On the interpretation of removable interactions: A survey of the field 33 years after Loftus

In a classic 1978 Memory &Cognition article, Geoff Loftus explained why noncrossover interactions are removable. These removable interactions are tied to the scale of measurement for the dependent variable and therefore do not allow unambiguous conclusions about latent psychological processes. In the present article, we present concrete examples of how this insight helps prevent experimental psychologists from drawing incorrect conclusions about the effects of forgetting and aging. In addition, we extend the Loftus classification scheme for interactions to include those on the cusp between removable and nonremovable. Finally, we use various methods (i.e., a study of citation histories, a questionnaire for psychology students and faculty members, an analysis of statistical textbooks, and a review of articles published in the 2008 issue of Psychology andAging) to show that experimental psychologists have remained generally unaware of the concept of removable interactions. We conclude that there is more to interactions in a 2 × 2 design than meets the eye

Detection of antibodies directed at M. hyorhinis p37 in the serum of men with newly diagnosed prostate cancer

<p>Abstract</p> <p>Background</p> <p>Recent epidemiologic, genetic, and molecular studies suggest infection and inflammation initiate certain cancers, including cancers of the prostate. Over the past several years, our group has been studying how mycoplasmas could possibly initiate and propagate cancers of the prostate. Specifically, <it>Mycoplasma hyorhinis </it>encoded protein p37 was found to promote invasion of prostate cancer cells and cause changes in growth, morphology and gene expression of these cells to a more aggressive phenotype. Moreover, we found that chronic exposure of benign human prostate cells to <it>M. hyorhinis </it>resulted in significant phenotypic and karyotypic changes that ultimately resulted in the malignant transformation of the benign cells. In this study, we set out to investigate another potential link between mycoplasma and human prostate cancer.</p> <p>Methods</p> <p>We report the incidence of men with prostate cancer and benign prostatic hyperplasia (BPH) being seropositive for <it>M. hyorhinis</it>. Antibodies to <it>M. hyorhinis </it>were surveyed by a novel indirect enzyme-linked immunosorbent assay (ELISA) in serum samples collected from men presenting to an outpatient Urology clinic for BPH (N = 105) or prostate cancer (N = 114) from 2006-2009.</p> <p>Results</p> <p>A seropositive rate of 36% in men with BPH and 52% in men with prostate cancer was reported, thus leading us to speculate a possible connection between <it>M. hyorhinis </it>exposure with prostate cancer.</p> <p>Conclusions</p> <p>These results further support a potential exacerbating role for mycoplasma in the development of prostate cancer.</p

Mapping of the Disease Locus and Identification of ADAMTS10 As a Candidate Gene in a Canine Model of Primary Open Angle Glaucoma

Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide, with elevated intraocular pressure as an important risk factor. Increased resistance to outflow of aqueous humor through the trabecular meshwork causes elevated intraocular pressure, but the specific mechanisms are unknown. In this study, we used genome-wide SNP arrays to map the disease gene in a colony of Beagle dogs with inherited POAG to within a single 4 Mb locus on canine chromosome 20. The Beagle POAG locus is syntenic to a previously mapped human quantitative trait locus for intraocular pressure on human chromosome 19. Sequence capture and next-generation sequencing of the entire canine POAG locus revealed a total of 2,692 SNPs segregating with disease. Of the disease-segregating SNPs, 54 were within exons, 8 of which result in amino acid substitutions. The strongest candidate variant causes a glycine to arginine substitution in a highly conserved region of the metalloproteinase ADAMTS10. Western blotting revealed ADAMTS10 protein is preferentially expressed in the trabecular meshwork, supporting an effect of the variant specific to aqueous humor outflow. The Gly661Arg variant in ADAMTS10 found in the POAG Beagles suggests that altered processing of extracellular matrix and/or defects in microfibril structure or function may be involved in raising intraocular pressure, offering specific biochemical targets for future research and treatment strategies

Unique Structure and Stability of HmuY, a Novel Heme-Binding Protein of Porphyromonas gingivalis

Infection, survival, and proliferation of pathogenic bacteria in humans depend on their capacity to impair host responses and acquire nutrients in a hostile environment. Among such nutrients is heme, a co-factor for oxygen storage, electron transport, photosynthesis, and redox biochemistry, which is indispensable for life. Porphyromonas gingivalis is the major human bacterial pathogen responsible for severe periodontitis. It recruits heme through HmuY, which sequesters heme from host carriers and delivers it to its cognate outer-membrane transporter, the TonB-dependent receptor HmuR. Here we report that heme binding does not significantly affect the secondary structure of HmuY. The crystal structure of heme-bound HmuY reveals a new all-β fold mimicking a right hand. The thumb and fingers pinch heme iron through two apical histidine residues, giving rise to highly symmetric octahedral iron co-ordination. The tetrameric quaternary arrangement of the protein found in the crystal structure is consistent with experiments in solution. It shows that thumbs and fingertips, and, by extension, the bound heme groups, are shielded from competing heme-binding proteins from the host. This may also facilitate heme transport to HmuR for internalization. HmuY, both in its apo- and in its heme-bound forms, is resistant to proteolytic digestion by trypsin and the major secreted proteases of P. gingivalis, gingipains K and R. It is also stable against thermal and chemical denaturation. In conclusion, these studies reveal novel molecular properties of HmuY that are consistent with its role as a putative virulence factor during bacterial infection

Geographic range predicts photosynthetic and growth response to warming in co-occurring tree species

www.nature.comPopulations near the warm edge of species ranges may be particularly sensitive to climate change, but lack of empirical data on responses to warming represents a key gap in understanding future range dynamics. Herein we document the impacts of experimental warming on the performance of 11 boreal and temperate forest species that co-occur at the ecotone between these biomes in North America. We measured in situ net photosynthetic carbon gain and growth of >4,100 juvenile trees from local seed sources exposed to a chamberless warming experiment that used infrared heat lamps and soil heating cables to elevate temperatures by +3.4 °C above- and belowground for three growing seasons across 48 plots at two sites. In these ecologically realistic field settings, species growing nearest their warm range limit exhibited reductions in net photosynthesis and growth, whereas species near their cold range limit responded positively to warming. Differences among species in their three-year growth responses to warming parallel their photosynthetic responses to warming, suggesting that leaf-level responses may scale to whole-plant performance. These responses are consistent with the hypothesis, from observational data and models, that warming will reduce the competitive ability of currently dominant southern boreal species compared with locally rarer co-occurring species that dominate warmer neighbouring regions. © 2015 Macmillan Publishers Limited. All rights reserved

Developmental Considerations for Assessment and Treatment of Impulsivity in Older Adults

Impulsivity is an important factor in many clinical disorders, especially alcohol and substance use disorders. Most of the research on impulsivity in this domain has focused on adolescence and young adulthood, as this developmental period is characterized by onset of and escalation in alcohol and substance use, likely driven in part by brain development patterns. Although many individuals eventually “mature out” of these behaviors in middle adulthood, a critical subset of people do not. The role of impulsivity in middle-to-older adulthood, when certain individuals transition from normative to disordered substance use, has not been carefully examined. The goal of this paper is to review the literature on measuring and modifying impulsivity from adolescence through older adulthood, with a special focus on middle-to-older adulthood. We propose that impulsivity research should include data on middle-to-older adulthood as an important time of transition to disordered use. We consider how impulsivity might have unique meaning at different stages of the adult lifespan and suggest modifications for assessing and treating impulsivity in older adults