12 research outputs found

    The β€œJourney” of Doctoral Study in Applied Psychology: Lived Experiences of Students in Counseling, Clinical, and School Psychology

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    A qualitative methodology was adopted to explore the lived experiences of doctoral level students in applied psychology. A total of 15 students ranging in age from 24 to 43, who were at varying levels of their doctoral education, participated in individual semi-structured interviews exploring themes related to influences for the pursuit of graduate study, experiences in their program of study, and general reflections of the graduate school journey. All interviews were conducted from a constructivist-interpretivist model, transcribed verbatim, and analyzed using a phenomenological coding approach (Creswell, 2012; Moustakas, 1994). Emergent broad themes included antecedents leading to graduate study, current experience of doctoral education, and reflections on the doctoral experience. Implications for future research are discussed and recommendations for graduate programs based on findings are provided

    Invasion of Wolbachia into Anopheles and Other Insect Germlines in an Ex vivo Organ Culture System

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    The common bacterial endosymbiont Wolbachia manipulates its host's reproduction to promote its own maternal transmission, and can interfere with pathogen development in many insects making it an attractive agent for the control of arthropod-borne disease. However, many important species, including Anopheles mosquitoes, are uninfected. Wolbachia can be artificially transferred between insects in the laboratory but this can be a laborious and sometimes fruitless process. We used a simple ex vivo culturing technique to assess the suitability of Wolbachia-host germline associations. Wolbachia infects the dissected germline tissue of multiple insect species when the host tissue and bacteria are cultured together. Ovary and testis infection occurs in a density-dependent manner. Wolbachia strains are more capable of invading the germline of their native or closely related rather than divergent hosts. The ability of Wolbachia to associate with the germline of novel hosts is crucial for the development of stably-transinfected insect lines. Rapid assessment of the suitability of a strain-host combination prior to transinfection may dictate use of a particular Wolbachia strain. Furthermore, the cultured germline tissues of two major Anopheline vectors of Plasmodium parasites are susceptible to Wolbachia infection. This finding further enhances the prospect of using Wolbachia for the biological control of malaria

    Wolbachia Infections Are Virulent and Inhibit the Human Malaria Parasite Plasmodium Falciparum in Anopheles Gambiae

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    Endosymbiotic Wolbachia bacteria are potent modulators of pathogen infection and transmission in multiple naturally and artificially infected insect species, including important vectors of human pathogens. Anopheles mosquitoes are naturally uninfected with Wolbachia, and stable artificial infections have not yet succeeded in this genus. Recent techniques have enabled establishment of somatic Wolbachia infections in Anopheles. Here, we characterize somatic infections of two diverse Wolbachia strains (wMelPop and wAlbB) in Anopheles gambiae, the major vector of human malaria. After infection, wMelPop disseminates widely in the mosquito, infecting the fat body, head, sensory organs and other tissues but is notably absent from the midgut and ovaries. Wolbachia initially induces the mosquito immune system, coincident with initial clearing of the infection, but then suppresses expression of immune genes, coincident with Wolbachia replication in the mosquito. Both wMelPop and wAlbB significantly inhibit Plasmodium falciparum oocyst levels in the mosquito midgut. Although not virulent in non-bloodfed mosquitoes, wMelPop exhibits a novel phenotype and is extremely virulent for approximately 12–24 hours post-bloodmeal, after which surviving mosquitoes exhibit similar mortality trajectories to control mosquitoes. The data suggest that if stable transinfections act in a similar manner to somatic infections, Wolbachia could potentially be used as part of a strategy to control the Anopheles mosquitoes that transmit malaria

    Almost There: Transmission Routes of Bacterial Symbionts between Trophic Levels

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    Many intracellular microbial symbionts of arthropods are strictly vertically transmitted and manipulate their host's reproduction in ways that enhance their own transmission. Rare horizontal transmission events are nonetheless necessary for symbiont spread to novel host lineages. Horizontal transmission has been mostly inferred from phylogenetic studies but the mechanisms of spread are still largely a mystery. Here, we investigated transmission of two distantly related bacterial symbionts – Rickettsia and Hamiltonella – from their host, the sweet potato whitefly, Bemisia tabaci, to three species of whitefly parasitoids: Eretmocerus emiratus, Eretmocerus eremicus and Encarsia pergandiella. We also examined the potential for vertical transmission of these whitefly symbionts between parasitoid generations. Using florescence in situ hybridization (FISH) and transmission electron microscopy we found that Rickettsia invades Eretmocerus larvae during development in a Rickettsia-infected host, persists in adults and in females, reaches the ovaries. However, Rickettsia does not appear to penetrate the oocytes, but instead is localized in the follicular epithelial cells only. Consequently, Rickettsia is not vertically transmitted in Eretmocerus wasps, a result supported by diagnostic polymerase chain reaction (PCR). In contrast, Rickettsia proved to be merely transient in the digestive tract of Encarsia and was excreted with the meconia before wasp pupation. Adults of all three parasitoid species frequently acquired Rickettsia via contact with infected whiteflies, most likely by feeding on the host hemolymph (host feeding), but the rate of infection declined sharply within a few days of wasps being removed from infected whiteflies. In contrast with Rickettsia, Hamiltonella did not establish in any of the parasitoids tested, and none of the parasitoids acquired Hamiltonella by host feeding. This study demonstrates potential routes and barriers to horizontal transmission of symbionts across trophic levels. The possible mechanisms that lead to the differences in transmission of species of symbionts among species of hosts are discussed

    Neural and Synaptic Defects in slytherin, a Zebrafish Model for Human Congenital Disorders of Glycosylation

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    Congenital disorder of glycosylation type IIc (CDG IIc) is characterized by mental retardation, slowed growth and severe immunodeficiency, attributed to the lack of fucosylated glycoproteins. While impaired Notch signaling has been implicated in some aspects of CDG IIc pathogenesis, the molecular and cellular mechanisms remain poorly understood. We have identified a zebrafish mutant slytherin (srn), which harbors a missense point mutation in GDP-mannose 4,6 dehydratase (GMDS), the rate-limiting enzyme in protein fucosylation, including that of Notch. Here we report that some of the mechanisms underlying the neural phenotypes in srn and in CGD IIc are Notch-dependent, while others are Notch-independent. We show, for the first time in a vertebrate in vivo, that defects in protein fucosylation leads to defects in neuronal differentiation, maintenance, axon branching, and synapse formation. Srn is thus a useful and important vertebrate model for human CDG IIc that has provided new insights into the neural phenotypes that are hallmarks of the human disorder and has also highlighted the role of protein fucosylation in neural development

    Pancreatic Ξ²-Cell Death in Response to Pro-Inflammatory Cytokines Is Distinct from Genuine Apoptosis

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    A reduction in functional Ξ²-cell mass leads to both major forms of diabetes; pro-inflammatory cytokines, such as interleukin-1beta (IL-1Ξ²) and gamma-interferon (Ξ³-IFN), activate signaling pathways that direct pancreatic Ξ²-cell death and dysfunction. However, the molecular mechanism of Ξ²-cell death in this context is not well understood. In this report, we tested the hypothesis that individual cellular death pathways display characteristic phenotypes that allow them to be distinguished by the precise biochemical and metabolic responses that occur during stimulus-specific initiation. Using 832/13 and INS-1E rat insulinoma cells and isolated rat islets, we provide evidence that apoptosis is unlikely to be the primary pathway underlying Ξ²-cell death in response to IL-1Ξ²+Ξ³-IFN. This conclusion was reached via the experimental results of several different interdisciplinary strategies, which included: 1) tandem mass spectrometry to delineate the metabolic differences between IL-1Ξ²+Ξ³-IFN exposure versus apoptotic induction by camptothecin and 2) pharmacological and molecular interference with either NF-ΞΊB activity or apoptosome formation. These approaches provided clear distinctions in cell death pathways initiated by pro-inflammatory cytokines and bona fide inducers of apoptosis. Collectively, the results reported herein demonstrate that pancreatic Ξ²-cells undergo apoptosis in response to camptothecin or staurosporine, but not pro-inflammatory cytokines

    Will to Meaning: A Pilot Study on Teaching Existential Theory through Creative Techniques

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    Early career clinicians have reported limited experience utilizing existential concepts in their clinical practice. This deficit may be attributed to a gap in training. Further, utilizing creative techniques to elucidate conceptual understanding has a demonstrated history of effectiveness in the classroom. This study explored whether the use of creative instructional techniques supports student learning of existential counseling theory, and, if so, which specific tools do students prefer. Through pairing existential concepts with creative instructional techniques, the researchers hypothesized that understanding would increase. Students reported a significant increase in their knowledge of existential concepts following the use of creative instructional techniques and notated their preferences. Resources for integrating these techniques in counselor education are provided alongside future research directions
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