Publications by authors named "James Knight"

We present a Spiking Neural Network (SNN) model that incorporates learnable synaptic delays through two approaches: per-synapse delay learning via Dilated Convolutions with Learnable Spacings (DCLS) and a dynamic pruning strategy that also serves as a form of delay learning. In the latter approach, the network dynamically selects and prunes connections, optimizing the delays in sparse connectivity settings. We evaluate both approaches on the Raw Heidelberg Digits keyword spotting benchmark using Backpropagation Through Time with surrogate gradients.

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Central nervous system (CNS) metastases of atypical carcinoid tumors are exceptionally rare. Isolated studies suggest a survival benefit in patients who receive whole-brain radiotherapy (WBRT); however, it has been known to have detrimental effects on long-term memory and executive function. Here, we present a case of a patient initially diagnosed with stage IIB bronchopulmonary carcinoid who later developed hepatic and intracranial metastases despite receiving adjuvant systemic therapy over a two-year period.

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Visual navigation is a key capability for robots and animals. Inspired by the navigational prowess of social insects, a family of insect-inspired route navigation algorithms-familiarity-based algorithms-have been developed that use stored panoramic images collected during a training route to subsequently derive directional information during route recapitulation. However, unlike the ants that inspire them, these algorithms ignore the sequence in which the training images are acquired so that all temporal information/correlation is lost.

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Despite the established use of immune checkpoint inhibitors (ICIs) to treat non-small cell lung cancer (NSCLC), only a subset of patients benefit from treatment and ∼50% of patients whose tumors respond eventually develop acquired resistance (AR). To identify novel drivers of AR, we generated murine Msh2 knock-out (KO) lung tumors that initially responded but eventually developed AR to anti-PD-1, alone or in combination with anti-CTLA-4. Resistant tumors harbored decreased infiltrating T cells and reduced cancer cell-intrinsic MHC-I and MHC-II levels, yet remained responsive to IFNγ.

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Article Synopsis
  • Brain metastatic carcinoma from prostate cancer is uncommon, but identification through imaging like [Ga]PSMA PET/CT can be complicated by other brain tumors that also show uptake.
  • A 70-year-old male with high-risk prostate cancer had a solitary brain lesion confirmed as metastatic adenocarcinoma after surgical resection, followed by targeted Gamma Knife radiosurgery and androgen deprivation therapy.
  • The case highlights the importance of confirming the diagnosis histologically and shows that with appropriate treatment, significant control of the cancer can be achieved, even in rare brain metastases.
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Physical phantom models have been integral to surgical training, yet they lack realism and are unable to replicate the presence of blood resulting from surgical actions. Existing domain transfer methods aim to enhance realism, but none facilitate blood simulation. This study investigates the overlay of blood on images acquired during endoscopic transsphenoidal pituitary surgery on phantom models.

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A phenanthroline-type ligand containing an annealed 1,2,4-triazine ring was used to prepare novel Ir(III) complexes 3 and 4. The complexes are non-luminescent but show luminogenic behaviour following the inverse electron demand Diels-Alder (IEDDA) reaction with bicyclononyne (BCN) derivatives. It was observed that the complexes react with BCN-C10 faster than the corresponding free ligands.

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The central complex of insects contains cells, organised as a ring attractor, that encode head direction. The 'bump' of activity in the ring can be updated by idiothetic cues and external sensory information. Plasticity at the synapses between these cells and the ring neurons, that are responsible for bringing sensory information into the central complex, has been proposed to form a mapping between visual cues and the heading estimate which allows for more accurate tracking of the current heading, than if only idiothetic information were used.

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Current clinical diagnostic imaging methods for lung metastases are sensitive only to large tumours (1-2 mm cross-sectional diameter), and early detection can dramatically improve treatment. We have previously demonstrated that an antibody-targeted MRI contrast agent based on microparticles of iron oxide (MPIO; 1 μm diameter) enables the imaging of endothelial vascular cell adhesion molecule-1 (VCAM-1). Using a mouse model of lung metastasis, upregulation of endothelial VCAM-1 expression was demonstrated in micrometastasis-associated vessels but not in normal lung tissue, and binding of VCAM-MPIO to these vessels was evident histologically.

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Objective: To study the identification of rare genetic variants in the PCDH genetic family in a cohort of transgender women (TGW) and their potential role in gender identity.

Design: Exome sequencing and functional ontology analysis.

Setting: Outpatient gender health and reproductive endocrinology clinics.

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Article Synopsis
  • A study explored whether the COX-2 inhibitor celecoxib, when added to standard chemotherapy, could lower the recurrence risk and improve survival for patients with stage III colon cancer.
  • While celecoxib did not show significant benefits for all patients, a subgroup analysis revealed that those with PIK3CA gain-of-function mutations had better disease-free survival (DFS) and overall survival compared to those without these mutations.
  • The findings suggest that mutational status, specifically PIK3CA, may help guide the selective use of COX-2 inhibitors along with standard treatment for this type of cancer.
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Ants are capable of learning long visually guided foraging routes with limited neural resources. The visual scene memory needed for this behaviour is mediated by the mushroom bodies; an insect brain region important for learning and memory. In a visual navigation context, the mushroom bodies are theorised to act as familiarity detectors, guiding ants to views that are similar to those previously learned when first travelling along a foraging route.

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Purpose We sought to explore the feasibility of using the current co-planar Halcyon ring delivery system (RDS) with a novel multileaf collimator (MLC) aperture shape controller in delivering a single high dose of 30 Gy to solitary lung lesions via stereotactic body radiotherapy (SBRT). Materials and methods Thirteen non-small-cell lung cancer (NSCLC) patients previously treated with a single dose of 30 Gy to lung lesions via SBRT on the TrueBeam (6MV-FFF) using non-coplanar volumetric modulated arc therapy (VMAT) arcs were anonymized and replanned onto the Halcyon RDS (6MV-FFF) following RTOG-0915 single-fraction criteria. The Halcyon plans utilized a novel dynamic conformal arc (DCA)-based MLC-fitting approach before VMAT optimization with a user-defined aperture shape controller option.

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Click chemistry has become a commonly used synthetic method due to the simplicity, efficiency, and high selectivity of this class of chemical reactions. Since their initial discovery, further click chemistry methods have been identified and added to the toolbox of click chemistry reactions for biomedical applications. However, selecting the most suitable reaction for a specific application is often challenging, as multiple factors must be considered, including selectivity, reactivity, biocompatibility, and stability.

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The molecular basis of mullerian aplasia, also known as Mayer-Rokitansky-Kuster Hauser (MRKH) or congenital absence of the uterus and vagina, is largely unknown. We applied a multifaceted genetic approach to studying the pathogenesis of MRKH including exome sequencing of trios and duos, genome sequencing of families, qPCR, RT-PCR, and Sanger sequencing to detect intragenic deletions, insertions, splice variants, single nucleotide variants, and rearrangements in 132 persons with MRKH. We identified two heterozygous variants in ZNHIT3 localized to a commonly involved CNV region at chromosome 17q12 in two different families with MRKH.

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Calorie restriction (CR) provides anti-aging benefits through diverse processes, such as reduced metabolism and growth and increased mitochondrial activity. Although controversy still exists regarding CR-mediated lifespan effects, many researchers are seeking interventions that mimic the effects of CR. Yeast has proven to be a useful model system for aging studies, including CR effects.

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Background: MUPPITS-2 was a randomized, placebo-controlled clinical trial that demonstrated mepolizumab (anti-IL-5) reduced exacerbations and blood and airway eosinophils in urban children with severe eosinophilic asthma. Despite this reduction in eosinophilia, exacerbation risk persisted in certain patients treated with mepolizumab. This raises the possibility that subpopulations of airway eosinophils exist that contribute to breakthrough exacerbations.

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Synaptophysin is expressed on fibrogenic hepatic myofibroblasts. C1-3 is a single chain human antibody (scAb) that binds specifically to synaptophysin on hepatic myofibroblasts, providing a targeting vector for novel in vivo imaging agents of chronic liver disease. C1-3 and a negative control scAb, CSBD9, were radiolabelled with zirconium-89 via desferrioxamine chelation to enable non-invasive molecular imaging with positron emission tomography (PET).

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Secondary Cerenkov-induced fluorescence imaging (SCIFI) is an emerging biomedical optical imaging modality that leverages Cerenkov luminescence, primarily generated by β-emitting radioisotopes, to excite fluorophores that offer near-infrared emissions with optimal tissue penetrance. Dual-functionalized immunoconjugates composed of an antibody, a near-infrared fluorophore, and a β-emitting radioisotope have potential utility as novel SCIFI constructs with high specificity for molecular biomarkers of disease. Here, we report the synthesis and characterization of [Zr]Zr-DFO-trastuzumab-BOD665, a self-excitatory HER2-specific "immunoSCIFI" probe capable of yielding near-infrared fluorescence without external excitation.

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Article Synopsis
  • Extreme disease phenotypes, like infectious purpura fulminans (PF), can reveal important insights into common health conditions but are hard to study due to their rarity.
  • Researchers utilized a new method called the rare variant trend test (RVTT) to analyze genetic risk factors associated with PF, examining both prospective patient samples and historical records from large hospital systems.
  • They discovered a significant increase in low-frequency variants in the complement system among PF patients, linking these genetic changes to severe hyperinflammation in sepsis through loss and gain of function in complement receptors CR3 and CR4.
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Obesity-linked fatty liver is a significant risk factor for hepatocellular carcinoma (HCC); however, the molecular mechanisms underlying the transition from non-alcoholic fatty liver disease (NAFLD) to HCC remains unclear. The present study explores the role of the endoplasmic reticulum (ER)-associated protein NgBR, an essential component of the cis-prenyltransferases (cis-PTase) enzyme, in chronic liver disease. Here we show that genetic depletion of NgBR in hepatocytes of mice (N-LKO) intensifies triacylglycerol (TAG) accumulation, inflammatory responses, ER/oxidative stress, and liver fibrosis, ultimately resulting in HCC development with 100% penetrance after four months on a high-fat diet.

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Objective: Preoperative grading of nonenhancing motor eloquent gliomas is hampered by a lack of specific imaging surrogates. Tumor grading is crucial for the informed consent discussion before tumor resection. In this paper, the authors hypothesized that navigated transcranial magnetic stimulation (nTMS)-derived metrics could provide significant information to distinguish between high- and low-grade motor eloquent gliomas that present as nonenhancing tumors and therefore contribute to improving patient counseling, timing of treatment, preoperative planning, and intraoperative strategies.

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Hedgehog signaling mediates embryologic development of the central nervous system and other tissues and is frequently hijacked by neoplasia to facilitate uncontrolled cellular proliferation. Meningiomas, the most common primary brain tumor, exhibit Hedgehog signaling activation in 6.5% of cases, triggered by recurrent mutations in pathway mediators such as SMO.

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Many animals use motion vision information to control dynamic behaviors. Predatory animals, for example, show an exquisite ability to detect rapidly moving prey, followed by pursuit and capture. Such target detection is not only used by predators but is also important in conspecific interactions, such as for male hoverflies defending their territories against conspecific intruders.

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