339 research outputs found
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Facies architecture and production characteristics of strandplain reservoirs in the Frio Formation, Texas
UT Librarie
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Midland Core Repository.
The facility continues to be organized and data continue to be entered into the same database that contains the Austin facility`s information. This is expected to continue throughout FY98
Bidirectional Partner Violence Among Homeless Young Adults: Risk Factors and Outcomes
One of the most prevalent forms of violence in contemporary society is the victimization of intimate partners. Although it has been established that homeless young people experience high levels of victimization on the street, little is known about partner violence (PV) experiences among this group, especially bidirectional violence. As such, the purpose of this study is to examine the prevalence of PV and bidirectional violence and to investigate risk factors and outcomes of this form of violence using a sample of homeless young adults. Overall, 59% of the sample experienced bidirectional violence. Multivariate results reveal that sexual abuse and neglect are significant correlates of PV. In addition, being either a victim or perpetrator of PV is associated with more severe substance use and higher levels of posttraumatic stress disorder (PTSD). Finally, there is support for bidirectional violence among homeless young adults even after controlling for early histories of maltreatment
Oil accumulation, production characteristics, and targets for additional recovery in major oil reservoirs of Texas
UT Librarie
Use of Two Pathogen-inhibiting Streptomyces Isolates for Biocontrol of Scab Disease of Raphanus sativus
Streptomyces species are ubiquitous soil bacteria that are promising as biological control agents due to their prolific antibiotic production that can inhibit soil-borne plant pathogens. This includes Streptomyces scabies, which causes scab disease on underground storage organs. The goal of this research was to test two Streptomyces isolates that have known inhibitory and biocontrol abilities against S. scabies in a potato (Solanum tuberosum) agricultural system for their effectiveness in biocontrol of this pathogen in a radish (Raphanus sativus) greenhouse assay. Pathogenic S. scabies were mixed into either pasteurized or unpasteurized soil prior to planting. Radish seeds or radish roots were soaked in a spore suspension of the two biocontrol Streptomyces isolates. Controls of treatments without the pathogen and the biocontrol Streptomyces were included. Radish plants were grown to maturity. Upon harvesting, the radish taproot was rated for scab disease and tuber weight and length were determined. Disease levels were reduced in the presence of the two biocontrol Streptomyces. Taproot weight was greater in the treatments that included the biocontrol Streptomyces. In addition, evidence was sought to determine the ability of these Streptomyces isolates and other pathogen-inhibiting bacteria to enter into an endophytic relationship with the radish plant. For this, several protocols were assessed to try to optimize the isolation of endophytic bacteria from stem and taproot tissue. Surface-sterilized tissue sections (stem and taproot) or macerated stem tissue spread on agar plates have indicated the presence of several bacterial endophytes, including two putative Streptomycete isolates from the stem tissue sections. The search for additional endophytic bacteria capable of inhibiting the scab pathogen are currently underway. The results of this study are promising for the use of these Streptomyces isolates for biocontrol against scab disease in radish
EEFlux: A Landsat-based Evapotranspiration mapping tool on the Google Earth Engine
“EEFlux” is an acronym for ‘Earth Engine Evapotranspiration Flux.’ EEFlux is based on the operational surface energy balance model “METRIC” (Mapping ET at high Resolution with Internalized Calibration), and is a Landsat-imagebased process. Landsat imagery supports the production of ET maps at resolutions of 30 m, which is the scale of many human-impacted and human-interest activities including agricultural fields, forest clearcuts and vegetation systems along streams. ET over extended time periods provides valuable information regarding impacts of water consumption on Earth resources and on humans. EEFlux uses North American Land Data Assimilation System hourly gridded weather data collection for energy balance calibration and time integration of ET. Reference ET is calculated using the ASCE (2005) Penman-Monteith and GridMET weather data sets. The Statsgo soil data base of the USDA provides soil type information. EEFlux will be freely available to the public and includes a web-based operating console. This work has been supported by Google, Inc. and is possible due to the free Landsat image access afforded by the USGS
CHOMPTT (CubeSat Handling of Multisystem Precision Timing Transfer): From Concept to Launch Pad
Here we present the evolution of a university nanosatellite mission, demonstrating state of the art ground-to-space clock synchronization. The CHOMPTT (CubeSat Handling of Multisystem Precision Time Transfer) mission will be presented from its original concept as a candidate for the University NanoSatellite Program 8 to a spacecraft ready for launch in Fall of 2017 on ELaNa XIX (Educational Launch of Nanosatellites). This technology may be used in the future for precision navigation beyond the GPS sphere, networking of satellite swarms, synchronization of terrestrial time standards over continental distances, and verification of new space atomic clocks. The 3U CubeSat houses a 1 kg, 1U OPTI (Optical Precision Timing Instrument) payload, designed and built at the University of Florida, and a 1.5U EDSN/NODeS-derived bus from NASA Ames Research Center. The OPTI payload comprises 1) a supervisor board that handles payload data, power management, and mode settings, 2) an optics assembly with six 1 cm retroreflectors and four laser diodes used as a beacon for ground-tracking, and 3) two fully redundant timing channels, each consisting of a chip-scale atomic clock (CSAC), a microprocessor with clock counter, a picosecond event timer, and an avalanche photodetector (APD) with band-pass filter. Several iterations of OPTI have been designed, developed, and tested leading to its final configuration – a laboratory breadboard (v1.0), a 1.5U high altitude balloon design (v2.0), an engineering unit (v3.0), and the flight unit (v3.1). In-lab testing of OPTI indicates a short-term precision of 100 ps, equivalent to a range accuracy of 3 cm, which is below the primary mission objective of \u3c 200 ps. The long-term timing accuracy is 20 ns over one orbit (1.5 hours), limited by the frequency stability of the on-board CSACs. After the spacecraft reaches its nominal 500 km, 85 deg inclination orbit, an experimental laser ranging facility at the Kennedy Space Center in Florida will track CHOMPTT and emit 1064 nm nanosecond optical pulses toward it. The laser pulses will then reflect off the retroreflector array mounted on the nadir face of CHOMPTT, returning the pulses to the laser ranging facility, which will record the round-trip time-of-flight. An APD will record the arrival time of the pulses at the nanosatellite. By combining the arrival time of the pulse at the CubeSat and the transmit and receive times of the pulse at the laser ranging facility, the clock discrepancy between the ground and CubeSat atomic clocks can be determined. The design and verification of the flight version of CHOMPTT will be reviewed and an overview of the lifetime development and progression of CHOMPTT from the inception to launch pad will be presented
A pre-docking source for the power-law behavior of spontaneous quantal release: application to the analysis of LTP
In neurons, power-law behavior with different scaling exponents has been reported at many different levels, including fluctuations in membrane potentials, synaptic transmission up to neuronal network dynamics. Unfortunately in most cases the source of this nonlinear feature remains controversial. Here we have analyzed the dynamics of spontaneous quantal release at hippocampal synapses and characterized their power-law behavior. While in control conditions a fractal exponent greater than zero was rarely observed, its value was greatly increased by α-latrotoxin (α-LTX), a potent stimulator of spontaneous release, known to act at the very last step of vesicle fusion. Based on computer modeling, we confirmed that at an increase in fusion probability would unmask a pre-docking phenomenon with 1/f structure, where α estimated from the release series appears to sense the increase in release probability independently from the number of active sites. In the simplest scenario the pre-docking 1/f process could coincide with the Brownian diffusion of synaptic vesicles. Interestingly, when the effect of long-term potentiation (LTP) was tested, a ∼200% long-lasting increase in quantal frequency was accompanied by a significant increase in the scaling exponent. The similarity between the action of LTP and of α-LTX suggests an increased contribution of high release probability sites following the induction of LTP. In conclusion, our results indicate that the source of the synaptic powerlaw behavior arises before synaptic vesicles dock to the active zone and that the fractal exponent α is capable of sensing a change in release probability independently from the number of active sites or synapses. © 2015 Lamanna, Signorini, Cerutti and Malgaroli
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