Publications by authors named "Joyce Chew"

Article Synopsis
  • The manifold scattering transform is a deep learning tool designed for analyzing data on Riemannian manifolds, extending concepts from convolutional neural networks to more complex geometries.
  • Previous research primarily examined its theoretical aspects but lacked practical numerical methods, particularly outside of two-dimensional settings.
  • This new work introduces diffusion map-based techniques for applying the transform to high-dimensional datasets, such as those found in single-cell genetics, demonstrating effectiveness in classifying signals and manifolds.
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Equal partitioning of the multi-copy 2-micron plasmid of the budding yeast Saccharomyces cerevisiae requires association of the plasmid Rep1 and Rep2 proteins with the plasmid STB partitioning locus. Determining how the Rep proteins contribute has been complicated by interactions between the components. Here, each Rep protein was expressed fused to the DNA-binding domain of the bacterial repressor protein LexA in yeast harboring a replication-competent plasmid that had LexA-binding sites but lacked STB.

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Equilibrium hard modeling of spectrophotometric titration data with binding parameters (ΔG° or logK values) involves nonlinear mathematical relationships and correlated experimental uncertainties. Therefore, uncertainty quantification techniques based on standard error computation substantially underestimate the true error for the calculated binding parameters. We show that the bootstrapping technique can provide accurate uncertainty quantification with no a priori knowledge of experimental error levels.

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The use of the budding yeast Saccharomyces cerevisiae as a model genetic organism has been facilitated by the availability of a wide range of yeast shuttle vectors, plasmids that can be propagated in Escherichia coli and also in yeast, where they are stably maintained at low- or high-copy number, depending on the plasmid system. Here we provide an introduction to the low-copy (ARS/CEN) and multi-copy (2-μm-based) plasmids, the marker genes commonly used for plasmid selection in yeast, methods for transforming yeast and monitoring plasmid inheritance, and tips for working with yeast transformants.

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Chronic obstructive pulmonary disease (COPD) is a complex disease and the management is focused on improving breathlessness, quality of life and healthcare utilisation. Our understanding of COPD phenotypes has improved in recent years and there is an increased drive towards delivering phenotype-based therapies. Lung volume reduction can offer the prospect of life changing benefit in breathlessness and quality of life in a select group of patients with severe emphysema already receiving maximum medical treatment.

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The yeast 2-μm plasmid is a remarkable genetic parasite, managing efficient maintenance at high-copy number with minimal impact on the host. Equal partitioning of the plasmid upon host cell division requires plasmid proteins Rep1 and Rep2 and the plasmid STB locus. The Rep proteins and the plasmid-encoded Raf protein also regulate plasmid gene transcription.

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Cyanoacrylate injection is a recognised endoscopic treatment option for variceal haemorrhage. We describe a 34-year old man with hepatitis B cirrhosis who presented to the hospital with upper gastrointestinal haemorrhage from gastric and oesophageal varices. Haemostasis was achieved via cyanoacrylate injection sclerotherapy and banding.

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The 2 microm circle plasmid confers no phenotype in wild-type Saccharomyces cerevisiae but in a nib1 mutant, an elevated plasmid copy number is associated with cell death. Complementation was used to identify nib1 as a mutant allele of the ULP1 gene that encodes a protease required for removal of a ubiquitin-like protein, Smt3/SUMO, from protein substrates. The nib1 mutation replaces conserved tryptophan 490 with leucine in the protease domain of Ulp1.

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The majority of chromosomes in Oreochromis niloticus, as with most fish karyotyped to date, cannot be individually identified owing to their small size. As a first step in establishing a physical map for this important aquaculture species of tilapia we have analyzed the location of the vertebrate telomeric repeat sequence, (TTAGGG)n, in O. niloticus.

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