574 research outputs found

    Micro-PIV of Self-Propelling Bi-Slugs in a Micro Channel

    Get PDF
    Bi-slugs are fluid entities involving two dissimilar fluids that move “on their own” due to differences in surface tension. At the micro-fluidic scale this sort of motion may be useful to efficiently transport small quantities of fluid from place to place. This study uses Micro-Particle Image Velocimetry (µ-PIV) techniques to investigate self propelling bi-slug flows. The bi-slugs examined are made of ethylene glycol and Xiameter PMX-200 Silicone Fluid (5cst and 10cst) and placed in a glass micro-channel of approximately 1mm diameter. The Reynolds number (Re) range considered (based on ethylene glycol in the slug) is 2.54 - 1.07 and the capillary number (Ca) range is 1.23x10-3 - 5.18x10-4. In particular, we are interested in the flow field in the region near the interfacial meniscus, and the shear forces along the micro-channel. Quantitative velocity field images and streamline images of the silicon fluid in motion are shown. To the best of the author’s knowledge these µ-PIV measurements are the first such measurements made in self propelling bi-slugs. In addition to the velocity field results, methods for creating self propelling bi-slugs, and issues related to the challenges of achieving adequate seeding of the ethylene glycol and silicone fluid with dyed micro-spheres will be presented

    Immunological identification of the alternative oxidase of Acanthamoeba castellanii mitochondria

    Get PDF
    AbstractMitochondria of the protozoa Acanthamoeba castellanii possess a cyanide-insensitive oxidase cross-reacting with monoclonal antibodies raised against the plant alternative oxidase. Immunoblotting revealed three monomeric forms (38, 35, and 32 kDa) and very low amounts of a single 65 kDa dimeric form. Cross-linking studies suggest that while in plants the alternative oxidase occurs as a dimer, in amoeba it functions as a monomer. Immunologically detectable protein levels change with the age of amoeba cell culture. Increased amounts of the 35 kDa protein are accompanied by an increase in the activity of cyanide-resistant respiration

    Eye movements and mental imagery during reading of literary texts with different narrative styles

    Get PDF
    Based on Kuzmicova's (2014) phenomenological typology of narrative styles, we studied the specific contributions of mental imagery to literary reading experience and to reading behavior by combining questionnaires with eye-tracking methodology. Specifically, we focused on the two main categories in Kuzmicova's (2014) typology, i.e., texts dominated by an "enactive" style, and texts dominated by a "descriptive" style. "Enactive" style texts render characters interacting with their environment, and "descriptive" style texts render environments dissociated from human action. The quantitative analyses of word category distributions of two dominantly enactive and two dominantly descriptive texts indicated significant differences especially in the number of verbs, with more verbs in enactment compared to descriptive texts. In a second study, participants read two texts (one theoretically cueing descriptive imagery, the other cueing enactment imagery) while their eye movements were recorded. After reading, participants completed questionnaires assessing aspects of the reading experience generally, as well as their text-elicited mental imagery specifically. Results show that readers experienced more difficulties conjuring up mental images during reading descriptive style texts and that longer fixation duration on words were associated with enactive style text. We propose that enactive style involves more imagery processes which can be reflected in eye movement behavior

    Medical educators' experiences on medically unexplained symptoms and intercultural communication

    Get PDF
    Background Medically unexplained symptoms (MUS) are highly prevalent and remain challenging in healthcare and medical education, along with the increase in the importance of intercultural issues regarding MUS. However, less is known about the challenges of professionally addressing patients with MUS in the interprofessional and intercultural contexts. Thus, the present study aims to provide the first exploration of the experiences of medical specialists regarding treating MUS in intercultural contexts and inputs for training development on the intercultural aspects of MUS. Methods Three focus groups (total n = 13) consisting of medical specialists from a Hungarian university who were teaching at the medical faculty in intercultural settings and also worked for the university health services were interviewed. The topics covered the participants' personal experiences on addressing MUS and the challenges of intercultural communication and the intercultural educational context. Thematic analysis was used to yield a qualitative account of the interviews as guided by the research questions. Results Representing the different aspects of medical specialists, the study identified three main themes in the experiences of medical specialists, namely, 1) the need to adapt to the personal world of patients and search for common frames to understand MUS, 2) the need to discover methods for adapting to cultural differences and 3) the need to enhance the interprofessional coordination of knowledge and practices. Conclusions The results are in line with the distinct conclusions of previous studies. Moreover, an integrated educational program on the intercultural aspects of MUS may address the main themes separately and, subsequently, support their integration. Therefore, the study discusses the manner in which an integrated educational program on the intercultural aspects of MUS may address the needs recognized in these aspects

    CYRI/ Fam49 proteins represent a new class of Rac1 interactors

    Get PDF
    Fam49 proteins, now referred to as CYRI (CYFIP-related Rac Interactor), are evolutionarily conserved across many phyla. Their closest relative by amino acid sequence is CYFIP, as both proteins contain a domain of unknown function DUF1394. We recently showed that CYRI and the DUF1394 can mediate binding to Rac1 and evidence is building to suggest that CYRI plays important roles in cell migration, chemotaxis and pathogen entry into cells. Here we discuss how CYRI proteins fit into the current framework of the control of actin dynamics by positive and negative feedback loops containing Rac1, the Scar/WAVE Complex, the Arp2/3 Complex and branched actin. We also provide data regarding the interaction between Rac1 and CYRI in an unbiassed mass spectrometry screen for interactors of an active mutant of Rac1

    Mapping trends in water table depths in a brazilian cerrado area

    Get PDF
    Abstract The Cerrado region is the most extensive woodland-savanna

    Gaze Restriction and Reactivation of Place-bound Content Drive Eye Movements During Mental Imagery

    Get PDF
    When we imagine a picture, we move our eyes even though the picture is physically not present. These eye movements provide information about the ongoing process of mental imagery. Eye movements unfold over time, and previous research has shown that the temporal gaze dynamics of eye movements in mental imagery have unique properties, which are unrelated to those in perception. In mental imagery, refixations of previously fixated locations happen more often and in a more systematic manner than in perception. The origin of these unique properties remains unclear. We tested how the temporal structure of eye movements is influenced by the complexity of the mental image. Participants briefly saw and then maintained a pattern stimulus, consisting of one (easy condition) to four black segments (most difficult condition). When maintaining a simple pattern in imagery, participants restricted their gaze to a narrow area, and for more complex stimuli, eye movements were more spread out to distant areas. At the same time, fewer refixations were made in imagery when the stimuli were complex. The results show that refixations depend on the imagined content. While fixations of stimulus-related areas reflect the so-called ‘looking at nothing’ effect, gaze restriction emphasizes differences between mental imagery and perception
    corecore