Identification and quantification of juvenile hormone biosynthesized by larval and adult Australian sheep blowfly Lucilia cuprina (Diptera: Calliphoridae)

Recent evidence indicates that higher dipterans biosynthesize predominantly the novel juvenile hormone (JH) bisepoxide, methyl (2E,6trans)-6,7,10,11-bisepoxy-3,7,11-trimethyl-2-dodecen oate (JHB3), together with a small proportion of methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (JHIII) and possibly its 6,7-epoxy isomer. A strategy of gas chromatography-mass spectrometry (GC-MS) involving cool on-column GC and negative-ion chemical ionization MS has enabled the selective analysis of underivatized JH-like products released in vitro by ring glands and corpora allata of Lucilia cuprina. JHB3 is released to the exclusion of mono-epoxidized and unepoxidized esters. The rate of JHB3 release in adult females increases dramatically after protein feeding from 0.2 to 5.2 pmol/h/gland. Values agree well with the rate of JH biosynthesis determined by radiochemical assay. As revealed by thin-layer chromatography, the radiolabel is predominantly incorporated into JHB3, of which only 2% is retained in the corpus allatum indicating almost immediate release from the gland. Approximately 5% of radioactive material retained in the glands co-migrates with JHIII and may be an intermediate in JHB3 synthesis. We conclude that JHB3 is the only juvenile hormone biosynthesized in vitro by L. cuprina. The data suggest that JHB3 may be the exclusive JH synthesized by higher dipterans.     

Model discrimination: Posterior probabilities

Expressions were derived for the computation of regression model posterior probabilities under a number of assumptions regarding the form of the uniform parameter prior probability density function. It was demonstrated that some of these forms may lead to a bias in the model posterior probabilities. The variance known and unknown situations were considered under both homoscedastic and heteroscedastic conditions. Bias of the model posterior probabilities may partly explain the unstable behaviour reported by previous workers.     

Chemicals to prevent the moulding of hay and other crops

Fungi from hay, Paecilomyces varioti and species of the Asperigillus glaucus group tolerate and metabolise propionic acid. These may be inhibited in vitro by low concentrations (0.001-3%) of 8-hydroxyquinoline and some derivatives. Addition of 10% of these derivatives to propionic acid diminished by a factor of two the amount needed to prevent heating and moulding of hay and other crops, in laboratory and field tests.     

Mid-infrared diffuse reflection of a strongly absorbing analyte on non-absorbing and absorbing matrices. Part I: homogeneous powders

KBr disks of caffeine were prepared quantitatively so that the absorptivity of caffeine in this environment could be measured. The disks were then ground up finely and their diffuse reflection spectrum was measured. The average path length traveled by remitted photons was then calculated by the simple application of the Beer-Lambert law. The path length that an average photon travels within a finely powdered matrix of KBr is approximately 4 mm when the concentration of a uniformly dispersed, strongly absorbing analyte such as caffeine is 0.01% or less. This path length then decreases as the concentration of the analyte increases as more photons are absorbed by the analyte. When carbon black is added to the mixture of caffeine and KBr and the measurements are repeated, the effective path length drops even further. The average photon that is remitted from a fine infrared-transparent powder containing a very low concentration of an analyte has been shown to encounter at least 400 particles, indicating a highly random path. The more strongly the matrix absorbs, the shorter the path length. When 0.1% of carbon black is added to the disk, the path length drops to about 100 microm.     

Fine-Scale Characterization of the Turbulent Shear Layer of an Instream Pebble Cluster

This study characterizes the shear layer and associated vortex shedding around an isolated submerged pebble cluster in a gravel-bed river. The approach combines flow visualization and high frequency three-dimensional velocity (acoustic Doppler velocimeter) measurements. Two vortex shedding modes in the wake of the cluster were identified: A small scale high frequency initial instability mode and a lower frequency mode that scales with cluster height. The lower frequency mode arose from the intermittent interaction and amalgamation of the small-scale instability vortices. Reynolds shear stresses, velocity spectra, and coherence functions indicated a dominance of longitudinal-vertical shedding vortices in the wake of the cluster. Simultaneous flow visualization was required to determine the nature and behavior of the shedding modes. Quadrant analysis revealed that Q2 and Q4 events contributed 80% of the local longitudinal-vertical component Reynolds shear stress, and demonstrated a dominance of ejection events in the wake of the cluster. Through flow visualization, the behavior of the shear layer was seen to vertically expand and contract with the passage of Q2 and Q4 events, respectively.     

Are they really that happy? Exploring scale recalibration in estimates of well-being.

Objective: The authors addressed a lingering concern in research on hedonic adaptation to adverse circumstances. This research typically relies on self-report measures of well-being, which are subjective and depend on the standards that people use in making judgments. The authors employed a novel method to test for, and rule out, such scale recalibration in self-reports of well-being. Design: The authors asked patients with chronic illness (either lung disease or diabetes) and nonpatients to evaluate quality of life (QoL) for the patients' disease. In addition, the authors also asked them to rank and rate the aversiveness of a diverse set of adverse circumstances, allowing examination of both the numerical ratings and ordering among items. Main Outcome Measures: The authors compared patients' and nonpatients' ratings and rankings for the patients' disease and other conditions. Results and Conclusion: The authors found that patients not only assigned higher numerical QoL ratings to their own disease than did nonpatients but also ranked it higher among the broad set of conditions. These results suggest that scale recalibration cannot account for discrepant QoL ratings between patients and nonpatients. More generally, this study presents a new approach for measuring well-being that is not subject to the problem of scale recalibration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Compiler Optimization Correctness by Temporal Logic

Rewrite rules with side conditions can elegantly express many classical compiler optimizations for imperative programming languages. In this paper, programs are written in an intermediate language and transformation-enabling side conditions are specified in a temporal logic suitable for describing program data flow.The purpose of this paper is to show how such transformations may be proven correct. Our methodology is illustrated by three familiar optimizations: dead code elimination, constant folding, and code motion. A transformation is correct if whenever it can be applied to a program, the original and transformed programs are semantically equivalent, i.e., they compute the same input-output function. The proofs of semantic equivalence inductively show that a transformation-specific bisimulation relation holds between the original and transformed program computations.     

Numerical investigation of large-scale seasonal rock-pit energy storage system

A twodimensional axisymmetric model, which is computationally inexpensive, has been proposed to predict the property changes that occur in a seasonal rock-pit energy storage (RPES) system. The geometry of the rock-pit has been simplified into a shape that can be extended for any seasonal storage system with a three-dimensional conical geometry. The computational domain has been solved using both linear thermal equilibrium (LTE) and linear thermal non-equilibrium (LTNE) models, and the former has been found to be computationally quick and accurate. The model has predicted a 95% energy saving at the highest flow conditions required in the mine. Further analysis has suggested that the increase in storage capacity by decreasing the porosity of rocks in the rock-pit is insignificant compared to the corresponding increase in fan power. Furthermore, the investigation done on natural rocks has indicated an increased ability to store heat in the rock-pit when rocks with higher thermal mass have been used. The use of RPES has shown a significant potential to reduce the carbon footprint. Finally, an economic analysis done on the system has shown a return on investment of just under 12 years.