Publications by authors named "Diana Hunter"

We demonstrate GPU-accelerated modelling of ultrafast optical parametric oscillators (OPOs) via the χ nonlinear envelope equation with 1265× improvement in execution time compared with a CPU-based approach. Incorporating an adaptive step-size algorithm and absorbing boundary conditions, our model is capable of simulating OPOs containing long (>10 mm) nonlinear crystals or significant intracavity dispersion with outputs generated in less than 1 minute, allowing the investigation of systems that were previously computationally prohibitive to explore. We implement real-world parameters such as optical coatings, material absorption, and non-ideal poling domains within quasi-phase matched nonlinear crystals, producing excellent agreement with the spectral tuning behaviour and average power from a previously reported prism-based OPO.

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We demonstrate a synchronously-pumped optical parametric oscillator (OPO) with a cavity formed from high refractive index inverted prisms, also known as Brewster mirrors. Exploiting a single total internal reflection, this is the simplest device capable of deviating a laser beam by 180. The OPO produced a chirped signal output tunable from 1060 - 1570 nm with a maximum power of 114 mW.

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Article Synopsis
  • Zebrafish serve as a useful model for human heart function and can help study heart disorders and medications, but their cardiac repolarization mechanisms differ slightly from humans due to the absence of a functional hERG1b gene.
  • The research identified that zkcnh6a in zebrafish is similar to human hERG1a, but there is also a variant, zkcnh6b, which showed no functional role in the heart's electrical activity.
  • These findings emphasize the importance of recognizing species differences when using zebrafish to study human cardiac repolarization, especially since they lack the hERG1b gene that plays a significant role in human cardiac function and drug interactions.
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Aims: Long QT syndrome type 2 (LQTS2) is associated with inherited variants in the cardiac human ether-à-go-go-related gene (hERG) K+ channel. However, the pathogenicity of hERG channel gene variants is often uncertain. Using CRISPR-Cas9 gene-edited hiPSC-derived cardiomyocytes (hiPSC-CMs), we investigated the pathogenic mechanism underlying the LQTS-associated hERG R56Q variant and its phenotypic rescue by using the Type 1 hERG activator, RPR260243.

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Clustered regularly interspaced short palindromic repeats (CRISPR) in animal models enable precise genetic manipulation for the study of physiological phenomena. Zebrafish have been used as an effective genetic model to study numerous questions related to heritable disease, development, and toxicology at the whole-organ and -organism level. Due to the well-annotated and mapped zebrafish genome, numerous tools for gene editing have been developed.

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Spinal cord injury chronically alters cardiac structure and function and is associated with increased odds for cardiovascular disease. Here, we investigate the cardiac consequences of spinal cord injury on the acute-to-chronic continuum, and the contribution of altered bulbospinal sympathetic control to the decline in cardiac function following spinal cord injury. By combining experimental rat models of spinal cord injury with prospective clinical studies, we demonstrate that spinal cord injury causes a rapid and sustained reduction in left ventricular contractile function that precedes structural changes.

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We demonstrate a synchronously-pumped optical parametric oscillator (OPO) cavity in which traditional dielectric mirrors are replaced by all-planar Brewster angle prism retroreflectors, also known as Pellin-Broca prisms. Exploiting total internal reflection, these prisms form a cavity supporting >350-fs chirped signal pulses that were externally compressible to sub-150-fs durations. This simple architecture produces wavelengths tuneable across 1100 - 1350 nm, suitable for basic multi-photon applications.

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Article Synopsis
  • Spinal cord injuries (SCI) lead to significant problems with genitourinary and gastrointestinal functions due to the impact on pelvic ganglia (PG) neurons that control these systems.* -
  • Using a rat model of upper thoracic SCI (T3 transection), researchers observed changes in the size of PG neurons, indicating atrophy that starts as early as one week after the injury.* -
  • The findings highlight the importance of understanding these changes over time to develop potential treatments for improving autonomic functions affected by SCI.*
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Spinal cord injury (SCI) disconnects supraspinal micturition centers from the lower urinary tract resulting in immediate and long-term changes in bladder structure and function. While cervical and high thoracic SCI have a greater range of systemic effects, clinical data suggest that those with lower (suprasacral) injuries develop poorer bladder outcomes. Here we assess the impact of SCI level on acute changes in bladder activity.

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Promoter-based genetic recombination (via, e.g., Cre-lox) is most useful when all cells of interest express a particular gene.

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"Rods and rings" (RR) and loukoumasomes are similarly shaped, subcellular macromolecular structures with as yet unknown function. RR, so named because of their shape, are formed in response to inhibition in the GTP or CTP synthetic pathways and are highly enriched in the two key enzymes of the nucleotide synthetic pathway. Loukoumasomes also occur as linear and toroidal bodies and were initially inferred to be the same as RR, largely due to their shared shape and size and the fact that it was unclear if they shared the same subcomponents.

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Type 1 long-interspersed nuclear elements (L1s) are autonomous retrotransposable elements that retain the potential for activity in the human genome but are suppressed by host factors. Retrotransposition of L1s into chromosomal DNA can lead to genomic instability, whereas reverse transcription of L1 in the cytosol has the potential to activate innate immune sensors. We hypothesized that HIV-1 infection would compromise cellular control of L1 elements, resulting in the induction of retrotransposition events.

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The secreted growth factor progranulin (PGRN) has been shown to be important for regulating neuronal survival and outgrowth, as well as synapse formation and function. Mutations in the PGRN gene that result in PGRN haploinsufficiency have been identified as a major cause of frontotemporal dementia (FTD). Here we demonstrate that PGRN is colocalized with dense-core vesicle markers and is co-transported with brain-derived neurotrophic factor (BDNF) within axons and dendrites of cultured hippocampal neurons in both anterograde and retrograde directions.

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The genetic diversity of HIV-1 represents a major challenge in vaccine development. In this study, we establish a rationale for eliminating HIV-1-infected cells by targeting cellular immune responses against stable human endogenous retroviral (HERV) antigens. HERV DNA sequences in the human genome represent the remnants of ancient infectious retroviruses.

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T-cell responses to human endogenous retrovirus (HERV) K(HML-2) Gag and Env were mapped in HIV-1-infected subjects using 15 mer peptides. Small peptide pools and high concentrations were used to maximize sensitivity. In the 23 subjects studied, only three bona fide HERV-K(HML-2)-specific responses were detected.

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The presence of interleukin-2 (IL-2)-producing human immunodeficiency virus type 1 (HIV-1)-specific CD4(+) T-cell responses has been associated with the immunological control of HIV-1 replication; however, the causal relationship between these factors remains unclear. Here we show that IL-2-producing HIV-1-specific CD4(+) T cells can be cloned from acutely HIV-1-infected individuals. Despite the early presence of these cells, each of the individuals in the present study exhibited progressive disease, with one individual showing rapid progression.

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