Master of Fine Arts

thesisThe questions posed in this research involve the physical socialization of the female body and how inhibitive socialization can be challenged. The female body in traditionally patriarchal societies has been socialized to take up less space than a male body, be focused on how the body appears instead of acts, and be inhibited from utilizing full physical capabilities when moving. I examine how the socialized body can be challenged through female friendships and creative spaces. For this research, I focused on dance as a creative and physical form that challenges the body. The dance space itself is a social space and dancers' bodies are constantly scrutinized by the audience, instructors, and the dancer herself. In shifting the focus for "successful" choreography from the gaze of the audience to the experience of the performer, the dance space becomes one of bodily autonomy and integrity, focused on action. In creating choreographic work for this research, I question what it means to utilize a feminist process when creating choreography. While the need to create a product may have created an imperfect feminist process, the creation of the product relied on knowledge from the performers' bodies and not from a hierarchical structure. In allowing the dancers to produce material from their bodily experiences, they were able to remove themselves from the implication that their bodies are not as worthy as their minds and recognize that their bodies hold just as much worth as their mental processes. The implication for this research is two-fold. First, social structures are constantly being questioned, just by allowing the female body to take up space and access complete physicality. In recognizing the importance of female relationships, we are socially validating the female bodily experience through those relationships. Second, the implications for the dance field are to continue to question feminist training in dance. What is the role of the choreographer? What is the role of the expert? How can creating dance be inclusive of all walks of life? Additionally, how do we, as choreographers, refrain from placing our bodily expectations, and potentially stereotypes, onto the bodies of our dancers

Insight on Hole-Hole Interaction and Magnetic Order from Dichroic Auger-Photoelectron Coincidence Spectra

The absence of sharp structures in the core-valence-valence Auger line shapes of partially filled bands has severely limited the use of electron spectroscopy in magnetic crystals and other correlated materials. Here by a novel interplay of experimental and theoretical techniques we achieve a combined understanding of the Photoelectron, Auger %$M_{23}M_{45}M_{45}$ and Auger-Photoelectron Coincidence Spectra (APECS) of CoO. This is a prototype antiferromagnetic material in which the recently discovered Dichroic Effect in Angle Resolved (DEAR) APECS reveals a complex pattern in the strongly correlated Auger line shape. A calculation of the \textit{unrelaxed} spectral features explains the pattern in detail, labeling the final states by the total spin. The present theoretical analysis shows that the dichroic effect arises from a spin-dependence of the angular distribution of the photoelectron-Auger electron pair detected in coincidence, and from the selective power of the dichroic technique in assigning different weights to the various spin components. Since the spin-dependence of the angular distribution exists in the antiferromagnetic state but vanishes at the N\'eel temperature, the DEAR-APECS technique detects the phase transition from its local effects, thus providing a unique tool to observe and understand magnetic correlations in such circumstances, where the usual methods (neutron diffraction, specific heat measurements) are not applicable.Comment: Accepted by: Physical Review Letter

Study of the isotropic contribution to the analysis of photoelectron diffraction experiments at the ALOISA beamline

The angular distribution of the intensity in photoemission experiments is affected by electron diffraction patterns and by a smoothly varying ISO contribution originated by both intrumental details and physical properties of the samples. The origin of the various contributions to the ISO component has been identified since many years. Nonetheless in this work we present original developement of the ED analysis, which arises from the evolution of instrumental performance, in terms of analyzers positioning and angular resolution, as well as collimation and size of X-ray beams in third generation synchrotron sources. The analytical treatement of the instrumental factors is presented in detail for the end station of the ALOISA beamline (Trieste Synchrotron), where a wide variety of scattering geometries is available for ED experiments. We present here the basic formulae and their application to experimental data taken on the Fe/Cu3Au(001) system in order to highlight the role of the various parameters included in the distribution function. A specific model for the surface illumination has been developed as well as the overlayer thickness and surface roughness have been considered.Comment: RevTex, nine pages with five eps figures; to be published in J. Electron Spectrosc. Relat. Pheno

Quantum size effects in the low temperature layer-by-layer growth of Pb on Ge(001)

The electronic properties of thin metallic films deviate from the corresponding bulk ones when the film thickness is comparable with the wavelength of the electrons at the Fermi level due to quantum size effects (QSE). QSE are expected to affect the film morphology and structure leading to the low temperature (LT) ``electronic growth'' of metals on semiconductors. In particular, layer-by-layer growth of Pb(111) films has been reported for deposition on Ge(001) below 130 K. An extremely flat morphology is preserved throughout deposition from four up to a dozen of monolayers. These flat films are shown to be metastable and to reorganize into large clusters uncovering the first Pb layer, pseudomorphic to the substrate, already at room temperature. Indications of QSE induced structural variations of the growing films have been reported for Pb growth on Ge(001), where the apparent height of the Pb(111) monatomic step was shown to change in an oscillatory fashion by He atom scattering (HAS) during layer-by-layer growth. The extent of the structural QSE has been obtained by a comparison of the HAS data with X-ray diffraction (XRD) and reflectivity experiments. Whereas step height variations as large as 20 % have been measured by HAS reflectivity, the displacement of the atomic planes from their bulk position, as measured by XRD, has been found to mainly affect the topmost Pb layer, but with a lower extent, i.e. the QSE observed by HAS are mainly due to a perpendicular displacement of the topmost layer charge density. The effect of the variable surface relaxation on the surface vibration has been studied by inelastic HAS to measure the acoustic dispersion of the low energy phonons.Comment: 28 pages (laTex,elsart) and 13 figures (eps); updated reference

Electronic properties and orbital-filling mechanism in Rb-intercalated copper phthalocyanine

The evolution of the electronic properties of a thin film of copper phthalocyanine deposited on Al(100) and progressively intercalated with rubidium atoms was followed by photoemission and X-ray absorption spectroscopies. Electron donation from the Rb atoms to the C32H16N8Cu molecules results in the lifting of the degeneracy in the e(g) ligand-derived molecular orbital and the lowering of the molecular symmetry. For Rb similar to 2C32H16N8Cu, spectral evidence indicates that both donated electrons reside in the first split-off e(g)-derived level, thus creating an electronic inequivalence between the C atoms in the benzene rings. For higher Rb concentrations, a reduction of the Cu oxidation state is observed, together with a new Cu-derived state in valence-band photoemission spectra, testifying to the filling of the b(1g) orbital. Thus, even though b(1g) is the lowest unoccupied orbital of the neutral molecule, in the film, the Cu-derived b(1g)-derived states are occupied only after a partial filling of the e.-derived band has taken place. Despite the fact that the eg-derived spectral weight becomes larger as the rubidium content in the RbxC32H16N8Cu compound increases, no spectral density was observed at the Fermi level, showing that the film remains insulating for all of the investigated stoichiometries

A comparative multi-farm study on Salmonella risk factors for pig farms in a high pig density area in Germany

In this study, herds with a high frequency of animals with antibodies against Salmonella are compared to herds with a low frequency of such animals in order to evaluate the relevance of presumed risk factors and/or to identify so far unknown risk factors. A standardised, validated questionnaire was used to document a multitude of characteristics from each farm. Faeces and environmental samples were also gathered with the intention of corroborating the salmonella-specific relevance of the potential risk factors as queried by the survey. These samples were analyzed by means of Real-Time PCR

Orexin signaling during social defeat stress influences subsequent social interaction behaviour and recognition memory

Orexins are neuropeptides synthesized in the lateral hypothalamus that influence arousal, feeding, reward pathways, and the response to stress. However, the role of orexins in repeated stress is not fully characterized. Here, we examined how orexins and their receptors contribute to the coping response during repeated social defeat and subsequent anxiety-like and memory-related behaviors. Specifically, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to stimulate orexins prior to each of five consecutive days of social defeat stress in adult male rats. Additionally, we determined the role of the orexin 2 receptor in these behaviors by using a selective orexin 2 receptor antagonist (MK-1064) administered prior to each social defeat. Following the 5 day social defeat conditioning period, rats were evaluated in social interaction and novel object recognition paradigms to assess anxiety-like behavior and recognition memory, respectively. Activation of orexin neurons by DREADDs prior to each social defeat decreased the average latency to become defeated across 5 days, indicative of a passive coping strategy that we have previously linked to a stress vulnerable phenotype. Moreover, stimulation of orexin signaling during defeat conditioning decreased subsequent social interaction and performance in the novel object recognition test indicating increased subsequent anxiety-like behavior and reduced working memory. Blocking the orexin 2 receptor during repeated defeat did not alter these effects. Together, our results suggest that orexin neuron activation produces a passive coping phenotype during social defeat leading to subsequent anxiety-like behaviors and memory deficits

Orexin 2 receptor regulation of the hypothalamic–pituitary–adrenal (HPA) response to acute and repeated stress

Orexins are hypothalamic neuropeptides that have a documented role in mediating the acute stress response. However, their role in habituation to repeated stress, and the role of orexin receptors (OX1R and OX2R) in the stress response, has yet to be defined. Orexin neuronal activation and levels in the cerebrospinal fluid were found to be stimulated with acute restraint, but were significantly reduced by day five of repeated restraint. As certain disease states such as panic disorder are associated with increased central orexin levels and failure to habituate to repeated stress, the effect of activating orexin signaling via Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) on the hypothalamic-pituitary-adrenal (HPA) response was evaluated after repeated restraint. While vehicle-treated rats displayed habituation of Adrenocorticotropic Hormone (ACTH) from day 1 to day 5 of restraint, stimulating orexins did not further increase ACTH beyond vehicle levels for either acute or repeated restraint. We delineated the roles of orexin receptors in acute and repeated stress by using a selective OX2R antagonist (MK-1064). Pretreatment with MK-1064 reduced day 1 ACTH levels, but did not allow further habituation on day 5 compared with vehicle-treated rats, indicating that endogenous OX2R activity plays a role in acute stress, but not in habituation to repeated stress. However, in restrained rats with further stimulated orexins by DREADDs, MK-1064 decreased ACTH levels on day 5. Collectively, these results indicate that the OX2R plays a role in acute stress, and can prevent habituation to repeated stress under conditions of high orexin release