Multi-objective engineering shape optimization using differential evolution interfaced to the Nimrod/O tool

This paper presents an enhancement of the Nimrod/O optimization tool by interfacing DEMO, an external multiobjective optimization algorithm. DEMO is a variant of differential evolution – an algorithm that has attained much popularity in the research community, and this work represents the first time that true multiobjective optimizations have been performed with Nimrod/O. A modification to the DEMO code enables multiple objectives to be evaluated concurrently. With Nimrod/O’s support for parallelism, this can reduce the wall-clock time significantly for compute intensive objective function evaluations. We describe the usage and implementation of the interface and present two optimizations. The first is a two objective mathematical function in which the Pareto front is successfully found after only 30 generations. The second test case is the three-objective shape optimization of a rib-reinforced wall bracket using the Finite Element software, Code_Aster. The interfacing of the already successful packages of Nimrod/O and DEMO yields a solution that we believe can benefit a wide community, both industrial and academic

The Influence of Neighborhood Poverty on Blood Glucose Levels: Findings from the Community Initiative to Eliminate Stroke (CITIES) program

Objectives:  To examine the relationship between both individual and neighborhood level characteristics and non-fasting blood glucose levels.Study design: This study used a cross sectional design using data from the Community Initiative to Eliminate Stroke Program in NC (2004-2008).  A total of 12,809 adults nested within 550 census block groups from two adjacent urban counties were included in the analysis.Methods:   Participants completed a cardiovascular risk factor assessment with self-reported demographics, stroke-risk behaviors, and biometric measurements.  Neighborhood level characteristics were based upon census data.  Three multilevel models were constructed for data analysis.Results:  Mean blood glucose level of this sample population was 103.61mg/dL.  The unconditional model 1 suggested a variation in mean blood glucose levels among the neighborhoods (τ00 = 13.39; P < .001).  Both models 2 and 3 suggested that the neighborhood composite deprivation index had a significant prediction on each neighborhood’s mean blood glucose level (¡01= .69; P < 0.001,¡01= .36; P = .004).  Model 3 also suggested that across all the neighborhoods, on average, after controlling for individual level risk factors, deprivation remained a significant predictor of blood glucose levels.Conclusions:  The findings provide evidence that neighborhood disadvantage is a significant predictor of neighborhood and individual level blood glucose levels.  One approach to diabetes prevention could be for policymakers to address the problems associated with environmental determinants of health

Mesquite bugs, other insects, and a bat in the diet of pallid bats in southeastern Arizona

The pallid bat (Antrozous pallidus) is a species of western North America, inhabiting ecoregions ranging from desert to oak and pine forest. They are primarily insectivorous predators on large arthropods that occasionally take small vertebrate prey, and are at least seasonally omnivorous in certain parts of their geographic range where they take nectar from cactus flowers and eat cactus fruit pulp and seeds. Until recently, mesquite bugs were primarily tropical-subtropical inhabitants of Mexico and Central America but have since occupied the southwestern United States where mesquite trees occur. Using a noninvasive method, we investigated the bats’ diet at the Cienega Creek Natural Preserve, Arizona, by collecting food parts discarded beneath three night roosts in soil-piping cavities in a mesquite bosque. We also made phenological and behavioral observations of mesquite bugs, Thasus neocalifornicus, and their interactions with the mesquite trees. We determined that the bats discarded inedible parts of 36 species in 8 orders of mainly large-bodied and nocturnal insects below the night-roosts. In addition, one partial bat wing represents probable predation upon a phyllostomid bat, Choeronycteris mexicana. About 17 of the insect taxa are newly reported as prey for pallid bats, as is the bat C. mexicana. The majority of culled insect parts (88%) were from adult mesquite bugs. Mesquite bug nymphs did not appear in the culled insect parts. After breeding in late summer, when nighttime low temperatures dropped below 21 °C, the adult bugs became immobile on the periphery of trees where they probably make easy prey for opportunistic foliage-gleaning pallid bats. Proximity of night-roosts to mesquite bug habitat probably also enhances the bats’ exploitation of these insects in this location