Increasing the Multiplexing Capacity of TMTs Using Reporter Ion Isotopologues with Isobaric Masses

Quantitative mass spectrometry methods offer near-comprehensive proteome coverage; however, these methods still suffer with regards to sample throughput. Multiplex quantitation via isobaric chemical tags (e.g., TMT and iTRAQ) provides an avenue for mass spectrometry-based proteome quantitation experiments to move away from simple binary comparisons and toward greater parallelization. Herein, we demonstrate a straightforward method for immediately expanding the throughput of the TMT isobaric reagents from 6-plex to 8-plex. This method is based upon our ability to resolve the isotopic shift that results from substituting a (15)N for a (13)C. In an accommodation to the preferred fragmentation pathways of ETD, the TMT-127 and -129 reagents were recently modified such that a (13)C was exchanged for a (15)N. As a result of this substitution, the new TMT reporter ions are 6.32 mDa lighter. Even though the mass difference between these reporter ion isotopologues is incredibly small, modern high-resolution and mass accuracy analyzers can resolve these ions. On the basis of our ability to resolve and accurately measure the relative intensity of these isobaric reporter ions, we demonstrate that we are able to quantify across eight samples simultaneously by combining the (13)C- and (15)N-containing reporter ions. Considering the structure of the TMT reporter ion, we believe this work serves as a blueprint for expanding the multiplexing capacity of the TMT reagents to at least 10-plex and possibly up to 18-plex.     

The value of reputation

Reputation plays a central role in human societies. Empirical and theoretical work indicates that a good reputation is valuable in that it increases one''s expected payoff in the future. Here, we explore a game that couples a repeated Prisoner''s Dilemma (PD), in which participants can earn and can benefit from a good reputation, with a market in which reputation can be bought and sold. This game allows us to investigate how the trading of reputation affects cooperation in the PD, and how participants assess the value of having a good reputation. We find that depending on how the game is set up, trading can have a positive or a negative effect on the overall frequency of cooperation. Moreover, we show that the more valuable a good reputation is in the PD, the higher the price at which it is traded in the market. Our findings have important implications for the use of reputation systems in practice.     

An alternative method for fire smoke toxicity assessment using human lung cells

An alternative method for fire smoke toxicity testing using human lung cells has been investigated. A laboratory-scale vertical tube furnace was used for the generation of combustion products. Experiments were conducted under isothermal oxidative non-flaming conditions. A range of building and train interiors including polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyvinyl chloride (PVC), fiberglass reinforced polymer (FRP), and melamine-faced plywood (MFP) were studied. The exposure of combustion toxicants to human lung cells (A549) at the air/liquid interface was acquired using a Harvard Navicyte Chamber. Cytotoxic effects on human cells were assessed based on cell viability using the MTS assay (Promega). Cytotoxicity results were expressed as NOAEC (No Observable Adverse Effect Concentration), IC₁₀ (10% inhibitory concentration), IC₅₀ (50% inhibitory concentration) and total lethal concentration (TLC) values (mg/L). These cytotoxicity results were compared to published combustion toxicity data. Mass loss data and toxic product yield were also determined. The following toxicity ranking was observed from the most toxic to the least toxic: PVC>PE>PP> FRP-10>PC> FRP-16>MFP. The method described here could potentially be an alternative to current fire toxicity standard test methods.     

Application of a design-for-remanufacture framework to the selection of product life-cycle fastening and joining methods

This paper describes efforts towards product design that facilitates remanufacture. Insights on how to design products for ease of remanufacture were obtained from literature and collaboration with remanufacturers. The most essential aspect of design for remanufacture was found to conflict with other design-for-x methodologies, such as design for assembly and design for recycling. Design for remanufacture was therefore viewed in the context of other life-cycle domains, specifically manufacture and assembly, maintenance, and scrap-material recycling. Since fastening and joining issues are common to all these domains, a framework that evaluates the effect of joint design on each of these life-cycle stages was developed. This framework estimates the cost of remanufacture relative to other life-cycle costs determined by the joint design, and was applied to case studies of joints that did not facilitate remanufacture.     

The Strong African American Families Program: Prevention of youths' high-risk behavior and a test of a model of change.

In this study, the efficacy of the Strong African American Families Program (SAAF) was tested. The trial, which included 332 families, indicated that families who participated in SAAF experienced increases over time in regulated, communicative parenting; increases in targeted parenting behaviors, according to youths' reports; and low rates of high-risk behavior initiation among youths. Changes in regulated, communicative parenting mediated the intervention's impact on youths' recognition of changes in parenting, which in turn was linked to changes in youths' high-risk behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment-related changes in objectively measured parenting behaviors in the multimodal treatment study of children with attention-deficit/hyperactivity disorder.

The present study examined treatment outcomes for objectively measured parenting behavior in the Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (ADHD). Five hundred seventy-nine ethnically and socioeconomically diverse children with ADHD-combined type (ages 7.0-9.9 years) and their parent(s) were recruited at 6 sites in the United States and Canada and randomly assigned to 1 of 4 treatment groups for 14 months of active intervention: medication management (MedMgt), intensive behavior therapy, combination of the 2 (Comb), or a community-treated comparison (CC). Baseline and posttreatment laboratory observations of parent-child interactions were coded by observers blind to treatment condition. Comb produced significantly greater improvements in constructive parenting than did MedMgt or CC, with effect sizes approaching medium for these contrasts. Treatment effects on child behaviors were not significant. The authors discuss the importance of changes in parenting behavior for families of children with ADHD and the need for reliable and objective measures in evaluating treatment outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)