F; Rodrigues, J L

    2015-10-01

    Oocyte selection based on the brilliant cresyl blue (BCB) staining test has been successfully used to differentiate between competent and incompetent bovine oocytes. Here, the expression of genes involved in transport of monocarboxylates (Mct1-4) and oogenesis specific genes (Bmp15, Gdf9 and Has2) in BCB+ and BCB- selected immature and mature bovine cumulus-oocyte complexes (COC) was evaluated. In order to find specific molecular markers to characterize successful oocyte maturation, our study was also aimed at identifying the expression of Mcts and oogenesis specific genes in denuded oocytes and cumulus cells. Immature COCs morphological appropriate were (i) stained with 26 mm BCB for 90 min before IVM, (ii) exposed to same incubation conditions as stained COCs, but without BCB (holding group) or (iii) transferred into a maturation medium immediately after morphological selection (control group). mRNA expression was investigated by RT-PCR in COCs before and after IVM. No relationship was observed in the relative expression of Has2, Gdf9, Bmp15 or Mct1, 2 and 4 transcripts between BCB+ and BCB- COCs. Transcripts analysis showed that Gdf9 and Bmp15 in BCB+, BCB- and holding groups were up-regulated (p < 0.05) before IVM, while Has2 was up-regulated (p < 0.01) after IVM in the control group. Other genes remained stable during maturation (Mct1, 2 and 4). Our results showed, for the first time, Mct1, 2 and 4 expression in bovine COCs. Mct1 and Mct4 transcripts were present in denuded oocytes and cumulus cell, while Mct2 was detected only in cumulus cells. These differences between the three isoforms in localization suggest unique roles for each in monocarboxylate transport during maturation.

  16. Increased New lncRNA-mRNA Gene Pair Levels in Human Cumulus Cells Correlate With Oocyte Maturation and Embryo Development.

    PubMed

    Li, Juan; Cao, Yunxia; Xu, Xiaofeng; Xiang, Huifen; Zhang, Zhiguo; Chen, Beili; Hao, Yan; Wei, Zhaolian; Zhou, Ping; Chen, Dawei

    2015-08-01

    The close relationship between cumulus cells and oocyte indicates that the analysis of cumulus gene expression is a potential noninvasive method to aid embryo selection and in vitro fertilization outcome. Long noncoding RNAs (LncRNAs) could regulate essential pathways that contribute to human oocyte maturation, fertilization, and embryo development, which indicates that lncRNA would be valuable biomarkers. In our previous study, AK124742 is a newly detected lncRNA that was identified as being natural antisense to PSMD6, but its role in oocyte and embryo development is still not elucidated and needs to be investigated. Here, the expression of AK124742 and PSMD6 was measured in 40 pairs of cumulus cells from oocytes that result in high-quality embryos (HCCs) and from oocytes that result in poor-quality embryos (PCCs) by real-time quantitative reverse transcriptase polymerase chain reaction. The predictive value of AK124742 and PSMD6 was evaluated using a receiver-operating characteristic (ROC) curve. Notably, elevated expression levels of AK124742 and PSMD6 were observed in HCCs compared to PCCs (72.5% and 62.5%, respectively; P < .01). Expression of AK124742 was potentially positively associated with the PSMD6 levels. The relative expression levels of AK124742 and PSMD6 in the pregnancy group were significantly higher than those in the nonpregnancy group (P < .01).The area under the ROC curve of AK124742 was 0.78 (95% confidence interval: 0.64-0.93). In conclusion, AK124742 and PSMD6 as a new lncRNA-messenger RNA gene pair in human cumulus cells may be considered as potential biomarkers to aid embryo selection.

  17. Research Resources: Comparative MicroRNA Profiles in Human Corona Radiata Cells and Cumulus Oophorus Cells Detected by Next-Generation Small RNA Sequencing

    PubMed Central

    Zhang, Yuan-Wei; Liu, Yu-Sheng; Ma, Chun-Hong

    2014-01-01

    During folliculogenesis, cumulus cells surrounding the oocyte differentiate into corona radiata cells (CRCs) and cumulus oophorus cells (COCs), which are involved in gonadal steroidogenesis and the development of germ cells. Several studies suggested that microRNAs (miRNAs) play an important regulatory role at the post-transcriptional level in cumulus cells. However, comparative miRNA profiles and associated processes in human CRCs and COCs have not been reported before. In this study, miRNA profiles were obtained from CRCs and COCs using next generation sequencing in women undergoing controlled ovarian stimulation for IVF. A total of 785 and 799 annotated miRNAs were identified in CRCs and COCs, while high expression levels of six novel miRNAs were detected both in CRCs and in COCs. In addition, different expression patterns in CRCs and COCs were detected in 72 annotated miRNAs. To confirm the miRNA profile in COCs and CRCs, quantitative real-time PCR was used to validate the expression of annotated miRNAs, differentially expressed miRNAs, and novel miRNAs. The miRNAs in the let-7 family were found to be involved in the regulation of a broad range of biological processes in both cumulus cell populations, which was accompanied by a large amount of miRNA editing. Bioinformatics analysis showed that amino acid and energy metabolism were targeted significantly by miRNAs that were differentially expressed between CRCs and COCs. Our work extends the current knowledge of the regulatory role of miRNAs and their targeted pathways in folliculogenesis, and provides novel candidates for molecular biomarkers in the research of female infertility. PMID:25188034

  18. Comparative importance of fatty acid beta-oxidation to nuclear maturation, gene expression, and glucose metabolism in mouse, bovine, and porcine cumulus oocyte complexes.

    PubMed

    Paczkowski, Melissa; Silva, Elena; Schoolcraft, William B; Krisher, Rebecca L

    2013-05-01

    The objective of these experiments was to evaluate the importance of fatty acid beta-oxidation (FAO) in the cumulus oocyte complex (COC) during in vitro maturation (IVM) to oocyte nuclear maturation and gene expression in both the oocyte and cumulus cells in three species with differing amounts of oocyte intracellular lipids (mouse, low; bovine, moderate; porcine, high). We inhibited FAO using etomoxir at 0, 10, 25, 100, or 250 μM. Completion of oocyte nuclear maturation was inhibited after COC exposure to 250 μM etomoxir in mouse oocytes, 100 μM etomoxir in bovine oocytes, and as little as 10 μM etomoxir in porcine oocytes (P < 0.05). When FAO was inhibited in mouse and porcine COCs resulting in inhibition of meiosis, the abundance of FAO, glycolytic, and oxidative stress gene transcripts were decreased in oocytes and cumulus cells (P < 0.05), although to a much greater extent in the pig. In bovine oocytes and cumulus cells, FAO gene transcripts were increased and glycolytic gene expression altered following meiotic inhibition due to etomoxir. Etomoxir, at doses that did not inhibit nuclear maturation in bovine and murine COCs, increased glucose consumption (P < 0.05), suggesting glucose metabolism is increased to meet the metabolic demands of the COCs when fatty acid metabolism is compromised. Our data demonstrates that FAO is essential to oocyte nuclear maturation in all three species. Sensitivity of nuclear maturation to FAO inhibition reflects the amount of lipid present in the ooplasm and may suggest a relative reliance on this metabolic pathway.

  19. Characterization of pig sperm hyaluronidase and improvement of the digestibility of cumulus cell mass by recombinant pSPAM1 hyaluronidase in an in vitro fertilization assay.

    PubMed

    Yoon, Sungwon; Chang, Kyu-Tae; Cho, Hongsang; Moon, Jisang; Kim, Ju-Sung; Min, Sung-Hun; Koo, Deog-Bon; Lee, Sang-Rae; Kim, Sang-Hyun; Park, Ki-Eun; Park, Young Il; Kim, Ekyune

    2014-11-30

    Although sperm hyaluronidase is thought to play an important role in mammalian fertilization, the molecular function underlying these steps remains largely unknown. In mouse models, sperm-specific SPAM1 and HYAL5 hyaluronidase are believed to function in both sperm penetration of the cumulus matrix and sperm-ZP binding. However, gene-targeting studies for SPAM1 or HYAL5 show that hyaluronidases are not essential for fertilization, despite the fact that exogenous hyaluronidase can disrupt the cumulus matrix. Therefore, to evaluate whether sperm hyaluronidase is essential for mammalian fertilization, it is necessary to generate HYAL5/SPAM1 double-knockout mice. However, generating double-knockout mice is very difficult because these two genes exist on the same chromosome. Recently, investigators have begun to employ the pig model system to study human disease due to its similarities to human anatomy and physiology. In this study, we confirmed that pig SPAM1 exists as a single copy gene on chromosome 18 and is specifically expressed in the testis. In addition, we expressed recombinant pig SPAM1 in human embryonic kidney 293 cells and showed that these enzymes possess hyaluronidase activity. We also demonstrated that a polyclonal antibody against pig sperm hyaluronidase inhibits sperm-egg interactions in an in vitro fertilization (IVF) assay. Our results suggest that pig SPAM1 may play a critical role in pig fertilization and that recombinant SPAM1 can disperse the oocyte-cumulus complex in an IVF assay.

  20. The Goddard Cumulus Ensemble Model: Model Description and Its Application for Studying the TOGA COARE and GATE Convective Systems

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The Goddard Cumulus Ensemble (GCE) model was utilized in two and three dimensions in order to examine the behavior and response of simulated deep tropical cloud systems occurred in west Pacific warm pool region and Atlantic ocean. The periods chosen for simulation were convectively active period over the TOGA-COARE IFA (19-27 December 1992) and GATE (September 1 to 7, 1974). The TOGA COARE IFA period was also in the framework of the GEWEX Cloud System Study (GCSS) WG4 case 2. We will examine the differences between the microphysics (warm rain and ice processes, evaporation/sublimation and condensation/deposition), Q1 (Temperature) and Q2 (Water vapor) budgets between these two convective events occurred in different large-scale environments. The contribution of stratiform precipitation and its relationship to the vertical shear of the large-scale horizontal wind will also be examined. The results from GCSS model intercomparsion will be presented. The new improvements (i.e., microphysics, cloud radiation interaction, surface processes and numerical advection scheme) of the GCE model as well as their sensitivity to the model results will be discussed.

  1. 3D Aerosol-Cloud Radiative Interaction Observed in Collocated MODIS and ASTER Images of Cumulus Cloud Fields

    NASA Technical Reports Server (NTRS)

    Wen, Guoyong; Marshak, Alexander; Cahalan, Robert F.; Remer, Lorraine A.; Kleidman, Richard G.

    2007-01-01

    3D aerosol-cloud interaction is examined by analyzing two images containing cumulus clouds in biomass burning regions in Brazil. The research consists of two parts. The first part focuses on identifying 3D clo ud impacts on the reflectance of pixel selected for the MODIS aerosol retrieval based purely on observations. The second part of the resea rch combines the observations with radiative transfer computations to identify key parameters in 3D aerosol-cloud interaction. We found that 3D cloud-induced enhancement depends on optical properties of nearb y clouds as well as wavelength. The enhancement is too large to be ig nored. Associated biased error in 1D aerosol optical thickness retrie val ranges from 50% to 140% depending on wavelength and optical prope rties of nearby clouds as well as aerosol optical thickness. We caution the community to be prudent when applying 1D approximations in comp uting solar radiation in dear regions adjacent to clouds or when usin g traditional retrieved aerosol optical thickness in aerosol indirect effect research.

  2. Variability in surface meteorology and air-sea fluxes due to cumulus convective systems observed during CINDY/DYNAMO

    NASA Astrophysics Data System (ADS)

    Yokoi, Satoru; Katsumata, Masaki; Yoneyama, Kunio

    2014-03-01

    This study examines the variability in surface meteorological parameters and air-sea heat fluxes due to cold pools emanating from cumulus convective systems observed over the tropical Indian Ocean in November 2011. In particular, this study focuses on convective systems that are spatially smaller than mesoscale convective systems in a southeasterly trade wind environment. Composite analyses of convectively active periods show an increase in the sensible heat flux by 15-20 W m-2 that is primarily attributed to an increase in the difference between the surface air temperature and sea surface temperature and an increase in the latent heat flux by 30-70 W m-2 due to enhanced surface wind speeds. A succession of convectively active periods leads to a greater influence than those occurring independently. The direction of the surface wind velocity anomaly due to cold pools tends to be close to that of the environmental wind velocity, resulting in an efficient enhancement of wind speed. This study also demonstrates the close relation between cold pool intensities and convective activity. In particular, two measures of cold pool intensity, a minimum surface air temperature and a maximum amount of surface wind speed enhancement, are correlated with each other and with the convective activity around the observation point measured by radar-estimated rainfall and radar echo coverage.

  3. A new approach for the oocyte genotoxicity assay: adaptation of comet assay on mouse cumulus-oocyte complexes.

    PubMed

    Greco, F; Perrin, J; Auffan, M; Tassistro, V; Orsière, T; Courbiere, B

    2015-07-01

    Conventional genotoxicity tests are technically difficult to apply to oocytes, and results obtained on somatic cells cannot be extrapolated to gametes. We have previously described a comet assay (original-CA) on denuded mouse oocytes, but, in vivo, oocytes are not isolated from their surrounding follicular cells. Our objective was to develop a comet assay on cumulus-oocyte complexes (COC-CA) for a more physiological approach to study the genotoxicity of environmental factors on oocytes. For COC-CA, whole COC were exposed directly to exogenous agents after ovulation and removal from oviducts. Three conditions were studied: a negative control group, and two positive control groups, one of which was exposed to hydrogen peroxide (H2O2) and the other group was incubated with cerium dioxide nanoparticles (CeO2 NPs). With both tests, DNA damage was significant in the presence of both H2O2 and CeO2 NPs compared with the negative control. COC-CA offers an interesting tool for assaying the genotoxicity of environmental agents towards germinal cells. Furthermore, COC-CA is less time-consuming and simplifies the protocol of the original-CA, because COC-CA is easier to perform without the washing-out procedure.

  4. Metabolic differences in bovine cumulus-oocyte complexes matured in vitro in the presence or absence of follicle-stimulating hormone and bone morphogenetic protein 15.

    PubMed

    Sutton-McDowall, Melanie L; Mottershead, David G; Gardner, David K; Gilchrist, Robert B; Thompson, Jeremy G

    2012-10-01

    Bidirectional communication between cumulus cells and the oocyte is necessary to achieve oocyte developmental competence. The aim of the present study was to examine the effects of recombinant human bone morphogenetic protein 15 (rhBMP15) and follicle-stimulating hormone (FSH) supplementation on bovine cumulus-oocyte complex (COC) metabolism during maturation. Bovine COCs were matured in the presence of absence of FSH, rhBMP15, or both for 23 h. The addition of FSH and rhBMP15 increased blastocyst development (without rhBMP15 and FSH, 28.4% ± 7.4%; with FSH and rhBMP15, 51.5% ± 5.4%; P < 0.05). Glucose uptake and lactate production was significantly increased by greater than 2-fold with FSH (P < 0.05), whereas rhBM15 supplementation did not increase these levels. rhBMP15 supplementation (regardless of FSH) significantly decreased ADP levels in COCs, leading to an increase in ATP:ADP ratios (P < 0.05). Indicators of mitochondrial activity and cellular REDOX, oxidized flavin adenine dinucleotide (FAD(++)) and reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H), levels within the oocyte of COCs were significantly higher with rhBMP15 alone, whereas the presence of FSH diminished the rhBMP15 effect. Regardless of treatment, no changes in REDOX state (FAD(++):NAD(P)H). The significant increase in FAD(++) and NAD(P)H in COCs with rhBMP15 was mediated via cumulus cells, because no differences were found in denuded oocytes cultured in the presence or absence of FSH, rhBMP15, or both. The present study demonstrates that a principal metabolic consequence of FSH supplementation of COCs is to alter the glycolytic rate of cumulus cells, whereas that of rhBMP15 is to regulate oxidative phosphorylation in the oocyte, even though it acts via cumulus cells. These effects are tempered when FSH and rhBMP15 are present together but, nonetheless, yield the best oocyte developmental competence.

  5. Influence of FSH and hCG on the resumption of meiosis of bovine oocytes surrounded by cumulus cells connected to membrana granulosa.

    PubMed

    van Tol, H T; van Eijk, M J; Mummery, C L; van den Hurk, R; Bevers, M M

    1996-10-01

    Cumulus oocyte complexes (COCs) and cumulus oocyte complexes connected to a piece of the membrane granulosa (COCGs) were isolated from bovine antral follicles with a diameter of 2 to 8 mm. After culture of COCGs without gonadotrophic hormones for 22 hr approximately 50% of the oocytes were still in the germinal vesicle (GV) stage. Histology of the COCGs showed that the pieces of the membrana granulosa were free of thecal cells and parts of the basal membrane. This indicates that the membrana granulosa solely inhibits the progression of meiosis. To investigate the effect of gonadotropins on the resumption of meiosis of oocytes from small and medium sized antral follicles, COCs and COCGs were cultured with or without rec-hFSH or hCG. Addition of 0.05 IU rec-hFSH to the culture medium of COCGs resulted in germinal vesicle breakdown in 97.8% of the oocytes compared to 46% in the control group, and an increase of the diameter of the COCs (479 microns vs. 240 microns in the control group). Addition of 0.05 IU hCG to the culture medium had no effect on nuclear maturation (47.2% GV vs. 48.5% GV in the control group) nor on cumulus expansion (246 microns vs. 240 microns in the control group). RT-PCR on cDNA of the follicular wall, cumulus cells, granulosa cells, COCs, and oocytes revealed that mRNA for FSH receptor was present in all cell types except oocytes. mRNA of the LH receptor was detected exclusively in thecal cells. Nucleotide sequence analysis and alignment of the cloned PCR products showed the presence of two isoforms of the FSH receptor mRNA and two isoforms of the LH receptor mRNA. It is concluded that, in vitro, resumption of meiosis of oocytes, originating from small and medium sized antral follicles and meiotically arrested by the membrana granulosa, is triggered by FSH and not by LH. This is supported by the fact that receptors for FSH, but not for LH, are transcribed in the cumulus and granulosa cells of these follicles. PMID:8914080

  6. Technical Study of a Standalone Photovoltaic–Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia

    PubMed Central

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. PMID:26121032

  7. Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

    PubMed

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.

  8. Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

    PubMed

    Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

    2015-01-01

    Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. PMID:26121032

  9. miR-483-5p and miR-486-5p are down-regulated in cumulus cells of metaphase II oocytes from women with polycystic ovary syndrome.

    PubMed

    Shi, Lin; Liu, Shan; Zhao, Wanqiu; Shi, Juanzi

    2015-10-01

    The aim of this study was to compare the expression of microRNAs (miRNAs) in cumulus cells from polycystic ovary syndrome (PCOS) and non-PCOS women. In the present study, miRNA expression profiles of the cumulus cell samples were determined by miRNA microarrays. Quantification of selected miRNAs and predicted target genes was performed using quantitative real-time PCR (qRT-PCR). The results showed that miR-483-5p and miR-486-5p are significantly decreased in cumulus cells of PCOS patients PCOS (fold change >2, false discovery rate <0.001). qRT-PCR found that four predicted genes, SOCS3, SRF, PTEN and FOXO1, were significantly increased in PCOS cumulus cells (all P < 0.001), and IGF2 (host gene of miR-483-5p) was significantly decreased in PCOS cumulus cells (P < 0.001). These results indicated that miR-483-5p might play an important role in reducing insulin resistance, and that miR-486-5p might promote cumulus cell proliferation through activation of PI3K/Akt. The findings from this study provided new insights into the complex molecular mechanisms involved in PCOS by revealing pathways possibly regulated by miRNAs. The differences in miRNAs (miR-483-5p, miR-486-5p) and their target gene expression in cumulus cells may provide clues for future research and help to explain aberrant follicular development and subfertility in women with PCOS.

  10. Transcriptome based identification of mouse cumulus cell markers that predict the developmental competence of their enclosed antral oocytes

    PubMed Central

    2013-01-01

    Background The cumulus cells (CCs) enveloping antral and ovulated oocytes have been regarded as putative source of non-invasive markers of the oocyte developmental competence. A number of studies have indeed observed a correlation between CCs gene expression, embryo quality, and final pregnancy outcome. Here, we isolated CCs from antral mouse oocytes of known developmental incompetence (NSN-CCs) or competence (SN-CCs) and compared their transcriptomes with the aim of identifying distinct marker transcripts. Results Global gene expression analysis highlighted that both types of CCs share similar transcriptomes, with the exception of 422 genes, 97.6% of which were down-regulated in NSN-CCs vs. SN-CCs. This transcriptional down-regulation in NSN-CCs was confirmed by qRT-PCR analysis of CC-related genes (Has2, Ptx3, Tnfaip6 and Ptgs2). Only ten of the 422 genes were up-regulated with Amh being the most up-regulated in NSN-CCs, with an average 4-fold higher expression when analysed by qRT-PCR. Conclusions The developmental incompetence (NSN) or competence (SN) of antral oocytes can be predicted using transcript markers expressed by their surrounding CCs (i.e., Has2, Ptx3, Tnfaip6, Ptgs2 and Amh). Overall, the regulated nature of the group of genes brought out by whole transcriptome analysis constitutes the molecular signature of CCs associated either with developmentally incompetent or competent oocytes and may represent a valuable resource for developing new molecular tools for the assessment of oocyte quality and to further investigate the complex bi-directional interaction occurring between CCs and oocyte. PMID:23758669

  11. Characterisation of Secondary Organic Aerosol Formed from the Photooxidation of Isoprene during Cloud Condensation-Evaporation Cycles (CUMULUS Project)

    NASA Astrophysics Data System (ADS)

    Doussin, J. F.; Giorio, C.; Bregonzio-Rozier, L.; Siekmann, F.; Temime-Roussel, B.; Gratien, A.; Ravier, S.; Pangui, E.; Tapparo, A.; Kalberer, M.; Vermeylen, R.; Claeys, M.; Monod, A.

    2014-12-01

    Biogenic volatile organic compounds (BVOCs) undergo many oxidation processes in the atmosphere accompanied by formation of water-soluble compounds. These compounds could partition into atmospheric water droplets, and react within the aqueous phase producing higher molecular weight and less volatile compounds which could form new aerosol (Ervens et al., 2011). This work investigates the formation and composition of secondary organic aerosol (SOA) from the photooxidation of isoprene and methacrolein (its main first-generation oxidation product) and the effect of cloud water on SOA formation and composition. The experiments were performed within the CUMULUS project (CloUd MULtiphase chemistry of organic compoUndS in the troposphere) at the 4.2 m3 stainless steel CESAM chamber (Wang et al., 2011). In each experiment, isoprene or methacrolein was injected in the chamber together with HONO under dry conditions before irradiation. The experimental protocol was optimised to generate cloud events in the chamber, lasting for ca. 10 minutes in the presence of light. Gas phase compounds were analyzed on-line by a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-ToF-MS), a Fourier Transform Infrared Spectrometer (FTIR), NOx and O3 analyzers. SOA formation and composition were analysed on-line with a Scanning Mobility Particle Sizer (SMPS) and an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and off-line through sampling on filters and analysis in GC-MS and LC-MS. We observed that during cloud formation water soluble gas-phase oxidation products readily partitioned into cloud droplets and new SOA was promptly produced. Chemical composition, elemental ratios and density of SOA were compared before, during cloud formation and after cloud evaporation. Ervens, B. et al. (2011) Atmos. Chem. Phys. 11, 11069-11102. Wang, J. et al. (2011) Atmos. Measur. Tech. 4, 2465-2494.

  12. Absence of seasonal changes in FSHR gene expression in the cat cumulus-oocyte complex in vivo and in vitro.

    PubMed

    Hobbs, Rebecca J; Howard, JoGayle; Wildt, David E; Comizzoli, Pierre

    2012-07-01

    Domestic cat oocytes are seasonally sensitive to FSH. Compared with those collected during the breeding season, oocytes from the nonbreeding (NB) season require more FSH during in vitro maturation to achieve comparable developmental competence. This study tested the hypothesis that this seasonal variation was due to altered expression of FSH receptors (FSHR) and/or FSH-induced genes. Relative expression levels of FSHR mRNA and FSH-enhanced gene estrogen receptor β (ESR2) were measured by qPCR in whole ovaries and immature cumulus-oocyte complexes (COCs) isolated from cat ovaries during the natural breeding vs NB seasons. Expression levels of FSH-induced genes prostaglandin-endoperoxide synthase 2 (PTGS2), early growth response protein-1 (EGR1), and epidermal growth factor receptor (EGFR) were examined in mature COCs from both seasons that were a) recovered in vivo or b) matured in vitro with conventional (1 μg/ml) or high (10 μg/ml) FSH concentrations. Overall, FSHR mRNA levels were lower in whole ovaries during the NB compared with breeding season but were similar in immature COCs, whereas ESR2 levels did not differ in either group between intervals. We observed changes in PTGS2, EGR1, and EGFR mRNA expression patterns across maturation in COCs within but not between the two seasons. The lack of seasonal differentiation in FSH-related genes was not consistent with the decreased developmental capacity of oocytes fertilized during the NB season. These findings reveal that the seasonal decrease in cat oocyte sensitivity to FSH occurs both in vivo and in vitro. Furthermore, this decline is unrelated to changes in expression of FSHR mRNA or mRNA of FSH-induced genes in COCs from antral follicles.

  13. Differential expression dynamics of Growth differentiation factor9 (GDF9) and Bone morphogenetic factor15 (BMP15) mRNA transcripts during in vitro maturation of buffalo (Bubalus bubalis) cumulus-oocyte complexes.

    PubMed

    Kathirvel, Muralidharan; Soundian, Eswari; Kumanan, Vijayarani

    2013-12-01

    The present study has evaluated the association of growth differentiation factor9 (GDF9) and bone morphogenetic protein15 (BMP15) mRNA expression in cumulus-oocyte complexes (COCs) of buffalo ovary during in vitro maturation (IVM). GDF9 and BMP15 are expressed specifically in mammalian oocytes and also participate in cumulus-oocyte crosstalk. Quantitative real-time polymerase chain reaction (qRT-PCR) technique was applied to investigate the relative abundance (RA) of GDF9 and BMP15 mRNA transcripts throughout the IVM process. Relative mRNA expression pattern of these specific genes were assessed in oocytes and cumulus cells at 0, 6, 12 and 24 h of in vitro culture. Our results revealed that RA of GDF9 during different hours of IVM showed significant reduction between 0 h and 24 h of maturation in oocytes and BMP15 transcript increased significantly (P<0.05) between 6 h and 12 h and decreased again between 12 h and 24. In cumulus cells, GDF9 remained stable during IVM upto 12 h of maturation and decreased significantly between 12 h and 24 h of maturation. Conversely, significant reduction of BMP15 was observed between 0 h and 6 h, stayed stable upto 12 h and became undetectable at 24 h of maturation. In conclusion, these two genes were differentially expressed during the period of oocyte maturation process and notably, BMP15 expression pattern is associated specifically with the period of cumulus cell expansion.

  14. Differential gene expression in cumulus oocyte complexes collected by ovum pick up from repeat breeder and normally fertile Holstein Friesian heifers.

    PubMed

    Puglisi, Roberto; Cambuli, Caterina; Capoferri, Rossana; Giannino, Laura; Lukaj, Aleksander; Duchi, Roberto; Lazzari, Giovanna; Galli, Cesare; Feligini, Maria; Galli, Andrea; Bongioni, Graziella

    2013-09-01

    The aim of this study was to establish whether perturbed gene expression during cumulus oocyte development causes repeat breeding in cattle. In this study, a repeat breeder was defined as a normal estrous cycling animal that did not become pregnant after three inseminations despite the absence of clinically detectable reproductive disorders. Transcripts of genes extracted from cumulus oocyte complexes (COC) that were collected from three repeat breeder and three normally fertile Holstein Friesian heifers were compared. Up to 40 COC were collected from each heifer by means of repeated sessions of ovum pick up in the absence of hormonal stimulation; immediately plunged into liquid nitrogen; and stored at -80°C until analysis. For each heifer, RNA was extracted from the pooled COC and hybridized on GeneChip(®) Bovine Gene Array (Affymetrix). Analysis of gene expression profiles of repeat breeder and control COC showed that 178 genes were differentially expressed (log2 fold change>1.5). Of these genes, 43 (24%) were up-regulated and 135 (76%) were down-regulated in repeat breeder relative to control heifers. This altered pattern of expression occurred in genes involved in several cellular biological processes and cellular components such as metabolism, angiogenesis, substrate/ion transport, regulation/signaling, cell adhesion and cytoskeleton. From these, 13 genes potentially involved in cumulus oocyte growth were subjected to validation by qRT-PCR and nine genes (annexin A1, ANXA1; lactoferrin, LTF; interferon stimulated exonuclease 20kDa, ISG20/HEM45; oxidized low density lipoprotein receptor 1, OLR1; fatty acid desaturase 2, FADS2; glutathione S-transferase A2 and A4, GSTA2 and GSTA4; glutathione peroxidase 1, GPX1; endothelin receptor type A, EDNRA) were confirmed to be differentially expressed. This study identified potential marker genes for fertility in dairy cattle.

  15. Primary cumulus platinum minerals in the Monts de Cristal Complex, Gabon: magmatic microenvironments inferred from high-definition X-ray fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Barnes, Stephen J.; Fisher, Louise A.; Godel, Bélinda; Pearce, Mark A.; Maier, Wolfgang D.; Paterson, David; Howard, Daryl L.; Ryan, Christopher G.; Laird, Jamie S.

    2016-03-01

    An unusual occurrence of Pt-enriched pyroxenites in the Monts de Cristal igneous complex is characterized by unusually high ratios of Pt to other platinum-group elements (PGEs) and very low Cu and sulfide contents. Synchrotron X-ray fluorescence microscopy was used to identify over a hundred discrete grains of platinum minerals and relate their occurrence to textural associations in the host heteradcumulate orthopyroxenites. Element associations, backed up by FIB-SEM and PIXE probe observations, indicate that most of the Pt is associated with either As- or trace Cu-Ni-rich sulfides, or both. Some of the Pt-As grains can be identified as sperrylite, and most are likely to be Pt-Fe alloy. The relative abundances and volumes of Pt minerals to sulfide minerals are very large compared with typical magmatic sulfides. Almost all of the grains observed lie at or within a few tens of μm of cumulus orthopyroxene grain boundaries, and there is no significant difference between the populations of grains located inside or outside plagioclase oikocrysts. These oikocrysts are inferred to have crystallized either at the cumulus stage or very shortly thereafter, on the basis of their relationship to Ti enrichment in the margins of pyroxene grains not enclosed in oikocrysts. This relationship precludes a significant role of trapped intercumulus liquid in Pt deposition or mobilization and also allows a confident inference that Pt-rich and Pt-As-enriched phases precipitated directly from the magma at the cumulus stage. These observations lead to the conclusion that fractionation of Pt from other PGEs in this magmatic system is a consequence of a solubility limit for solid Pt metal and/or Pt arsenide.

  16. Robust triboelectric nanogenerator based on rolling electrification and electrostatic induction at an instantaneous energy conversion efficiency of ∼ 55%.

    PubMed

    Lin, Long; Xie, Yannan; Niu, Simiao; Wang, Sihong; Yang, Po-Kang; Wang, Zhong Lin

    2015-01-27

    In comparison to in-pane sliding friction, rolling friction not only is likely to consume less mechanical energy but also presents high robustness with minimized wearing of materials. In this work, we introduce a highly efficient approach for harvesting mechanical energy based on rolling electrification and electrostatic induction, aiming at improving the energy conversion efficiency and device durability. The rolling triboelectric nanogenerator is composed of multiple steel rods sandwiched by two fluorinated ethylene propylene (FEP) thin films. The rolling motion of the steel rods between the FEP thin films introduces triboelectric charges on both surfaces and leads to the change of potential difference between each pair of electrodes on back of the FEP layer, which drives the electrons to flow in the external load. As power generators, each pair of output terminals works independently and delivers an open-circuit voltage of 425 V, and a short-circuit current density of 5 mA/m(2). The two output terminals can also be integrated to achieve an overall power density of up to 1.6 W/m(2). The impacts of variable structural factors were investigated for optimization of the output performance, and other prototypes based on rolling balls were developed to accommodate different types of mechanical energy sources. Owing to the low frictional coefficient of the rolling motion, an instantaneous energy conversion efficiency of up to 55% was demonstrated and the high durability of the device was confirmed. This work presents a substantial advancement of the triboelectric nanogenerators toward large-scope energy harvesting and self-powered systems.

  17. Robust triboelectric nanogenerator based on rolling electrification and electrostatic induction at an instantaneous energy conversion efficiency of ∼ 55%.

    PubMed

    Lin, Long; Xie, Yannan; Niu, Simiao; Wang, Sihong; Yang, Po-Kang; Wang, Zhong Lin

    2015-01-27

    In comparison to in-pane sliding friction, rolling friction not only is likely to consume less mechanical energy but also presents high robustness with minimized wearing of materials. In this work, we introduce a highly efficient approach for harvesting mechanical energy based on rolling electrification and electrostatic induction, aiming at improving the energy conversion efficiency and device durability. The rolling triboelectric nanogenerator is composed of multiple steel rods sandwiched by two fluorinated ethylene propylene (FEP) thin films. The rolling motion of the steel rods between the FEP thin films introduces triboelectric charges on both surfaces and leads to the change of potential difference between each pair of electrodes on back of the FEP layer, which drives the electrons to flow in the external load. As power generators, each pair of output terminals works independently and delivers an open-circuit voltage of 425 V, and a short-circuit current density of 5 mA/m(2). The two output terminals can also be integrated to achieve an overall power density of up to 1.6 W/m(2). The impacts of variable structural factors were investigated for optimization of the output performance, and other prototypes based on rolling balls were developed to accommodate different types of mechanical energy sources. Owing to the low frictional coefficient of the rolling motion, an instantaneous energy conversion efficiency of up to 55% was demonstrated and the high durability of the device was confirmed. This work presents a substantial advancement of the triboelectric nanogenerators toward large-scope energy harvesting and self-powered systems. PMID:25555045

  18. A case study of the Thunderstorm Research International Project. 2. Interrelations among the observable parameters controlling electrification

    SciTech Connect

    Nisbet, J.S.; Kasha, J.R.; Forbes, G.S. )

    1990-04-20

    In Part 1 of this paper, the data obtained at the time of the Thunderstorm Research International Project storm at the Kennedy Space Center on July 11, 1978, are discussed and analyzed in a model-independent manner. Here the parameters of the electrical system that would be consistent with these observations are discussed. Three-dimensional electrodynamic modeling of the thundercloud electrification allowed estimates to be made of the current moments and electrical power generated continuously throughout the evolution of the two cells of the storm that were studied. The evolution and configuration of the currents were consistent with the separation of an originally neutral ensemble of particles by gravity in the region of 7 km in the region close to the maximum of the updraft velocity. After about 370 s the effect of wind shears would have caused the particles to separate in the convective system of the cells. Rain did not appear to be the dominant charge carrier. The current moments generated were compared with the current moments transferred by intercloud and cloud-to-ground lightning. It is shown that for the southern cell, which produced a charge moment of about 8.4 (MC m), lightning utilized about 84% of the charge moment separated, while for the northern cell, which produced about 1.1 (MC m), this figure was approximately 60%. It was shown that the times of initiation and maximum electrical power generated correspond best with the normalized mass above 7.5 km. It was deduced that the median diameter heavier particles had a fall velocity of about 3 m/s. The generator currents, flash rates, cloud conductivities, and mean charge per flash were used to estimate the volume associated with the lower region of current divergence.

  19. A mass-flux cumulus parameterization scheme for large-scale models: description and test with observations

    NASA Astrophysics Data System (ADS)

    Wu, Tongwen

    2012-02-01

    A simple mass-flux cumulus parameterization scheme suitable for large-scale atmospheric models is presented. The scheme is based on a bulk-cloud approach and has the following properties: (1) Deep convection is launched at the level of maximum moist static energy above the top of the boundary layer. It is triggered if there is positive convective available potential energy (CAPE) and relative humidity of the air at the lifting level of convection cloud is greater than 75%; (2) Convective updrafts for mass, dry static energy, moisture, cloud liquid water and momentum are parameterized by a one-dimensional entrainment/detrainment bulk-cloud model. The lateral entrainment of the environmental air into the unstable ascending parcel before it rises to the lifting condensation level is considered. The entrainment/detrainment amount for the updraft cloud parcel is separately determined according to the increase/decrease of updraft parcel mass with altitude, and the mass change for the adiabatic ascent cloud parcel with altitude is derived from a total energy conservation equation of the whole adiabatic system in which involves the updraft cloud parcel and the environment; (3) The convective downdraft is assumed saturated and originated from the level of minimum environmental saturated equivalent potential temperature within the updraft cloud; (4) The mass flux at the base of convective cloud is determined by a closure scheme suggested by Zhang (J Geophys Res 107(D14), doi: 10.1029/2001JD001005 , 2002) in which the increase/decrease of CAPE due to changes of the thermodynamic states in the free troposphere resulting from convection approximately balances the decrease/increase resulting from large-scale processes. Evaluation of the proposed convection scheme is performed by using a single column model (SCM) forced by the Atmospheric Radiation Measurement Program

  20. The effect of FF-MAS on porcine cumulus-oocyte complex maturation, fertilization and pronucleus formation in vitro.

    PubMed

    Faerge, Inger; Strejcek, Frantisek; Laurincik, Jozef; Rath, Detlef; Niemann, Heiner; Schellander, Karl; Rosenkranz, Christine; Hyttel, Poul Maddox; Grøndahl, Christian

    2006-08-01

    Follicular fluid meiosis-activating sterol (FF-MAS) has been isolated from the follicular fluid (FF) of several species including man. FF-MAS increases the quality of in vitro oocyte maturation, and thus the developmental potential of oocytes exposed to FF-MAS during in vitro maturation is improved. The aim of the present study was to investigate the effects of FF-MAS on porcine oocyte maturation and pronucleus formation in vitro. Porcine cumulus-oocyte complexes (COCs) were isolated from abattoir ovaries and in vitro matured for 48 h in NCSU 37 medium supplemented with 1 mg/l cysteine, 10 ng/ml epidermal growth factor and 50 microM 2-mercaptoethanol with or without 10% porcine follicular fluid (pFF). For the first 22 h, 1 mM db-cAMP and 10 I.E PMSG/hCG was added. The medium was supplemented with 1 microM, 3 microM, 10 microM, 30 microM or 100 microM FF-MAS dissolved in ethanol. After maturation the COCs were denuded mechanically using a fine glass pipette under constant pH and in vitro fertilized with fresh semen (5 x 10(5) spermatozoa/ml). The presumptive zygotes were evaluated 18 h after fertilization. The addition of pFF increased the monospermic as well as the polyspermic penetration of oocytes. In the absence of pFF, the addition of FF-MAS decreased the polyspermic penetration rate, whereas FF-MAS in combination with pFF decreased monospermic and increased polyspermic penetration. The degeneration rate of ova decreased in the presence of FF-MAS irrespective of the presence or absence of pFF. In the absence of pFF, FF-MAS at 3-10 microM increased the number of zygotes with advanced maternal pronuclear stages. In supraphysiological doses, i.e. 30-100 microM, FF-MAS dose-dependently and reversibly inhibited nuclear maturation in the absence of pFF.

  1. The relevance of aerosol optical depth to cumulus fraction changes: a five-year climatology at the ACRF SGP site

    NASA Astrophysics Data System (ADS)

    Kassianov, E. I.; Berg, L. K.; Flynn, C.; McFarlane, S.

    2007-08-01

    The objective of this study is to investigate, by observational means, the magnitude and sign of the actively discussed relationship between cloud fraction N and aerosol optical depth τa. Collocated and coincident ground-based measurements and Terra/Aqua satellite observations at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site form the basis of this study. The N-τa relationship occurred in a specific 5-year dataset of fair-weather cumulus (FWC) clouds and mostly non-absorbing aerosols. To reduce possible contamination of the aerosols on the cloud properties estimation (and vice versa), we use independent datasets of τa and N obtained from the Multi-filter Rotating Shadowband Radiometer (MFRSR) measurements and from the ARM Active Remotely Sensed Clouds Locations (ARSCL) value-added product, respectively. Optical depth of the FWC clouds τcld and effective radius of cloud droplets re are obtained from the MODerate resolution Imaging Spectroradiometer (MODIS) data. We found that relationships between cloud properties (N,τcld, re) and aerosol optical depth are time-dependent (morning versus afternoon). Observed time-dependent changes of cloud properties, associated with aerosol loading, control the variability of surface radiative fluxes. In comparison with pristine clouds, the polluted clouds are more transparent in the afternoon due to smaller cloud fraction, smaller optical depth and larger droplets. As a result, the corresponding correlation between the surface radiative flux and τa is positive (warming effect of aerosol). Also we found that relationship between cloud fraction and aerosol optical depth is cloud size dependent. The cloud fraction of large clouds (larger than 1 km) is relatively insensitive to the aerosol amount. In contrast, cloud fraction of small clouds (smaller than 1 km) is strongly positively correlated with τa. This suggests that an ensemble of polluted clouds tends to be

  2. Assessments of Wind-Energy Potential in Selected Sites from Three Geopolitical Zones in Nigeria: Implications for Renewable/Sustainable Rural Electrification

    PubMed Central

    Okeniyi, Joshua Olusegun; Ohunakin, Olayinka Soledayo; Okeniyi, Elizabeth Toyin

    2015-01-01

    Electricity generation in rural communities is an acute problem militating against socioeconomic well-being of the populace in these communities in developing countries, including Nigeria. In this paper, assessments of wind-energy potential in selected sites from three major geopolitical zones of Nigeria were investigated. For this, daily wind-speed data from Katsina in northern, Warri in southwestern and Calabar in southeastern Nigeria were analysed using the Gumbel and the Weibull probability distributions for assessing wind-energy potential as a renewable/sustainable solution for the country's rural-electrification problems. Results showed that the wind-speed models identified Katsina with higher wind-speed class than both Warri and Calabar that were otherwise identified as low wind-speed sites. However, econometrics of electricity power simulation at different hub heights of low wind-speed turbine systems showed that the cost of electric-power generation in the three study sites was converging to affordable cost per kWh of electric energy from the wind resource at each site. These power simulations identified cost/kWh of electricity generation at Kaduna as €0.0507, at Warri as €0.0774, and at Calabar as €0.0819. These bare positive implications on renewable/sustainable rural electrification in the study sites even as requisite options for promoting utilization of this viable wind-resource energy in the remote communities in the environs of the study sites were suggested. PMID:25879063

  3. A Simple Approach to Characterize Gas-Aqueous Liquid Two-phase Flow Configuration Based on Discrete Solid-Liquid Contact Electrification.

    PubMed

    Choi, Dongwhi; Lee, Donghyeon; Kim, Dong Sung

    2015-10-14

    In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two-phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, precise measurement, and cost-effectiveness. By using electric potential that is spontaneously generated by discrete solid-liquid contact electrification, the configurations of the gas-aqueous liquid two-phase flow such as size of a gas slug and flow rate are precisely characterized. According to the experimental and numerical analyses on parameters that affect electric potential, gas slugs have been verified to behave similarly to point electric charges when the measuring point of the electric potential is far enough from the gas slug. In addition, the configuration of the gas-aqueous liquid two-phase microfluidic system with multiple gas slugs is also characterized by using the presented approach. For a proof-of-concept demonstration of using the proposed approach in a self-triggered sensor, a gas slug detector with a counter system is developed to show its practicality and applicability.

  4. Hypothesis: the reversal of the relation between economic growth and health progress in Sweden in the nineteenth and twentieth centuries was caused by electrification.

    PubMed

    Milham, Samuel

    2014-01-01

    The expected decline of health indicators with economic recessions and improvement with economic growth in the nineteenth century Sweden was reversed in the twentieth century, giving the counterintuitive pattern of higher mortality and lower life expectancy in economic expansions and improvement of these indices in recessions. The change or "tipping point" occurred at the end of the nineteenth century or early in the twentieth century when electrification was introduced into Sweden. All 5 of the reversals of annual industrial electric energy use in the US between 1912 and 1970 were accompanied by recessions with lowered GDP, increased unemployment, decreased mortality and increased life expectancy. The health indices were not related to residential electricity use. The mortality improvement between 1931 and 1932 by state in the US strongly favored urban areas over rural areas. Rural unemployment by state in 1930 was significantly positively correlated with residential electrification percentage by state in 1930. The health effects of economic change are mediated by electrical exposure. PMID:23803154

  5. A Simple Approach to Characterize Gas-Aqueous Liquid Two-phase Flow Configuration Based on Discrete Solid-Liquid Contact Electrification

    NASA Astrophysics Data System (ADS)

    Choi, Dongwhi; Lee, Donghyeon; Sung Kim, Dong

    2015-10-01

    In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two-phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, precise measurement, and cost-effectiveness. By using electric potential that is spontaneously generated by discrete solid-liquid contact electrification, the configurations of the gas-aqueous liquid two-phase flow such as size of a gas slug and flow rate are precisely characterized. According to the experimental and numerical analyses on parameters that affect electric potential, gas slugs have been verified to behave similarly to point electric charges when the measuring point of the electric potential is far enough from the gas slug. In addition, the configuration of the gas-aqueous liquid two-phase microfluidic system with multiple gas slugs is also characterized by using the presented approach. For a proof-of-concept demonstration of using the proposed approach in a self-triggered sensor, a gas slug detector with a counter system is developed to show its practicality and applicability.

  6. A Simple Approach to Characterize Gas-Aqueous Liquid Two-phase Flow Configuration Based on Discrete Solid-Liquid Contact Electrification

    PubMed Central

    Choi, Dongwhi; Lee, Donghyeon; Sung Kim, Dong

    2015-01-01

    In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two–phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, precise measurement, and cost-effectiveness. By using electric potential that is spontaneously generated by discrete solid–liquid contact electrification, the configurations of the gas-aqueous liquid two-phase flow such as size of a gas slug and flow rate are precisely characterized. According to the experimental and numerical analyses on parameters that affect electric potential, gas slugs have been verified to behave similarly to point electric charges when the measuring point of the electric potential is far enough from the gas slug. In addition, the configuration of the gas-aqueous liquid two-phase microfluidic system with multiple gas slugs is also characterized by using the presented approach. For a proof-of-concept demonstration of using the proposed approach in a self-triggered sensor, a gas slug detector with a counter system is developed to show its practicality and applicability. PMID:26462437

  7. Assessments of wind-energy potential in selected sites from three geopolitical zones in Nigeria: implications for renewable/sustainable rural electrification.

    PubMed

    Okeniyi, Joshua Olusegun; Ohunakin, Olayinka Soledayo; Okeniyi, Elizabeth Toyin

    2015-01-01

    Electricity generation in rural communities is an acute problem militating against socioeconomic well-being of the populace in these communities in developing countries, including Nigeria. In this paper, assessments of wind-energy potential in selected sites from three major geopolitical zones of Nigeria were investigated. For this, daily wind-speed data from Katsina in northern, Warri in southwestern and Calabar in southeastern Nigeria were analysed using the Gumbel and the Weibull probability distributions for assessing wind-energy potential as a renewable/sustainable solution for the country's rural-electrification problems. Results showed that the wind-speed models identified Katsina with higher wind-speed class than both Warri and Calabar that were otherwise identified as low wind-speed sites. However, econometrics of electricity power simulation at different hub heights of low wind-speed turbine systems showed that the cost of electric-power generation in the three study sites was converging to affordable cost per kWh of electric energy from the wind resource at each site. These power simulations identified cost/kWh of electricity generation at Kaduna as €0.0507, at Warri as €0.0774, and at Calabar as €0.0819. These bare positive implications on renewable/sustainable rural electrification in the study sites even as requisite options for promoting utilization of this viable wind-resource energy in the remote communities in the environs of the study sites were suggested.

  8. Assessments of wind-energy potential in selected sites from three geopolitical zones in Nigeria: implications for renewable/sustainable rural electrification.

    PubMed

    Okeniyi, Joshua Olusegun; Ohunakin, Olayinka Soledayo; Okeniyi, Elizabeth Toyin

    2015-01-01

    Electricity generation in rural communities is an acute problem militating against socioeconomic well-being of the populace in these communities in developing countries, including Nigeria. In this paper, assessments of wind-energy potential in selected sites from three major geopolitical zones of Nigeria were investigated. For this, daily wind-speed data from Katsina in northern, Warri in southwestern and Calabar in southeastern Nigeria were analysed using the Gumbel and the Weibull probability distributions for assessing wind-energy potential as a renewable/sustainable solution for the country's rural-electrification problems. Results showed that the wind-speed models identified Katsina with higher wind-speed class than both Warri and Calabar that were otherwise identified as low wind-speed sites. However, econometrics of electricity power simulation at different hub heights of low wind-speed turbine systems showed that the cost of electric-power generation in the three study sites was converging to affordable cost per kWh of electric energy from the wind resource at each site. These power simulations identified cost/kWh of electricity generation at Kaduna as €0.0507, at Warri as €0.0774, and at Calabar as €0.0819. These bare positive implications on renewable/sustainable rural electrification in the study sites even as requisite options for promoting utilization of this viable wind-resource energy in the remote communities in the environs of the study sites were suggested. PMID:25879063

  9. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

    DOE PAGESBeta

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations.more » The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.« less

  10. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

    SciTech Connect

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations. The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.

  11. Up-regulation of 3'5'-cyclic guanosine monophosphate-specific phosphodiesterase in the porcine cumulus-oocyte complex affects steroidogenesis during in vitro maturation.

    PubMed

    Sasseville, Maxime; Côté, Nancy; Gagnon, Marie-Claude; Richard, François J

    2008-11-01

    The 3'5'-cyclic GMP (cGMP) pathway is known to influence ovarian functions, including steroidogenesis, ovulation, and granulosa cell proliferation. We show here that cGMP-phosphodiesterase (PDE) activity increased in a gonadotropin-dependent manner more than 3-fold in the cumulus-oocyte complex (COC) after 24 h in vitro maturation (IVM) and up to 5-fold after 48 h. Further characterization of this increase demonstrated that the activity was located primarily in cumulus cells, and was sensitive to sildenafil and zaprinast, two inhibitors specific to both type 5 and 6 PDEs. RT-PCR experiments showed that the mRNAs for cGMP-degrading PDEs 5A and 6C are present in the COC before and after 30 h IVM. Western blotting confirmed the presence of PDE 5A in the COC. Western blotting of PDE 6C revealed a significant up-regulation in the COC during IVM. Isolation and analysis of detergent-resistant membranes suggested that PDE 6C protein, along with half of the total sildenafil-sensitive cGMP-degradation activity, is associated with detergent-resistant membrane in the COC after 30 h IVM. Treatment of porcine COC with sildenafil during IVM caused a significant decrease in gonadotropin-stimulated progesterone secretion. Together, these results constitute the first report exploring the contribution of cGMP-PDE activity in mammalian COC, supporting a functional clustering of the enzyme, and providing the first evidence of its role in steroidogenesis.

  12. Increasing the cAMP concentration during in vitro maturation of pig oocytes improves cumulus maturation and subsequent fertilization in vitro.

    PubMed

    Appeltant, R; Beek, J; Vandenberghe, L; Maes, D; Van Soom, A

    2015-02-01

    Porcine IVF faces various problems such as incomplete cytoplasmic maturation of the oocyte and polyspermy. Previous studies proved the importance of cAMP in regulating nuclear and cytoplasmic maturation of oocytes. This study investigated the effect of the cAMP-modulating agents 3-isobutyl-1-methylxanthine (IBMX) and dibutyryl cAMP sodium salt (dbcAMP) on several parameters during in vitro production of porcine embryos. First, we wanted to see if oocyte collection in IBMX could meiotically arrest oocytes and, as such, improve synchronization of nuclear and cytoplasmic maturation. To this end, cumulus-oocyte complexes (COCs) were collected from gilts in HEPES-buffered Tyrode balanced salt solution medium with 0.5-mM IBMX or without IBMX. At the end of oocyte collection, the effect of IBMX on chromatin configuration was evaluated. However, no differences could be observed in nuclear configuration between IBMX- and IBMX+ oocytes (P > 0.05). Second, we added dbcAMP during IVM to improve cytoplasmic maturation and evaluated cumulus expansion (lack of adhesion), a disintegrin and metalloproteinase with thrombospondin-like repeats (ADAMTS-1) levels in cumulus cells, fertilization, and blastocyst rates. Cumulus-oocyte complexes were matured in modified North Carolina State University medium 37 with or without 1-mM dbcAMP. Frozen-thawed, epididymal, boar spermatozoa were used for IVF. After IVF, presumed zygotes were cultured for 7 days in North Carolina State University medium 23. Penetration rate decreased in dbcAMP+ (57.3%) compared with dbcAMP- (67.8%), but the polyspermy rate also decreased (43.3% vs. 53.4%, respectively) leading to an increased normal fertilization rate (56.7% vs. 46.6%, respectively; P < 0.05). Only 7.2% of the COCs showed adhesion in dbcAMP+ which was lower than 15.7% in dbcAMP- (P < 0.05) probably because of an upregulation of the ADAMTS-1 protein by dbcAMP. When the adherent oocytes were removed during maturation, no difference could be

  13. Formation and Cross-Cumulus Migration of Silica-Rich Liquids in the Skaergaard Intrusion, East Greenland

    NASA Astrophysics Data System (ADS)

    Larsen, R. B.; Sorensen, B. E.; Muller, A.

    2008-12-01

    In a recent publication on the Skaergaard intrusion evidence for the formation of silica-rich melts by silicate- silicate liquid immiscibility was proposed (Jakobsen et al., Geology 33, 2005). Coexisting iron-rich and silica- rich microscopic melt inclusions were trapped in apatite during crystallisation of the Skaergaard melts. Given this evidence for liquid immiscibility it is possible to explain the formation of macroscopic accumulations of silica rich entities throughout the magmatic stratigraphy. Previously, the formation and emplacement of these granophyric entities were challenging to explain. Examples include decimetre to metre size granophyric /melano-granophyric aggregates in either gabbroic pegmatite, in chimney shaped columns intersecting the layering or in isolated pods. Particularly, the presence of numerous granophyric pods a few metres above large gabbroic pegmatite were enigmatic. Moving the granophyric melts from the pegmatite where they formed (Larsen and Brooks, Journal of Petrology 35, 1994) and several metres across the magmatic stratigraphy would require unconsolidated cumulates i.e. a crystal mush. Geothermobarometric estimates from fluid inclusions, amphibole and feldspars show that the silica-rich aggregations solidified between 900 and 660 C at P from 1.8 to 2.9 kb. However, to be true products of liquid immiscibility they should form at T > 1050 C. With an average of 960 ppm Zr, the silica-rich aggregates are extremely Zr rich. Zr saturation thermometry imply minimum T's of 1070 (c. 2000 ppm Zr) to 900 C (c. 700 ppm Zr). Ti in Zr thermometry is progressing and may further constrain the T of formation. Although large uncertainties apply, a T of 1070 C or higher, would agree with a formation by liquid immiscibility. Assuming T > 1070 C the cumulus stratigraphy was unconsolidated with > 30 vol% intercumulus melts in the lower part of the magmachamber. With a density of 2.4-2.6 g/cm3, the silica-rich melts were much lighter than the ambient

  14. A method to determine true air temperature fluctuations in clouds with liquid water fraction and estimate water droplet effect on the calculations of the spectral structure of turbulent heat fluxes in cumulus clouds based on aircraft data

    NASA Astrophysics Data System (ADS)

    Strunin, Alexander M.; Zhivoglotov, Dmitriy N.

    2014-03-01

    Liquid water droplets could distort aircraft temperature measurements in clouds, leading to errors in calculated heat fluxes and incorrect flux distribution pattern. The estimation of cloud droplet effect on the readings of the high-frequency aircraft thermometer employed at the Central Aerological Observatory (CAO) was based on an experimental study of the sensor in a wind tunnel, using an air flow containing liquid water droplets. Simultaneously, calculations of the distribution of speed and temperature in a flow through the sensitive element of the sensor were fulfilled. This permitted estimating the coefficient of water content effect on temperature readings. Another way of estimating cloud droplet effect was based on the analysis of data obtained during aircraft observations of cumulus clouds in a tropical zone (Cuba Island). As a result, a method of correcting air temperature and recovering true air temperature fluctuations inside clouds was developed. This method has provided consistent patterns of heat flux distribution in a cumulus area. Analysis of the results of aircraft observations of cumulus clouds with temperature correction fulfilled has permitted investigation of the spectral structure of the fields of air temperature and heat fluxes to be performed in cumulus zones based on wavelet transformation. It is shown that mesoscale eddies (over 500 m in length) were the main factor of heat exchange between a cloud and the ambient space. The role of turbulence only consisted in mixing inside the cloud.

  15. Effect of inhibition of sterol delta 14-reductase on accumulation of meiosis-activating sterol and meiotic resumption in cumulus-enclosed mouse oocytes in vitro.

    PubMed

    Leonardsen, L; Strömstedt, M; Jacobsen, D; Kristensen, K S; Baltsen, M; Andersen, C Y; Byskov, A G

    2000-01-01

    Two sterols of the cholesterol biosynthetic pathway induce resumption of meiosis in mouse oocytes in vitro. The sterols, termed meiosis-activating sterols (MAS), have been isolated from human follicular fluid (FF-MAS, 4,4-dimethyl-5 alpha-cholest-8,14,24-triene-3 beta-ol) and from bull testicular tissue (T-MAS, 4,4-dimethyl-5 alpha-cholest-8,24-diene-3 beta-ol). FF-MAS is the first intermediate in the cholesterol biosynthesis from lanosterol and is converted to T-MAS by sterol delta 14-reductase. An inhibitor of delta 7-reductase and delta 14 reductase, AY9944-A-7, causes cells with a constitutive cholesterol biosynthesis to accumulate FF-MAS and possibly other intermediates between lanosterol and cholesterol. The aim of the present study was to evaluate whether AY9944-A-7 added to cultures of cumulus-oocyte complexes (COC) from mice resulted in accumulation of MAS and meiotic maturation. AY9944-A-7 stimulated dose dependently (5-25 mumol l-1) COC to resume meiosis when cultured for 22 h in alpha minimal essential medium (alpha-MEM) containing 4 mmol hypoxanthine l-1, a natural inhibitor of meiotic maturation. In contrast, naked oocytes were not induced to resume meiosis by AY9944-A-7. When cumulus cells were separated from their oocytes and co-cultured, AY9944-A-7 did not affect resumption of meiosis, indicating that intact oocyte-cumulus cell connections are important for AY9944-A-7 to exert its effect on meiosis. Cultures of COC with 10 mumol AY9944-A-7 l-1 in the presence of [3H]mevalonic acid, a natural precursor for steroid synthesis, resulted in accumulation of labelled FF-MAS, which had an 11-fold greater amount of radioactivity incorporated per COC compared with the control culture without AY9944-A-7. In contrast, incorporation of radioactivity into the cholesterol fraction was reduced 30-fold in extracts from the same oocytes. The present findings demonstrate for the first time that COC can synthesize cholesterol from mevalonate and accumulate FF-MAS in

  16. The new system of shorter porcine oocyte in vitro maturation (18 hours) using ≥8 mm follicles derived from cumulus-oocyte complexes.

    PubMed

    Kwak, Seong-Sung; Yoon, Junchul David; Cheong, Seung-A; Jeon, Yubyeol; Lee, Eunsong; Hyun, Sang-Hwan

    2014-01-15

    Despite recent efforts to improve in vitro maturation (IVM) systems for porcine oocytes, developmental competence of in vitro-matured oocytes is still suboptimal compared with those matured in vivo. In this study, we compared oocytes obtained from large (≥8 mm; LF) and medium (3-7 mm; MF) sized follicles in terms of nuclear maturation, intracellular glutathione and reactive oxygen species levels, gene expression, and embryo developmental competence after IVM. In the control group, cumulus-oocyte complexes (COCs) were aspirated from MF and matured for 22 hours with hormones and subsequently matured for 18 to 20 hours without hormones at 39 °C, 5% CO2 in vitro. In the LF group, COCs were obtained from follicles larger than 8 mm and were subjected to IVM for only 18 hours. The ovaries have LF were averagely obtained with 1.7% per day during 2012 and it was significantly higher in the winter season. The results of the nuclear stage assessment of the COCs from the LFs are as follows: before IVM (0 hours); germinal vesicle stage (15.2%), metaphase I (MI) stage (55.4%), anaphase and telophase I stages (15.8%), and metaphase II (MII) stage (13.6%). After 6 hours IVM; germinal vesicle (4.2%), MI (43.6%), anaphase and telophase I (9.4%), and MII (42.8%). After 18-hour IVM; MI (9.7%) and MII (90.3%). Oocytes from LF showed a significant (P < 0.001) increase in intracellular glutathione (1.41 vs. 1.00) and decrease in reactive oxygen species (0.8 vs. 1.0) levels compared with the control. The cumulus cells derived from LFs showed lower (P < 0.1) mRNA expression of COX-2 and TNFAIP6, and higher (P < 0.1) mRNA expression of PCNA and Nrf2 compared with the control group-derived cumulus cells. After parthenogenetic activation, in vitro fertilization and somatic cell nuclear transfer (SCNT) using matured oocytes from LFs, the embryo development was significantly improved (greater blastocyst formation rates and total cell numbers in blastocysts) compared with the control group

  17. Identification of altered microRNAs and mRNAs in the cumulus cells of PCOS patients: miRNA-509-3p promotes oestradiol secretion by targeting MAP3K8.

    PubMed

    Huang, Xin; Liu, Chang; Hao, Cuifang; Tang, Qianqing; Liu, Riming; Lin, Shaoxia; Zhang, Luping; Yan, Wei

    2016-06-01

    Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women and is characterised by polycystic ovaries, hyperandrogenism and chronic anovulation. Although the clinical and biochemical signs of PCOS are typically heterogeneous, abnormal folliculogenesis is considered a common characteristic of PCOS. Our aim is to identify the altered miRNA and mRNA expression profiles in the cumulus cells of PCOS patients to investigate their molecular function in the aetiology and pathophysiology of PCOS. In this study, the miRNA expression profiles of the cumulus cell samples isolated from five PCOS and five control patients were determined by an miRNA microarray. At the same time, the altered mRNA profiles of the same cumulus cell samples were also identified by a cDNA microarray. From the microarray data, 17 miRNAs and 1263 mRNAs showed significantly different expression in the PCOS cumulus cells. The differentially expressed miRNA-509-3p and its potential target gene (MAP3K8) were identified from the miRNA and mRNA microarrays respectively. The expression of miRNA-509-3p was up-regulated and MAP3K8 was down-regulated in the PCOS cumulus cells. The direct interaction between miRNA-509-3p and MAP3K8 was confirmed by a luciferase activity assay in KGN cells. In addition, miRNA-509-3p mimics or inhibitor transfection tests in KGN cells further confirmed that miRNA-509-3p improved oestradiol (E2) secretion by inhibiting the expression of MAP3K8 These results help to characterise the pathogenesis of anovulation in PCOS, especially the regulation of E2 production.

  18. Characterization of cumulus cloud fields using trajectories in the center of gravity versus water mass phase space: 1. Cloud tracking and phase space description

    NASA Astrophysics Data System (ADS)

    Heiblum, Reuven H.; Altaratz, Orit; Koren, Ilan; Feingold, Graham; Kostinski, Alexander B.; Khain, Alexander P.; Ovchinnikov, Mikhail; Fredj, Erick; Dagan, Guy; Pinto, Lital; Yaish, Ricki; Chen, Qian

    2016-06-01

    We study the evolution of warm convective cloud fields using large eddy simulations of continental and trade cumulus. Individual clouds are tracked a posteriori from formation to dissipation using a 3-D cloud-tracking algorithm, and results are presented in the phase space of center of gravity altitude versus cloud liquid water mass (CvM space). The CvM space is shown to contain rich information on cloud field characteristics, cloud morphology, and common cloud development pathways, together facilitating a comprehensive understanding of the cloud field. In this part we show how the meteorological (thermodynamic) conditions that determine the cloud properties are projected on the CvM phase space and how changes in the initial conditions affect the clouds' trajectories in this space. This part sets the stage for a detailed microphysical analysis that will be shown in part II.

  19. Cloud Properties Simulated by a Single-Column Model. Part II: Evaluation of Cumulus Detrainment and Ice-phase Microphysics Using a Cloud Resolving Model

    NASA Technical Reports Server (NTRS)

    Luo, Yali; Krueger, Steven K.; Xu, Kuan-Man

    2005-01-01

    This paper is the second in a series in which kilometer-scale-resolving observations from the Atmospheric Radiation Measurement program and a cloud-resolving model (CRM) are used to evaluate the single-column model (SCM) version of the National Centers for Environmental Prediction Global Forecast System model. Part I demonstrated that kilometer-scale cirrus properties simulated by the SCM significantly differ from the cloud radar observations while the CRM simulation reproduced most of the cirrus properties as revealed by the observations. The present study describes an evaluation, through a comparison with the CRM, of the SCM's representation of detrainment from deep cumulus and ice-phase microphysics in an effort to better understand the findings of Part I. It is found that detrainment occurs too infrequently at a single level at a time in the SCM, although the detrainment rate averaged over the entire simulation period is somewhat comparable to that of the CRM simulation. Relatively too much detrained ice is sublimated when first detrained. Snow falls over too deep of a layer due to the assumption that snow source and sink terms exactly balance within one time step in the SCM. These characteristics in the SCM parameterizations may explain many of the differences in the cirrus properties between the SCM and the observations (or between the SCM and the CRM). A possible improvement for the SCM consists of the inclusion of multiple cumulus cloud types as in the original Arakawa-Schubert scheme, prognostically determining the stratiform cloud fraction and snow mixing ratio. This would allow better representation of the detrainment from deep convection, better coupling of the volume of detrained air with cloud fraction, and better representation of snow field.

  20. Cellular and molecular events during oocyte maturation in mammals: molecules of cumulus-oocyte complex matrix and signalling pathways regulating meiotic progression.

    PubMed

    Kimura, N; Hoshino, Y; Totsukawa, K; Sato, E

    2007-01-01

    Mammalian oocytes acquire their intrinsic ability in a stepwise manner through ovarian folliculogenesis, ultimately reaching the competence to undergo complete oocyte maturation at the final stage of Graafian follicle development. The fully-grown oocyte is tightly surrounded by compact layers of specialized granulosa cells (cumulus cells) to form a cumulus-oocyte complex (COC). After a preovulatory gonadotrophin surge, the COCs rapidly organize a special muco-elastic extracellular matrix (ECM) consisting of large amounts of hyaluronan (HA) and HA binding matrix glycoproteins. Simultaneously, the oocytes undergo meiotic resumption and cytoplasmic modification and attain the fertilizable metaphase II (MII) stage. These cellular events that immediately occur in COCs in the ovulatory phase are strictly regulated by pituitary hormones, steroids, growth factors and so on. Knowledge of the efficient mechanisms and the downstream cascades of the key molecules controlling oocyte maturation may gradually lead to improvement of the present oocyte/ embryo culture systems and gamete biotechnology. Recent studies by our group imply that i) the interaction of HA-CD44 identified in the porcine COC matrix is likely to participate in gap junctional communication and meiotic progression, and that ii) phosphatidylinositol 3-kinase (P13-K) and Akt contribute to the progress of follicle stimulating hormone (FSH)-induced meiosis in mice. Furthermore, this review focuses on the current understanding of biosynthetic regulation, the presumptive role of COC matrix molecules and the signalling pathways for meiotic modulators, such as the protein kinase A (PKA) pathway, the P13-K/Akt pathway and the mitogen activated protein kinase (MAPK) pathway.

  1. Photovoltaic rural electrification

    SciTech Connect

    Williams, N.

    1996-12-31

    This paper describes projects taken on by the Solar Electric Light Fund in various developing countries to implement the use of Solar Home Systems. Such systems have seen dramatic drops in demand for kerosene from families purchasing such systems. They provide a source of power which does not put a carbon load back in the atmosphere, while providing power which can be used for lighting and other appliance usage.

  2. The Electrification of Thunderstorms.

    ERIC Educational Resources Information Center

    Williams, Earle R.

    1988-01-01

    Discusses the natural phenomena of lightning. States that the exact microphysical processes responsible for the charging of storm clouds remain in dispute although for centuries it has been known that lightning is a form of electricity. Uses diagrams to explain the structures of thunderclouds and charge transfer. (RT)

  3. Targeted Disruption of Mapk14 (p38MAPKα) in Granulosa Cells and Cumulus Cells Causes Cell-Specific Changes in Gene Expression Profiles that Rescue COC Expansion and Maintain Fertility

    PubMed Central

    Liu, Zhilin; Fan, Heng-Yu; Wang, Yibin; Richards, JoAnne S.

    2010-01-01

    MAPK14 (p38MAPKα) is critical for FSH and prostaglandin E (PGE)2 signaling cascades in granulosa cells (GCs) and cumulus cell-oocyte complexes (COCs) in culture, indicating that this kinase might impact follicular development and COC expansion in vivo. Because Mapk14 knockout mice are embryonic lethal, we generated GC specific Mapk14 knockout mice (Mapk14gc−/−) by mating Mapk14fl/fl and Cyp19-Cre mice. Unexpectedly, the Mapk14gc−/− female mice were fertile. Analyses of gene expression patterns showed that amphiregulin (Areg) and epiregulin (Ereg), two key regulators of ovulation and COC expansion, were up-regulated in the GCs but down-regulated in cumulus cells of the mutant mice in vivo. COCs from the mutant mice expanded and expressed matrix-related genes, if cultured with AREG, but not when cultured with forskolin or PGE2, the latter being a key factor regulating MAPK14 activity in cumulus cells. Conversely, when GCs from the Mapk14gc−/− mice were cultured with forskolin, they produced more Areg and Ereg mRNA than did wild-type GCs. These results indicate that disruption of Mapk14 selectively alters the expression of Areg and other genes in each cell type. Greater AREG and EREG produced by the GCs appears to by-pass and compensate for the critical need for MAPK14 signaling and induction of Areg/Ereg (and hence matrix genes) by PGE2 in cumulus cells of the mutant mice. In conclusion, although MAPK14 is not overtly essential for preovulatory follicle development or events associated with ovulation and luteinization in vivo, it does impact gene expression profiles. PMID:20610537

  4. 3D Cloud Radiative Effects on Aerosol Optical Thickness Retrievals in Cumulus Cloud Fields in the Biomass Burning Region in Brazil

    NASA Technical Reports Server (NTRS)

    Wen, Guo-Yong; Marshak, Alexander; Cahalan, Robert F.

    2004-01-01

    Aerosol amount in clear regions of a cloudy atmosphere is a critical parameter in studying the interaction between aerosols and clouds. Since the global cloud cover is about 50%, cloudy scenes are often encountered in any satellite images. Aerosols are more or less transparent, while clouds are extremely reflective in the visible spectrum of solar radiation. The radiative transfer in clear-cloudy condition is highly three- dimensional (3D). This paper focuses on estimating the 3D effects on aerosol optical thickness retrievals using Monte Carlo simulations. An ASTER image of cumulus cloud fields in the biomass burning region in Brazil is simulated in this study. The MODIS products (i-e., cloud optical thickness, particle effective radius, cloud top pressure, surface reflectance, etc.) are used to construct the cloud property and surface reflectance fields. To estimate the cloud 3-D effects, we assume a plane-parallel stratification of aerosol properties in the 60 km x 60 km ASTER image. The simulated solar radiation at the top of the atmosphere is compared with plane-parallel calculations. Furthermore, the 3D cloud radiative effects on aerosol optical thickness retrieval are estimated.

  5. Cumulus Cells Gene Expression Profiling in Terms of Oocyte Maturity in Controlled Ovarian Hyperstimulation Using GnRH Agonist or GnRH Antagonist

    PubMed Central

    Devjak, Rok; Fon Tacer, Klementina; Juvan, Peter; Virant Klun, Irma; Rozman, Damjana; Vrtačnik Bokal, Eda

    2012-01-01

    In in vitro fertilization (IVF) cycles controlled ovarian hyperstimulation (COH) is established by gonadotropins in combination with gonadotropin-releasing hormone (GnRH) agonists or antagonists, to prevent premature luteinizing hormone (LH) surge. The aim of our study was to improve the understanding of gene expression profile of cumulus cells (CC) in terms of ovarian stimulation protocol and oocyte maturity. We applied Affymetrix gene expression profiling in CC of oocytes at different maturation stages using either GnRH agonists or GnRH antagonists. Two analyses were performed: the first involved CC of immature metaphase I (MI) and mature metaphase II (MII) oocytes where 359 genes were differentially expressed, and the second involved the two GnRH analogues where no differentially expressed genes were observed at the entire transcriptome level. A further analysis of 359 differentially genes was performed, focusing on anti-Müllerian hormone receptor 2 (AMHR2), follicle stimulating hormone receptor (FSHR), vascular endothelial growth factor C (VEGFC) and serine protease inhibitor E2 (SERPINE2). Among other differentially expressed genes we observed a marked number of new genes connected to cell adhesion and neurotransmitters such as dopamine, glycine and γ-Aminobutyric acid (GABA). No differential expression in CC between the two GnRH analogues supports the findings of clinical studies where no significant difference in live birth rates between both GnRH analogues has been proven. PMID:23082142

  6. Insights from preliminary modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    NASA Astrophysics Data System (ADS)

    Mechem, D. B.; Fish, C. S.; Giangrande, S. E.; Borque, P.; Kollias, P.

    2013-12-01

    A case of extensive precipitating cumulus congestus sampled during the MC3E field campaign is analyzed using a multi-sensor observational approach and numerical simulation. The ARM SGP (Atmospheric Radiation Measurement Program Southern Great Plains) radar suite characterizes the evolving statistical behavior of the precipitating cloud system through distributions of reflectivity, horizontal divergence, and different measures of cloud geometry. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Specifically, we address how the characteristic spatial scale of the forcing imposed on the simulation influences the evolution of cloud system properties. Additionally, the importance of time-varying vs. steady-state large-scale forcing is evaluated in assessing the model's ability to capture the transient behavior of the cloud system sampled by the radar suite. The long-term goal of this effort is to promote cross-pollination between high-resolution cloud radar observations and LES.

  7. The effects of superoxide dismutase addition to the transport medium on cumulus-oocyte complex apoptosis and IVF outcome in cats (Felis catus).

    PubMed

    Cocchia, Natascia; Corteggio, Annunziata; Altamura, Gennaro; Tafuri, Simona; Rea, Silviana; Rosapane, Isabella; Sica, Alessandro; Landolfi, Francesco; Ciani, Francesca

    2015-03-01

    The aim of the present study was to examine the effects of superoxide dismutase (SOD) addition to the ovary transport medium (4°C, 3-72 h) on ovarian cell viability and apoptosis and in vitro embryo production (IVEP) in domestic cats. The ovaries collected from 76 mixed-breed domestic queens were randomly assigned to the control or SOD-treated groups and incubated for 3, 24, 48 or 72 h. The ovaries were then subjected to the following: (1) fixed in formalin to assess the incidence of apoptosis (fragmented DNA in situ detection kit), (2) stored at -196°C in liquid nitrogen to evaluate the expression of the pro-apoptotic Bax gene and the anti-apoptotic Bcl-2 gene (RT-PCR), and (3) used to obtain the cumulus-oocyte complexes (COCs) in order to test the cell viability (carboxyfluorescein or trypan blue staining) and IVEP. The incidence of apoptosis appeared to be higher in the control compared with the SOD-treated ovaries. The ovarian expression of Bax was lower and the Bcl-2 expression was higher in the SOD-treated group compared with the control group. The presence of SOD in the transport medium increased the viability of COCs and IVEP compared with the control medium. In summary, the supplementation of the ovary transport medium with SOD reduced cellular apoptosis and enhanced COC survival and IVEP in domestic cats. PMID:25726378

  8. Impacts of cloud microphysics on trade wind cumulus: which cloud microphysics processes contribute to the diversity in a large eddy simulation?

    NASA Astrophysics Data System (ADS)

    Sato, Yousuke; Nishizawa, Seiya; Yashiro, Hisashi; Miyamoto, Yoshiaki; Kajikawa, Yoshiyuki; Tomita, Hirofumi

    2015-12-01

    This study investigated the impact of several cloud microphysical schemes on the trade wind cumulus in the large eddy simulation model. To highlight the differences due to the cloud microphysical component, we developed a fully compressible large eddy simulation model, which excluded the implicit scheme and approximations as much as possible. The three microphysical schemes, the one-moment bulk, two-moment bulk, and spectral bin schemes were used for sensitivity experiments in which the other components were fixed. Our new large eddy simulation model using a spectral bin scheme successfully reproduced trade wind cumuli, and reliable model performance was confirmed. Results of the sensitivity experiments indicated that precipitation simulated by the one-moment bulk scheme started earlier, and its total amount was larger than that of the other models. By contrast, precipitation simulated by the two-moment scheme started late, and its total amount was small. These results support those of a previous study. The analyses revealed that the expression of two processes, (1) the generation of cloud particles and (2) the conversion from small droplets to raindrops, were crucial to the results. The fast conversion from cloud to rain and the large amount of newly generated cloud particles at the cloud base led to evaporative cooling and subsequent stabilization in the sub-cloud layer. The latent heat released at higher layers by the condensation of cloud particles resulted in the development of the boundary layer top height.

  9. A shape-adaptive thin-film-based approach for 50% high-efficiency energy generation through micro-grating sliding electrification.

    PubMed

    Zhu, Guang; Zhou, Yu Sheng; Bai, Peng; Meng, Xian Song; Jing, Qingshen; Chen, Jun; Wang, Zhong Lin

    2014-06-18

    Effectively harvesting ambient mechanical energy is the key for realizing self-powered and autonomous electronics, which addresses limitations of batteries and thus has tremendous applications in sensor networks, wireless devices, and wearable/implantable electronics, etc. Here, a thin-film-based micro-grating triboelectric nanogenerator (MG-TENG) is developed for high-efficiency power generation through conversion of mechanical energy. The shape-adaptive MG-TENG relies on sliding electrification between complementary micro-sized arrays of linear grating, which offers a unique and straightforward solution in harnessing energy from relative sliding motion between surfaces. Operating at a sliding velocity of 10 m/s, a MG-TENG of 60 cm(2) in overall area, 0.2 cm(3) in volume and 0.6 g in weight can deliver an average output power of 3 W (power density of 50 mW cm(-2) and 15 W cm(-3)) at an overall conversion efficiency of ∼ 50%, making it a sufficient power supply to regular electronics, such as light bulbs. The scalable and cost-effective MG-TENG is practically applicable in not only harvesting various mechanical motions but also possibly power generation at a large scale. PMID:24692147

  10. Effects of co-culture of cumulus oocyte complexes with denuded oocytes during in vitro maturation on the developmental competence of cloned bovine embryos.

    PubMed

    Ha, A-N; Fakruzzaman, M; Lee, K-L; Bang, J-I; Deb, G-K; Wang, Z; Kong, I-K

    2015-04-01

    This study evaluated the effects of co-culture of immature cumulus oocyte complexes (COCs) with denuded immature oocytes (DO) during in vitro maturation on the developmental competence and quality of cloned bovine embryos. We demonstrated that developmental competence, judged by the blastocyst formation rate, was significantly higher in the co-cultured somatic cell nuclear transfer (SCNT+DO, 37.1 ± 1.1%) group than that in the non-co-cultured somatic cell nuclear transfer (SCNT-DO, 25.1 ± 0.9%) group and was very similar to that in the control IVF (IVF, 38.8 ± 2.8%) group. Moreover, the total cell number per blastocyst in the SCNT+DO group (101.7 ± 6.2) was higher than that in the SCNT-DO group (81.7 ± 4.3), while still less than that in the IVF group (133.3 ± 6.0). Furthermore, our data showed that mRNA levels of the methylation-related genes DNMT1 and DNMT3a in the SCNT+DO group were similar to that in the IVF group, while they were significantly higher in the SCNT-DO group. Similarly, while the mRNA levels of the deacetylation-related genes HDAC2 and HDAC3 were significantly higher in the SCNT-DO group, they were comparable between the IVF and SCNT+DO groups. However, the mRNA levels of HDAC1 and DNMT3B were significantly higher in the SCNT+DO group than in the other groups. In conclusion, the present study demonstrated that co-culture of COCs with DO improves the in vitro developmental competence and quality of cloned embryos, as evidenced by increased total cell number.

  11. Optimization of cryoprotectant treatment for the vitrification of immature cumulus-enclosed porcine oocytes: comparison of sugars, combinations of permeating cryoprotectants and equilibration regimens

    PubMed Central

    SOMFAI, Tamás; MEN, Nguyen Thi; NOGUCHI, Junko; KANEKO, Hiroyuki; KASHIWAZAKI, Naomi; KIKUCHI, Kazuhiro

    2015-01-01

    Our aim was to optimize the cryoprotectant treatment for the preservation of immature porcine cumulus-oocyte complexes (COCs) by solid surface vitrification. In each experiment, the vitrification solution consisted of 50 mg/ml polyvinyl pyrrolidone, 0.3 M of the actual sugar and in total 35% (v/v) of the actual permeating cryoprotectant (pCPA) combination. After warming, the COCs were subjected to in vitro maturation, fertilization and embryo culture. In Experiment 1, trehalose and sucrose were equally effective during vitrification and warming in terms of facilitating oocyte survival and subsequent embryo development. In Experiment 2, when equilibration was performed at 38.5 C in a total of 4% (v/v) pCPA for 15 min, the combination of ethylene glycol and propylene glycol (EG + PG = 1:1) was superior to EG and dimethyl sulfoxide (EG + DMSO = 1:1) in terms of oocyte survival after vitrification and the quality of resultant blastocysts. In Experiment 3, equilibration in 4% (v/v) pCPA for 15 min before vitrification was superior to that in 15% (v/v) CPA for 5 min for achievement of high survival rates irrespective of the pCPA combination used. In Experiment 4, when equilibration was performed in 4% EG + PG for 5 min, 15 min or 25 min, there was no difference in oocyte survival and subsequent embryo development after vitrification and warming; however, the developmental competence of cleaved embryos was tendentiously reduced when equilibration was performed for 25 min. In conclusion, trehalose and sucrose were equally effective in facilitating vitrification, and the optimum pCPA treatment was 5–15 min equilibration in 4% (v/v) of EG + PG followed by vitrification in 35% (v/v) EG + PG. PMID:26411536

  12. Synchrotron X-ray diffraction to detect glass or ice formation in the vitrified bovine cumulus-oocyte complexes and morulae.

    PubMed

    Anzar, Muhammad; Grochulski, Pawel; Bonnet, Brennan

    2014-01-01

    Vitrification of bovine cumulus-oocyte complexes (COCs) is not as successful as bovine embryos, due to oocyte's complex structure and chilling sensitivity. Synchrotron X-ray diffraction (SXRD), a powerful method to study crystal structure and phase changes, was used to detect the glass or ice formation in water, tissue culture medium (TCM)-199, vitrification solution 2 (VS2), and vitrified bovine COCs and morulae. Data revealed Debye's rings and peaks associated with the hexagonal ice crystals at 3.897, 3.635, 3.427, 2.610, 2.241, 1.912 and 1.878 Å in both water and TCM-199, whereas VS2 showed amorphous (glassy) appearance, at 102K (-171°C). An additional peak of sodium phosphate monobasic hydrate (NaH2PO4.H2O) crystals was observed at 2.064 Å in TCM-199 only. All ice and NaH2PO4.H2O peaks were detected in the non-vitrified (control) and vitrified COCs, except two ice peaks (3.145 and 2.655 Å) were absent in the vitrified COCs. The intensities of majority of ice peaks did not differ between the non-vitrified and vitrified COCs. The non-vitrified bovine morulae in TCM-199 demonstrated all ice- and NaH2PO4.H2O-associated Debye's rings and peaks, found in TCM-199 alone. There was no Debye's ring present in the vitrified morulae. In conclusion, SXRD is a powerful method to confirm the vitrifiability of a solution and to detect the glass or ice formation in vitrified cells and tissues. The vitrified bovine COCs exhibited the hexagonal ice crystals instead of glass formation whereas the bovine morulae underwent a typical vitrification.

  13. Expression of cumulus-oocyte complex genes and embryonic development in goats subjected to progestogen-based estrus synchronization.

    PubMed

    Thammasiri, Jiratti; Navanukraw, Chainarong; Uriyapongson, Suthipong; Khanthusaeng, Vilaivan; Kamollirt, Chuchat

    2016-07-15

    The objective was to investigate the effect of short-term (7 days) and long-term (14 days) progesterone-based estrus synchronization on number of follicles, progesterone concentrations, cumulus-oocyte complex (COC) gene expression, and embryonic development in goats. Nulliparous Thai-native goats (n = 45) were randomly assigned to one of two estrus synchronization treatments. Goats were treated with intravaginal sponges containing 60-mg medroxyprogesterone acetate (MAP; Synchrogest esponjas, Spain) during 7 or 14 days (short-term or long-term protocol, respectively). Multiple follicular development was induced by intramuscularly injections of 300-IU eCG in both groups (1 day before sponge withdrawal). An ovariectomy was performed at 24 hours after sponge removal to evaluate number of follicle and collect oocyte for IVF. Oocyte quality (healthy or nonhealthy) was determined by morphology of COCs before IVM. Recovery of COCs and total cellular RNA isolation were applied to determine apoptosis-related gene expression. After IVF, embryos were evaluated during the eight-day culture as numbers of cleaved oocyte, morula, and blastocyst embryo. Total numbers of follicles and oocytes were similar for both treatments. Plasma progesterone concentrations were not different during MAP insertion period (P > 0.05). However, goats that received the short-term protocol had a greater number of 4 to 6-mm follicle, healthy oocytes, cleaved oocytes, and morula embryos than goats that received the long-term protocol (P < 0.01). In addition, the expression of B-cell lymphoma 2 messenger RNA was greater (P < 0.05) in COCs derived from the 7 days MAP-treated when compared to the 14 days MAP-treated goats. These data highlight that the 7-day progestin-based treatment may contribute to quality of oocytes and embryonic development in goats.

  14. Bi-directional communication with the cumulus cells is involved in the deficiency of XY oocytes in the components essential for proper second meiotic spindle assembly.

    PubMed

    Xu, Baozeng; Noohi, Saeid; Shin, Jonghyun S; Tan, Seang Lin; Taketo, Teruko

    2014-01-15

    The oocyte becomes competent for embryonic development by involving mutual communication with cumulus cells (CCs) during folliculogenesis. How this communication takes place under physiological conditions is not fully understood. Current study examined oocyte-CCs communication in the XY sex-revered female mouse. We have previously found that the XY oocyte is defective in its cytoplasm, causing abnormal MII-spindle assembly and a failure in embryonic development. Our present study showed that transcript levels of Pfkp, Pkm2 and Ldh1 involved in glycolysis were lower in the CCs surrounding XY oocytes than in those surrounding XX oocytes. ATP contents in XY oocytes were also lower than those in XX oocytes, suggesting that lower glycolytic gene expression in CCs resulted in lower ATP contents in the enclosed oocyte. Co-culture of oocytectomized CC-oocyte complexes (COCs) with denuded oocytes showed that XY oocytes were less efficient than XX oocytes in promoting glycolytic gene expression in CCs. Furthermore, both glycolytic gene expression levels in CCs and ATP contents in oocytes of XY COCs increased to similar levels to those of XX COCs after culture for 20h in the presence of milrinone (=preincubation), which prevented spontaneous oocyte maturation. By increasing ATP levels in XY oocytes by either COC preincubation or ATP microinjection into oocytes prior to in vitro maturation, an improvement in MII-spindle assembly was observed. We conclude that the XY oocyte produces lesser amounts of paracrine factors that affect its companion CCs, which in turn make the ooplasm deficient in its components, including ATP, essential for MII-spindle assembly. PMID:24247007

  15. Altered Theca and Cumulus Oocyte Complex Gene Expression, Follicular Arrest and Reduced Fertility in Cows with Dominant Follicle Follicular Fluid Androgen Excess

    PubMed Central

    Summers, Adam F.; Pohlmeier, William E.; Sargent, Kevin M.; Cole, Brizett D.; Vinton, Rebecca J.; Kurz, Scott G.; McFee, Renee M.; Cushman, Robert A.; Cupp, Andrea S.; Wood, Jennifer R.

    2014-01-01

    Aspiration of bovine follicles 12–36 hours after induced corpus luteum lysis serendipitously identified two populations of cows, one with High androstenedione (A4; >40 ng/ml; mean = 102) and another with Low A4 (<20 ng/ml; mean = 9) in follicular fluid. We hypothesized that the steroid excess in follicular fluid of dominant follicles in High A4 cows would result in reduced fertility through altered follicle development and oocyte maternal RNA abundance. To test this hypothesis, estrous cycles of cows were synchronized and ovariectomy was performed 36 hours later. HPLC MS/MS analysis of follicular fluid showed increased dehydroepiandrosterone (6-fold), A4 (158-fold) and testosterone (31-fold) in the dominant follicle of High A4 cows. However, estrone (3-fold) and estradiol (2-fold) concentrations were only slightly elevated, suggesting a possible inefficiency in androgen to estrogen conversion in High A4 cows. Theca cell mRNA expression of LHCGR, GATA6, CYP11A1, and CYP17A1 was greater in High A4 cows. Furthermore, abundance of ZAR1 was decreased 10-fold in cumulus oocyte complexes from High A4 cows, whereas NLRP5 abundance tended to be 19.8-fold greater (P = 0.07). There was a tendency for reduction in stage 4 follicles in ovarian cortex samples from High A4 cows suggesting that progression to antral stages were impaired. High A4 cows tended (P<0.07) to have a 17% reduction in calving rate compared with Low A4 cows suggesting reduced fertility in the High A4 population. These data suggest that the dominant follicle environment of High A4 cows including reduced estrogen conversion and androgen excess contributes to infertility in part through altered follicular and oocyte development. PMID:25330369

  16. Hormone-induced expression of tumor necrosis factor alpha-converting enzyme/A disintegrin and metalloprotease-17 impacts porcine cumulus cell oocyte complex expansion and meiotic maturation via ligand activation of the epidermal growth factor receptor.

    PubMed

    Yamashita, Yasuhisa; Kawashima, Ikkou; Yanai, Yoshiari; Nishibori, Masahide; Richards, Joanne S; Shimada, Masayuki

    2007-12-01

    The epidermal growth factor (EGF)-like growth factors, amphiregulin (AREG) and epiregulin (EREG), are expressed in murine cumulus oocyte complexes (COCs) where they impact the function of cumulus cells and oocyte maturation during LH-mediated ovulation. Because TNFalpha-converting enzyme (TACE)/a disintegrin and metalloprotease-17 (ADAM17) is essential for ectodomain shedding of AREG and EREG from the surface of other cell types, the expression and function of TACE/ADAM17 was analyzed in a porcine COC culture system in which FSH- and LH-mediated expansion and oocyte meiotic maturation have been well characterized and shown to occur between 20 and 40 h. In this model, Areg, Ereg, and Tace/Adam17 mRNAs increased significantly with maximal levels observed between 5 and 20 h of culture with FSH plus LH. TACE/ADAM17 protein and protease activity were up-regulated markedly at 10 h and maintained to 40 h. Treatment of COCs with the TACE/ADAM17-selective inhibitor TNFalpha-processing inhibitor-2 (TAPI-2) significantly suppressed in a time-dependent manner downstream targets of EGF receptor activation such as ERK1/2 phosphorylation, Ptgs2, Has2, and Tnfaip6 mRNA expression, hormone-induced COC expansion, and meiotic maturation of the oocytes. Addition of EGF to COCs cultured in the presence of FSH/LH reversed the inhibitory effects of TAPI-2 on these ovulation-related processes. Gonadotropin-induced phosphorylation of ERK1/2 was also inhibited in rat granulosa cells treated with TAPI-2 or after transfection with Tace/Adam17 small interfering RNA. Induced expression of Tnfaip6 mRNA was also reduced by Tace/Adam17 small interfering RNA. Thus, TACE/ADAM17 is induced and the activity is involved in porcine COC expansion as well as oocyte meiotic maturation through the activation of EGF receptor in cumulus cells.

  17. Estrus synchronization and ovarian hyper-stimulation treatments have negligible effects on cumulus oocyte complex gene expression whereas induction of ovulation causes major expression changes.

    PubMed

    Agca, Cansu; Yakan, Akin; Agca, Yuksel

    2013-02-01

    The effects of exogenous hormones, used for estrus synchronization and ovarian hyper stimulation, on cumulus oocyte complexes (COCs) gene expression in sexually mature rats were determined using microarrays. Gene expression in COCs collected from GnRH (G(trt)), GnRH + eCG (G + E(trt)), and GnRH + eCG + hCG (G + E + H(trt)) treatments were compared to COCs from naturally cycling (NC) rats before the preovulatory luteninizing hormone surge. There was no significant difference in gene expression among NC, G(trt), and G + E(trt); however, over 2,600 genes were significantly different between NC and G + E + H(trt) (P < 0.05). Genes upregulated in G + E + H(trt) encode for: proteins that are involved in prostaglandin synthesis (Ptgs2, Pla2g4a, and Runx1) and cholesterol biosynthesis (Hmgcr, Sc4mol, and Dhcr24); receptors that allow cholesterol uptake (Ldlr and Scarb1), regulate progesterone synthesis (Star), and inactivate estrogen (Sult1e1); and downstream effectors of LH signal (Pgr, Cebpb, Creb3l1, Areg, Ereg, and Adamts1). Conversely, G + E + H(trt) downregulated genes encoding proteins involved in: DNA replication and cell cycle progression (Ccne2, Orc5l, Rad50, and Mcm6); reproductive developmental process; and granulosa cell expansion (Gdf9, Bmp15, Amh, Amhr2, Bmpr1b, Tgfb2, Foxl2, Pde3a, Esr2, Fshr, Ybx2, Ccnd2, Ccnb1ip1, and Zp3); maternal effect genes required for embryo development (Zar1, Npm2, Nlrp5, Dnmt1, H1foo, and Zfp57); amino acid degradation; and ketogenesis (Hmgcs2, and Cpt1b). These results from the rat show that hormones used for estrus synchronization (G(trt)) and ovarian hyper stimulation (G + E(trt)) had minimal effects on gene expression, whereas induction of ovulation (G + E + H(trt)) caused major changes in gene expression of rat COCs. This study provides comprehensive information about regulated genes during late follicle development and ovulation induction.

  18. Effect of temporary meiosis block during prematuration of bovine cumulus-oocyte complexes on pregnancy rates in a commercial setting for in vitro embryo production.

    PubMed

    Guemra, Samuel; da Silva Santo, Eriko; Zanin, Renato; Monzani, Paulo Sergio; Sovernigo, Tobias Canan; Ohashi, Otávio Mitio; Verde Leal, Cláudia Lima; Adona, Paulo Roberto

    2014-04-15

    Ovum pick up (OPU) associated with in vitro production (IVP) of embryos has been shown as an important tool in cattle breeding to increase the number of descendants from animals of high genetic value. In herds maintained distant from the laboratory, collecting cumulus-oocyte complexes (COCs) and transporting them to the laboratory may take several hours and decrease COCs viability, representing a challenge for commercial settings. In this study, a prematuration culture to induce temporary meiosis block was evaluated in a commercial scale IVP setting as a strategy to transport bovine OPU-derived COCs from Nelore and Brangus donors. Effects on embryo yield and pregnancy rates were assessed. Viable COCs from each donor were destined to one of the experimental groups (control, blocks 1 and 2). Control group COCs were placed in cryotubes with 1 mL TCM199-HEPES. In block groups (1 and 2), COCs were placed in cryotubes with 300 μL TCM 199 + 12 μM butyrolactone I (block medium). All groups were gassed and kept in a thermos bottle for 4 hours at 36 °C. Next, COCs in the control group were transferred to IVM medium and block 1 group to block medium, and cultured for 22 hours and 15 hours, respectively, at 38.5 °C and 5% CO2 in air. Block 2 COCs were kept in the cryotubes and in the thermos bottle for another 15 hours at 36 °C to simulate long-term transport conditions. After meiosis block in prematuration culture, blocks 1 and 2 COCs were matured in vitro for 22 hours as for the control group. After IVM, COCs in all groups were submitted to IVF and IVC, and blastocyst rates were evaluated on day 7. Embryos were transferred and pregnancy rates evaluated at 60 days of gestation. The mean total number of COCs retrieved by OPU did not differ between Nelore and Brangus donors (16.8 and 17.2, respectively, P > 0.05), but Nelore donors produced more viable COCs than Brangus (10.1 and 7.6, respectively, P < 0.05) and more embryos/cow (3.8 and 2.7, respectively, P

  19. Expanding access to off-grid rural electrification in Africa: An analysis of community-based micro-grids in Kenya

    NASA Astrophysics Data System (ADS)

    Kirubi, Charles Gathu

    Community micro-grids have played a central role in increasing access to off-grid rural electrification (RE) in many regions of the developing world, notably South Asia. However, the promise of community micro-grids in sub-Sahara Africa remains largely unexplored. My study explores the potential and limits of community micro-grids as options for increasing access to off-grid RE in sub-Sahara Africa. Contextualized in five community micro-grids in rural Kenya, my study is framed through theories of collective action and combines qualitative and quantitative methods, including household surveys, electronic data logging and regression analysis. The main contribution of my research is demonstrating the circumstances under which community micro-grids can contribute to rural development and the conditions under which individuals are likely to initiate and participate in such projects collectively. With regard to rural development, I demonstrate that access to electricity enables the use of electric equipment and tools by small and micro-enterprises, resulting in significant improvement in productivity per worker (100--200% depending on the task at hand) and a corresponding growth in income levels in the order of 20--70%, depending on the product made. Access to electricity simultaneously enables and improves delivery of social and business services from a wide range of village-level infrastructure (e.g. schools, markets, water pumps) while improving the productivity of agricultural activities. Moreover, when local electricity users have an ability to charge and enforce cost-reflective tariffs and electricity consumption is closely linked to productive uses that generate incomes, cost recovery is feasible. By their nature---a new technology delivering highly valued services by the elites and other members, limited local experience and expertise, high capital costs---community micro-grids are good candidates for elite-domination. Even so, elite control does not necessarily

  20. Ion transfer in contact electrification

    NASA Astrophysics Data System (ADS)

    Diaz, Arthur F.; Fenzel-Alexander, Debra; Wollmann, Daphne; Eisenberg, A.

    1990-07-01

    The contact charge on polymers is influenced by added organic salts, and the charge is higher when the additive is polymer-bound rather than molecular.'7 In our studies, the presence of an ionomer consisting of a polystyrene random copolymer with pendent N-methylpyridinium toluenesulfonate groups in the host resin produces a positive charge, and the charge is higher than with the molecular analog, 4-ethyl-N-methylpyridinium toluenesulfonate.68 These studies were made with powders, and the charge was activated by rolling the powder with larger sized particles. The charging is attributed to ion transfer, where the toluenesulfonate anion (OTs) transfers from one particle surface to the other, and the proposal is supported by the observation of OTs on the second surface by XPS. l'he different charge levels were attributed to the relative mobilities of the cation and the anion, where in the ionomers, the cation is 'anchored' to the polymer and only OTs is mobile. With the molecular salt, both ions can transfer, although in unequal amounts, thus producing a smaller net charge. We now report our results from the analyses of the charged powders with a Simpson charge spectrometer, which allow us to relate the charge distributions with the charge levels in these materials.

  1. NRECA`s electrification model

    SciTech Connect

    Waddle, D.

    1997-12-01

    This paper looks at the role of the National Rural Electric Cooperative Association (NRECA) with regard to applying renewable energy in a village setting. This group has historically been active with state utilities to promote extension of the grid system, and until recently has no historical involvement with renewable resources. They have realized that most future clients will not be served by extending the grid, because of the costs involved, and that renewables play a part of the solution to this problem. NRECA has sought to provide project management and management consultant services, emphasizing training, management efficiency, cost of services studies, and assistance in dealing with regulations. They specialize in forming, training, and supporting user-owned electric service companies, and rely on other partners for technological services and support.

  2. The Southeast Asia Regional Climate Downscaling (SEACLID) / CORDEX Southeast Asia Project and The Results of Its Sensitivity Experiments of RegCM4 Cumulus and Ocean Fluxes Parameterization Schemes on Temperature and Extremes.

    NASA Astrophysics Data System (ADS)

    Tangang, Fredolin; Juneng, Liew; Cruz, Faye; Narisma, Gemma; Dado, Julie; Van, Tan-Phan; Ngo-Duc, Thanh; Trinh-Tuan, Long; Nguyen-Xuan, Thanh; Santisirisomboon, Jerasorn; Singhruck, Patama; Gunawan, Dodo; Aldrian, Edvin

    2015-04-01

    The Southeast Asia (SEA) region is one of the more vulnerable regions to the impacts of climate change because of the large population exposed to climate-related hazards, mostly living in countries with low adaptive capabilities. In order to adequately prepare and adapt to these future climate change impacts, it is therefore crucial for high-resolution climate projections to be available for this region. The Southeast Asia Regional Climate Downscaling/CORDEX Southeast Asia (SEACLID/CORDEX-SEA) project aims to provide these projections through a collaborative effort in regional climate downscaling. As a first step, model simulations with the 4th version of Regional Climate Model system (RegCM4) developed by International Centre for Theoretical Physics (ICTP) were performed for the SEA domain (80°E-145°E; 15°S-40°N) at 36 km spatial resolution, to determine an optimal configuration of the model for the region. Using the ECMWF ERA Interim data as boundary condition, a total of 18 sensitivity experiments were done with different cumulus parameterization and ocean flux schemes for the period of 1989-2008. In this study, the model's performance in simulating mean temperature is evaluated against APHRODITE, a gridded observed temperature dataset. Initial results showed that RegCM4 tends to enhance the cold bias from the boundary forcing. There is also a consistent cold bias among all simulations over the Tibetan plateau and Indochina, especially during the boreal winter. Consequently, simulations had the smallest biases during boreal summer. The correlation of the model with the observed data is high over the northern half of the region, in contrast with the low correlation over the southern half, which may be due to uncertainties in the APHRODITE dataset over this region. Consistent with the spatial analysis, the analysis of the regional means indicates an overall better performance of the MIT Emanuel scheme, in terms of seasonality and spatial distribution. The

  3. Reviews Book: Marie Curie and Her Daughters Resource: Cumulus Equipment: Alpha Particle Scattering Apparatus Equipment: 3D Magnetic Tube Equipment: National Grid Transmission Model Book: Einstein's Physics Equipment: Barton's Pendulums Equipment: Weather Station Web Watch

    NASA Astrophysics Data System (ADS)

    2013-09-01

    WE RECOMMEND Marie Curie and Her Daughters An insightful study of a resilient and ingenious family and their achievements Cumulus Simple to install and operate and with obvious teaching applications, this weather station 'donationware' is as easy to recommend as it is to use Alpha Particle Scattering Apparatus Good design and construction make for good results National Grid Transmission Model Despite its expense, this resource offers excellent value Einstein's Physics A vivid, accurate, compelling and rigorous treatment, but requiring an investment of time and thought WORTH A LOOK 3D Magnetic Tube Magnetic fields in three dimensions at a low cost Barton's Pendulums A neat, well-made and handy variant, but not a replacement for the more traditional version Weather Station Though not as robust or substantial as hoped for, this can be put to good use with the right software WEB WATCH An online experiment and worksheet are useful for teaching motor efficiency, a glance at CERN, and NASA's interesting information on the alpha-magnetic spectrometer and climate change

  4. Evaluating the impacts of cumulus, land surface and ocean surface schemes on summertime rainfall simulations over East-to-southeast Asia and the western north Pacific by RegCM4

    NASA Astrophysics Data System (ADS)

    Li, Yu-Bin; Tam, Chi-Yung; Huang, Wan-Ru; Cheung, Kevin K. W.; Gao, Zhiqiu

    2016-04-01

    This study evaluates the sensitivity of summertime rainfall simulations over East-to-southeast Asia and the western north Pacific in the regional climate model version 4 (RegCM4) to cumulus (including Grell with Arakawa-Schubert type closure, Grell with Fritsch-Chappell type closure, and Emanuel), land surface (Biosphere-atmosphere transfer scheme or BATS, and the community land model or CLM) and ocean surface (referred to as Zeng1, Zeng2 and BATS1e in the model) schemes by running the model with different combinations of these parameterization packages. For each of these experiments, ensemble integration of the model was carried out in the extended boreal summer of May-October from 1998 to 2007. The simulated spatial distribution, intensity and inter-annual variation of the precipitation, latent heat flux, position of the subtropical high and tropical cyclone genesis patterns from these numerical experiments were analyzed. Examinations show that the combination of Emanuel, CLM and Zeng2 (E-C-Z2) yields the best overall results, consistent with the fact that physical mechanisms considered in E-C-Z2 tend to be more comprehensive in comparison with the others. Additionally, the rainfall quantity is found very sensitive to sea surface roughness length, and the reduction of the roughness length constant (from 2 × 10-4 to 5 × 10-5 m) in our modified BATS1e mitigates the drastic overestimation of latent heat flux and rainfall, and is therefore preferable to the default value for simulations in the western north Pacific region in RegCM4.

  5. Analysis of in vivo oocyte maturation, in vitro embryo development and gene expression in cumulus cells of dairy cows and heifers selected for one fertility quantitative trait loci (QTL) located on BTA3.

    PubMed

    Coyral-Castel, S; Brisard, D; Touzé, J-L; Dupont, M; Ramé, C; Uzbekova, S; Dupont, J

    2012-06-01

    We have previously shown that Holstein cows selected for their homozygous favorable ("fertil+") or unfavorable ("fertil-") haplotype at one quantitative trait loci (QTL) of female fertility located on chromosome 3 (QTL-F-Fert-BTA3) had a different success rate 35 and 90 days after the first artificial insemination. To determine whether the lower fertility in "fertil-" animals could be related to oocyte quality, we analyzed the embryo development rate in vitro and the oocyte meiotic maturation in vivo in "fertil+" and "fertil-" heifers. In vitro maturation and fertilization of immature oocytes recovered by ovum pick-up from "fertil+" and "fertil-" heifers resulted in similar cleavage and blastocyst rates in the two haplotypes. However the percentage of expanded blastocysts and the number of cells per blastocyst were significantly higher in "fertil+". Oocytes from presumptive preovulatory follicles were analyzed after ovarian stimulation. A similar rate of immature (from prophase to metaphase-I) and mature oocytes (metaphase-II) was obtained in the two haplotypes, whereas a significantly higher percentage of oocytes from metaphase-I to metaphase-II was observed in "fertil+" compared to "fertil-" heifers. Since cumulus cells (CCs) could reflect the developmental competence of oocytes, we analyzed the expression of seven genes included in the QTL-F-Fert-BTA3 using real-time PCR in bovine CCs after in vivo or in vitro maturation, as a model of higher and lower competence, respectively. Transcript levels of TAGLN2, EEF1A1 and PIGM were higher in CCs after in vitro maturation (IVM) compared to in vivo maturation, whereas no difference was observed for IFI16, KIRREL, SPTA1 and PEX19 expression. The expression levels of all these genes in in preovulatory CCs were not significantly different between "fertil+" and "fertil-" heifers. In conclusion, the lower fertility of "fertil-" females could be partially due to a lowest quality of the oocytes and consequently of

  6. Influence of epidermal growth factor and insulin-like growth factor 1 on nuclear maturation and fertilization of buffalo cumulus oocyte complexes in serum free media and their subsequent development in vitro.

    PubMed

    Purohit, G N; Brady, M S; Sharma, S S

    2005-07-01

    The in vitro maturation, fertilization and development of Indian water buffalo (Bubalus sp.) cumulus oocyte complexes (COCs) to blastocysts were studied during culture, either in serum free tissue culture medium 199 (TCM 199) or Waymouth MB (WM). Based on different supplements added to these media, the experimental groups included: (a) no supplement (control); (b) hormones (FSH, LH and oestradiol) (c) Epidermal growth factor (EGF); (d) IGF-1; and (e) EGF + IGF-1. Experiments were conducted to note three end points: (1) nuclear maturation 24 h after culture (eight replicates); (2) fertilization 24 h after insemination (10 replicates); (3) development to blastocysts (nine replicates). The oocytes were cultured in groups of up to five per drop. Using a two-way (5 x 2) factorial model with interactions, the results were compared using generalized linear models with binomial errors and the logit link function. In experiment 1, the proportion of oocytes reaching metaphase II was higher for all the supplement treatments than the control treatment (t = 3.68, p < 0.0001). The proportion of oocytes reaching metaphase II was 74.7, 63.2, 64.7 and 81% with hormone (chi2 = 17.23, p < 0.0001), EGF (chi2 = 7.07, p = 0.007), IGF-1 (chi2 = 19.21, p = 0.002) and EGF + IGF-1 (chi2 = 33.04, p < 0.0001) supplementation, respectively, compared to 46.6% in the control (no supplement) group. Media did not have an effect on outcome. In experiment 2, the proportion of oocytes fertilized was significantly higher with hormones (31.0%, chi2 = 12.5, p = 0.0004), IGF-1 (35.7%, chi2 = 20.53, p < 0.0001), and the EGF + IGF-1 combination (49.7%, chi2 = 51.35, p < 0.0001) compared to control (16.2%). No significant effect of media was seen. In experiment 3, the proportion of oocytes that cleaved at 48 h after culturing was significantly higher for all supplement treatments compared to control. IGF-1 supplementation was the only treatment that did not produce a significantly higher rate of progression

  7. Effect of heat stress on the survival and development of in vitro cultured bovine preantral follicles and on in vitro maturation of cumulus-oocyte complex.

    PubMed

    Paes, V M; Vieira, L A; Correia, H H V; Sa, N A R; Moura, A A A; Sales, A D; Rodrigues, A P R; Magalhães-Padilha, D M; Santos, F W; Apgar, G A; Campello, C C; Camargo, L S A; Figueiredo, J R

    2016-09-01

    The deleterious effect of heat stress (HS) on competence of oocytes from antral follicles is well recognized, but there is a lack of data regarding its impact on the viability and growth of preantral follicles. In this study, we used in vitro preantral follicle cultures to investigate the effects of HS on the following parameters: survival and development of primordial follicles after in vitro culture of ovarian fragments (experiment I); growth and antrum formation of isolated advanced secondary follicles (experiment II); and maturation rates after in vitro maturation (IVM) of cumulus-oocyte complexes (COCs) from antral follicles (>2-6 mm) grown in vivo (experiment III). Furthermore, the following end points were evaluated in all experiments: follicle/oocyte survival, reactive oxygen species (ROS), estradiol (E2) and progesterone (P4) production, as well as mRNA expression for select genes related to stress (HSP70) and apoptosis (MCL1 and BAX). In all experiments, HS consisted of exposing the structures (ovarian fragments, isolated preantral follicles and COCs) to 41 °C for 12 hours and then to 38.5 °C until the end of the culture (7 days for experiments I and II and 24 hours for experiment III). The temperature for the control group was held at 38.5 °C for the entire culture period. Heat stress increased (P < 0.05) the percentage of developing follicles (intermediate, primary, and secondary follicles) at 12 hours and increased levels of ROS at all evaluated time points (12, 24 hours, and D7), when compared to the control (experiment I). Heat stress did not affect (P > 0.05) any identified end points when preantral follicles were cultured in their isolated form (experiment II). However, in experiment III, HS decreased (P < 0.05) both the rates of metaphase II after 24 hours and E2 production at 12 hours of IVM. Moreover, HS increased (P < 0.0001) levels of P4 after IVM and ROS production at every evaluated time point, compared with the

  8. Advancing Transportation through Vehicle Electrification - PHEV

    SciTech Connect

    Bazzi, Abdullah; Barnhart, Steven

    2014-12-31

    FCA US LLC viewed the American Recovery and Reinvestment Act (ARRA) as an historic opportunity to learn about and develop PHEV technologies and create the FCA US LLC engineering center for Electrified Powertrains. The ARRA funding supported FCA US LLC’s light-duty electric drive vehicle and charging infrastructure-testing activities and enabled FCA US LLC to utilize the funding on advancing Plug-in Hybrid Electric Vehicle (PHEV) technologies for production on future programs. FCA US LLC intended to develop the next-generations of electric drive and energy batteries through a properly paced convergence of standards, technology, components and common modules. To support the development of a strong, commercially viable supplier base, FCA US LLC also utilized this opportunity to evaluate various designated component and sub-system suppliers. The original proposal of this project was submitted in May 2009 and selected in August 2009. The project ended in December 2014.

  9. A mission to earth - Global rural electrification

    NASA Astrophysics Data System (ADS)

    Leonard, Raymond S.

    In pursuit of space-based 'missions to earth' addressing such progressive aspirations as the general improvement of living standards for developing nations, a technological requirements and economic feasibility evaluation is conducted on the distribution of electrical power to Third World rural areas from orbit. The furnishing of power by such means offers a moral rationale for the undertaking of space exploration and industrialization. A capital recovery factor equation is used to calculate launch and hardware costs for a photovoltaic generation/microwave-transmission demonstration system, in constant 1988 dollars; an overall cost of less than $0.5 billion is obtained for the demonstrator, by comparison with $77 million for a terrestrial system of comparable output.

  10. Recovery Act Final Project Report -- Transportation Electrification

    SciTech Connect

    Gogineni, Kumar

    2013-12-31

    ChargePoint America demonstrated the viability, economic and environmental benefits of an electric vehicle-charging infrastructure. Electric vehicles (EVs) and plug-in electric vehicles (PHEVs) arrived in late 2010, there was a substantial lack of infrastructure to support these vehicles. ChargePoint America deployed charging infrastructure in ten (10) metropolitan regions in coordination with vehicle deliveries targeting those same regions by our OEM partners: General Motors, Nissan, Fisker Automotive, Ford, smart USA, and BMW. The metropolitan regions include Central Texas (Austin/San Antonio), Bellevue/Redmond (WA), Southern Michigan, Los Angeles area (CA), New York Metro (NY), Central Florida (Orlando/Tampa), Sacramento (CA), San Francisco/San Jose (CA), Washington DC and Boston (MA). ChargePoint America installed more than 4,600 Level 2 (220v) SAE J1772™ UL listed networked charging ports in home, public and commercial locations to support approximately 2000 program vehicles. ChargePoint collected data to analyze how individuals, businesses and local governments used their vehicles. Understanding driver charging behavior patterns will provide the DoE with critical information as EV adoption increases in the United States.

  11. Taking the Pulse of PyroCumulus Clouds

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Varnai, T.; Poudyal, R.; Ichoku, C.; King, M. D.

    2012-01-01

    Forest fires can burn large areas, but can also inject smoke into the upper troposphere/lower stratosphere (UT/LS), where stakes are even higher for climate, because emissions tend to have a longer lifetime, and can produce significant regional and even global climate effects, as is the case with some volcanoes. Large forest fires are now believed to be more common in summer, especially in the boreal regions, where pyrocumulus (pyroCu), and occasionally pyrocumuionimbus (pyroCb) clouds are formed, which can transport emissions into the UT/LS. A major difficulty in developing realistic fire plume models is the lack of observational data within fire plumes that resolves structure at a few 100 m scales, which can be used to validate these models. Here, we report detailed airborne radiation measurements within strong pyroCu taken over boreal forest fires in Saskatchewan, Canada during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) summer field campaign in 2008. We find that the angular distribution of radiance within the pyroCu is closely related to the diffusion domain in water clouds and can be described by very similar simple cosine functions. We demonstrate with Monte Carlo simulations that radiation transport in pyroCu is inherently a 3D phenomenon and must account for particle absorption. However, the simple cosine function promises to offer an easy solution for climate models. The presence of a prominent smoke core, defined by strong extinction in the UV, VIS and NIR, suggests that the core might be an important pathway for emission transport to the upper troposphere and lower stratosphere. We speculate that this plume injection core is generated and sustained by complex processes not yet well understood, but not necessarily related directly to the intense fires that originally initiated the plume rise.

  12. Goddard Cumulus Ensemble (GCE) Model: Application for Understanding Preciptation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The global hydrological cycle is central to climate system interactions and the key to understanding their behavior. Rainfall and its associated precipitation processes are a key link in the hydrologic cycle. Fresh water provided by tropical rainfall and its variability can exert a large impact upon the structure of the upper ocean layer. In addition, approximately two-thirds of the global rain falls in the Tropics, while the associated latent heat release accounts for about three-fourths of the total heat energy for the Earth's atmosphere. Precipitation from convective cloud systems comprises a large portion of tropical heating and rainfall. Furthermore, the vertical distribution of convective latent-heat releases modulates large-scale tropical circulations (e.g., the 30-60-day intraseasonal oscillation), which, in turn, impacts midlatitude weather through teleconnection patterns such as those associated with El Nino. Shifts in these global circulations can result in prolonged periods of droughts and floods, thereby exerting a tremendous impact upon the biosphere and human habitation. And yet, monthly rainfall over the tropical oceans is still not known within a factor of two over large (5 degrees latitude by 5 degrees longitude) areas. Hence, the Tropical Rainfall Measuring Mission (TRMM), a joint U.S./Japan space project, can provide a more accurate measurement of rainfall as well as estimate the four-dimensional structure of diabatic heating over the global tropics. The distributions of rainfall and inferred heating can be used to advance our understanding of the global energy and water cycle. In addition, this information can be used for global circulation and climate models for testing and improving their parameterizations.

  13. Microphysical development of a pulsating cumulus tower - A case study

    NASA Technical Reports Server (NTRS)

    Keller, V. W.; Sax, R. I.

    1981-01-01

    In-cloud microphysical data collected within a 22-minute period during seven consecutive passes at the -13 C sampling level of a deep (base +22 C) convective cloud provide observational evidence for a secondary ice production mechanism at work in the Florida environment. The observed microphysical characteristics of the convective tower, particularly the spatial distribution and habit of the ice phase relative to the updraft, are consistent with a rime-splintering hypothesis for secondary ice production. It is shown that the cloud's updraft structure is critically important in governing the timing of the ice production by controlling the flux of graupel particles through the critical temperature zone (-3 C to -8 C). The importance of the cloud's pulsation growth dynamics on the microphysics is emphasized, particularly as it relates to rapidly glaciating cumuli.

  14. Constraints on Cumulus Parameterization from Simulations of Observed MJO Events

    NASA Technical Reports Server (NTRS)

    Del Genio, Anthony; Wu, Jingbo; Wolf, Audrey B.; Chen, Yonghua; Yao, Mao-Sung; Kim, Daehyun

    2015-01-01

    Two recent activities offer an opportunity to test general circulation model (GCM) convection and its interaction with large-scale dynamics for observed Madden-Julian oscillation (MJO) events. This study evaluates the sensitivity of the Goddard Institute for Space Studies (GISS) GCM to entrainment, rain evaporation, downdrafts, and cold pools. Single Column Model versions that restrict weakly entraining convection produce the most realistic dependence of convection depth on column water vapor (CWV) during the Atmospheric Radiation Measurement MJO Investigation Experiment at Gan Island. Differences among models are primarily at intermediate CWV where the transition from shallow to deeper convection occurs. GCM 20-day hindcasts during the Year of Tropical Convection that best capture the shallow–deep transition also produce strong MJOs, with significant predictability compared to Tropical Rainfall Measuring Mission data. The dry anomaly east of the disturbance on hindcast day 1 is a good predictor of MJO onset and evolution. Initial CWV there is near the shallow–deep transition point, implicating premature onset of deep convection as a predictor of a poor MJO simulation. Convection weakly moistens the dry region in good MJO simulations in the first week; weakening of large-scale subsidence over this time may also affect MJO onset. Longwave radiation anomalies are weakest in the worst model version, consistent with previous analyses of cloud/moisture greenhouse enhancement as the primary MJO energy source. The authors’ results suggest that both cloud-/moisture-radiative interactions and convection–moisture sensitivity are required to produce a successful MJO simulation.

  15. Shortwave spectral radiative forcing of cumulus clouds from surface observations

    NASA Astrophysics Data System (ADS)

    Kassianov, E.; Barnard, J.; Berg, L. K.; Long, C. N.; Flynn, C.

    2011-04-01

    The spectral changes of the shortwave total, direct and diffuse cloud radiative forcing (CRF) at surface are examined for the first time using spectrally resolved all-sky flux observations and clear-sky fluxes. The latter are computed applying a physically based approach, which accounts for the spectral changes of aerosol optical properties and surface albedo. Application of this approach to 13 summertime days with single-layer continental cumuli demonstrates: (i) the substantial contribution of the diffuse component to the total CRF, (ii) the well-defined spectral variations of total CRF in the visible spectral region, and (iii) the strong statistical relationship between spectral (500 nm) and shortwave broadband values of total CRF. Our results suggest that the framework based on the visible narrowband fluxes can provide important radiative quantities for rigorous evaluation of radiative transfer parameterizations and also can be applied for estimation of the shortwave broadband CRF.

  16. Rural electrification: Waste biomass Russian northern territories. Final report

    SciTech Connect

    Adamian, S.

    1998-02-01

    The primary objective of this pre-feasibility evaluation is to examine the economic and technical feasibility of replacing distillate fuel with local waste biomass in the village of Verkhni-Ozerski, Arkhangelsk Region, Russia. This village is evaluated as a pilot location representing the off-grid villages in the Russian Northern Territories. The U.S. Department of Energy (DOE) has agreed to provide technical assistance to the Ministry of Fuel and Energy (MFE). MFE has identified the Northern Territories as a priority area requiring NREL`s assistance. The program initially affects about 900 off-grid villages. Biomass and wind energy, and to a lesser extent small hydro (depending on resource availability) are expected to play the dominant role in the program, Geothermal energy may also have a role in the Russian Far East. The Arkhangelsk, Kariela, and Krasnoyarsk Regions, all in the Russian Northern Territories, have abundant forest resources and forest products industries, making them strong candidates for implementation of small-scale waste biomass-to-energy projects. The 900 or so villages included in the renewable energy program span nine administrative regions and autonomous republics. The regional authorities in the Northern Territories proposed these villages to MFE for consideration in the renewable energy program according to the following selection criteria: (a) Remote off-grid location, (b) high cost of transporting fuel, old age of existing power generation equipment, and (d) preliminary determination as to availability of alternative energy resources. Inclusion of indigenous minorities in the program was also heavily emphasized. The prefeasibility study demonstrates that the project merits continuation and a full feasibility analysis. The demonstrated rate of return and net positive cash flow, the willingness of Onegales and local/regional authorities to cooperate, and the immense social benefits are all good reasons to continue the project.

  17. New light on rural electrification: the evidence from Bolivia

    SciTech Connect

    Tendler, J.

    1980-09-01

    In 1973-74, A.I.D. financed a project to expand existing municipal electrical systems in Bolivia to seven outlying rural areas with the aim of servicing an additional 81,000 rural customers within 10 years. This report evaluates the project's impact on the rural poor in terms of three project objectives: improving the quality of life; stimulating economic production; and creating viable electric utilities.

  18. Transportation Electrification Load Development For A Renewable Future Analysis: Preprint

    SciTech Connect

    Markel, T.; Mai, T.; Kintner-Meyer, M.

    2010-12-01

    The transition to electricity as a transportation fuel will create a new load for electricity generation. A set of regional hourly load profiles for electrified vehicles was developed for the 2010 to 2050 timeframe. The transportation electrical energy was determined using regional population forecast data, historical vehicle per capita data, and market penetration growth functions to determine the number of plug-in electric vehicles (PEVs) in each analysis region. Market saturation scenarios of 30% and 50% of sales of PEVs consuming on average approx. 6 kWh per day were considered. PEV aggregate load profiles from previous work were combined with vehicle population data to generate hourly loads on a regional basis. A transition from consumer-controlled charging toward utility-controlled charging was assumed such that by 2050 approximately 45% of the transportation energy demands could be delivered across four daily time slices under optimal control from the utility?s perspective. This electrified transportation analysis resulted in an estimate for both the flexible load and fixed load shapes on a regional basis that may evolve under two PEV market penetration scenarios.

  19. Sino-American cooperation for rural electrification in China

    SciTech Connect

    Wallace, W.L.; Tsuo, Y.S.; Taylor, R.

    1997-12-01

    This paper discusses primarily two different renewable energy programs which are in progress in China. One is in Gansu province, based on a solar home system project. This project is stressing a sustainable market development, provision of small lighting systems for residential and small schools, and water pumping and telecommunications support. It seeks involvement of 600 households as a minimum over 18 months. The second project is a very aggressive renewable energy project in Inner Mongolia, where there are excellent wind and solar resources, and where there are already 110,000 small wind turbines installed, in addition to more than 9 hybrid power systems for villages. These programs have major involvement from the Chinese government and industry, with some guidance and support from the USA.

  20. Rural Electrification and Level of Living: Evaluation of Impact.

    ERIC Educational Resources Information Center

    Davis, J. Michael; Saunders, John

    Utilizing an ex-post-facto experimental design, all occupied households located within the rural area of Canton San Carlos in Costa Rica (La Fortuna) were studied in August of 1972 for purposes of testing the hypothesis that electricity use is positively associated with level of living. Interviews with 452 heads of households (when possible)…

  1. The role of electrification in a sustainable energy future

    SciTech Connect

    Gellings, C.

    1993-04-01

    Recent natural disasters such as the Loma Prieta earthquake, hurricanes Andrew and Iniki, and the recent hurricane-snowstorm that [open quotes]ate the East[close quotes] have reminded all Americans of their dependence on energy service, particularly electricity. Within seconds, tens of thousands of people suddenly could not turn on lights or television sets, refrigerate perishable food, cook a meal, or get from automatic teller machines to pay for batteries and supplies. At its most basic, this loss of electricity service disrupted residents' familiar patterns of life: people flipped often-used switches and nothing happened.

  2. Mixed phase clouds, cloud electrification and remote sensing.

    SciTech Connect

    Chylek, P.; Borel, C. C.; Klett, James

    2004-01-01

    Most of hypothesis trying to explain charge separation in thunderstorm clouds require presence of ice and supercooled water. Thus the existence of ice or at least mixed phase regions near cloud tops should be a necessary (but not a sufficient) condition for development of lightning. We show that multispectral satellite based instruments, like the DOE MTI (Multispectral Thermal Imager) or NASA MODIS (Moderate Resolution Imaging Spectroradiometer), using the near infrared and visible spectral bands are able to distinguish between water, ice and mixed phase cloud regions. An analysis of the MTI images of mixed phase clouds - with spatial resolution of about 20 m - shows regions of pure water, pure ice as well as regions of water/ice mixtures. We suggest that multispectral satellite instruments may be useful for a short time forecast of lightning probabilities.

  3. Thunderstorm electrification of hail and graupel by polar dribble.

    PubMed

    Gunn, R

    1966-02-11

    Hail and graupel falling through rain collect water that selectively dribbles upward from the upper surface of a hailstone. When the hailstones are polarized by nearly vertical electrostatic field these vertically discharged water drops carry away free charge of the same sign as that induced on the upper surfaces. The hail thereby accumulates an equilibrium charge of opposite sign, corresponding to the charges induced on the bottom surfaces. The equilibrium charges are large enough to be important in thunderstorms.

  4. A Comparison of AgI and CO2 Seeding Effects in Alberta Cumulus Clouds.

    NASA Astrophysics Data System (ADS)

    English, Marianne; Marwitz, John D.

    1981-05-01

    Three convective clouds extending above a stratocumulus layer were identified as being seedable on one day and were then seeded in a random sequence with CO2 pellets, a placebo and droppable AgI flares. The radar and microphysical seeding effects were observed with the Alberta Hail Project S-band radar and with the University of Wyoming Queen Air aircraft. Distinct seeding effects were observed in both seeded clouds by both data systems. The CO2 seeded cloud developed a single curtain of precipitation particles 18 min after seeding which reached the ground 20 min after seeding and ceased precipitating 10 min later. The placebo cloud failed to develop any precipitation-sized particles or radar echo and dissipated after 30 min. The AgI seeded cloud developed its first echo 8 min after seeding near the threshold temperature for AgI (7°C), produced precipitation at the ground 20 min after seeding, and continued to develop a new echo near the 7°C level and precipitate for 1 h. A natural echoing storm which occurred nearby was examined by radar and found to develop and evolve in a manner quite unlike the seeded clouds. It is plausible that the AgI continued to generate ice crystals in such a manner as to first initiate and then prolong the lifetime of precipitation while the curtain of CO2 pellets failed to initiate more than a single precipitation curtain.

  5. Artificial rain enhancement in warms cumulus clouds using aircraft sea water seeding

    NASA Astrophysics Data System (ADS)

    Martin, Inácio M.; Imai, Takeshi; Seguchi, Tomio

    This paper describes the development of a new process to induce enhancement of local rains with higher intensity by seeding clouds with sea water droplets of controlled size sown by aircraft. Clouds were selected for seeding based on meteorological radar observations. The radar operates in the C-band and was specially calibrated for this study. The seeding droplets were similar in size to those naturally found in clouds. The radar was used to track clouds that may produce rain over areas of interest, such as a drainage basin feeding a major city or a hydroelectric power plant, and reforested or even agricultural areas in the state of São Paulo, a Brazil. The radar allowed the determination of cloud position, height, volume, trajectory, speed and water content. These are important parameters; they helped the seeder aircraft locate clouds above the area where the artificial rain is necessary or required. In the past, experiments in warm clouds that did not yield positive results were based on the use of silver iodide acting as a nucleating agent or solid particles of sodium chloride acting as a humectant. In our process, clouds are seeded with plain liquid sea water in the form of controlled-sized droplets. The seeding experiment was carried out during the local rainy season, from November 2007 to February 2008, in the region of Bragaña Paulista (22o 57'07" S, 46o 32'31" W), located c 90 km northeast of São Paulo. Forty five seeding flights were conducted during this period a of experiment. SABESP, the largest water supply company in Brazil, verified that the cloud seeding experiment produced an enhancement of 20

  6. Theoretical development of Monte Carlo codes for modeling cumulus cloud fields

    NASA Technical Reports Server (NTRS)

    Welch, R. M.

    1984-01-01

    Reflected fluxes are calculated for stratocumulus cloud fields as a function of skycover, cloud aspect ratio, and cloud shape. Cloud liquid water volume is held invariant as cloud shape is varied so that the results can be utilized more effectively by general circulation models and climate models. On the basis of required accuracy in the Earth Radiation Budget Experiment program, an order of magnitude value of 10 W/sq m is used to estimate significant differences between plane parallel and broken cloudiness. This limit is exceeded for cloud covers between 10% and 90%, indicating that plane paralel calculations are not satisfactory at most values of cloud cover. The choice of cloud shape also leads to large differences in reflected fluxes. These differences are traced to the anisotropic intensity pattern out the cloud sides, to the size and shape of the holes between clouds, and to variations in cloud area as viewed from the solar direction. An empirical relationship for effective cloud cover is given at solar zenith angle of theta = 60 deg. This relationship allows for the relatively accurate (delta F = 10 - 15 W/sq m.) computation of broken cloud field reflected fluxes from plane parallel calculations.

  7. Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds

    NASA Astrophysics Data System (ADS)

    Wehner, B.; Werner, F.; Ditas, F.; Shaw, R. A.; Kulmala, M.; Siebert, H.

    2015-10-01

    During the CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) campaign, the interaction between aerosol particles and cloud microphysical properties was investigated in detail, which also includes the influence of clouds on the aerosol formation. During two intensive campaigns in 2010 and 2011, helicopter-borne measurement flights were performed to investigate the thermodynamic, turbulent, microphysical, and radiative properties of trade-wind cumuli over Barbados. During these flights, 91 cases with increased aerosol particle number concentrations near clouds were detected. The majority of these cases are also correlated with enhanced irradiance in the ultraviolet (UV) spectral wavelength range. This enhancement reaches values up to a factor of 3.3 greater compared to background values. Thus, cloud boundaries provide a perfect environment for the production of precursor gases for new particle formation. Another feature of cloud edges is an increased turbulence, which may also enhance nucleation and particle growth. The observed events have a mean length of 100 m, corresponding to a lifetime of less than 300 s. This implies that particles with diameters of at least 7 nm grew several nanometers per minute, which corresponds to the upper end of values in the literature (Kulmala et al., 2004). Such high values cannot be explained by sulfuric acid alone; thus extremely low volatility organic compounds (ELVOCs) are probably involved here.

  8. Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds

    NASA Astrophysics Data System (ADS)

    Wehner, B.; Werner, F.; Ditas, F.; Shaw, R. A.; Kulmala, M.; Siebert, H.

    2015-04-01

    During the CARRIBA-campaign (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) the interaction between aerosol particles and cloud microphysical properties has been investigated in detail which includes also the influence of clouds on the aerosol formation. During two intensive campaigns in 2010 and 2011 helicopter-borne measurement flights have been performed to investigate the thermodynamic, turbulent, microphysical, and radiative properties of trade wind cumuli over Barbados. During these flights 91 cases with increased aerosol particle number concentrations near clouds were detected. The majority of these cases are also correlated with enhanced irradiance in the ultraviolet spectral wavelength range (UV). This enhancement reaches values up to a factor of 3.3 compared to background values. Thus, cloud boundaries provide a perfect environment for the production of precursor gases for new particle formation. Another feature of cloud edges is an increased turbulence which may also enhance nucleation and particle growth. The observed events have a mean length of 100 m corresponding to a lifetime of less than 300 s. This implies that particles with diameters of at least 7 nm grew several nm per minute which corresponds to the upper end of values in the literature (Kulmala et al., 2004). Such high values cannot be explained by sulfuric acid alone, thus probably extremely low volatile organic compounds (ELVOCs) are involved here.

  9. Twomey effect observed from collocated microphysical and remote sensing measurements over shallow cumulus

    NASA Astrophysics Data System (ADS)

    Werner, F.; Ditas, F.; Siebert, H.; Simmel, M.; Wehner, B.; Pilewskie, P.; Schmeissner, T.; Shaw, R. A.; Hartmann, S.; Wex, H.; Roberts, G. C.; Wendisch, M.

    2014-02-01

    Clear experimental evidence of the Twomey effect for shallow trade wind cumuli near Barbados is presented. Effective droplet radius (reff) and cloud optical thickness (τ), retrieved from helicopter-borne spectral cloud-reflected radiance measurements, and spectral cloud reflectivity (γλ) are correlated with collocated in situ observations of the number concentration of aerosol particles from the subcloud layer (N). N denotes the concentration of particles larger than 80 nm in diameter and represents particles in the activation mode. In situ cloud microphysical and aerosol parameters were sampled by the Airborne Cloud Turbulence Observation System (ACTOS). Spectral cloud-reflected radiance data were collected by the Spectral Modular Airborne Radiation measurement sysTem (SMART-HELIOS). With increasing N a shift in the probability density functions of τ and γλ toward larger values is observed, while the mean values and observed ranges of retrieved reff decrease. The relative susceptibilities (RS) of reff, τ, and γλ to N are derived for bins of constant liquid water path. The resulting values of RS are in the range of 0.35 for reff and τ, and 0.27 for γλ. These results are close to the maximum susceptibility possible from theory. Overall, the shallow cumuli sampled near Barbados show characteristics of homogeneous, plane-parallel clouds. Comparisons of RS derived from in situ measured reff and from a microphysical parcel model are in close agreement.

  10. Estimation of Droplet Size and Liquid Water Content Using Radar and Lidar: Marine Cumulus Clouds

    NASA Astrophysics Data System (ADS)

    Vivekanandan, J. Vivek; Jensen, Jorgen; Ellis, Scott; Morley, Bruce; Tsai, Peisang; Spuler, Scott; Ghate, Virendra; Schwartz, Christian

    2016-04-01

    During the Cloud Systems Evolution in the Trades (CSET) field campaign airborne measurements from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Cloud Radar (HCR) and the High Spectral Resolution Lidar (HSRL) were made in the North Pacific. In addition, in situ observations of cloud and aerosols size distributions and radiation were also collected. The HCR operated at a frequency of 94 GHz (3 mm wavelength) and collected observations at high temporal (0.5 sec) and range (30 m) resolution. The capability of HCR is enhanced by the coordination with the HSRL that made high temporal and range resolution observations of calibrated backscatter and extinction. The lidar, designed and built by the University of Wisconsin. The radar and lidar are designed to fly on the NCAR Gulfstream V HIAPER aircraft. The remote and in situ measurements collected during CSET offer opportunities for evaluating the engineering performance of the instruments and developing cloud microphysical scientific products. The coincident HCR and HSRL measurements are analyzed for assess their utility to characterize cloud boundaries, estimate liquid water content (LWC) and mean particle size. Retrievals of LWC and mean particle sizes from remote radar and lidar measurements will be compared with those from the in situ instruments.

  11. Ice crystal concentration in cumulus clouds: influence of the drop spectrum.

    PubMed

    Mossop, S C; Hallett, J

    1974-11-15

    Secondary ice crystals are thrown off when supercooled cloud drops are captured and freeze on a moving target in a cloud at -5 degrees C. The rate of production of these ice crystals is proportional to the rate of accretion of drops of the diameter >/=24 micrometers.

  12. Turbulent Boundary Layer Dynamics and its Relationship to Shallow Cumulus Convection over the Central Equatorial Pacific

    NASA Astrophysics Data System (ADS)

    Faloona, I. C.; Conley, S. A.; Lenschow, D. H.; Bandy, A. R.

    2011-12-01

    Eleven research flights of the National Center for Atmospheric Research (NCAR) C-130 aircraft are analyzed in the vicinity of Christmas Island (2°N, 157°W) during August/September 2007 as part of the Pacific Atmospheric Sulfur Experiment (PASE). In addition to sulfur gases DMS and SO2, and other chemical scalars (O3 and CCN), standard meteorological variables such as temperature, moisture, and winds were measured in-situ at high rate. The nocturnal and daytime flights of PASE were focused on turbulent flux profiles below the trade wind inversion (observed at a mean altitude of 1350m asl). Vertical profiles and long, level legs from near the surface to the lower free troposphere were used to characterize the mean vertical structure of the marine boundary layer (MBL, typically located up to near cloud base at ~550m asl) and the buffer layer (BuL, the intermittently turbulent and occasionally cloudy layer above.) A budget of turbulent kinetic energy (TKE) exhibited evenly distributed shear production throughout the MBL along with the expected linear profile of buoyancy production. Two loci of approximately equal parts shear production, transport, and buoyancy production sustain TKE in the BuL at levels of ~70% that within the MBL. A mean cloud fraction profile from the experiment evinces a bimodal distribution of trade wind cumuli with a major peak at the top and a secondary peak in the lower third of the BuL, consistent with the picture of shallow convection supplying the bulk of the TKE to this layer, but not uniformly in the vertical. On eight of the eleven flights a low level jet was observed either within or just above the BuL, and contributes significantly to turbulent activity in the BuL. Moreover, observations of the mean profiles of various reactive scalars provide a unique constraint on average BuL mixing time scales. During the four week mission, sea surface temperatures over the region decreased by 1.5K as the advancing cold tongue brought cooler water and higher winds to the equatorial mid Pacific. This large scale phenomenon is shown to be principally responsible for a subsiding trade inversion and the increasing trends observed in TKE and cloud cover over the region during late boreal summer.

  13. Interactions between cumulus convection and its environment as revealed by the MC3E sounding array

    DOE PAGESBeta

    Xie, Shaocheng; Zhang, Yunyan; Giangrande, Scott E.; Jensen, Michael P.; McCoy, Renata; Zhang, Minghua

    2014-10-27

    This study attempts to understand interactions between midlatitude convective systems and their environments through a heat and moisture budget analysis using the sounding data collected from the Midlatitude Continental Convective Clouds Experiment (MC3E) in central Oklahoma. Distinct large-scale structures and diabatic heating and drying profiles are presented for cases of weaker and elevated thunderstorms as well as intense squall line and supercell thunderstorm events during the campaign. The elevated cell events were nocturnal convective systems occurring in an environment having low convective available potential energy (CAPE) and a very dry boundary layer. In contrast, deeper convective events happened during themore » morning into early afternoon within an environment associated with large CAPE and a near-saturated boundary layer. As the systems reached maturity, the diagnosed diabatic heating in the latter deep convective cases was much stronger and of greater vertical extent than the former. Both groups showed considerable diabatic cooling in the lower troposphere, associated with the evaporation of precipitation and low-level clouds. The horizontal advection of moisture also played a dominant role in moistening the lower troposphere, particularly for the deeper convective events, wherein the near surface southeasterly flow allows persistent low-level moisture return from the Gulf of Mexico to support convection. The moisture convergence often was present before these systems develop, suggesting a strong correlation between the large-scale moisture convergence and convection. As a result, sensitivity tests indicated that the uncertainty in the surface precipitation and the size of analysis domain mainly affected the magnitude of these analyzed fields rather than their vertical structures.« less

  14. Interactions between cumulus convection and its environment as revealed by the MC3E sounding array

    SciTech Connect

    Xie, Shaocheng; Zhang, Yunyan; Giangrande, Scott E.; Jensen, Michael P.; McCoy, Renata; Zhang, Minghua

    2014-10-27

    This study attempts to understand interactions between midlatitude convective systems and their environments through a heat and moisture budget analysis using the sounding data collected from the Midlatitude Continental Convective Clouds Experiment (MC3E) in central Oklahoma. Distinct large-scale structures and diabatic heating and drying profiles are presented for cases of weaker and elevated thunderstorms as well as intense squall line and supercell thunderstorm events during the campaign. The elevated cell events were nocturnal convective systems occurring in an environment having low convective available potential energy (CAPE) and a very dry boundary layer. In contrast, deeper convective events happened during the morning into early afternoon within an environment associated with large CAPE and a near-saturated boundary layer. As the systems reached maturity, the diagnosed diabatic heating in the latter deep convective cases was much stronger and of greater vertical extent than the former. Both groups showed considerable diabatic cooling in the lower troposphere, associated with the evaporation of precipitation and low-level clouds. The horizontal advection of moisture also played a dominant role in moistening the lower troposphere, particularly for the deeper convective events, wherein the near surface southeasterly flow allows persistent low-level moisture return from the Gulf of Mexico to support convection. The moisture convergence often was present before these systems develop, suggesting a strong correlation between the large-scale moisture convergence and convection. As a result, sensitivity tests indicated that the uncertainty in the surface precipitation and the size of analysis domain mainly affected the magnitude of these analyzed fields rather than their vertical structures.

  15. Temporal Variability of Fair-Weather Cumulus Statistics at the ACRF SGP Site

    SciTech Connect

    Berg, Larry K.; Kassianov, Evgueni I.

    2008-07-01

    Continental fair-weather cumuli exhibit significant diurnal, day-to-day, and year-to-year variability. This study describes the climatology of cloud macroscale properties, including the cloud-base height, cloud-top height, cloud thickness, and cloud chord length over the U.S. Department of Energy¹s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARCF) Southern Great Plains (SGP) site. The diurnal cycle of cloud fraction, cloud-base height, and cloud-thickness were well defined. The cloud fraction reached its maximum value near 14:00 CST. The average cloud-base height increased throughout the day, while the average cloud thickness decreased with time. In contrast to the other cloud properties, the average cloud-chord length remained nearly constant throughout the day. The sensitivity of the cloud properties to the year-to-year variability and to changes in low-level moisture were compared. The cloud-base height was found to be sensitive to both the year and the low-level moisture, the cloud thickness was much more sensitive to the year then to the low-level moisture, and the cloud fraction and cloud chord length were more sensitive to the low-level moisture than to the year. Distributions of the cloud-chord length over the ARCF SGP site were computed and were well fit by an exponential distribution. The contribution of clouds of each cloud-chord length to the total cloud fraction was computed, and it was found the clouds with a chord length of about 1 km contributed the most to the observed cloud fraction.

  16. Dependence of Cumulus Anvil Radiative Properties on Environmental Conditions in the Tropical West Pacific

    NASA Technical Reports Server (NTRS)

    Ye, B.; DelGenio, A. D.

    1999-01-01

    Areally extensive, optically thick anvil clouds associated with mesoscale convective clusters dominate the shortwave cloud forcing in the tropics and provide longwave forcing comparable to that of thin cirrus. Changes in the cover and optical thickness of tropical anvils as climate warms can regulate the sign of cloud feedback. As a prelude to the study of MMCR data from the ARM TWP sites, we analyze ISCCP-derived radiative characteristics of anvils observed in the tropical west Pacific during the TOGA-COARE IOP. Anvils with radius greater than 100 km were identified and tracked from inception to decay using the Machado-Rossow algorithm. Corresponding environmental conditions just prior to the start of the convectove event were diagnosed using the Lin-Johnson objective analysis product. Small clusters (100-200 km radius) are observed to have a broad range of optical thicknesses (10-50), while intermediate optical thickness clusters are observed to range in size from 100 km to almost 1000 km. Large-size clusters appear to be favored by strong pre-storm large scale upward motion throughout the troposphere, moist low-to-midlevel relative humidities, environments with slightly higher CAPE than those for smaller clusters, and strong front-to-rear flow. Optically thick anvils are favored in situations of strong low-level moisture convergence and strong upper-level shear.

  17. The modification and application of Kuo's parameterization of cumulus convection in middle latitudes

    NASA Technical Reports Server (NTRS)

    Liang, W. J.

    1978-01-01

    An evaluation to reveal physical insight into the involved mechanisms through a combination of the large scale heat and moisture budgets and formulation of the latent heat released was performed. To improve upon the treatment of the interaction of deep convection with the environment, modifications consisting of considerations of the large scale moisture supply and of the vertical transport of moisture and of dry static energy inside the cloud are made. Also, a two layer cloud ensemble model is combined with the modified scheme. An examination of the modified scheme is performed by combining the large scale heat and moisture budgets and the modified formulation of the latent heat released. The modified parameterization procedures are compared with the original scheme, and the results of tests of both schemes are discussed. A variational optimization scheme is developed to analyze the wind field such that the integrated continuity equation and the global boundary condition are satisfied.

  18. Photochemical production of ozone in the upper troposphere in association with cumulus convection over Indonesia

    NASA Astrophysics Data System (ADS)

    Kita, K.; Kawakami, S.; Miyazaki, Y.; Higashi, Y.; Kondo, Y.; Nishi, N.; Koike, M.; Blake, D. R.; Machida, T.; Sano, T.; Hu, W.; Ko, M.; Ogawa, T.

    2003-02-01

    The Biomass Burning and Lightning Experiment phase A (BIBLE-A) aircraft observation campaign was conducted from 24 September to 10 October 1998, during a La Niña period. During this campaign, distributions of ozone and its precursors (NO, CO, and nonmethane hydrocarbons (NMHCs)) were observed over the tropical Pacific Ocean, Indonesia, and northern Australia. Mixing ratios of ozone and its precursors were very low at altitudes between 0 and 13.5 km over the tropical Pacific Ocean. The mixing ratios of ozone precursors above 8 km over Indonesia were often significantly higher than those over the tropical Pacific Ocean, even though the prevailing easterlies carried the air from the tropical Pacific Ocean to over Indonesia within several days. For example, median NO and CO mixing ratios in the upper troposphere were 12 parts per trillion (pptv) and 72 parts per billion (ppbv) over the tropical Pacific Ocean and were 83 pptv and 85 ppbv over western Indonesia, respectively. Meteorological analyses and high ethene (C2H4) mixing ratios indicate that the increase of the ozone precursors was caused by active convection over Indonesia through upward transport of polluted air, mixing, and lightning all within the few days prior to observation. Sources of ozone precursors are discussed by comparing correlations of some NMHCs and CH3Cl concentrations with CO between the lower and upper troposphere. Biomass burning in Indonesia was nearly inactive during BIBLE-A and was not a dominant source of the ozone precursors, but urban pollution and lightning contributed importantly to their increases. The increase in ozone precursors raised net ozone production rates over western Indonesia in the upper troposphere, as shown by a photochemical model calculation. However, the ozone mixing ratio (~20 ppbv) did not increase significantly over Indonesia because photochemical production of ozone did not have sufficient time since the augmentation of ozone precursors. Backward trajectories show that many air masses sampled over the ocean south of Indonesia and over northern Australia passed over western Indonesia 4-9 days prior to being measured. In these air masses the mixing ratios of ozone precursors, except for short-lived species, were similar to those over western Indonesia. In contrast, the ozone mixing ratio was higher by about 10 ppbv than that over Indonesia, indicating that photochemical production of ozone occurred during transport from Indonesia. The average rate of ozone increase (1.8 ppbv/d) during this transport is similar to the net ozone formation rate calculated by the photochemical model. This study shows that active convection over Indonesia carried polluted air upward from the surface and had a discernable influence on the distribution of ozone in the upper troposphere over the Indian Ocean, northern Australia, and the south subtropical Pacific Ocean, combined with NO production by lightning.

  19. Photochemical production of ozone in the upper troposphere in association with cumulus convection over Indonesia

    NASA Astrophysics Data System (ADS)

    Kita, K.; Kawakami, S.; Miyazaki, Y.; Higashi, Y.; Kondo, Y.; Nishi, N.; Koike, M.; Blake, D. R.; Machida, T.; Sano, T.; Hu, W.; Ko, M.; Ogawa, T.

    2002-02-01

    The Biomass Burning and Lightning Experiment phase A (BIBLE-A) aircraft observation campaign was conducted from 24 September to 10 October 1998, during a La Niña period. During this campaign, distributions of ozone and its precursors (NO, CO, and nonmethane hydrocarbons (NMHCs)) were observed over the tropical Pacific Ocean, Indonesia, and northern Australia. Mixing ratios of ozone and its precursors were very low at altitudes between 0 and 13.5 km over the tropical Pacific Ocean. The mixing ratios of ozone precursors above 8 km over Indonesia were often significantly higher than those over the tropical Pacific Ocean, even though the prevailing easterlies carried the air from the tropical Pacific Ocean to over Indonesia within several days. For example, median NO and CO mixing ratios in the upper troposphere were 12 parts per trillion (pptv) and 72 parts per billion (ppbv) over the tropical Pacific Ocean and were 83 pptv and 85 ppbv over western Indonesia, respectively. Meteorological analyses and high ethene (C2H4) mixing ratios indicate that the increase of the ozone precursors was caused by active convection over Indonesia through upward transport of polluted air, mixing, and lightning all within the few days prior to observation. Sources of ozone precursors are discussed by comparing correlations of some NMHCs and CH3Cl concentrations with CO between the lower and upper troposphere. Biomass burning in Indonesia was nearly inactive during BIBLE-A and was not a dominant source of the ozone precursors, but urban pollution and lightning contributed importantly to their increases. The increase in ozone precursors raised net ozone production rates over western Indonesia in the upper troposphere, as shown by a photochemical model calculation. However, the ozone mixing ratio (˜20 ppbv) did not increase significantly over Indonesia because photochemical production of ozone did not have sufficient time since the augmentation of ozone precursors. Backward trajectories show that many air masses sampled over the ocean south of Indonesia and over northern Australia passed over western Indonesia 4-9 days prior to being measured. In these air masses the mixing ratios of ozone precursors, except for short-lived species, were similar to those over western Indonesia. In contrast, the ozone mixing ratio was higher by about 10 ppbv than that over Indonesia, indicating that photochemical production of ozone occurred during transport from Indonesia. The average rate of ozone increase (1.8 ppbv/d) during this transport is similar to the net ozone formation rate calculated by the photochemical model. This study shows that active convection over Indonesia carried polluted air upward from the surface and had a discernable influence on the distribution of ozone in the upper troposphere over the Indian Ocean, northern Australia, and the south subtropical Pacific Ocean, combined with NO production by lightning.

  20. Calreticulin is required for development of the cumulus oocyte complex and female fertility

    PubMed Central

    Tokuhiro, Keizo; Satouh, Yuhkoh; Nozawa, Kaori; Isotani, Ayako; Fujihara, Yoshitaka; Hirashima, Yumiko; Matsumura, Hiroyuki; Takumi, Kazuhiro; Miyano, Takashi; Okabe, Masaru; Benham, Adam M.; Ikawa, Masahito

    2015-01-01

    Calnexin (CANX) and calreticulin (CALR) chaperones mediate nascent glycoprotein folding in the endoplasmic reticulum. Here we report that these chaperones have distinct roles in male and female fertility. Canx null mice are growth retarded but fertile. Calr null mice die during embryonic development, rendering indeterminate any effect on reproduction. Therefore, we conditionally ablated Calr in male and female germ cells using Stra8 (mcKO) and Zp3 (fcKO) promoter-driven Cre recombinase, respectively. Calr mcKO male mice were fertile, but fcKO female mice were sterile despite normal mating behavior. Strikingly, we found that Calr fcKO female mice had impaired folliculogenesis and decreased ovulatory rates due to defective proliferation of cuboidal granulosa cells. Oocyte-derived, TGF-beta family proteins play a major role in follicular development and molecular analysis revealed that the normal processing of GDF9 and BMP15 was defective in Calr fcKO oocytes. These findings highlight the importance of CALR in female reproduction and demonstrate that compromised CALR function leads to ovarian insufficiency and female infertility. PMID:26388295

  1. Impact of cumulus initialization on the spinup of precipitation forecasts in the tropics

    NASA Technical Reports Server (NTRS)

    Kasahara, Akira; Mizzi, Arthur P.; Donner, Leo J.

    1992-01-01

    To ameliorate the precipitation spinup problem, i.e., the prediction model's inability to produce realistic precipitation rates at the beginning of the forecast period, the impact of a tropical initialization procedure on precipitation forecasts is examined. Attention is focused on the examination of the time behavior of precipitation rates and the closely associated variables of horizontal divergence and moisture during the first 42 time steps corresponding to 10.5 h. It is determined that the originally analyzed tropical divergence fields have realistic geographical distributions but there intensities seem to be too low by a factor of two.

  2. Cumulus moistening, the diurnal cycle, and large-scale tropical dynamics

    NASA Astrophysics Data System (ADS)

    Ruppert, James H., Jr.

    Observations and modeling techniques are employed to diagnose the importance of the diurnal cycle in large-scale tropical climate. In the first part of the study, soundings, radar, and surface flux measurements collected in the Indian Ocean DYNAMO experiment (Dynamics of the Madden--Julian Oscillation, or MJO) are employed to study MJO convective onset. According to these observations, MJO onset takes place as follows: moistening of the low--midtroposphere is accomplished by cumuliform clouds that deepen as the drying by large-scale subsidence and horizontal advection simultaneously wane. This relaxing of subsidence is tied to decreasing column radiative cooling, which links back to the evolving cloud population. A new finding from these observations is the high degree to which the diurnal cycle linked to air-sea and radiative fluxes invigorates clouds and drives column moistening each day. This diurnally modulated cloud field exhibits pronounced mesoscale organization in the form of open cells and horizontal convective rolls. Based on these findings, it is hypothesized that the diurnal cycle and mesoscale cloud organization represent two manners in which local convective processes promote more vigorous day-to-day tropospheric moistening than would otherwise occur. A suite of model tests are carried out in the second part of the study to 1) test the hypothesis that the diurnal cycle drives moistening on longer timescales, and 2) better understand the relative roles of diurnally varying sea surface temperature (SST) and direct atmospheric radiative heating in the diurnal cycle of convection. Moist convection is explicitly represented in the model, the diurnal cycle of SST is prescribed, and cloud-interactive radiation is simulated with a diurnal cycle in shortwave heating. The large-scale dynamics are parameterized using the spectral weak temperature gradient (WTG) technique recently introduced by Herman and Raymond. In this scheme, external (i.e., large-scale) vertical motion wwtg is diagnosed based on the internal diabatic heating in the model. wwtg is then used to advect model temperature and humidity. wwtg opposes domain-averaged temperature anomalies via adiabatic warming and cooling, thereby yielding a feedback between the model diabatic heating and the large-scale column moisture source associated with large-scale vertical motion. With a control simulation that successfully replicates a regime of shallow convection similar to nature, it is found through sensitivity tests that the diurnal cycle in tropospheric radiative heating is the dominant driver of both diurnal column moisture variations and nocturnal rainfall in this regime, the latter of which agrees with previous findings by Randall et al. The diurnal cycle in SST and surface fluxes, in turn, drives the daytime convective regime, which is distinct from the nocturnal regime by its rooting in the boundary layer. A simulation in which the diurnal cycle is stretched to 48 h amplifies an important nonlinear feedback at work in the diurnal cycle, which owes to the high-amplitude diurnal cycle in column relative humidity RH. This diurnal cycle in RH limits the amount of evaporation, and hence evaporative cooling, that takes place in the cloud layer. By throttling down the diabatic cooling, the diurnal cycle throttles down the daily-mean moisture sink driven by large-scale subsidence, such that the environment drifts toward a more moist state, all else being equal. When the diurnal cycle is not present, this nonlinear moisture source is weaker, and the environment drier. This feedback rectifies diurnal moistening onto longer timescales, thereby linking the diurnal cycle to longer timescales. These findings suggest that 1) the diurnal cycle of moist convection, as observed in DYNAMO, cannot be ruled out as an column moisture source important to MJO initiation, and 2) that proper representation of the diurnal cycle is prerequisite to accurate representation of large-scale climate, at least within the regime studied herein.

  3. New Concepts for Refinement of Cumulus Parameterization in GCM's the Arakawa-Schubert Framework

    NASA Technical Reports Server (NTRS)

    Sud, Y. C.; Walker, G. K.; Lau, William (Technical Monitor)

    2002-01-01

    Several state-of-the-art models including the one employed in this study use the Arakawa-Schubert framework for moist convection, and Sundqvist formulation of stratiform. clouds, for moist physics, in-cloud condensation, and precipitation. Despite a variety of cloud parameterization methodologies developed by several modelers including the authors, most of the parameterized cloud-models have similar deficiencies. These consist of: (a) not enough shallow clouds, (b) too many deep clouds; (c) several layers of clouds in a vertically demoralized model as opposed to only a few levels of observed clouds, and (d) higher than normal incidence of double ITCZ (Inter-tropical Convergence Zone). Even after several upgrades consisting of a sophisticated cloud-microphysics and sub-grid scale orographic precipitation into the Data Assimilation Office (DAO)'s atmospheric model (called GEOS-2 GCM) at two different resolutions, we found that the above deficiencies remained persistent. The two empirical solutions often used to counter the aforestated deficiencies consist of a) diffusion of moisture and heat within the lower troposphere to artificially force the shallow clouds; and b) arbitrarily invoke evaporation of in-cloud water for low-level clouds. Even though helpful, these implementations lack a strong physical rationale. Our research shows that two missing physical conditions can ameliorate the aforestated cloud-parameterization deficiencies. First, requiring an ascending cloud airmass to be saturated at its starting point will not only make the cloud instantly buoyant all through its ascent, but also provide the essential work function (buoyancy energy) that would promote more shallow clouds. Second, we argue that training clouds that are unstable to a finite vertical displacement, even if neutrally buoyant in their ambient environment, must continue to rise and entrain causing evaporation of in-cloud water. These concepts have not been invoked in any of the cloud parameterization schemes so far. We introduced them into the DAO-GEOS-2 GCM with McRAS (Microphysics of Clouds with Relaxed Arakawa-Schubert Scheme).

  4. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    NASA Astrophysics Data System (ADS)

    Chen, Xiangyu; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei

    2015-09-01

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm2, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  5. Surface energy fluxes at Central Florida during the convection and precipitation electrification experiment

    NASA Technical Reports Server (NTRS)

    Nie, D.; Demetriades-Shah, T. D.; Kanemasu, E. T.

    1993-01-01

    One of the objectives of CaPE is to better understand the convective process in central and south Florida during the warm season. The energy and moisture exchanges between the surface and the atmosphere are closely related to this process. Some recent studies have shown that the surface energy balance plays an important role in the climatic fields (Shukla and Mintz, 1982; Sud and Smith, 1985; Sato et. al, 1989). Surface energy fluxes and related surface processes such as evapotranspiration and sensible heat transfer directly effect the temperature, humidity, cloud formation and precipitation. For example, mesoscale circulation around a discontinuity in vegetation type were shown to be stronger with wet soil than with dry soil using an evapotranspiration model (Pinty et. al, 1989). In order to better describe the processes in the atmosphere at various scales and improve our ability of modeling and predicting weather related events, it is crucial to understand the mechanism of surface energy transfer in relation to atmospheric events. Surface energy flux measurements are required to fully understand the interactions between the atmosphere and the surface.

  6. Further laboratory investigations into the Relative Diffusional Growth Rate theory of thunderstorm electrification

    NASA Astrophysics Data System (ADS)

    Emersic, C.; Saunders, C. P. R.

    2010-11-01

    Predictions from the Relative Diffusional Growth Rate theory have allowed us to further examine controls over the sign of graupel charge in laboratory experiments involving collisions between ice crystals and riming graupel. This has been achieved primarily through the use of two-cloud experiments in which a supercooled droplet cloud and an ice crystal cloud are mixed together. A range of crystal-cloud nucleation techniques has enabled substantial control over the preconditioning of ice crystal surface growth rates such as to control transient rapid crystal growth on mixing with a droplet cloud prior to interaction with a riming target. We have qualitatively identified the effects that crystal surface growth rate and size have on the rate of transient rapid growth after mixing. Crystals with higher surface growth rates in environments nearer to water saturation reduce the effect of transient rapid growth on mixing leading to positive graupel charging. Crystals with lower surface growth rates in environments nearer to ice saturation enhance transient rapid growth on mixing - particularly for smaller crystal sizes - to promote negative graupel charging. This is consistent with the Relative Diffusional Growth Rate theory which has been developed from many laboratory studies and shows that in collisions between ice particles, the surface growing faster by diffusion charges positively. Using both the shortest and longest nucleation techniques developed, it was possible to extend negative charging to approximately -20 °C and -14 °C respectively. Being able to control cloud microphysics and determine its effect on charge sign has led to the conclusion that numerical models of thunderstorm charge development need to take account of the wide range of specific microphysical conditions and their effects on cloud particle charging throughout many regions and the lifetime of a thunderstorm. We also provide evidence in support of new interpretations of the results of other researchers by using predictions of the Relative Diffusional Growth Rate theory to enable the development of experimental techniques to promote negative graupel charging to record high temperatures, and consequently allow negative charging at any sub-zero temperature applicable to thunderstorms.

  7. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    SciTech Connect

    Chen, Xiangyu E-mail: ouyangwei@phy.ecnu.edu.cn; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei E-mail: ouyangwei@phy.ecnu.edu.cn

    2015-09-14

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm{sup 2}, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  8. Utilization Assessment of Target Electrification Vehicles at Naval Air Station Whidbey Island: Task 3

    SciTech Connect

    Schey, Steve

    2015-05-01

    Several U.S. Department of Defense based studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of the charging infrastructure required to support this replacement, which is the subject of a separate report.

  9. Electrification in Hurricanes over the Tropical Americas: Implication for Stratospheric Water Vapor

    NASA Technical Reports Server (NTRS)

    Pittman, Jasna V.; Chronis, Themis G.; Robertson, Franklin R.; Miller, Timothy L.

    2007-01-01

    This study explores the relation between lightning activity and water vapor in the Tropical Tropopause Layer (TTL) over hurricane systems in the Tropical Americas. The hypothesis herein is that hurricanes that exhibit enhanced lightning activity are associated with stronger updrafts that can transport more moisture directly into the TTL (and subsequently into the tropical stratosphere) or even directly into the tropical stratosphere over this region. The TTL over the Tropical Americas, which includes the Caribbean and Gulf of Mexico, is of particular interest, because summertime cold point tropopause is the lowest in height and thus the warmest in temperature over the tropics. The latter condition implies higher saturation values and thus potential for more water vapor to enter the stratosphere. Climate forecast is very sensitive to stratospheric water vapor abundance, because of the key role that water vapor plays in regulating the chemical and radiative properties of the stratosphere. Given the potential for increases in hurricane intensity and frequency under predicted warmer conditions, it becomes essential to understand the effect of hurricanes on stratospheric water vapor. In this study, we use a combination of ground and space-borne observations as well as trajectory calculations. The observations include: cloud-to-ground (CG) lightning data from the U.S. National Lightning Detection Network (NLDN), geostationary infrared observations from the National Climatic Data Center Hurricane Satellite (HURSAT) data set, cloud properties from Aqua-MODIS, and water vapor from Aura-MLS. We analyze hurricanes from the 2005 season when Aura-MLS data are available, namely: Dennis, Emily, Katrina, Rita, and Wilma. Our analysis consists of examining CG lightning, cloud-top properties, and TTL water vapor (i.e., 100 and 147 mb) over the hurricane while it remains over water in the Tropical Americas region. We investigate daily as well as diurnal statistical properties. The hurricanes analyzed in this study showed that lightning activity is negatively correlated with minimum infrared brightness temperature and positively correlated with 100-mb water vapor. An examination of the maxima in water vapor observed over the hurricane not only shows larger magnitudes, but also larger differences between water vapor averages and water vapor maxima over the hurricane as lightning activity increases. Trajectory calculations are performed using the Flextra model in order to investigate the fate of the moister air masses found in the TTL.

  10. Utilization Assessment of Target Electrification Vehicles at Marine Corps Base Camp Lejeune. Task 3

    SciTech Connect

    Schey, Stephen; Francfort, Jim

    2015-11-01

    Battelle Energy Alliance, LLC, managing and operating contractor for the U.S. Department of Energy’s Idaho National Laboratory, is the lead laboratory for U.S. Department of Energy Advanced Vehicle Testing. Battelle Energy Alliance, LLC contracted with Intertek Testing Services, North America (Intertek) to conduct several U.S. Department of Defense base studies to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 1 consisted of a survey of the non-tactical fleet of vehicles at MCBCL to begin the review of vehicle mission assignments and types of vehicles in service. Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of the charging infrastructure required to support this replacement, which is the subject of a separate report. Intertek acknowledges the support of Idaho National Laboratory, Marine Corps headquarters, and Marine Corps Base Camp Lejeune Fleet management and personnel for participation in this study. Intertek is pleased to provide this report and is encouraged by enthusiasm and support from MCBCL personnel.

  11. 75 FR 5902 - Guarantees for Bonds and Notes Issued for Electrification or Telephone Purposes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-05

    ... cooperative and other not- for-profit lenders that make loans for eligible electric and telephone purposes.... The intended effect is to update agency regulations to reflect current statutory authority. DATES....regulations.gov . In the ``Search Documents'' box, enter RUS-09- Electric-0005, check the box under the...

  12. Nonequilibrium mechanisms of weak electrolyte electrification under the action of constant voltage

    NASA Astrophysics Data System (ADS)

    Stishkov, Yu. K.; Chirkov, V. A.

    2016-07-01

    The formation of space charge in weak electrolytes, specifically in liquid dielectrics, has been considered. An analytical solution is given to a simplified set of Nernst-Planck equations that describe the formation of nonequilibrium recombination layers in weak electrolytes. This approximate analytical solution is compared with computer simulation data for a complete set of Poisson-Nernst-Planck equations. It has been shown that the current passage in weak electrolytes can be described by a single dimensionless parameter that equals the length of a near-electrode recombination layer divided by the width of the interelectrode gap. The formation mechanism and the structure of charged nonequilibrium near-electrode layers in the nonstationary regime have been analyzed for different injection-to-conduction current ratios. It has been found that almost all charge structures encountered in weak dielectrics can be accounted for by the nonequilibrium dissociation-recombination mechanism of space charge formation.

  13. Wind energy harvesting and self-powered flow rate sensor enabled by contact electrification

    NASA Astrophysics Data System (ADS)

    Su, Yuanjie; Xie, Guangzhong; Xie, Tao; Zhang, Hulin; Ye, Zongbiao; Jing, Qingshen; Tai, Huiling; Du, Xiaosong; Jiang, Yadong

    2016-06-01

    We have developed a free-standing-mode based triboelectric nanogenerator (F-TENG) that consists of indium tin oxide (ITO) foils and a polytetrafluoroethylene (PTFE) thin film. By utilizing the wind-induced resonance vibration of a PTFE film between two ITO electrodes, the F-TENG delivers an open-circuit voltage up to 37 V and a short-circuit current of 6.2 μA, which can be used as a sustainable power source to simultaneously and continuously light up tens of light emitting diodes (LEDs) and charge capacitors. Moreover, uniform division of the electrode into several parallel units efficiently suppresses the inner counteracting effect of undulating film and leads to an enhancement of output current by 95%. The F-TENG holds prominent durability and an excellent linear relationship between output current and flow rate, revealing its feasibility as a self-powered sensor for detecting wind speed. This work demonstrates potential applications of the triboelectric generator in gas flow harvesters, self-powered air navigation, self-powered gas sensors and wind vector sensors.

  14. The mechanisms of fine particle generation and electrification during Mount St. Helens volcanic eruption

    NASA Technical Reports Server (NTRS)

    Cheng, R. J.

    1982-01-01

    Microscopical investigation of volcanic ash collected from ground stations during Mount St. Helens eruptions reveal a distinctive bimodel size distribution with high concentrations of particle ranges at (1) 200-100 microns and (2) 20-0.1 microns. Close examination of individual particles shows that most larger ones are solidified magma particles of porous pumice with numerous gas bubbles in the interior and the smaller ones are all glassy fragments without any detectable gas bubbles. Elemental analysis demonstrates that the fine fragments all have a composition similar to that of the larger pumice particles. Laboratory experiments suggest that the formation of the fine fragments is by bursting of glassy bubbles from a partially solidified surface of a crystallizing molten magma particle. The production of gas bubbles is due to the release of absorbed gases in molten magma particles when solubility decreases during phase transition. Diffusion cloud chamber experiments strongly indicate that sub-micron volcanic fragments are highly hygroscopic and extremely active as cloud condensation nuclei. Ice crystals also are evidently formed on those fragments in a supercooled (-20 C) cloud chamber. It has been reported that charge generation from ocean volcanic eruptions is due to contact of molten lava with sea water. This seems to be insufficient to explain the observed rapid and intense lightning activities over Mount St. Helens eruptions. Therefore, a hypothesis is presented here that highly electrically charged fine solid fragments are ejected by bursting of gas bubbles from the surface of a crystallizing molten magma particles.

  15. Electrification of the proof mass of a drag-free or accelerometric satellite

    NASA Technical Reports Server (NTRS)

    Juillert, R.; Philippon, J. P.

    1977-01-01

    The exploitation of the data provided by the Cactus accelerometer, which makes up the payload of the D5B Castor Satellite of CNES confirmed the existence of an electric current charging the proof mass under the influence of the magnetospheric protons, and revealed a periodic variation of this current, due to the passage of the apogee through the South Atlantic magnetic anomaly. Results of in-orbit measurements of this charging current are presented, as well as calculations made for determining this current and its variations from data on proton flux at the satellite altitudes. The comparison of measured and calculated values shows that the calculation method is valid and precise enough to be used for drag-free or accelerometric satellites.

  16. Electrification of the transportation sector: Is there a need for restructuring the automotive parts suppliers?

    NASA Astrophysics Data System (ADS)

    Bekaslan, A. Ebru

    The future of the transportation sector has significant implications for the mitigation of climate change through reduced GHG emissions as well as achieving energy efficiency and energy independence. Battery-powered, plug-in, and hybrid electric vehicles are widely seen as the greatest source of a solution. This thesis analyzes the historical development and growth of the automotive industry as well as the restructuring toward the next generation technologies in comparison with the U.S. and China to shed light on the question of how a developing country can structure its strategies to be able to upgrade and be competitive over time. Conventional business models can become obsolete. Companies will find it difficult to maintain their market position unless they gain new perspectives on the outlook of the industry as a whole, and take into account the successful business models of tomorrow. The potential for further growth of the Turkish automotive supplier base particularly in the next generation of automotive technologies is therefore highly dependent on policies and strategies at the national level as much as its dependence on the global strategies of the automotive industry's major players. In this sense, the key questions that motivate this study are whether there are foreseeable technological changes and product-segmentation strategies that could significantly enhance the competitiveness of local Turkish suppliers of automotive components. The thesis builds on the theory of innovative enterprise and evolutionary agglomeration to examine the competitive potential of the Konya Auto Part Suppliers' Cluster in Turkey.

  17. Citizen Hydrology and Compressed-Air Hydropower for Rural Electrification in Haiti

    NASA Astrophysics Data System (ADS)

    Allen, S. M.

    2015-12-01

    At the present time, only one in eight residents of Haiti has access to electricity. Two recent engineering and statistical innovations have the potential for vastly reducing the cost of installation of hydropower in Haiti and the rest of the developing world. The engineering innovation is that wind, solar and fluvial energy have been used to compress air for generation of electricity for only 20 per megawatt-hour, in contrast to the conventional World Bank practice of funding photovoltaic cells for 156 per megawatt-hour. The installation of hydropower requires a record of stream discharge, which is conventionally obtained by installing a gaging station that automatically monitors gage height (height of the water surface above a fixed datum). An empirical rating curve is then used to convert gage height to stream discharge. The multiple field measurements of gage height and discharge over a wide range of discharge values that are required to develop and maintain a rating curve require a manpower of hydrologic technicians that is prohibitive in remote and impoverished areas of the world. The statistical innovation is that machine learning has been applied to the USGS database of nearly four million simultaneous measurements of gage height and discharge to develop a new classification of rivers so that a rating curve can be developed solely from the stream slope, channel geometry, horizontal and vertical distances to the nearest upstream and downstream confluences, and two pairs of discharge - gage height measurements. The objective of this study is to organize local residents to monitor gage height at ten stream sites in the northern peninsula of Haiti over a one-year period in preparation for installation of hydropower at one of the sites. The necessary baseline discharge measurements and channel surveying are being carried out for conversion of gage height to discharge. Results will be reported at the meeting.

  18. 75 FR 42571 - Guarantees for Bonds and Notes Issued for Electrification or Telephone Purposes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... entitled, ``Department Programs and Activities Excluded from Executive Order 12372,'' (50 FR 47034... (75 FR 5902). This rule amends the Agency's policies and procedures for granting guarantees to... implementing the program were published in the Federal Register on October 29, 2004, 69 FR 63045. Section...

  19. To amend the Rural Electrification Act of 1936, and for other purposes.

    THOMAS, 112th Congress

    Rep. Gibson, Christopher P. [R-NY-20

    2012-06-05

    06/27/2012 Referred to the Subcommittee on Rural Development, Research, Biotechnology, and Foreign Agriculture. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  20. Thunderstorm Electrification and Raindrop Collisions and Disjection in an Electric Field.

    PubMed

    Gunn, R

    1965-11-12

    Raindrop collisions in an electric field selectively transfer charges of one sign to the larger disjected drops. The disjected drops, falling away from the smaller drops, separate free charge to establish electric fields as large as those observed in thunderstorms.