Hybrid Nanoparticle–Polymer Brush Composites for Detection of Low‐Level Radiostrontium in Water

Combining extraction and scintillation properties within the same material is a relatively new approach in development of sensors for detection of radioactive elements. Structural organization of such materials at a nanoscale typically offers higher efficiency of detection and shorter response time. In this contribution, several new protocols are discussed for fabrication of stable extractive scintillating systems based on commercial Superlig 620 (SL) material with high affinity to radiostrontium. Application of hybrid organic–inorganic beads with SL particles used as core and halloysite clay nanotubes (HNT) modified with a polyvinyltoluene (PVT) brush as a permeable shell combines high‐performance extracting properties of the SL material with efficient light emission properties of the polymer scintillator. The developed SL–HNT–PVT hybrid extractive scintillating material allows real‐time detection of low‐level concentrations of radiostrontium in water. Moreover, the suggested approach is not limited to detection of Sr but can find broader application in development of chemical, biological, or radioluminescent sensors and multifunctional materials.     

Whey beverages decrease blood pressure in prehypertensive and hypertensive young men and women

Whey protein beverages reduced blood pressure in young men and women in a six week controlled intervention. There were no differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), or mean arterial pressure (MAP) observed between groups consuming 28 g per day of either hydrolyzed or non-hydrolyzed whey protein in a beverage. However, in young adults with elevated DBP and SBP, whey beverage consumption significantly decreased SBP, DBP, and MAP by 8.0, 8.6, and 6.4 mm Hg, respectively (P ≤ 0.001 for all comparisons). In subjects with elevated SBP only, SBP significantly decreased by 3.8 mm Hg (P ≤ 0.04) after the whey beverage intervention. Subjects with normal blood pressure had no change in SBP, DBP, and MAP. Whey beverages also significantly decreased total and low-density lipoprotein cholesterol concentrations (P ≤ 0.001 and 0.05, respectively). Whey protein beverages may be useful for the dietary treatment of prehypertension and/or stage 1 hypertension.     

PELTI: Measuring the Passing Efficiency of an Airborne Low Turbulence Aerosol Inlet

In an effort to improve the accuracy of airborne aerosol studies, we compared a new porous-diffuser low-turbulence inlet (LTI) with three other inlets on the NSF/NCAR C-130, using both dust and sea salt as test aerosols. Analysis of bulk filters behind the LTI and an external reference total aerosol sampler (TAS) found no significant differences, while both the NASA shrouded solid diffuser inlet (SD) and NCAR community aerosol inlet (CAI) passed smaller amounts. However, scanning electron microscopic analyses of particles behind the LTI and TAS confirmed the model prediction that the LTI porous diffuser (PD) enhanced 7 μm particle concentrations by about 60%. Aerodynamic particle size distributions behind the other inlets began to diverge from enhancement-corrected LTI values above 2 μm, with mass concentrations of larger particles lower by as much as a factor of ten behind the CAI and a factor of 2 behind the SD. We conclude that the corrected LTI distributions were closer to ambient values than those from either the CAI or the SD. Since tubing losses contributed the most uncertainty when deducing ambient supermicron size distributions from LTI data, minimizing them should be a high priority for future experiments. Measured transfer tubing losses were larger than model estimates, in part because of some complex pieces for which no suitable model exists. The LTI represents a significant advance in our ability to sample populations of large particles from aircraft. A necessary part of using an LTI is the calculation of and correction for large-particle enhancement using a computational fluid dynamics (CFD) program. Although the solid diffuser inlet performed well under some conditions, its large-particle efficiency cannot be modeled, varies with humidity and particle morphology, and involves wall contact that has the potential to modify some particles.     

Oligomeric A2 + B3 synthesis of highly branched polysulfone ionomers: novel candidates for ionic polymer transducers

Highly branched poly(arylene ether sulfone)s with systematically varied degrees of branching and sulfonation were synthesized through oligomeric A₂ + B₃ methods for application as ionic polymer transducer (IPT) membranes. IPTs are a class of electroactive polymer devices that leverage ionomeric membranes to perform electromechanical transduction as actuators and/or sensors. Synthesis of controlled molecular weight A₂ oligomeric polysulfones targeted the global degree of branching (DB_global) to approximately 1–3% in the absence of gelation. Size exclusion chromatography confirmed molecular weights greater than 20 000 g mol^?1 were achieved for linear and branched polysulfones. Increased degree of sulfonation of the A₂ oligomers reduced the development of molecular weight in the oligomeric A₂ + B₃ branching reaction; the formation of tough, flexible, ion‐conducting membranes is required for emerging transducer applications. Variation in the DB_global attained did not affect the thermal transitions or elastic modulus as significantly as changes in the degree of sulfonation. However, an ionic dissociation temperature was detected below the glass transition temperature of the polysulfone matrix and was relatively independent of the degree of sulfonation. Successful synthesis and characterization of these well‐defined branched polysulfone ionomers provide a basis for future investigation of polymer topology effects on IPT performance. Copyright © 2009 Society of Chemical Industry     

Minority Business Access to Mainstream Markets

As minority‐owned firms have penetrated the broader national marketplace—selling goods and services to corporate as well as government clients—the issue of capacity has surfaced. Particularly in government markets, one claim is that minority business enterprises (MBEs) are smaller, younger firms than nonminorities, and hence they often lack the capacity to compete effectively for government contracts. Affirmative action procurement programs, in this view, provide preferential treatment for less qualified businesses, generating reverse discrimination against the dominant, typically white‐male group of business owners. A counterclaim, put forth by proponents of preferential procurement programs, is that discriminatory barriers such as entrenched old‐boy networks impede MBE expansion into mainstream markets. Do the entrenched networks really thwart MBEs, or do they simply lack the capacity to compete? Empirical findings of this study support the discriminatory barrier explanation.     

Hydrologic alteration of the lower Rio Grande terminus: a quantitative assessment

The lower Rio Grande is one of several imperilled river reaches in North America. Drought and water withdrawals for agriculture and municipal use are acknowledged as primary sources of riverine degradation. We agree that these are critical components adversely affecting the river but also suggest disruption in the normal flood‐pulse cycle of the lower Rio Grande, resulting from impoundment of Falcon Lake and poor management of releases from Falcon Lake Dam, have contributed substantially to decline in ecosystem integrity. We provide statistical evidence and real observations in support of the hypothesis that loss of the natural flood‐pulse cycle of the lower Rio Grande has detrimentally affected the riparian ecosystem. Although the presence of adverse effects from disruption of the flood‐pulse cycle is intuitive, this is the first report quantifying the degree of alteration in the lower Rio Grande. Copyright © 2008 John Wiley & Sons, Ltd.     

A principal components analysis of dynamic spatial memory biases.

Research has shown that spatial memory for moving targets is often biased in the direction of implied momentum and implied gravity, suggesting that representations of the subjective experiences of these physical principles contribute to such biases. The present study examined the association between these spatial memory biases. Observers viewed targets that moved horizontally from left to right before disappearing or viewed briefly shown stationary targets. After a target disappeared, observers indicated the vanishing position of the target. Principal components analysis revealed that biases along the horizontal axis of motion loaded on separate components from biases along the vertical axis orthogonal to motion. The findings support the hypothesis that implied momentum and implied gravity biases have unique influences on spatial memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are health and happiness the product of wisdom? The relationship of general mental ability to educational and occupational attainment, health, and well-being.

This study tested a structural model explaining the effects of general mental ability on economic, physical, and subjective well-being. A model was proposed that linked general mental ability to well-being using education, unhealthy behaviors (smoking and excessive drinking), occupational prestige, and health as mediating variables. The sample consisted of 398 individuals, from whom measures were collected across 4 periods. The results supported a model that includes direct and indirect (through unhealthy behaviors and occupational prestige) links from mental ability to physical well-being (i.e., health) and economic well-being. Furthermore, the results supported the relationships of economic well-being and physical well-being to subjective well-being. Overall, the study underscores the importance of general mental ability to work and nonwork outcomes, including physical, economic, and psychological well-being. (PsycINFO Database Record (c) 2010 APA, all rights reserved)