The Self of the Field and the Work of Donnel Stern

No study has taken an updated and comprehensive review of Donnel Stern’s writings. An investigation of his philosophical assumptions, locating Stern’s work socioculturally and historically, along with an elucidation of Stern’s background in traditional psychoanalytic literature and clinical practice, brings out the meanings and enigmas present in his theories of dissociation, enactment, unformulated experience, multiple self-states, and reflection. Stern has offered one of the best-integrated theoretical models in relational psychoanalytic theory. An examination of his theories within the theoretical traditions to which he makes claim (psychoanalytic, interpersonal, hermeneutic, postmodern, and democratic) helps elucidate the challenge posed by relational psychoanalysis to the Cartesian split and scientism in psychological study and praxis, while also attending to important clinical implications of Stern’s model. The electronic version of this dissertation is at OhioLink ETD Center, www.ohiolink.edu/et

The Self of the Field and the Work of Donnel Stern

No study has taken an updated and comprehensive review of Donnel Stern’s writings. An investigation of his philosophical assumptions, locating Stern’s work socioculturally and historically, along with an elucidation of Stern’s background in traditional psychoanalytic literature and clinical practice, brings out the meanings and enigmas present in his theories of dissociation, enactment, unformulated experience, multiple self-states, and reflection. Stern has offered one of the best-integrated theoretical models in relational psychoanalytic theory. An examination of his theories within the theoretical traditions to which he makes claim (psychoanalytic, interpersonal, hermeneutic, postmodern, and democratic) helps elucidate the challenge posed by relational psychoanalysis to the Cartesian split and scientism in psychological study and praxis, while also attending to important clinical implications of Stern’s model. The electronic version of this dissertation is at OhioLink ETD Center, www.ohiolink.edu/et

Peptidergic control in a fruit crop pest: The spotted-wing drosophila, Drosophila suzukii

Neuropeptides play an important role in the regulation of feeding in insects and offer potential targets for the development of new chemicals to control insect pests. A pest that has attracted much recent attention is the highly invasive Drosophila suzukii, a polyphagous pest that can cause serious economic damage to soft fruits. Previously we showed by mass spectrometry the presence of the neuropeptide myosuppressin (TDVDHVFLRFamide) in the nerve bundle suggesting that this peptide is involved in regulating the function of the crop, which in adult dipteran insects has important roles in the processing of food, the storage of carbohydrates and the movement of food into the midgut for digestion. In the present study antibodies that recognise the C-terminal RFamide epitope of myosuppressin stain axons in the crop nerve bundle and reveal peptidergic fibres covering the surface of the crop. We also show using an in vitro bioassay that the neuropeptide is a potent inhibitor (EC50 of 2.3 nM) of crop contractions and that this inhibition is mimicked by the non-peptide myosuppressin agonist, benzethonium chloride (Bztc). Myosuppressin also inhibited the peristaltic contractions of the adult midgut, but was a much weaker agonist (EC50 = 5.7 μM). The oral administration of Bztc (5 mM) in a sucrose diet to adult female D. suzukii over 4 hours resulted in less feeding and longer exposure to dietary Bztc led to early mortality. We therefore suggest that myosuppressin and its cognate receptors are potential targets for disrupting feeding behaviour of adult D. suzukii

Direct Identification of the Meloidogyne incognita Secretome Reveals Proteins with Host Cell Reprogramming Potential

The root knot nematode, Meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. Infection is associated with secretion of proteins surrounded by proliferating cells. Many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (PAMPs, e.g., flagellin) that trigger basal immunity through the nematode stylet into the plant cell. This leads to suppression of innate immunity and reprogramming of plant cells to form a feeding structure containing multinucleate giant cells. Effectors have generally been discovered using genetics or bioinformatics, but M. incognita is non-sexual and its genome sequence has not yet been reported. To partially overcome these limitations, we have used mass spectrometry to directly identify 486 proteins secreted by M. incognita. These proteins contain at least segmental sequence identity to those found in our 3 reference databases (published nematode proteins; unpublished M. incognita ESTs; published plant proteins). Several secreted proteins are homologous to plant proteins, which they may mimic, and they contain domains that suggest known effector functions (e.g., regulating the plant cell cycle or growth). Others have regulatory domains that could reprogram cells. Using in situ hybridization we observed that most secreted proteins were produced by the subventral glands, but we found that phasmids also secreted proteins. We annotated the functions of the secreted proteins and classified them according to roles they may play in the development of root knot disease. Our results show that parasite secretomes can be partially characterized without cognate genomic DNA sequence. We observed that the M. incognita secretome overlaps the reported secretome of mammalian parasitic nematodes (e.g., Brugia malayi), suggesting a common parasitic behavior and a possible conservation of function between metazoan parasites of plants and animals