Blocking Enzyme’s Self-Destruction Process May Mitigate Age-Related Diseases (Medicine)

Penn researchers discovered a potential new way to maintain a key enzyme, SIRT1, tied to aging.

Stopping the cannibalistic behavior of a well-studied enzyme could be the key to new drugs to fight age-related diseases, according to a new study published online in Nature Cell Biology. For the first time, researchers in the Perelman School of Medicine at the University of Pennsylvania show how the self-eating cellular process known as autophagy is causing the SIRT1 enzyme, long known to play a role in longevity, to degrade over time in cells and tissue in mice. Identifying an enzymatic target is an important step that may lead to new or modified existing therapeutics.

“Blocking this pathway could be another potential approach to restore the level of SIRT1 in patients to help treat or prevent age-related organ and immune system decline,” said first author Lu Wang, PhD, a postdoctoral researcher in the lab of Shelly Berger, PhD, a professor of Cell and Developmental Biology in the Perelman School of Medicine and a professor of Biology in the School of Arts and Sciences at Penn. Berger also serves as senior author on the paper.

“The findings may be of most interest to the immune aging field, as autophagy’s role in SIRT1 in immune cells is a concept that hasn’t been shown before,” Wang added. “Exploiting this mechanism presents us with a new possibility of restoring immune function.”

Cells are like leaky faucets, dripping away levels of proteins and enzymes, such as SIRT1, as the body ages, which can lead to chronic diseases, organ decline, and weaker immune responses to infections. New ways to stop these leaks and replenish SIRT1 have been demonstrated, including by cardiovascular researchers at Penn Medicine, but this is the first study to show autophagy’s role in that degradation during senescence–a natural process in which cells stop creating new cells–and aging.

SIRT1 is crucial for cell metabolism and immune responses, researchers have known, and has been shown to extend lifespan when overexpressed.

To determine the mechanism of SIRT1 loss during senescence, the researchers first ruled out it was driven by mRNA synthesis and stability, important factors in the control of gene expression, using RNA sequencing techniques on mouse cells. Instead, through further experiments, they found that “knocking out” the autophagic protein Atg7 in senescent cells left SIRT1 levels in place, indicating the autophagic pathway, and not proteasomes–the other recycling factory of the body–played a role in the loss of the enzyme. Immunofluorescence staining also showed that another autophagy protein, LC3, drives the loss of SIRT1 in senescent cells and tissue.

Treating mice with various drugs further supported autophagy’s role. A proteasome inhibitor–which blocks the breakdown of proteins in the cell–failed to restore SIRT1 protein in senescent cells and tissue, while treatment with Lys05, an autophagy inhibitor, rescued the loss of SIRTI, supporting that the enzyme is degraded through lysosomes. Lysosomes are the “stomach” of cells that help break down larger waste materials.

To determine autophagy’s role in SIRT1 in immune cells, the researchers treated human donor CD8 T cells with low-dose Lys05 and a proteasome inhibitor, and found that only Lys05 increased SIRT1 levels. The results, the authors said, indicate that SIRT1 is degraded at least in part through the autophagy-lysosome pathway during T cell aging in humans–a mechanism that could inform the reprograming of aged immune cells.

Next, the researchers will further explore the LC3 and SIRT1 interaction in preclinical studies and better characterize the signaling pathway to block it.

“Stabilizing SIRT1 protein level by interrupting this interaction could be a new direction for the design of anti-aging compounds,” the authors said.

References: Xu, C., Wang, L., Fozouni, P. et al. SIRT1 is downregulated by autophagy in senescence and ageing. Nat Cell Biol (2020). https://doi.org/10.1038/s41556-020-00579-5 link: https://www.nature.com/articles/s41556-020-00579-5

Provided by University Of Pennsylvania

Many Ventilation Systems May Increase Risk Of COVID-19 Exposure (Medicine)

Ventilation systems in many modern office buildings, which are designed to keep temperatures comfortable and increase energy efficiency, may increase the risk of exposure to the coronavirus, particularly during the coming winter, according to research published in the Journal of Fluid Mechanics.

A team from the University of Cambridge found that widely-used ‘mixing ventilation’ systems, which are designed to keep conditions uniform in all parts of the room, disperse airborne contaminants evenly throughout the space. These contaminants may include droplets and aerosols, potentially containing viruses.

The research has highlighted the importance of good ventilation and mask-wearing in keeping the contaminant concentration to a minimum level and hence mitigating the risk of transmission of SARS-CoV-2, the virus that causes COVID-19.

The evidence increasingly indicates that the virus is spread primarily through larger droplets and smaller aerosols, which are expelled when we cough, sneeze, laugh, talk or breathe. In addition, the data available so far indicate that indoor transmission is far more common than outdoor transmission, which is likely due to increased exposure times and decreased dispersion rates for droplets and aerosols.

“As winter approaches in the northern hemisphere and people start spending more time inside, understanding the role of ventilation is critical to estimating the risk of contracting the virus and helping slow its spread,” said Professor Paul Linden from Cambridge’s Department of Applied Mathematics and Theoretical Physics (DAMTP), who led the research.

“While direct monitoring of droplets and aerosols in indoor spaces is difficult, we exhale carbon dioxide that can easily be measured and used as an indicator of the risk of infection. Small respiratory aerosols containing the virus are transported along with the carbon dioxide produced by breathing, and are carried around a room by ventilation flows. Insufficient ventilation can lead to high carbon dioxide concentration, which in turn could increase the risk of exposure to the virus.”

The team showed that airflow in rooms is complex and depends on the placement of vents, windows and doors, and on convective flows generated by heat emitted by people and equipment in a building. Other variables, such as people moving or talking, doors opening or closing, or changes in outdoor conditions for naturally ventilated buildings, affect these flows and consequently influence the risk of exposure to the virus.

Ventilation, whether driven by wind or heat generated within the building or by mechanical systems, works in one of two main modes. Mixing ventilation is the most common, where vents are placed to keep the air in a space well mixed so that temperature and contaminant concentrations are kept uniform throughout the space.

The second mode, displacement ventilation, has vents placed at the bottom and the top of a room, creating a cooler lower zone and a warmer upper zone, and warm air is extracted through the top part of the room. As our exhaled breath is also warm, most of it accumulates in the upper zone. Provided the interface between the zones is high enough, contaminated air can be extracted by the ventilation system rather than breathed in by someone else. The study suggests that when designed properly, displacement ventilation could reduce the risk of mixing and cross-contamination of breath, thereby mitigating the risk of exposure.

As climate change has accelerated since the middle of the last century, buildings have been built with energy efficiency in mind. Along with improved construction standards, this has led to buildings that are more airtight and more comfortable for the occupants. In the past few years however, reducing indoor air pollution levels has become the primary concern for designers of ventilation systems.

“These two concerns are related, but different, and there is tension between them, which has been highlighted during the pandemic,” said Dr Rajesh Bhagat, also from DAMTP. “Maximising ventilation, while at the same time keeping temperatures at a comfortable level without excessive energy consumption is a difficult balance to strike.”

In light of this, the Cambridge researchers took some of their earlier work on ventilation for efficiency and reinterpreted it for air quality, in order to determine the effects of ventilation on the distribution of airborne contaminants in a space.

“In order to model how the coronavirus or similar viruses spread indoors, you need to know where people’s breath goes when they exhale, and how that changes depending on ventilation,” said Linden. “Using these data, we can estimate the risk of catching the virus while indoors.”

The researchers explored a range of different modes of exhalation: nasal breathing, speaking and laughing, each both with and without a mask. By imaging the heat associated with the exhaled breath, they could see how it moves through the space in each case. If the person was moving around the room, the distribution of exhaled breath was markedly different as it became captured in their wake.

“You can see the change in temperature and density when someone breathes out warm air – it refracts the light and you can measure it,” said Bhagat. “When sitting still, humans give off heat, and since hot air rises, when you exhale, the breath rises and accumulates near the ceiling.”

Their results show that room flows are turbulent and can change dramatically depending on the movement of the occupants, the type of ventilation, the opening and closing of doors and, for naturally ventilated spaces, changes in outdoor conditions.

The researchers found that masks are effective at reducing the spread of exhaled breath, and therefore droplets.

“One thing we could clearly see is that one of the ways that masks work is by stopping the breath’s momentum,” said Linden. “While pretty much all masks will have a certain amount of leakage through the top and sides, it doesn’t matter that much, because slowing the momentum of any exhaled contaminants reduces the chance of any direct exchange of aerosols and droplets as the breath remains in the body’s thermal plume and is carried upwards towards the ceiling. Additionally, masks stop larger droplets, and a three-layered mask decreases the amount of those contaminants that are recirculated through the room by ventilation.”

The researchers found that laughing, in particular, creates a large disturbance, suggesting that if an infected person without a mask was laughing indoors, it would greatly increase the risk of transmission.

“Keep windows open and wear a mask appears to be the best advice,” said Linden. “Clearly that’s less of a problem in the summer months, but it’s a cause for concern in the winter months.”

The team are now working with the Department for Transport looking at the impacts of ventilation on aerosol transport in trains and with the Department for Education to assess risks in schools this coming winter.

References: Rajesh K. Bhagat et al. ‘Effects of ventilation on the indoor spread of COVID-19.’ Journal of Fluid Mechanics (2020). DOI: 10.1017/jfm.2020.720.

Provided by University Of Cambridge

New Method Developed To Help Scientists Understand How The Brain Processes Color (Neuroscience)

Through the development of new technology, University of Minnesota researchers have developed a method that allows scientists to understand how a fruit fly’s brain responds to seeing color. Prior to this, being able to determine how a brain responds to color was limited to humans and animals with slower visual systems. A fruit fly, when compared to a human, has a visual system that is five times faster. Some predatory insects see ten times faster than humans.

“If we can understand how seeing color affects the brain, we will be able to better understand how different animals react to certain stimuli,” said Trevor Wardill, the study’s lead author and assistant professor in the College of Biological Sciences. “In doing so, we will know what interests them most, how it impacts their behavior, and what advantages different color sensitivities may give to an individual’s or a species’ survival.”

Published in Scientific Reports, Wardill and Rachel Feord — a University of Cambridge Ph.D. student in Wardill’s laboratory — developed the new approach by:

• Developing a filter-based optics system for a two-photon microscope that divided the visible spectrum in a way that allowed the fruit flies to see light without interfering with the brain imaging by partnering Semrock, an optical filter manufacturer;
• Testing high-speed projectors and screen materials to identify a screen that maintained a near-constant brightness of each wavelength band at all points of the screen from UV to red light; and
• Producing transgenic fly strains of the fruit fly (Drosophila melanogaster) that differed in one or more of the following ways: screening pigment density, photoreceptor function and calcium activity indicator.

Through this, researchers developed a method that allows for a fly to be presented with more than 50 different types of high intensity wavelength bands across the visual spectrum, while allowing for simultaneous, uninterrupted brain imaging with maximum sensitivity (i.e., able to collect photons for the full imaging duty cycle) when compared to previous methods. As a result of this testing, they found strain-specific sensitivities to colors among the fruit flies, with orange-eyed flies exhibiting a decreased sensitivity to light in the blue range and increased sensitivity in the green range when compared to their red-eyed counterparts.

“This work brings us one step closer to understanding which neurons react to which colors, the next step toward understanding how color sensitivities affect behavior and what advantages, if any, it can give an individual or species,” said Wardill.

References: Rachael C. Feord et al, A novel setup for simultaneous two-photon functional imaging and precise spectral and spatial visual stimulation in Drosophila, Scientific Reports (2020). DOI: 10.1038/s41598-020-72673-5 link: http://dx.doi.org/10.1038/s41598-020-72673-5

Provided by University of Minnesota

It Was Matter Ejected From The Chicxulub Crater That Led To Impact Winter (Paleontology)

Shelby Lyons and colleagues in their study found that K-pg extinction event caused mainly by sedimentary carbon ejected from the impact crater, not from wildfires.

A large asteroid (~12 km in diameter) hit Earth 66 million years ago, likely causing the end-Cretaceous mass extinction. Credit: Southwest Research Institute/Don Davis

An asteroid impact in the Yucatán Peninsula set off a sequence of events that led to the Cretaceous–Paleogene (K–Pg) mass extinction of 76% species, including the nonavian dinosaurs. The impact hit a carbonate platform and released sulfate aerosols and dust into Earth’s upper atmosphere, which cooled and darkened the planet—a scenario known as an impact winter. Organic burn markers are observed in K–Pg boundary records globally, but their source is debated.

In this new effort, the researchers suggest that while some of the material in K–Pg boundary records is likely from such burnt material, most of it came from material ejected from the crater at the impact site.

The work involved analyzing sediment samples from within the Chicxulub crater and from other ocean sites near the crater. In their analysis, the researchers focused on polycyclic aromatic hydrocarbons (PAHs), which can provide evidence of a source of black carbon. In so doing, they found that characteristics of polycyclic aromatic hydrocarbons (PAHs) in the Chicxulub crater sediments and at two deep ocean sites indicate a fossil carbon source that experienced rapid heating, consistent with organic matter ejected during the formation of the crater. Furthermore, PAH size distributions proximal and distal to the crater indicate the ejected carbon was dispersed globally by atmospheric processes.

Molecular and charcoal evidence indicated wildfires were also present but more delayed and protracted and likely played a less acute role in biotic extinctions than previously suggested. Based on stratigraphy near the crater, between 7.5 × 10^14 and 2.5 × 10^15 g of black carbon was released from the target and ejected into the atmosphere, where it circulated the globe within a few hours. This carbon, together with sulfate aerosols and dust, initiated an impact winter and global darkening that curtailed photosynthesis and is widely considered to have caused the K–Pg mass extinction.

References: Shelby L. Lyons et al. Organic matter from the Chicxulub crater exacerbated the K–Pg impact winter, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2004596117 link: https://www.pnas.org/content/early/2020/09/22/2004596117

CXOGBS J175553.2-281633 Is A Cataclysmic Variable System (Astronomy)

Astronomers in their paper presented modeling of the long term optical light curve and radial velocity curve of the binary stellar system CXOGBS J175553.2-281633 which was first detected in X-rays in the Galactic Bulge Survey. They analyzed 7 years of optical I-band photometry from OGLE and found long term variations from year to year. These long term variations can be explained with either an accretion disk of changing shape or luminosity, or a spotted secondary star.

Optical photometry of CX137 phased at the best orbital period of P = 10.34488 h. Credit: Gomez et al., 2020.

The orbital period of the system was estimated to be 10.34488 hours, which is consistent with previous observations.

Their results suggested that CX137 is a CV with a secondary star of spectral type K7. Using the light curve synthesis code, they derive that the mass of the primary star was calculated to be some 0.83 solar masses, while the companion’s mass was estimated to be about 0.65 solar masses. The size of the secondary star is comparable to that of our sun and its effective temperature is around 4,000 K.

According to the paper, CX137 is located about 2,865 light years away from the Earth and its systemic velocity is 54 km/s. The astronomers added that space velocity of the system, with respect to the sun, is about 62 km/s. This is statistically consistent with other known CVs.

The authors of the study also attempted to estimate the accretion rate for CX137. They found that it may reach the value of up to 100 quadrillion g/s, taking into the account the system’s relatively high orbital inclination (about 63 degrees). The accretion rate in non-magnetic CVs is likely underestimated by a factor of ∼ 2 for systems with inclinations of > 60 deg. This would bring the accretion rate to M ∼ 10^17 g s-¹, closer to the M expected for a Roche Lobe filling subgiant with an orbital period of 10 hours.

From all their observations and results they classified the source as a cataclysmic variable star with a long orbital period.

References: Sebastian Gomez, Manuel A. P. Torres, Peter G. Jonker, Zuzanna Kostrzewa-Rutkowska, Theo F. J. van Grunsven, Andrzej Udalski, Robert I. Hynes, Craig O. Heinke, Thomas J. Maccarone, Ricardo Salinas, Jay Strader, “Dynamical Modeling of CXOGBS J175553.2-281633: A 10 Hour Long Orbital Period Cataclysmic Variable”, pp. 1-16, 2020. arXiv:2009.08983 [astro-ph.HE] arxiv.org/abs/2009.08983 link: https://arxiv.org/abs/2009.08983

These Hybrid Membranes Can Filter Radioactive Elements From Water (Material Science)

Nuclear medicine uses various radioactive compounds for the administration into patients to diagnose and treat diseases, which generates large amounts of radioactively contaminated water. Currently, radioactively contaminated hospital wastewater has to be stored until the contained radionuclides have sufficiently decayed because cost-effective and efficient removal technologies are not available. Similar considerations apply in the nuclear power industry, with, however, decay times of the radionuclides several orders of magnitude higher.

Previously, Sreenath Bolisetty and colleagues reported hybrid membranes composed of amyloid fibrils produced from cheap and readily available proteins and activated carbon, which efficiently removed heavy metal ions and radioactive compounds from water. Now in their new study, they showed that these membranes are highly efficient in the adsorption & removal of diverse, clinically relevant radioactive compounds from hospital wastewater by single-step filtration.

The radionuclides technetium (Tc-99m), iodine (I-123) and gallium (Ga-68) can be removed from water with efficiencies above 99.8% in one single step. They also demonstrated the purification of a real clinical wastewater sample from a Swiss hospital containing iodine (I-131) and lutetium (Lu-177). With the use of single-photon emission computed tomography (SPECT) and positron emission tomography (PET), they were able to visualize the accumulation of the radioactive compounds within the membrane and demonstrate its outstanding performance.

By converting large volumes of radioactive wastewater into low volumes of solid radioactive waste, they concluded that the present technology can emerges as a possible game-changer in the treatment of nuclear wastewater.

References: Sreenath Bolisetty et al, Amyloid hybrid membranes for removal of clinical and nuclear radioactive wastewater, Environmental Science: Water Research & Technology (2020). DOI: 10.1039/D0EW00693A

Scientists Observed “Nutation” In Magnetic Materials For The First time (Physics)

Much of the ‘memory’ of the world and all our digital activities are based on media, hard disks, where the information is encoded thanks to magnetism, by orienting the spin of electrons in one direction or the opposite.

An international team of scientists has managed for the first time to observe the ‘nutation’ of spins in magnetic materials (the oscillations of their axis during precession). The measured nutation period was of the order of one picosecond. The discovery was published by Nature Physics Credit: Dunia Maccagni

An international team of scientists led by the Italian physicist Stefano Bonetti, professor at Ca’ Foscari University of Venice and the Stockholm University, has managed for the first time to observe the ‘nutation’ of these spins in magnetic materials, i.e. the oscillations of their axis during precession. The measured nutation period was of the order of one picosecond: one thousandth of a billionth of a second. The discovery was published by Nature Physics.

The axis of a spin performs nutation and precession, as with any object that revolves, from spinning tops to planets. In this research, physicists observed experimentally that the nutation of the magnetic spin axis is 1000 times faster than precession, a curiously similar ratio to that of Earth.

This new discovery on hitherto unknown physical characteristics of spins is fundamental in research to make digital technologies ever faster, compact and energetically efficient. To manipulate these phenomena at time scales of thousandths of billionths of a second, however, we first need to know their dynamics, including inertial dynamics.

“This is the first direct and experimental evidence of the inertial movements of magnetic spins,” explains Stefano Bonetti, who coordinates an ERC project on ultrafast magnetism, “with implications that affect, for example, data centres that store almost all of humanity’s digital information in bits with the north pole up or down, thus encoding the computer 0s and 1s. When these spins are reversed to write information, precession and nutation also come into play. Knowing the nutation period becomes essential as the rotation speed increases. This first observation of these movements paves the way for new technologies to improve the efficiency of our digital activities, which, among all human activities, are recording the highest increase in energy consumption.”

The experiment The experiment required collaboration with several European scientific laboratories in Germany (Helmholtz-Zentrum Dresden-Rossendorf, Chemnitz University of Technology, University of Duisburg-Essen, German Aerospace Center (DLR), TU Berlin) France (École Polytechnique) and Italy (Federico II University of Naples and ‘Parthenope’ University of Naples), with the key measurement made in the Helmholtz Research Centre in Dresden-Rossendorf, German. In this centre, the TELBE laboratory is capable of generating the intense terahertz radiation (i.e. the frequency range between microwaves and infrared) necessary for the experiment. The group led by Stefano Bonetti was among the first groups to use this laboratory and helped develop the actual machine.

“The first experiments were challenging,” says the Ca’ Foscari physicist, “but, after a couple of years, the machine was already operating at very high performance. These measurements were made over a year, on three different occasions, to check the reproducibility of this never-before observed effect.”

Stefano Bonetti’s activities are part of a broader context of investment by the Venetian university in scientific research and teaching of the Department of Molecular Sciences and Nanosystems. Starting from this academic year, this department is launching a degree programme in Engineering Physics, coordinated by Bonetti, himself a physics engineer: “Science is always evolving, and who knows what we will be exploring ten years from now, but the idea of the new degree programme is precisely to prepare a new generation of scientists who will be ready for the challenges of the future.”

References: Neeraj, K., Awari, N., Kovalev, S. et al. Inertial spin dynamics in ferromagnets. Nat. Phys. (2020). https://doi.org/10.1038/s41567-020-01040-y link: https://www.nature.com/articles/s41567-020-01040-y

Provided by Università Ca’ Foscari Venezia

Higuchi Discovered Second Alignment Plane of Solar System (Astronomy)

A study of comet motions indicates that the Solar System has a second alignment plane. Analytical investigation of the orbits of long-period comets shows that the aphelia of the comets, the point where they are farthest from the Sun, tend to fall close to either the well-known ecliptic plane where the planets reside or a newly discovered “empty ecliptic.” This has important implications for models of how comets originally formed in the Solar System.

Artist’s impression of the distribution of long-period comets. The converging lines represent the paths of the comets. The ecliptic plane is shown in yellow and the empty ecliptic is shown in blue. The background grid represents the plane of the Galactic disk. (Credit: NAOJ)

In the Solar System, the planets and most other bodies move in roughly the same orbital plane, known as the ecliptic, but there are exceptions such as comets. Comets, especially long-period comets taking tens-of-thousands of years to complete each orbit, are not confined to the area near the ecliptic; they are seen coming and going in various directions.

Models of Solar System formation suggest that even long-period comets originally formed near the ecliptic and were later scattered into the orbits observed today through gravitational interactions, most notably with the gas giant planets. But even with planetary scattering, the comet’s aphelion, the point where it is farthest from the Sun, should remain near the ecliptic. Other, external forces are needed to explain the observed distribution. The Solar System does not exist in isolation; the gravitational field of the Milky Way Galaxy in which the Solar System resides also exerts a small but non-negligible influence. Arika Higuchi, an assistant professor at the University of Occupational and Environmental Health in Japan and previously a member of the NAOJ RISE Project, studied the effects of the Galactic gravity on long-period comets through analytical investigation of the equations governing orbital motion. She showed that when the Galactic gravity is taken into account, the aphelia of long-period comets tend to collect around two planes. First the well-known ecliptic, but also a second “empty ecliptic.” The ecliptic is inclined with respect to the disk of the Milky Way by about 60 degrees. The empty ecliptic is also inclined by 60 degrees, but in the opposite direction. Higuchi calls this the “empty ecliptic” based on mathematical nomenclature and because initially it contains no objects, only later being populated with scattered comets.

Higuchi confirmed her predictions by cross-checking with numerical computations carried out in part on the PC Cluster at the Center for Computational Astrophysics of NAOJ. Comparing the analytical and computational results to the data for long-period comets listed in NASA’s JPL Small Body Database showed that the distribution has two peaks, near the ecliptic and empty ecliptic as predicted. This is a strong indication that the formation models are correct and long-period comets formed on the ecliptic. However, Higuchi cautions, “The sharp peaks are not exactly at the ecliptic or empty ecliptic planes, but near them. An investigation of the distribution of observed small bodies has to include many factors. Detailed examination of the distribution of long-period comets will be our future work. The all-sky survey project known as the Legacy Survey of Space and Time (LSST) will provide valuable information for this study.”

References: Arika Higuchi, “Anisotropy of Long-period Comets Explained by Their Formation Process”, The Astronomical Journal, Volume 160, Number 3, 2020 link: https://iopscience.iop.org/article/10.3847/1538-3881/aba94d

Provided by National Astronomical Observatory of Japan

High Noise Levels Can Decrease The Food Liking (Food)

Previous studies have shown that background noise can affect the liking of food. However, little is known about the liking of food in the presence of different background noise types and levels. Now, Mahmoud A. Alamir and colleagues in their paper investigated food liking, relative to the background noise in the room (i.e. no noise conditions), for three background noise types (relaxing music, road traffic noise and restaurant noise) and three noise levels (30, 40 and 50 dBA).

©gettyimages

Fifteen participants rated liking of food using an 11-point Likert scale. Dose-response relationships of food liking in the presence of different background noise types and levels were presented.

The results indicated that the type of background noise affected the liking of food (F(2, 97) = 134, p < 0.001). The increase in the level of the noise also decreased the liking of food regardless of the noise type (F(2, 77) = 41, p < 0.001). Relaxing music increased the liking of food at 30 and 40 dBA relative to the background noise in the room (i.e. no noise condition) by (mean ± SE) 60 ± 10 and 38 ± 10%, respectively. Restaurant noise and road traffic noise decreased the liking of food at all levels, compared to the background noise in the room (p < 0.001).

Their findings can help identify and quantify types and levels of background noise that can increase the enjoyment of food. These results could also be helpful in choosing and designing dining areas with background noise that increase food enjoyment.

References: Mahmoud A. Alamir, Kristy Hansen, “The effect of type and level of background noise on food liking: A laboratory non-focused listening test”, Applied Acoustics, Volume 172, 15 January 2021, 107600 doi: https://doi.org/10.1016/j.apacoust.2020.107600 link: https://www.sciencedirect.com/science/article/abs/pii/S0003682X20307040?via%3Dihub