Development and Validation of a Duplex RT-qPCR for Detection of Peach Latent Mosaic Viroid and Comparison of Different Nucleic-Acid-Extraction Protocols.

Peach latent mosaic viroid (PLMVd) is an important pathogen that causes disease in peaches. Control of this viroid remains problematic because most PLMVd variants are symptomless, and although there are many detection tests in use, the reliability of PCR-based methods is compromised by the complex, branched secondary RNA structure of the viroid and its genetic diversity. In this study, a duplex RT-qPCR method was developed and validated against two previously published single RT-qPCRs, which were potentially able to detect all known PLMVd variants when used in tandem. In addition, in order to simplify the sample preparation, rapid-extraction protocols based on the use of crude sap or tissue printing were compared with commercially available RNA purification kits. The performance of the new procedure was evaluated in a test performance study involving five participant laboratories. The new method, in combination with rapid-sample-preparation approaches, was demonstrated to be feasible and reliable, with the advantage of detecting all different PLMVd isolates/variants assayed in a single reaction, reducing costs for routine diagnosis.

Power and choice: their dynamic interplay in quenching the thirst for personal control.

Power and choice represent two fundamental forces that govern human behavior. Scholars have largely treated power as an interpersonal construct involving control over other individuals, whereas choice has largely been treated as an intrapersonal construct that concerns the ability to select a preferred course of action. Although these constructs have historically been studied separately, we propose that they share a common foundation--that both are rooted in an individual's sense of personal control. Because of this common underlying basis, we hypothesized that power and choice are substitutable; that is, we predicted that the absence of one would increase the desire for the other, which, when acquired, would serve to satisfy the broader need for control. We also predicted that choice and power would exhibit a threshold effect, such that once one source of control had been provided (e.g., power), the addition of the other (e.g., choice) would yield diminishing returns. Six experiments provide evidence supporting these predictions.

Molecular characterization of phytoplasmas in lilies with fasciation in the Czech Republic.

Lilium spp. with symptoms of severe fasciation were observed in Southern and central Bohemia during the period 1999-2003. Nucleic acids extracted from symptomatic and asymptomatic plants were used in nested-PCR assays with primers amplifying 16S-23S rRNA sequences specific for phytoplasmas. The subsequent nested-PCR with phytoplasma group-specific primers followed by RFLP analyses and the 16S ribosomal gene sequencing, allowed classification of the detected phytoplasmas in the aster yellows group, subgroups 16SrI-B and 16SrI-C alone, and in mixed infection. Samples infected by 16SrI-C phytoplasmas showed different overlapping RFLP profiles after TruI digestion of R16F2/R2 amplicons. Two of these amplicons were sequenced, one of them directly and the other after cloning; sequence analyses and blast alignment confirmed the presence of two different overlapping patterns in samples studied. The sequences obtained were closely related, respectively, to operon A and operon B ribosomal sequences of the clover phyllody phytoplasma. Direct PCR followed by RFLP analyses of the tuf gene with two restriction enzymes showed no differences from reference strain of subgroup 16SrI-C. Infection with aster yellows phytoplasmas of 16SrI-B subgroup in asymptomatic lilies cv. Sunray was also detected.

The psychological pleasure and pain of choosing: when people prefer choosing at the cost of subsequent outcome satisfaction.

This empirical investigation tested the hypothesis that the benefits of personal choosing are restricted to choices made from among attractive alternatives. Findings from vignette and laboratory studies show that contrary to people's self-predictions prior to actually choosing, choosers only proved more satisfied than nonchoosers when selecting from among more preferred alternatives. When selecting from among less preferred alternatives, nonchoosers proved more satisfied with the decision outcome than choosers. Subsequent analyses revealed that differences in outcome satisfaction between choosers and nonchoosers emerge even before the decision outcome is experienced and that interventions during the decision-making process can serve to attenuate these differences. Theoretical and practical implications are discussed.