Selection of colour of sticky trap for monitoring adult bean thrips, Caliothrips fasciatus (Thysanoptera: Thripidae)

Adult bean thrips, Caliothrips fasciatus (Pergande), overwintering inside the navel of navel oranges shipped from California to Australia, are an actionable pest for the importing country, i.e. infested lots are fumigated with methyl bromide. Strict quarantine regulations regarding C. fasciatus prompted studies on the best colour sticky trap that might be used to monitor for bean thrips populations in the vicinity of California citrus groves prior to harvesting fruit for export. Preliminary experiments identified the most attractive trap of each of four colours (blue, green, white, yellow) commonly used to sample adult Thysanoptera. Three trials of a field study were conducted, comparing C. fasciatus capture on the best card of each colour using asparagus ferns naturally infested with high levels of this pest. Based on significantly higher catch on green sticky cards, this colour trap is recommended for potential use in California's bean thrips mitigation plan designed to reduce thrips levels on citrus exported to Australia.     

A Landsat-based energy balance and evapotranspiration model in Western US water rights regulation and planning

The quantification of evapotranspiration (ET) from irrigated projects is important for water rights management, water resources planning and water regulation. Traditionally, ET has been estimated by multiplying a weather-based reference ET by crop coefficients (K_c) determined according to the crop type and the crop growth stage. However, there is typically question regarding whether crops grown compare with the conditions represented by the K_c values, especially in water short areas. In addition, it is difficult to estimate the correct crop growth stage dates for large populations of crops and fields. METRIC (Mapping Evapotranspiration at high Resolution and with Internalized Calibration) is an image-processing model for calculating ET as a residual of the surface energy balance. METRIC is a variant of SEBAL, an energy balance process developed in the Netherlands by Bastiaanssen and was extended to provide tighter integration with ground-based reference ET. METRIC was applied with Landsat images in southern Idaho to predict monthly and seasonal ET for water rights accounting and for operation of ground water models. ET “maps” (i.e., images) provide the means to quantify, in terms of both the amount and spatial distribution, the ET on a field by field basis. The ET maps have been used in Idaho to quantify net ground-water pumpage in areas where water extraction from underground is not measured and to estimate recharge from surface-irrigated lands. Application and testing of METRIC indicates substantial promise as an efficient, accurate, and relatively inexpensive procedure to predict the actual evaporation fluxes from irrigated lands throughout a growing season.     

Skeleton of Euplectella sp.: structural hierarchy from the nanoscale to the macroscale

Structural materials in nature exhibit remarkable designs with building blocks, often hierarchically arranged from the nanometer to the macroscopic length scales. We report on the structural properties of biosilica observed in the hexactinellid sponge Euplectella sp. Consolidated, nanometer-scaled silica spheres are arranged in well-defined microscopic concentric rings glued together by organic matrix to form laminated spicules. The assembly of these spicules into bundles, effected by the laminated silica-based cement, results in the formation of a macroscopic cylindrical square-lattice cagelike structure reinforced by diagonal ridges. The ensuing design overcomes the brittleness of its constituent material, glass, and shows outstanding mechanical rigidity and stability. The mechanical benefits of each of seven identified hierarchical levels and their comparison with common mechanical engineering strategies are discussed.     

In situ observations of a high-pressure phase of H2O Ice

A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.     

High-resolution protein structure determination by serial femtosecond crystallography

Structure determination of proteins and other macromolecules has historically required the growth of high-quality crystals sufficiently large to diffract x-rays efficiently while withstanding radiation damage. We applied serial femtosecond crystallography (SFX) using an x-ray free-electron laser (XFEL) to obtain high-resolution structural information from microcrystals (less than 1 micrometer by 1 micrometer by 3 micrometers) of the well-characterized model protein lysozyme. The agreement with synchrotron data demonstrates the immediate relevance of SFX for analyzing the structure of the large group of difficult-to-crystallize molecules.     

Evaluation of two non-destructive sampling methods for bean thrips (Thysanoptera: Thripidae) detection in navel oranges

Adult bean thrips, Caliothrips fasciatus (Pergande), over-wintering inside the navel of navel oranges in California are an export problem when detected in fruit sent to Australia. At present, a systems approach is used to reduce fruit infestation levels and one component of this approach is to search for thrips inside the navel by cutting 50 fruit per block prior to harvest and 75 fruit per grower lot before packing in the packinghouse with any detection of live bean thrips leading to that grower lot not being eligible for shipment to Australia. Given that bean thrips infestation levels are often 0.5% of the fruit or less, this amount of fruit cutting can lead to shipment of infested lots of citrus to Australia. As an alternative to cutting more fruit, two non-destructive methods of sampling for bean thrips inside the navel of navel oranges were investigated which might be used on larger numbers of fruit and result in fewer infested lots being shipped to Australia. A light trap at the apex of a pyramid-shaped black cloth tent caught 41.1% of adult bean thrips released at the bottom of the tent. When this experiment was repeated with the tent placed over a citrus bin two-thirds full of fruit, however, only 9.3% of thrips released at the bottom of the bin were captured. A second method of sampling, washing bean thrips out of the navel onto a screen, resulted in close to 90% recovery of thrips with each of the five spray rinses evaluated, including distilled water. Regression analysis indicated there was no statistical difference between results with the five rinses. Thus, it might be worthwhile trying to scale-up our laboratory method of rinsing with distilled water to a method that might be used in a commercial packinghouse for detection of bean thrips in large numbers of fruit. Even if one assumes that cutting fruit is 100% efficient in finding bean thrips inside the navel of navel oranges, sampling a much larger number of fruit using a method with 90% efficiency is shown to result in higher odds of finding any bean thrips that are present.     

Occurrence of PPCPs at a Wastewater Treatment Plant and in Soil and Groundwater at a Land Application Site

Pharmaceuticals and personal care products (PPCPs) can reach soil and aquatic environments through land application of wastewater effluent and agricultural runoff. The objective of this research was to assess the fate of PPCPs at field scale. PPCPs were measured systematically in a wastewater treatment plant (WWTP), and in soil and groundwater receiving treated effluent from the WWTP. A land application site in West Texas was used as the study site; it has received treated wastewater effluent from the WWTP for more than 70 years in order to remove additional nutrients and irrigate non-edible crops. Target compounds (estrone, 17??-estradiol, estriol, 17??-ethynylestradiol, triclosan, caffeine, ibuprofen, and ciprofloxacin) in wastewater, sewage sludge, soil, and groundwater were determined using HPLC/UV with qualitative confirmatory analyses using GC/MS. Samples were collected quarterly over 12 months for wastewater and sludge samples and over 9 months for soil and groundwater samples. Results indicated that concentrations of PPCPs in wastewater influent, effluent, sludge solid phase, and sludge liquid phase were in the range of non-detected (ND)-183 ??g/L, ND-83 ??g/L, ND-19 ??g/g, and ND-50 ??g/L, respectively. Concentrations in soil and groundwater samples were in the range of ND-319 ng/g and ND-1,745 ??g/L, respectively. GC/MS confirmation data were consistent with the results of HPLC/UV analyses. Overall, data indicate that PPCPs in the wastewater effluent from the WWTP transport both vertically and horizontally in the soil, and eventually reach groundwater following land application of the effluent.     

Hydraulic Loading Rate Effect on Removal Rates in a BioSand Filter: A Pilot Study of Three Conditions

Safe drinking water is a luxury to approximately 800 million people worldwide. The number of people without access to clean water has been reduced, thanks to technologies like the biosand filter (BSF), an intermittently operated household scale slow sand filter. The BSF outlet (control diameter 0.5??) was modified in this study by reducing the outlet diameter (0.37?? and 0.25??) to determine the effects of hydraulic retention time on removal rates. Filters were dosed with 20?L of spiked lake water daily and observed for pH, dissolved oxygen (DO), fecal coliforms (FC), turbidity, nitrate, nitrite, sulfate, and ammonia until initial flow rates dropped below 0.2?L/min. Consistent with previous studies, the average turbidity was reduced to below 1?NTU; the average DO was reduced by 45?%. No significant difference was observed between the modified BSFs and the control BSF. Removal efficiency of FC was not significantly different between the modified BSFs (93.3?% and 91.9?%) and the control BSF (89.6?%). Mean FC reduction during the startup period (17?days) was significantly greater in the modified 0.25?? BSF when compared with the control during the same time period. After the first 17?days of the experiment, the average reduction efficiency of all filters was >97?%. While source water was below guideline values for nitrate, nitrite, ammonia, and sulfate during the course of the experiment, total nitrogen reduction was observed. The reduction indicates that the plastic BSF is capable of accomplishing limited denitrification during the filtering process.     

Hydrogen radicals, nitrogen radicals, and the production of O3 in the upper troposphere

The concentrations of the hydrogen radicals OH and HO2 in the middle and upper troposphere were measured simultaneously with those of NO, O3, CO, H2O, CH4, non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The data allow a direct examination of the processes that produce O3 in this region of the atmosphere. Comparison of the measured concentrations of OH and HO2 with calculations based on their production from water vapor, ozone, and methane demonstrate that these sources are insufficient to explain the observed radical concentrations in the upper troposphere. The photolysis of carbonyl and peroxide compounds transported to this region from the lower troposphere may provide the source of HOx required to sustain the measured abundances of these radical species. The mechanism by which NO affects the production of O3 is also illustrated by the measurements. In the upper tropospheric air masses sampled, the production rate for ozone (determined from the measured concentrations of HO2 and NO) is calculated to be about 1 part per billion by volume each day. This production rate is faster than previously thought and implies that anthropogenic activities that add NO to the upper troposphere, such as biomass burning and aviation, will lead to production of more O3 than expected.