Browse Articles

Exploring the Factors that Drive Coffee Ratings

Agarwal et al. | May 19, 2025

Exploring the Factors that Drive Coffee Ratings

This study explores the factors that influence coffee quality ratings using data from the Coffee Quality Institute. Through a regression model based on gradient descent, the authors aimed to predict coffee ratings (total cup points) and hypothesized that sweetness and the coffee producer would be the most influential factors.

Read More...

Cutibacterium acnes sequence space topology implicates recA and guaA as potential virulence factors

Bohdan et al. | May 01, 2025

<i>Cutibacterium acnes</i> sequence space topology implicates <i>recA</i> and <i>guaA</i> as potential virulence factors
Image credit: Bohdan and Platje 2025

Cutibacterium acnes is a bacterium believed to play an important role in the pathogenesis of common skin diseases such as acne vulgaris. Currently, acne is known to be associated with strains from the type IA1 and IC clades of C. acnes, while those from the type IA2, IB, II, and III phylogroups are associated with skin health. This is the first study to explore the sequence space of individual gene products of different C. acnes phylogroups. Our analysis compared the sequence space topology of virulence factors to proteins with unknown functions and housekeeping proteins. We hypothesized that sequence space features of virulence factors are different from housekeeping protein features, which potentially provides an avenue to deduce unknown proteins’ functions. This proposition should be confirmed based on further experimental outcomes. A notable similarity in the sequence spaces’ topological features of previously known as housekeeping proteins encoded by recA and guaA genes to ‘putative virulence’ genes camp2 and tly was observed. Our research suggests further investigation of recA and guaA’s potential virulence properties to better understand acne pathogenesis and develop more targeted acne treatments.

Read More...

Open string vibrato: does it exist?

Ge et al. | May 01, 2025

Open string vibrato: does it exist?
Image credit: Ge and Zhang 2025

Vibrato, defined as a rapid and subtle oscillation in pitch, is a technique that is commonly used by musicians to add expression and colour to notes. However, on stringed instruments, there are certain notes (open string notes) on which it is impossible to perform the technique. Without vibrato, they can sound angular and unpleasant, especially when juxtaposed against other notes played with vibrato. String players therefore use an alternative to achieve the same vibrato effect on the open string — a technique referred to as “open string vibrato”. While the technique is widely used, it is unknown how much of a physical effect it has on the sound waves produced, if any at all. The purpose of this study is to analyse open string vibrato using a statistical approach to provide evidence to characterize the physical effect of the technique, and then compare it to normal vibrato. We hypothesised that it would have a noticeable and measurable effect on the sound waves produced because of the technique’s widespread usage. To test this, notes, with and without either open string vibrato or normal vibrato, were recorded on the violin. We analyzed the audio recordings using a computational and statistical approach. The results of the study partially agreed with our hypothesis: while the technique has an observable physical effect on the sound waves, the effect is weaker than expected. We concluded that open string vibrato does work, but has quite a subtle effect, and thus should only be used when there is no other option.

Read More...