186 research outputs found
First person - Sonal
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Sonal is the first author on ‘Myosin-II activity generates a dynamic steady state with continuous actin turnover in a minimal actin cortex’, published in Journal of Cell Science. Sonal conducted the research in this article while a PhD student in the lab of Petra Schwille at the Max Planck Institute of Biochemistry, Martinsried, Germany, studying biological pattern formation using a bottom-up reconstitution approach
Behavioral and physiological assessment of an animal model of post-traumatic stress disorder
No full textPost-traumatic stress disorder (PTSD) is an anxiety disorder triggered by exposure to a traumatic event. Despite recent progress, the causes and pathophysiology of PTSD remain poorly understood, partly because of ethical limitations inherent to human studies. One approach to circumvent this obstacle is to study PTSD in a valid animal model of the human syndrome. In one such model, extreme and long-lasting behavioral manifestations of anxiety develop in a subset of Lewis rats after exposure to an intense predator threat (PT) that mimics the type of life-or-death situation known to precipitate PTSD in humans. Thus, the first half of this thesis tested whether the Lewis rat model reproduces salient features of human PTSD. The results of these studies established the model’s face validity. The second half of this thesis used this model to identify alterations in the physiological properties of amygdala neurons that underlie the expression of PTSD. These studies revealed that PTSD is associated with differences in the synaptic responsiveness of central amygdala (CeA) neurons. Overall, these results suggest that the Lewis rat model of PTSD can be used to gain mechanistic insights in the pathophysiology of PTSD.Ph.D.Includes bibliographical referencesIncludes vitaby Sonal Goswam
From homeland to home: Widening Participation through the LEAP Macquarie Mentoring (Refugee Mentoring) Program
No full textMentoring is often conceptualised as a one-to-one interaction between peers, or as an academic to student interaction, with the aim of developing self-esteem, connectedness, identity, and academic attitudes within one party. While various researchers have provided support for effectiveness of mentoring in fostering the aforementioned qualities, limited studies have looked at the impacts of outreach mentoring programs. This article examines the impact of the LEAP-Macquarie Mentoring (Refugee Mentoring) program on high school students from refugee backgrounds who are mentees on the program and on the university students who are mentors on the program. A qualitative study was completed involving five focus groups, individual and semi structured interviews with 54 mentees and diary analysis of 45 mentors. Transcripts of interview and focus groups were analysed using a grounded approach. Key findings highlighted that the LEAP-Macquarie Mentoring (Refugee Mentoring) program supported both mentors and mentees in making a smooth personal, social, and academic transition from high school to university, helped them develop leadership potential, and provided them with a connection to community
Investigating the role of radixin in modulation of stereocilia length and stiffness
No full textMammalian hearing depends on deflection of stereocilia on the sensory outer hair cells of the inner ear. Previous data indicate that the stiffness of outer hair cell stereocilia are actively regulated. The molecular mechanism that regulate the deflection of stereocilia are presently less known. The aim of the study is to investigate the mechanistic pathway that underlie the stiffness modulation of outer hair cell stereocilia. Our hypothesis is that the membrane-cytoskeleton linker protein radixin, which is present at high concentration in stereocilia, could contribute to stiffness regulation. To test this hypothesis, we use the radixin blocker DX-52-1 which binds strongly and specifically to radixin. Time-resolved confocal imaging was used to visualize the sound-evoked motion of stereocilia in a semi-intact preparation of the guinea pig temporal bone. Cochlear microphonic potentials were also measured, using electrodes positioned in scala media. We found that the DX-52-1 inhibitor leads to an increase in stereocilia movements and decline in the amplitude of the cochlear microphonic potential. However, DX-52-1 caused a paradoxical increase in electromotility. These results suggest that radixin has a functionally important regulatory role in the mature inner ear.</p
Identification of Candidal Species from the Oral Cavity of Diabetic and Non-Diabetic Groups
No full textTrade-off between ordinary differential equation and Legendre polynomial methods to study guided modes in angle-ply laminate
No full textIt has been shown that the roots of guided waves in laminate plates produced by the ordinary differential equations (ODE) approach may not hold under to some computational conditions. A particular drawback of the 2D formulation of the ODE approach is the lack of reliability in the case of unidirectional laminates due to the decoupling properties between the SH and Lamb wave modes, which is caused by the unified matrix of roots. Due to this problem, the SH modes disappear from the unified roots of guided modes, then re-emerge with a separate computation of the SH and Lamb wave modes. Initially, we did not notice this computational “bug” in the event of a coupling between the SH and Lamb wave modes. In this context, the Legendre polynomial method is used to illustrate that fact. Results demonstrate how the polynomial method is pre-eminent to handle the laminate modelling over the ODE method for these specific requirements, however, a trade-off between these two methods needs to be considered to obtain stable and robust behavior of guided dispersion curves. This short study ends with conclusions and future perspectives.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Structural Integrity & Composite
Improved B cell development in humanized NOD-scid IL2Rγ(null) mice transgenically expressing human stem cell factor, granulocyte-macrophage colony-stimulating factor and interleukin-3.
No full textINTRODUCTION: Immunodeficient mice engrafted with human immune systems support studies of human hematopoiesis and the immune response to human-specific pathogens. A significant limitation of these humanized mouse models is, however, a severely restricted ability of human B cells to undergo class switching and produce antigen-specific IgG after infection or immunization.
METHODS: In this study, we have characterized the development and function of human B cells in NOD-scid IL2Rγ(null) (NSG) mice transgenically expressing human stem cell factor (SCF), granulocyte macrophage colony-stimulating factor (GM-CSF), and IL-3 (NSG-SGM3) following engraftment with human hematopoietic stem cells, autologous fetal liver, and thymic tissues (bone marrow, liver, thymus or BLT model). The NSG-SGM3 BLT mice engraft rapidly with human immune cells and develop T cells, B cells, and myeloid cells.
RESULTS: A higher proportion of human B cells developing in NSG-SGM3 BLT mice had a mature/naive phenotype with a corresponding decrease in immature/transitional human B cells as compared to NSG BLT mice. In addition, NSG-SGM3 BLT mice have higher basal levels of human IgM and IgG as compared with NSG BLT mice. Moreover, dengue virus infection of NSG-SGM3 BLT mice generated higher levels of antigen-specific IgM and IgG, a result not observed in NSG BLT mice.
CONCLUSIONS: Our studies suggest that NSG-SGM3 BLT mice show improved human B cell development and permit the generation of antigen-specific antibody responses to viral infection.
Immun Inflamm Dis 2016 Dec; 4(4):427-440
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