Advances in optical engineering for future telescopes

Significant optical engineering advances at the University of Arizona are being made for design,fabrication,and con-struction of next generation astronomical te...     

Towards an end-to-end airborne remote-sensing system for post-hazard assessment of damage to hyper-critical infrastructure: research progress and needs

The objective of this article is to synthesize research findings and requirements pertaining to development of time-sensitive remote-sensing systems (TSRSS) that support decision-making pertaining to post-hazard assessment of damage to what we define as hyper-critical infrastructure (HCI), based on an aerial imaging approach known as repeat station imaging (RSI). The following TSRSS components are addressed and related findings are reported: (1) understanding information requirements of emergency managers pertaining to damage of HCI; (2) flight planning and data capture requirements for supporting bi-temporal RSI pairs; (3) automatic image registration and shadow classification and normalization routines applied to RSI pairs; (4) damage detection and delineation approach that exploits simple temporal differences in image brightness to automatically, reliably, and robustly delineates new cracks associated with damage; and (5) rapid data and information transfer to emergency managers. The highest priority follow-on research topics are: (1) integrating small unmanned aerial systems (sUAS) with the RSI approach, while enabling multiple view perspectives other than vertical (i.e. nadir pointing) and (2) developing and testing of machine learning routines for automatic identification of damage features from RSI pairs, particularly those captured from integrated sUAS–RSI.     

Enhanced irradiation creep deformation due to gradual temperature reductions

Large irradiation creep strains were observed in WSA-4 mixed-oxide fuel pins at 7% burn-up and 10²³ n cm^?2 (E>0.1 MeV) which were exposed to temperature variations relative to pins irradiated at approximately constant temperature. A comparison of the fuel pin and pressurized tube samples exposed to gradual temperature reductions shows similar behaviour. The results show that the irradiation creep coefficient increases with increasing temperature reduction and initial irradiation temperature. The increase in irradiation creep and the previously reported increase in swelling with temperature reduction appears similar to other macroscopic strain reports of irradiation creep and swelling association.     

A meta-analytic review of the relationship between absence and turnover.

A meta-analysis that combined 33 correlations from 17 studies found a corrected average correlation of .330 between absence and turnover. The type of absence measure did not moderate the covariation between absence and turnover, but industry type and study duration did act as moderators. The results are discussed in the context of the "withdrawal" approach to understanding employee behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A versatile facility for laboratory studies of viscoelastic and poroelastic behaviour of rocks

Novel laboratory equipment has been modified to allow both torsional and flexural oscillation measurements at sub-microstrain amplitudes, thereby providing seismic-frequency constraints on both the shear and compressional wave properties of cylindrical rock specimens within the linear regime. The new flexural mode capability has been tested on experimental assemblies containing fused silica control specimens. Close consistency between the experimental data and the results of numerical modelling with both finite-difference and finite-element methods demonstrates the viability of the new technique. The capability to perform such measurements under conditions of independently controlled confining and pore-fluid pressure, with emerging strategies for distinguishing between local (squirt) and global (specimen-wide) fluid flow, will have particular application to the study of frequency-dependent seismic properties expected of cracked and fluid-saturated rocks of the Earth's upper crust.     

High dose flaxseed oil supplementation may affect fasting blood serum glucose management in human type 2 diabetics

Type 2 diabetes is characterized partially by elevated fasting blood serum glucose and insulin concentrations and the percentage of hemoglobin as HbA1c. It was hypothesized that each of blood glucose and its co-factors insulin and HbA1c and would show a more favorable profile as the result of flaxseed oil supplementation. Patients were recruited at random from a population pool responding to a recruitment advertisement in the local newspaper and 2 area physicians. Completing the trial were 10 flaxseed oil males, 8 flaxseed oil females, 8 safflower (placebo) oil males and 6 safflower oil females. Patients visited on two pre-treatment occasions each three months apart (visits 1 and 2). At visit 2 subjects were randomly assigned in double blind fashion and in equal gender numbers to take flaxseed oil or safflower oil for three further months until visit 3. Oil consumption in both groups was approximately 10 g/d. ALA intake in the intervention group was approximately 5.5 g/d. Power was 0.80 to see a difference of 1 mmol of glucose /L using 12 subjects per group with a p < 0.05. Flaxseed oil had no impact on fasting blood serum glucose, insulin or HbA1c levels. It is concluded that high doses of flaxseed oil have no effect on glycemic control in type 2 diabetics.     

Replacement of dietary fish oil with increasing levels of linseed oil: Modification of flesh fatty acid compositions in Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis>) using a fish oil finishing diet

Five groups of salmon, of initial mean weight 127±3 g, were fed increasing levels of dietary linseed oil (LO) in a regression design. The control diet contained capelin oil (FO) only, and the same oil was blended with LO to provide the experimental diets. After an initial period of 40 wk, all groups were switched to a finishing diet containing only FO for a further 24 wk. Growth and flesh lipid contents were not affected by dietary treatment. The FA compositions of flesh total lipids were linearly correlated with dietary FA compositions (r ²=0.88–1.00, P<0.0001). LO included at 50% of added dietary lipids reduced flesh DHA and EPA (20∶5n−3) concentrations to 65 and 58%, respectively, of the concentrations in fish fed FO. Feeding 100% LO reduced flesh DHA and EPA concentrations to 38 and 30%, respectively, of the values in fish fed FO. Differences between diet and flesh FA concentrations showed that 16∶0, 18∶1n−9, and especially DHA were preferentially retained in flesh, whereas 18∶2n−6, 18∶3n−3, and 22∶1n−11 were selected against and presumably utilized for energy. In fish previously fed 50 and 100% LO, feeding a finishing diet containing FO for 16 wk restored flesh DHA and EPA concentrations, to ≈80% of the values in fish fed FO throughout. Flesh DHA and EPA concentrations in fish fed up to 50% LO were above recommended intake values for humans for these EFA. This study suggests that LO can be used as a substitute for FO in seawater salmon feeds and that any reductions in DHA and EPA can be largely overcome with a finishing diethigh in FO before harvest.