Satellite-Based Energy Balance to Assess Within-Population Variance of Crop Coefficient Curves

Quantifying evapotranspiration (ET) from agricultural fields is important for field water management, water resources planning, and water regulation. Traditionally, ET from agricultural fields has been estimated by multiplying the weather-based reference ET by crop coefficients (Kc) determined according to the crop type and the crop growth stage. Recent development of satellite remote sensing ET models has enabled us to estimate ET and Kc for large populations of fields. This study evaluated the distribution of Kc over space and time for a large number of individual fields by crop type using ET maps created by a satellite based energy balance (EB) model. Variation of Kc curves was found to be substantially larger than that for the normalized difference vegetation index because of the impacts of random wetting events on Kc, especially during initial and development growth stages. Two traditional Kc curves that are widely used in Idaho for crop management and water rights regulation were compared against the satellite-derived Kc curves. Simple adjustment of the traditional Kc curves by shifting dates for emergence, effective full cover, and termination enabled the traditional curves to better fit Kc curves as determined by the EB model. Applicability of the presented techniques in humid regions having higher chances of cloudy dates was discussed.     

Creation and optimization of vertical-cavity X-modulators

We have developed a photon conserving, reversible optoelectronic intensity modulator. The device works by using quantum wells in a slightly asymmetric InGaAs-AlGaAs QW Fabry-Perot cavity to direct an incident optical beam to transmit through the device or to be reflected from the device depending upon the state of the switching element. The first experimental device simultaneously switches reflectivity and transmission from 6% to 60% and 60% to 6%, respectively. We also examine the cavity design parameter space and effects of incident angle on device performance. Furthermore, experimental results from combinations of stacked devices are discussed. A theoretical analysis of the X-modulator design parameter space is given as is an analysis of the system response of our two element stacked devices. Finally, a thorough theoretical treatment of crossbar switches using symmetric X-modulators is provided     

Zero chirp asymmetric Fabry-Perot electroabsorption modulator using coupled quantum wells

A zero-chirp asymmetric Fabry-Perot reflection InGaAs QW modulator is created by placing coupled quantum wells in the intrinsic region of a reverse-biased p-i-n diode asymmetric Fabry-Perot cavity. Unlike single quantum wells which necessarily produce chirping during the switching cycle, these coupled quantum wells provide large absorption changes with zero refractive index changes over the entire voltage swing; the resultant cavity structure shows reflectivity changes with zero experimental phase change over the same voltage range. The tradeoff in reflectivity change required in order to obtain zero chirp is described. This tradeoff is a result of the different switching mechanisms used in coupled quantum wells versus single quantum wells.     

Parallel optical interconnects for enterprise class server clusters: needs and technology solutions

We examine the status of enterprise-class server clusters and the communication issues that need to be addressed in future systems. With increasing system performance, new approaches beyond traditional copper-only communication solutions have to be examined. Parallel optics is an attractive solution to overcome copper's shortcomings, but traditional approaches to parallel optics have had their own limitations. We describe a new approach to parallel optics - dense parallel optics - and its relevance to enterprise servers. After discussing system communication needs, we examine dense parallel optics from both the passive cabling and active component views. We explain how dense parallel optics offers a unique way to address the performance, cost, reliability, and scalability of server systems. We also discuss how current approaches to dense parallel optics afford system opportunities beyond simple data transport.     

The Gloss of Edible Coatings as Affected by Surfactants, Lipids, Relative Humidity, and Time

ABSTRACT: Water-based whey protein isolate (WPI) coatings had the same gloss as shellac and zein coatings cast from ethanol solutions and water-based tapioca dextrin and hydroxypropyl methylcellulose (HPMC) coatings. For lipid dispersion coatings, the particle size of the dispersed phased influenced gloss values. WPI coatings had stable gloss values at 52%, 75%, and 95% relative humidity (RH). At 95% RH, shellac and zein coatings "blushed," and both dextrin and HPMC coatings became tacky. WPI and shellac films maintained a high gloss after 7.6 mo of storage at 23 °C and 75% RH and had higher gloss than whey protein concentrate (WPC) and HPMC coatings. The type and level of surfactant added to WPI coatings greatly influenced gloss.     

Brain Cholesterol Biosynthetic Pathway Is Altered in a Preclinical Model of Fragile X Syndrome

Fragile X Syndrome (FXS) is the most frequent form of inherited X-linked pathology, associated with an intellectual and developmental disability, and currently considered the first monogenic cause of autism spectrum disorder (ASD). Low levels of total cholesterol reported in the serum of FXS patients, and evidence that FMRP targets a subset of mRNAs encoding proteins of lipid synthesis and transport suggests that the cholesterol metabolism impairments could be involved in FXS. Thus, the aim of the presented work was to investigate the modulations of the cholesterol biosynthetic pathway and its end-products in a recently developed Fmr1-Δexon 8 rat model of FXS. Here, we show that this experimental model mimics what is found in FXS patients, exhibiting a lower serum cholesterol content, accompanied by a reduction in food intake and body weight compared to WT animals. Moreover, alterations of proteins committed to cholesterol synthesis and uptake have been observed in the amygdala, prefrontal cortex and nucleus accumbens. Interestingly, the end-products show a brain region-dependent modulation in Fmr1-Δexon 8 rats. Overall, our results demonstrate that the cholesterol biosynthetic pathway is altered in some brain regions of this preclinical model of FXS. This finding has relevance for future studies to delve deeper into the involvement of this metabolic process in FXS, and thus its possible role as a therapeutic target.     

Satellite-Based Energy Balance for Mapping Evapotranspiration with Internalized Calibration (METRIC)—Applications

Recent satellite image processing developments have provided the means to calculate evapotranspiration (ET) as a residual of the surface energy balance to produce ET “maps.” These ET maps (i.e., images) provide the means to quantify ET on a field by field basis in terms of both the rate and spatial distribution. The ET images show a progression of ET during the year or growing season as well as its spatial distribution. The mapping evapotranspiration at high resolution with internalized calibration (METRIC) is a satellite-based image-processing procedure for calculating ET. METRIC has been applied with high resolution Landsat images in southern Idaho, southern California, and New Mexico to quantify monthly and seasonal ET for water rights accounting, operation of ground water models, and determination of crop coefficient populations and mean curves for common crops. Comparisons between ET by METRIC, ET measured by lysimeter, and ET predicted using traditional methods have been made on a daily and monthly basis for a variety of crop types and land uses. Error in estimated growing season ET was 4% for irrigated meadow in the Bear River basin of Idaho and 1% for an irrigated sugar beet crop near Kimberly, Id. Standard deviation of error for time periods represented by each satellite image averaged about 13 to 20% in both applications. The results indicate that METRIC and similar methods such as SEBAL hold substantial promise as efficient, accurate, and inexpensive procedures to estimate actual evaporation fluxes from irrigated lands throughout growing seasons.