Development of Breathing Rat-Lung Models for Particulate Deposition Studies

ABSTRACT

Techniques have been developed for casting both solid and hollow lung models from rat-lung specimens. To make a solid model, an air line at a positive pressure of 25 cm of water was connected to the trachea to air-dry lungs which had been removed surgically from the animal. Using the lost wax technique, a hollow cast of the airways and the nasopharynx was made. A mechanical breathing system, capable of simulating different breathing patterns, was developed.     

International psychological research that matters for policy and practice.

After a brief history of the Committee on International Relations of the American Psychological Association, 3 points are made about international psychological research that matters. First, it matters when the definition of the research problem area and the findings can potentially be reflected in policy change, in the practice of educators or psychologists, or in the mindsets of a new generation of researchers. Person-centered analysis of adolescents’ social and political attitudes has this potential and can complement variable-centered analysis. A cluster analysis of the IEA Civic Education Study’s data in 5 Western European and 5 Eastern European countries illustrates this. The following 5 clusters of adolescents were identified: those supportive of social justice but not participative, those active in conventional politics and the community, those indifferent, those disaffected, and a problematic cluster of alienated adolescents. Second, research that matters is situated in a cultural context. It is proposed that publications using data from any single country be required to include information about the cultural context in which the research was conducted. Finally, it matters that attention be given to the dynamics of the collaborative international research process, not only to research results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemical Fertility Signaling in Termites: Idiosyncrasies and Commonalities in Comparison with Ants

Termites evolved eusociality independently from social Hymenoptera. As a common trait, reproductive monopoly is maintained through chemical communication. The queen (and in termites also a king) prevents workers from reproduction by conveying their reproductive status. In termites all soldiers are sterile, but workers’ potential to reproduce differs between species. It ranges from totipotency in wood-dwelling lower termites where workers are a transient stage from which all other castes develop, to sterile workers in some higher termites. Intermediate are species in which workers can develop into replacement sexuals within the nest but not into winged sexuals. I summarize the patchy picture about fertility signaling that we currently have for termites, pointing also to potential conflicts over reproduction that differ from those in social Hymenoptera. Recent findings imply that, similar to many social Hymenoptera, wood-dwelling termites that live in confined nests use long-chain cuticular hydrocarbons (CHCs) as fertility signals. Yet other compounds are important as well, comprising proteinaceous secretions and especially volatiles. For a subterranean termite, two volatiles have been identified as primer pheromones that prevent reproductive differentiation of workers. It requires more data to test whether wood-dwelling termites use CHCs, while species with larger colonies and less confined nests use volatiles, or whether all species rely on multicomponent signals. Ultimately, we need more effort to model and test potential conflicts over reproduction between queens, kings and workers. Here results from social Hymenoptera cannot be transferred to termites as the latter are diploid and commonly inbred. This review illustrates promising future research avenues.     

Optimization of a mist chamber (Cofer scrubber) for sampling water-soluble organics in air

While the atmospheric fate and transport of biogenic and anthropogenic hydrocarbons has been extensively studied, little is known about the behavior of first-, second-, and third generation photo-oxidation products that arise from OH radical oxidation of the parent species. The results of chamber experiments establish that *OH oxidation of biogenic and anthropogenic hydrocarbons yields carbonyls, dicarbonyls, hydroxycarbonyls, and keto-acids. However, little is known about the generation and fate of these products in the ambient atmospheric environment. This is changing because of the advent of methods that rely on 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) derivatization of carbonyls in concert with gas chromatography/ion trap mass spectrometry. Such methods provide the means to identify and quantify water-soluble organics, which historically have been difficult to measure. A limitation of existing sampling methods, however, is the use of devices that require low flow rates (0.5-1 L min(-1)). Accordingly, long sampling times (3-4 h) are needed to obtain pptv-ppbv detection limits. The mist chamber is an attractive device because of the high flow rates (25-70 L min(-1)) compatible with its use. Herein, we evaluate a mist chamber using a flow rate of 25-30 L min(-1) to provide short (10 min) sampling times and pptv limits of detection. The results establish a relationship between the Henry's law constant (KH) and the collection efficiency and demonstrate the suitability of the method to measure analytes with KH > or = 10(3) M atm(-1). Adjusting the pH, adding quaternary ammonium salts, or decreasing the temperature of the collecting solution in the mist chamber did not significantly affect the collection efficiency. We tested the method by sampling photooxidation products of isoprene (glyoxal, methylglyoxal, hydroxyacetone, and glycolaldehyde) in the Blodgett Forest, CA. This is the first report of a study the employs the mist chamberto sample hydroxycarbonyls. The accuracy and the reproducibility of the method were evaluated by the analysis of duplicate samples and field spikes. The mean recovery of field spikes was > or =80%, and the relative standard deviation was < or =22% between duplicate measurements. The detection limits were 48, 15, 7.7, and 2.7 pptv for glycolaldehyde, hydroxyacetone, methylglyoxal, and glyoxal, respectively. This work demonstrates the power of the mist chamber in concert with PFBHA derivatization and mass spectrometry to measure pptv concentrations of water-soluble organics with a sampling time of 10 min.     

Study of the aromatic by-products formed from ozonation of anilines in aqueous solution

Aqueous solutions of aniline and p-chloroaniline were treated with ozone in order to study the reaction and oxidation by-products. Aniline solutions were ozonated at low and high pH, so as to compare both molecular and hydroxyl free radical mechanisms, respectively. The main identified aromatic by-products were nitrobenzene and azobenzene when the experiment was carried out at acid pH. Formation of nitrobenzene, azobenzene, azoxybenzene and 2-pyridine-carboxylic was observed when the ozonation was carried out at basic pH. p-Chloroaniline was treated with ozone only at high pH and the identified by-products were in accordance with those obtained in the ozonation of aniline: p-chloronitrobenzene, 4,4'-dichloroazobenzene and 4-chloro-2-pyridine-carboxylic acid. All the aromatic by-products found were less toxic than the raw materials. The pseudo-first-order constants in aniline concentration were calculated, whilst kinetic in p-chloroaniline concentration could not be adjusted to a first-order reaction.     

Promoting quality improvement research

The authors show how an internal grant program can stimulate quality improvement research by providing technical and financial support to clinicians and employees.     

Autonomy and relatedness with parents and romantic development in African American adolescents.

The influence of adolescents' autonomy and relatedness to parents on romantic relationships was examined longitudinally over 5 years in 76 middle-class African American late adolescents (mean age = 18.43 years). Relatedness to parents in early adolescence led to longer duration and more supportive romantic relationships in late adolescence, but longer duration was concurrently associated with more negative romantic relationships. Cluster analyses yielded 3 profiles of early adolescent autonomy and relatedness; early adolescents who were high in relatedness and low in autonomy to parents in early adolescence reported longer duration romantic relationships in late adolescence than did adolescents who were moderate or high in relatedness and high in autonomy. The implications for romantic development in African American middle-class youth are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Skills required for participating in CMC courses: An empirical study

The development of new communication technologies and their applications has opened a broad spectrum of options to promote learning, of which a significant one is CMC – Computer-Mediated Communication. Yet, students use this medium to a relatively small extent. Our premise is that the use of these technologies depends on the level of skills and expertise of the individuals using them. The purpose of this study is to determine whether taking a Computer Literacy and Applications course (CLA) before taking CMC courses has an impact on students' participation in CMC courses and on the effective use of various CMC tools. The sample consisted of 153 students enrolled in CMC courses in the Social Sciences in the Spring 2001/2 and Fall 2002/3 semesters. Participants were divided into two groups: 80 students who had taken CLA, and 73 students who had not. A questionnaire to assess the impact of CLA on participation in CMC courses was administered to the two groups. The results of the study indicate that participation in CMC courses is more intensive in the group that had taken CLA. Based on these findings, we recommend mandating a CLA course, like the one developed at the Open University of Israel (OUI), before taking CMC courses.     

Seed-germination inhibition by volatile alcohols and other compounds associated withAmaranthus palmeri residues

Effects of 3-pentanone and eight low molecular weight aliphatic alcohols and aldehydes identifed in the mixtures of volatiles released byAmaranthus palmeri S. Wats. (AMAPA) residues were determined on germination of onion, carrot, AMAPA, and tomato seeds. Three-day exposures to these volatiles significantly inhibited germination of these assay seeds, and the inhibition was dependent upon exposure time and concentration. Based on the degree of inhibition observed in both time- and concentration-dependent assays, the following activity series was obtained: 2-heptanol > 3-methyl-1-butanol, 1-hexanol > hexanal, 1-pentanol, 3-pentanone, acetaldehyde > ethanol, 2-methyl-1-propanol. The activities of this group of compounds with that of 2-heptanone appear to be additive and related to test compound volatility and hydrophilicity. 2-Heptanol and 2-heptanone also significantly inhibited the germination of other species, including shepherdspurse, soybean, lettuce, alfalfa, common purslane, oats, and lovegrass.Name of companies or commercial products are given solely for the purpose of providing specific information; their mention does not imply recommendation or endorsement by the U.S. Department of Agriculture over others not mentioned.