Avis P.G.,Indiana University Northwest
Mycologia | Year: 2012
Fetid Russula are frequently dominant ectomycorrhizal fungi, and some appear to be especially nitrophilic. However, little is known about their phylogenetic relationships or how common nitrophilic traits are in this group. This study addresses this gap and presents a phylogenetic analysis of ITS rDNA sequences and a meta-analysis of studies that examine ectomycorrhizal fungi response to nitrogen increase. The phylogenetic analysis indicates that (i) this lineage contains numerous unidentified taxa; (ii) the taxa have distinct geographic distributions; and (iii) the misuse of names such as R. amoenolens, R. foetens or R. pectinatoides is common. Twenty-three well supported phylotypes were identified and include clades specific to western North America, eastern North America, Europe and Asia, while morphologically similar collections from tropical-equatorial regions are distinct. The metaanalysis shows that nitrophilic tendencies appear throughout fetid Russulas suggesting that this character is not an isolated trait within this subgenus but instead is a more general feature of the group overall. Mapping these tendencies across a broader portion of the Russulaceae shows that this trait is more regularly found in the basal Russula lineages and Lactarius spp., suggesting that this ability evolved early in these fungi. © 2012 by The Mycological Society of America.
Schulze-Halberg A.,Indiana University Northwest
European Physical Journal Plus | Year: 2013
We prove that iterations of confluent supersymmetric transformations (confluent SUSY chains) in quantum mechanics can be represented through Wronskian determinants. It is further shown that the latter Wronskian representation remains valid, if the SUSY chain is built from arbitrary combinations of confluent and non-confluent subchains. In addition, we obtain an integral representation of generalized eigenfunctions for quantum-mechanical Hamiltonians that proves useful for the application of confluent SUSY chains. Our results generalize former findings for second- and third-order chains. © Società Italiana di Fisica / Springer-Verlag 2013.
Sunsay C.,Indiana University Northwest |
Rebec G.V.,Indiana University
Behavioral Neuroscience | Year: 2014
The prediction-error model of dopamine (DA) signaling has largely been confirmed with various appetitive Pavlovian conditioning procedures and has been supported in tests of Pavlovian extinction. Studies have repeatedly shown, however, that extinction does not erase the original memory of conditioning as the prediction-error model presumes, putting the model at odds with contemporary views that treat extinction as an episode of learning rather than unlearning of conditioning. Here, we combined fast-scan cyclic voltammetry (FSCV) with appetitive Pavlovian conditioning to assess DA release directly during extinction and reinstatement. DA was monitored in the nucleus accumbens core, which plays a key role in reward processing. Following at least 4 daily sessions of 16 tone-food pairings, fast-scan cyclic voltammetry was performed while rats received additional tone-food pairings followed by tone alone presentations (i.e., extinction). Acquisition memory was reinstated with noncontingent presentations of reward and then tested with cue presentation. Tone-food pairings produced transient (1- to 3-s) DA release in response to tone. During extinction, the amplitude of the DA response decreased significantly. Following presentation of 2 noncontingent food pellets, subsequent tone presentation reinstated the DA signal. Our results support the prediction-error model for appetitive Pavlovian extinction but not for reinstatement. © 2014 American Psychological Association.
Morris J.R.,Indiana University Northwest
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013
We consider the possibility of a bosonic (meta)stabilization of a cosmic gauge string loop due to the presence of a gas of low-mass bosonic particles which become trapped within the string core. This boson gas exerts a pressure which tends to counteract the string tension, allowing a circular string loop to find a finite equilibrium radius, provided that gas particles do not escape the string core. However, high-energy bosons do escape, and, consequently, the loop shrinks, and the temperature rises. Estimates indicate that the bosonic stabilization mechanism is ineffective, and the loop is unstable against decay. © 2013 American Physical Society.
Davis J.K.,Indiana University Northwest
Psychiatric Services | Year: 2013
Objective: The purpose of this study was to examine factors that predict job satisfaction among peer providers employed on professional treatment teams in community-based behavioral health agencies. Methods: Surveys via Internet and postal mail gathered data from 100 members of the National Association of Peer Specialists who met study criteria. A multiple regression analysis was conducted to evaluate role clarity, psychological empowerment, supervisory alliance, coworker support, and inclusion and exclusion in organizational processes as predictors of job satisfaction. Results: The regression analysis revealed that of the five predictors, role clarity and psychological empowerment were significant predictors of job satisfaction when analyses controlled for age, level of education, and tenure. Conclusions: The results of this study reveal that peer providers found satisfaction in an integrated work environment that included clearly defined roles, independent functioning, and respect for the expertise that peer providers possess.