This study examines the higher harmonics in an oscillating string by analyzing the sound produced by a guitar with a spectrum analyzer. The authors mathematically hypothesized that the higher harmonics in the series of the directly excited 2nd harmonic contain the alternate frequencies of the fundamental series, the higher harmonics of the directly excited 3rd harmonic series contain every third frequency of fundamental series, and so on. To test the hypotheses, they enforced artificial nodes to excite the 2nd, 3rd, and 4th harmonics directly, and analyzed the resulting spectrum to verify the mathematical hypothesis. The data analysis corroborates both hypotheses.
Algal overgrowth often threatens to clog irrigation pipes and drinking water lines when left unchecked, as well as releasing possible toxins that threaten plant and human health. It is thus important to find natural, non-harmful agents that can decrease algal growth without threatening the health of plants and humans. In this paper, the authors test the efficacy of barely extract in either liquid or pellet form in decreasing algal growth. While their results were inconclusive, the experimental set-up allows them to investigate a wider range of agents as anti-algal treatments that could potentially be adopted on a wider scale.
One largely untapped source of clean energy is the use of osmotic gradients where freshwater and saltwater are mixed, for example at estuaries. To harness such energy, charge-selective membranes are needed to separate the anions and cations in saltwater, establishing an electric potential like a battery. The objective of this study was twofold: to investigate the creation of the polymer matrix and test the properties of boron nitride nanotubes, as both are essential in the creation of an ion-selective membrane. Out of three polymer samples tested in this study, the mixture known as Soltech 704 showed the best resistance to etching, as well as the highest UV cure rate.
This study sought to determine if there is an association between the single nucleotide polymorphism rs7528684 of the Fc receptor-like-3 (FCRL3) gene and asthma or allergic rhinitis (AR). Based on previous studies in an Asian population, we hypothesized that participants with an AA genotype of FCRL3 would be more likely to have asthma and/or allergic rhinitis. To test the hypothesis, surveys were administered to participants, and genotyping was performed on spit samples via PCR, restriction digest, and gel electrophoresis.
The current five-year survival rate of metastasized prostate cancer is only 30% and occurs in every one in nine men. Researchers have shown that people with a type of dwarfism called Laron’s Syndrome are immune to cancer due to their low levels of insulin-like growth factor-1 (IGF-1). For this reason, experimentally modifying the level of IGF-1 could provide better insight into whether lowering the levels of IGF-1 in prostate cancer cell lines (e.g. PC-3) could be an effective treatment to reduce their rates of proliferation and migration and increase apoptosis. We selected three compounds, which researchers have shown decrease IGF-1 levels, to test and combine to determine which is the most promising.
Physical therapy, especially for patients with spinal cord injuries, can be a difficult and tedious experience. This can result in negative health outcomes, such as patients dropping out of physical therapy or developing additional health problems. In this study, the authors develop and test a potential solution to these challenges: a mixed reality game called Skyfarer that replaces a standard physical therapy regimen with an immersive experience that can be shared with their friends and family. The findings of this study suggest that mixed reality games such as Skyfarer could be effective alternatives to conventional physical therapy.
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.
This study investigates the presence of alkaloids in a variety of medicinal plants using the Marquis reagent. They reveal some surprising results and how useful the Marquis reagent is.
Oligodendrocytes are specialized brain cells that can change to cells that produce myelin and protect nerves. This study investigates the capacity for different extracellular matrix cues to induce this effect in culture.
One common age-related health problem is the loss of bone mineral density (BMD), which can lead to a variety of negative health outcomes, including increased risk of spinal fracture. In this study, the authors investigate risk factors that may be predictive of an individual's risk of spinal fracture. Their findings provide valuable information that clinicians can use in patient evaluations.
