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Depletion of follicular B cell-derived antibody secreting cells does not attenuate angiotensin II-induced hypertension or vascular compliance
No full textIntroduction: Marginal zone and follicular B cells are known to contribute to the development of angiotensin II-induced hypertension in mice, but the effector function(s) mediating this effect (e.g., antigen presentation, antibody secretion and/or cytokine production) are unknown. B cell differentiation into antibody secreting cells (ASCs) requires the transcription factor Blimp-1. Here, we studied mice with a Blimp-1 deficiency in follicular B cells to evaluate whether antibody secretion underlies the pro-hypertensive action of B cells. Methods: 10- to 14-week-old male follicular B cell Blimp-1 knockout (FoB-Blimp-1-KO) and floxed control mice were subcutaneously infused with angiotensin II (0.7 mg/kg/d) or vehicle (0.1% acetic acid in saline) for 28 days. BP was measured by tail-cuff plethysmography or radiotelemetry. Pulse wave velocity was measured by ultrasound. Aortic collagen was quantified by Masson's trichrome staining. Cell types and serum antibodies were quantified by flow cytometry and a bead-based multiplex assay, respectively. Results: In control mice, angiotensin II modestly increased serum IgG3 levels and markedly increased BP, cardiac hypertrophy, aortic stiffening and fibrosis. FoB-Blimp-1-KO mice exhibited impaired IgG1, IgG2a and IgG3 production despite having comparable numbers of B cells and ASCs to control mice. Nevertheless, FoB-Blimp-1-KO mice still developed hypertension, cardiac hypertrophy, aortic stiffening and fibrosis following angiotensin II infusion. Conclusions: Inhibition of follicular B cell differentiation into ASCs did not protect against angiotensin II-induced hypertension or vascular compliance. Follicular B cell functions independent of their differentiation into ASCs and ability to produce high-affinity antibodies, or other B cell subtypes, are likely to be involved in angiotensin II-induced hypertension
What behavioural impact does tactile art therapy have on children aged four to nine who have experienced attachment trauma?
No full textA thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the La Trobe Rural Health School, La Trobe University, Victoria, Australia.This thesis was a recipient of the Nancy Millis Award for theses of exceptional merit.</p
Variation in plant morphology and leaf essential oil composition of a representative Cinnamomum verum collection from Sri Lanka
No full textAbstract: Sri Lankan cinnamon germplasm is an underexploited genetic resource of high breeding potential. A representative collection of a cultivated cinnamon germplasm with 48 accessions, is established at the University of Ruhuna, Sri Lanka. From that collection, 40 three-year-old vegetative-propagated accessions, were used in this study to study the variations in plant morphology and leaf oil composition. Flush colour was determined as four main categories of pink, red, brown, and green in all 48 accessions. Leaf length, leaf width, leaf length to width ratio and petiole length varied from 7.9 to 14.5 cm, 3.8 to 7.3 cm, 1.8 to 3.07 cm, and 1 to 2.2 cm, respectively, in the selected 40 accessions. Both the good fragrant aroma category of bark fragrance and the sweet pungent category of bark taste were recorded in 21 of the 40 accessions. Twenty (20) accessions from above collection were selected for leaf oil analysis. Gas chromatography-mass spectrometry (GC-MS) of leaf oil revealed the presence of 146 chemical compounds. Eugenol was the major compound of 17 accessions (52.2% to 79.5%). Two accessions with zero eugenol contained 86.8% and 91.9% of benzyl benzoate (BB), in contrast to that of 0%-0.65% from other accessions. One accession produced 16.6% eugenol and 22.3% BB. A green flush colour associated with a higher BB percentage suggested a potential morphological marker for BB. The PCA for 20 accessions explained 88.11% of total variance. The cinnamon accessions with high BB, KA11 and GB17, were clustered together, and HB12 was isolated on a different cluster. Positive correlations were detected between linalool and β-caryophyllene (0.649), linalool and BB (0.770) (p < 0.01), and negative correlations between eugenol and linalool (-0.630) and eugenol and BB (-0.886) (p <0.01).</p
MolDStruct: Modeling the dynamics and structure of matter exposed to ultrafast x-ray lasers with hybrid collisional-radiative/molecular dynamics
No full textWe describe a method to compute photon-matter interaction and atomic dynamics with x-ray lasers using a hybrid code based on classical molecular dynamics and collisional-radiative calculations. The forces between the atoms are dynamically determined based on changes to their electronic occupations and the formation of a free electron cloud created from the irradiation of photons in the x-ray spectrum. The rapid transition from neutral solid matter to dense plasma phase allows the use of screened potentials, reducing the number of non-bonded interactions. In combination with parallelization through domain decomposition, the hybrid code handles large-scale molecular dynamics and ionization. This method is applicable for large enough samples (solids, liquids, proteins, viruses, atomic clusters, and crystals) that, when exposed to an x-ray laser pulse, turn into a plasma in the first few femtoseconds of the interaction. We present four examples demonstrating the applicability of the method. We investigate the non-thermal heating and scattering of bulk water and damage-induced dynamics of a protein crystal using an x-ray pump-probe scheme. In both cases, we compare to the experimental data. For single particle imaging, we simulate the ultrafast dynamics of a methane cluster exposed to a femtosecond x-ray laser. In the context of coherent diffractive imaging, we study the fragmentation as given by an x-ray pump-probe setup to understand the evolution of radiation damage in the time range of hundreds of femtoseconds.</p
Characterization of outer membrane vesicles released by clinical isolates of Neisseria gonorrhoeae
No full textThe sexually transmitted pathogen Neisseria gonorrhoeae releases membrane vesicles including outer membrane vesicles (OMVs) during infections. OMVs traffic outer membrane molecules, such as the porin PorB and lipo-oligosaccharide (LOS), into host innate immune cells, eliciting programmed cell death pathways, and inflammation. Little is known, however, about the proteome and LOS content of OMVs released by clinical strains isolated from different infection sites, and whether these vesicles similarly activate immune responses. Here, we characterized OMVs from four N. gonorrhoeae isolates and determined their size, abundance, proteome, LOS content, and activation of inflammatory responses in macrophages. The overall proteome of the OMVs was conserved between the four different isolates, which included major outer membrane and periplasm proteins. Despite this, we observed differences in the rate of OMV biogenesis and the relative abundance of membrane proteins and LOS. Consequently, OMVs from clinical isolates induced varying rates of macrophage cell death and the secretion of interleukin-1 family members, such as IL-1α and IL-1β. Overall, these findings demonstrate that clinical isolates of N. gonorrhoeae utilize membrane vesicles to release proteins and lipids, which affects innate immune responses
The Multifaceted Interactions of Dictyostelium Atg1 with Mitochondrial Function, Endocytosis, Growth, and Development
No full textAutophagy is a degradative recycling process central to the maintenance of homeostasis in all eukaryotes. By ensuring the degradation of damaged mitochondria, it plays a key role in maintaining mitochondrial health and function. Of the highly conserved autophagy proteins, autophagy-related protein 1 (Atg1) is essential to the process. The involvement of these proteins in intracellular signalling pathways, including those involving mitochondrial function, are still being elucidated. Here the role of Atg1 was investigated in the simple model organism Dictyostelium discoideum using an atg1 null mutant and mutants overexpressing or antisense-inhibiting atg1. When evaluated against the well-characterised outcomes of mitochondrial dysfunction in this model, altered atg1 expression resulted in an unconventional set of phenotypic outcomes in growth, endocytosis, multicellular development, and mitochondrial homeostasis. The findings here show that Atg1 is involved in a tightly regulated signal transduction pathway coordinating energy-consuming processes such as cell growth and multicellular development, along with nutrient status and energy production. Furthermore, Atg1’s effects on energy homeostasis indicate a peripheral ancillary role in the mitochondrial signalling network, with effects on energy balance rather than direct effects on electron transport chain function. Further research is required to tease out these complex networks. Nevertheless, this study adds further evidence to the theory that autophagy and mitochondrial signalling are not opposing but rather linked, yet strictly controlled, homeostatic mechanisms
Comparing the Effects of an Off-Ice Sprint-Change of Direction Task on Trunk Kinematics and Gait Laterality in Collegiate Ice Hockey Players.
No full textLaterality preferences are intrinsic in most physical activities, and ice hockey is one domain wherein these preferences might influence performance. Biomechanical laterality between dominant and nondominant (or preferred and nonpreferred) limbs is believed to be an advantageous attribute that is linked with skilled performance. Yet little is known about the implications of motor asymmetries for skilled performers in dynamic, time-constrained, team-based activities in an off-ice environment. This can be extended to when player position is considered, notably for those playing in a defensive or an offensive position. In this study, fourteen semi-professional collegiate male ice hockey players (age: 21.87 ± 2.98 years; BMI: 25.26 ± 3.21 kg/m) performed a randomized repeated 15 m sprint-change of direction task. Assessments of lower limb laterality were carried out as participants commenced the 15 m sprint change of direction task in both a right and left foot rear setback position. Biomechanical laterality between right and left rear foot setback positions was inferred by an ActiGraph GTx3 triaxial accelerometer that was located on the participants’ spinous process, representing the trunk centre of mass (CoM). Overall, ANOVA results indicated significant differences across all sprint split times between the right and left foot rear setback positions, with times significantly quicker when players commenced in a right rear foot setback position (p < 0.001). ANOVA revealed significant differences in trunk CoM acceleration between in a right and left rear setback position, specifically during the initial 0–10 m sprint split, with offensive players observed to have lesser trunk anteroposterior and vertical CoM acceleration (p = 0.05) and during the final 5 m sprint split (p = 0.002, d = 0.7), despite overall smaller effect sizes seen in the left foot rear setback position. It appears that starting with the foot in a right rear setback position results in quicker 15 m performance times and concurrent lower magnitudes of trunk CoM acceleration. Although we demonstrated that offensive players were quicker and displayed less trunk CoM acceleration, we recommend that future studies use a greater number of participants for inter-limb symmetry in these movement tests
High-accuracy measurement, advanced theory and analysis of the evolution of satellite transitions in manganese Kα using XR-HERFD
No full textHere, the novel technique of extended-range high-energy-resolution fluorescence detection (XR-HERFD) has successfully observed the n = 2 satellite in manganese to a high accuracy. The significance of the satellite signature presented is many hundreds of standard errors and well beyond typical discovery levels of three to six standard errors. This satellite is a sensitive indicator for all manganese-containing materials in condensed matter. The uncertainty in the measurements has been defined, which clearly observes multiple peaks and structure indicative of complex physical quantum-mechanical processes. Theoretical calculations of energy eigenvalues, shake-off probability and Auger rates are also presented, which explain the origin of the satellite from physical n = 2 shake-off processes. The evolution in the intensity of this satellite is measured relative to the full Kα spectrum of manganese to investigate satellite structure, and therefore many-body processes, as a function of incident energy. Results demonstrate that the many-body reduction factor S02 should not be modelled with a constant value as is currently done. This work makes a significant contribution to the challenge of understanding many-body processes and interpreting HERFD or resonant inelastic X-ray scattering spectra in a quantitative manner
Gesture phrases and gesture units
No full textThese diagrams demonstrate the structure of a gesture phrase and a gesture unit and the constituent phases of gesture production. For use in teaching and research. </p
Variation in pointing
No full textDocumented variation in pointing handshape.
Original images by Lucy Maddox for Lauren Gawne. Grouped figures created by Lauren Gawne.</p