Category Archives: Science in the News

From catnip to bug spray

Researchers from Iwate University in Japan have published a new paper that explains one aspect of the intriguing response cats have to catnip. The paper, published on June 14th 2022, shows that chewing catnip leaves maximize the release of organic compounds and repels insects. Tamako Miyazaki, who led the research, hopes that the work will pave the way for development of new insect repellants.

A photo of a domesticated cat eliciting a behavioral response to catnip. Source

Catnip is a non-toxic plant in the mint family and it has been long known to elicit several responses in cats. And, it’s not just domesticated cats that are affected, catnip induced behavior has been seen across the feline family including leopards, cougars, tigers, and lions.

Figure 1: Effect of leaf damage on the airborne emission of nepetalactone. Data adapted from Miyazaki et al.

The behavioral response which includes rolling, licking and chewing is seen in two thirds of all felines. The prevalence of these responses led Miyazaki and his team to believe there was a biological importance of the behavior.

Miyazaki and his group have previously identified nepetalactone as the compound responsible for triggering the behaviors.

Nepetalactone is a iridoid compound that is present in high concentration in several plant species including catnip. The group’s previous work, published in 2014, showed that nepetalactone had a strong insect repellant effect. The behavioral response of rolling resulted in the transfer of nepetalactone to the cats fur and provided protection from insect bites.

Following on from this study the team turned there attention to why cats are often seen chewing catnip. Considering that this behavior was also linked to insect repellence the team began by measuring the airborne emission of Nepetalactone from intact and manually damaged leaves. The manual damage was intended to simulate the effects that chewing had on the leaves.

The results, shown in figure 1, was a 20 fold increase in nepetalactone emission in the manually damaged group. When tested on mosquitos, the damaged leaves showed a much greater repellant effect than intact ones. The research group also found that leaf damage affected the cat’s response duration. On average, the studied cats responded to damaged leaves 6 minutes longer than were presented with intact leaves.

The researchers propose that chewing the catnip leaves is an important evolved response that maximizes the amount of airborne nepetalactone. When combined with rolling, the behavior maximizes the protective qualities of catnip and offers a significant benefit to cats.

The paper concludes that there maybe something to be learnt from catnip. Specifically, further studying into the structure and synthesis of nepetalactone may lead to new kinds of insect repellents. While more studies are needed to assess the effectiveness of such a use one thing for sure is that it would have the seal of approval from cats.

 

 

Artificial Snow at Beijing Winter Olympics

Beijing’s bid for the 2022 Winter Olympics relied solely on covering their cold-but-dry mountain venues, Yangqing and Zhangjiakou, with 100% artificial snow. 

Snow machines were essential to Beijing’s Olympic bid (Source: Wikimedia Commons)

For every cubic meter of snow produced, half a cubic meter of water was required, raising concerns about Beijing’s bid. 

Clean water is a scarcity in the northern region around Beijing and within the city itself. The region pumps in 70% of its water from southern China. 

In their bid, Beijing estimated 49 million gallons of water would be needed to maintain the slopes, but, in reality, 343 million gallons were turned into snow.

Snow machines mix and cool compressed air and water, releasing tiny balls of ice onto the slopes and compacting four times denser than natural snow. 

The presence of artificial snow has increased in the Winter Olympics. Artificial snow made up 80% of Sochi’s snow, 90% of Pyeongchang’s snow, and 100% of Beijing’s snow.

Figure 1. Water consumption estimates for artificial snow production at the past four Winter Olympics

In 1980, Lake Placid was the first Olympic venue to use artificial snow, but troubles with lack of snowfall are a recurring theme. In 1964, Austrian soldiers hauled 20,000 blocks of ice to prevent cancellation of the winter games. Vancouver, in addition to snow machines, transported snow with semi-trucks from higher to lower elevations of Cypress mountain.

Cross-country skier competing at the 2022 Beijing Winter Olympics (Source: Wikimedia Commons)

Skiers expressed concerns over artificial snow courses. The snow’s closer packing allows faster ski times but increases the likelihood of collisions. Athletes crash on snow that “feels like concrete”. In turn, the density allows for easy construction of ski and snowboard ramps.

A study found that, with global temperatures rising, only one of the past 21 Winter Olympic venues, would be able to provide natural snow by the 2080 games.

To keep the global athletic competition alive, fake snow will be the way to go.

-Julia Sawitsky

Breaking Down Plastic, One Worm at a Time

A 2022 study by Sanluis-Verdes et al. has found that wax worm saliva is able to break down plastic in just a few hours.

The researchers collected saliva from Galleria mellonella worms and applied it to polyethylene (PE) films. After a few hours, the films had visibly deteriorated and analysis of the films determined that the plastic had oxidized and released additives, evidence that it had degraded.

Credit: Catherine Sheila

Generally, plastics require decades or even centuries to completely degrade through natural exposure to the environment. Because of humanity’s high consumption of plastic, simply dumping them in landfills or waterways only leads to an accumulation that smothers habitats and leaks toxic substances into the soil and water.

This makes finding a safe and quick way of breaking down plastic crucial for sustainable waste management.

Scientists in recent years have been particularly interested in biodegradation, in which naturally-produced enzymes from bacteria, fungi, or animals are used to decompose plastic.

However, scientists have only identified a handful of enzymes that are capable of this, and these enzymes still require years to degrade plastic. They are unable to accomplish the first step of degradation – oxidizing the polymer – and still rely on exposure to UV light and other environmental factors to do it, which usually takes years.

Currently known process of plastic degradation. Credit: Rebecca Yang

Sanluis-Verdes et al.’s experiment demonstrated that the enzymes in wax worm saliva are in fact able to accomplish this crucial step under normal physiological conditions – room temperature, neutral pH, typical background levels of UV – in just a few hours rather than years. The researchers identified an increased presence of ketones in the PE after only applying the saliva a few times, proof that it had been oxidized by the enzymes alone. 

The researchers also tried to identify the enzymes responsible. They were able to pick out two enzymes in the saliva that had a significant effect on PE degradation. Until now, it was believed that bacteria in the gut of wax worms were primarily responsible for plastic degradation, but this discovery indicated that it was the wax worms themselves that oxidized and broke down PE enough for it to then be completely decomposed by bacteria. The researchers also noted that the two enzymes were functionally different from known bacterial enzymes. This suggests that there may be other methods of biodegradation than what is currently known for bacteria.

The exact mechanism will require further studies to determine. If this can be identified and if the enzymes involved can be easily extracted or mass produced, using the enzymes found in wax worms may become a feasible way to naturally and quickly manage plastic waste.

Blue Light – A Propagated Myth!

https://unsplash.com/photos/N7Bjz9vY67E

Unsplash Photo by Lukas Blaskevicius (Editorial, Technology) Unsplash

Device users are not a risk of eye damage due to blue light emitted from their devices, but they may be at risk of poorer sleep.

In 2019, Director Dr. David Ramsey of Ophthalmic Research at Lahey Massachusets Hospital and his study maintained that “many retail stores have ambient illumination twice as great…as [ones] iPhone, [and that] the sun yields illumination ten times greater!”

Light sources such as incandescence (light bulbs) and LEDs emit a broad spectrum of light, namely 400 to 700 nanometers (nm). Blue light is in the 400 to 450 nm range, carrying more energy than red light, raising concern. 

Our retinas regularly absorb blue light emitted by the sun. For roughly 300,000 years, humans have sustained minor to no retinal damage: if it were damaging, we would have evolved optically blind.

Device intensities are much less than the sun and are regulated by manufacturers using light filters. 

In 2019, CBC News conducted a Marketplace undercover investigation to debunk the concerns. In addition, Dr. SUNIR J. GARG, American Board Ophthalmologist and clinical researcher, addressed the myth.

“Why you don’t need blue light lenses: Hidden camera investigation (Marketplace)” A 2019 CBC Interview with Dr. SUNIR J. GARG, American Board Ophthalmologist, about why blue light glasses are unnecessary. Youtube

However, in the Harvard study, Dr. Ramsey adds that using devices late at night mimics sunlight, restraining melatonin production, a sleep-inducing hormone. This stimulates your circadian clock (your body’s 24-hour sleep clock), tending to delay your sleep cycles, disrupting your sleep, and increasing drowsiness the following morning. 

By stopping use of electronic devices 30 minutes before bed, you can increase REM (deep-stage sleep), reduce morning drowsiness, and maintain a consistent circadian rhythm, which in itself has its own benefits. 

In short, research before propagating a supposed “scientific claim” and reduce your screen time before bed.

~ Octavian Turner

Non-Hormonal Birth Control Pills for Males May Be Within Reach

Recently, scientists at the University of Minnesota found two promising compounds that may become the first non-hormonal contraceptive drugs for males. Testing on mice found that these compounds reduce sperm count effectively and present no side effects.

There are currently no non-hormonal birth control pills on the market for females or males, despite these pills likely having fewer harmful side effects than the hormonal birth control methods available for females.

And since males continuously generate sperm while females are born with all potentially fertile eggs, it is easier for scientists to find approaches that reversibly stops sperm production in males rather than risk “spoiling” the non-renewable pool of eggs in females.

Picture depicting the meeting of sperm and egg, which leads to fertilization and pregnancy. Image Credit: https://flic.kr/p/MCcsUf

The first potential drug discovered is a chemical named YCT529, reported by Dr. Gunda Georg’s group in spring 2022. This molecule was designed to inhibit the function of the protein retinoic acid receptor alpha (RAR-α). Georg’s scientists found that a lack of RAR-α protein in male mice leads to sterilization, but no additional side effects. When YCT529 was orally administered to the mice for 4 weeks, their sperm count reduced drastically, and the drug was 99% effective in preventing pregnancy.

Chemical structure of non-hormonal male contraceptive YCT529. Image Credit: Ying Cai

The same group of scientists reported the second drug named EF-4-177 in early 2023. The target of this molecule is an enzyme named cyclin-dependent kinase 2 (CDK2) which helps in sperm cell production. The scientists reported an over 45% decrease in sperm count of the mice after 28 days of treatment with EF-4-177.

Currently, a startup named YourChoice Therapeutics based in Berkeley, California is working to market YCT529 to humans soon. According to their website, the company has tested on dogs and primates with positive results. Their graphics show that after two weeks of treatment with YCT529, sperm levels in dogs drop to zero and primates do not produce enough sperm to be fertile.

If a side effect-free non-hormonal birth control pill for males is introduced to the public, it would expand contraceptive options for those with testicles beyond condoms and vasectomy. As well, it would make it easier for the responsibility of pregnancy prevention to be shared between partners in a relationship.

Hopefully, more research to come will soon make non-hormonal birth control pills for males a reality.

~ Ying Cai

Exposing the dark side of the skin-lightening industry

Minnesota Department of Health warns consumers to steer clear from skin-lightening products (SLPs). Their recent investigation on SLPs revealed dangerously high concentrations of unlisted ingredients that can harm users’ health.

 

Skin lightening refers to the practice of lightening complexion by reducing the skin’s natural pigment, melanin. Dermatologists prescribe patients products with low concentrations of active ingredients to treat certain pigmentary conditions and post-inflammatory hyperpigmentation. However, due to potential adverse complications, many countries either banned or strictly regulate these ingredients. 

 

Skin colour has long been the social-economic benchmark in many countries, predominantly in Asia-Pacific, where individuals often affiliate lighter complexions with attractiveness and more career opportunities. A survey of 667 participants revealed that appearing lighter was the most common reported reason for using SLPs, followed by to appear more attractive, regular skincare products, social influences, and others (Table 1).  

Figure 1: Summary of users’ reasons for using SLPs from 667 participants.

These growing demands created the lucrative business of SLPs, which was valued at US$8.8 billion in 2020. 

 

Unsurprisingly, most toxic SLPs remain accessible in local markets and promote on social media. Some go undercover by omitting harmful ingredients or using counterfeit labels. 

Hydroquinone, a potent SL agent for hyperpigmentation treatments, causes permanent blue-black facial discoloration (Figure 1) or skin thinning with high-dosage applications, said Dr. Desai, a board-certified dermatologist at the University of Texas Southwestern Medical Center.

Figure 2: Discolouration from long-term usage of hydroquinone-containing products. Source: Wikimedia

 

UK-based optometrists recently diagnosed three patients with corneal degeneration. This condition leads to a loss of vision over time, most likely from using hydroquinone-containing products for years, as the patients reported.

Corticosteroid, a widely-used topical steroid for skin inflammation conditions, is also a potent bleaching agent. Steroid-dependent reactions (SDR) are the tell-tale signs of chronic misuse of corticosteroids over an extended period (Figure 2). Rashes, skin sensitivity to sunlight, and infections occur when SDR patients withdraw from topical steroids. 

Figure 3: Steroid-Dependent Reactions. Source: Wikimedia

 

Mercury, another dominating ingredient in unregulated SLPs, inhibits melanin production to reveal a lighter complexion. The well-documented list from Pan American Health Organization on associated risks from mercury poisoning does not look so pretty. 

These risks range from multiple major organ failures – kidney, liver, etc. – to psychological issues – psychosis, depression, anxiety, and early-childhood development issues. 

Moreover, determining factors when assessing a patient’s health on the severity of mercury exposure include the product’s concentration, period of exposure, other compounds changing mercury’s chemical properties, etc. The complex nature of different coexisting factors raises another problem for proper diagnoses, as indicative symptoms of mercury poisoning may not always manifest equally.

While mainly mercury poisoning from SLPs occurs via skin absorption, inhalation of mercury vapours is not off-limit. Simply put, users put not only themselves at risk of mercury poisoning, but also the whole household. 

So how should buyers go on from here?

“Consumers should always check the ingredients of their skin creams, be suspicious of low prices which are likely to indicate the lotion is fake and potentially harmful, and never use a product containing hydroquinone,” said Simon Blackburn, chairman of Local Government Association’s Safer and Stronger Communities.

 

Ashlynn Nguyen

 

 

 

Laugh Your Way to Death…

You must have heard the saying that “laughter is the best medicine,” but did you know that in rare cases, it may cause your death? Prolonged and intense laughter has been documented by researchers from University of Birmingham and Oxford to cause various medical conditions and, in some instances, death. 

Throughout history, since ancient Greece, people have died because of intense and prolonged laughter. While today some scientists claim that the cause of death was inaccurately reported due to the limited medical knowledge.  Laughter cannot directly cause someone’s death except suffocation triggered by laughing while eating.

Laughter is often recommended for promoting overall well-being and reducing stress. However, a recent study by researchers from the University of Birmingham and Oxford highlights the potential adverse effects of excessive laughter, particularly in individuals with pre-existing medical conditions.

Light laughter has been shown to benefit the cardiovascular system. However, excessive laughter can raise blood pressure and put strain on the heart. This can be particularly dangerous for those with heart problems such as coronary artery disease or congestive heart failure (CHF) -occurs when the heart muscle doesn’t pump blood as well as it should-. Simply put, a diseased heart may not be able to tolerate the increased heart rate and pressure caused by intense laughter.

Picture 3: Heart

In addition, excessive laughter can put pressure on the chest muscles. Therefore, it can be dangerous for those with respiratory complications such as collapsed lungs-the overlap of lung tissues-. Laughing too hard for extended periods of time can also lead to hyperventilation, causing shortness of breath and, in rare cases, temporary loss of consciousness.

Experts think that having a pre-existing illness was likely a significant contributor to death caused by laughing. Additionally, while it is not lethal, laughing excessively for an extended period can lead to difficulty breathing or even death.

Keep in mind that continuous loud laughter can be dangerous, but that doesn’t mean you should stop laughing altogether. A good hearty laughs every day is indeed the elixir of life, but make sure the laugh-out-loud moments don’t take your breath away. 🙂

 

Carcinogen Detected in Dry Shampoo Products

Consumers and retail workers hurried to remove dry shampoo brands, such as Dove, Bed Head, and TRESemmé, from their shelves due to the detection of carcinogenic benzene. The recall, announced by Unilever on October 18, 2022, applies to more than 1.5 million units sold from January 2020 to October 2022.

Benzene structure (Source: Wikimedia Commons)

Benzene is a known human carcinogen, increasing the risk of leukemia and blood cancer in bone marrow.

Volcanoes and forest fires naturally introduce the compound into the environment, and we inhale low doses daily from human-related activities. The American Cancer Society recommends steering clear of second-hand smoke and car exhaust to decrease exposure.

Within weeks of the recall announcement, Valisure, an independent laboratory, submitted a Citizen Petition on Benzene in Dry Shampoo Products to the Food and Drug Administration (FDA).

Valisure sampled air contaminated with dry shampoo products, and 11 product batches from 3 different brands exhibited benzene levels ten times the FDA limit of 2 parts per million. The persistent high concentration of benzene after product use indicates possible short- and long-term effects.

Unilever’s independent study assured customers that the amount of benzene in the products was “not expected to cause adverse health consequences”. In contrast, Health Canada received calls describing incidents or injuries related to dry shampoo products. Typically, customer injuries were irritations or allergic reactions.

Aerosol products could be contaminating your air (Source: Robert Howie on flickr)

Nine months before Unilever’s recall, Proctor & Gamble removed Pantene, Aussie and Herbal Essence dry shampoo and conditioner sprays from stores. On July 14, 2021, Johnson & Johnson recalled five Aveeno and Neutrogena spray sunscreens.

Valisure submitted multiple other Citizen Petitions regarding benzene contamination in consumer products, including body sprays, hand sanitizers, anti-fungal sprays and antiperspirants.

Obviously, benzene in aerosol products is no longer an uncommon occurrence.

Consumers should opt for powders and lotions as often as possible…or risk another recall.

Julia Sawitsky

Exposing the dark side of the skin-lightening industry

Healthcare experts are warning consumers to steer clear from skin-lightening products (SLPs) for the safety of their health. The 2020 CNN investigation on SLPs revealed dangerously high concentrations of some unlisted ingredients that can have detrimental complications to their users.

Hydroquinone, a potent skin-lightening agent used for hyperpigmentation treatments, can cause permanent blue-black facial discoloration or skin thinning with high-dosage application, said Dr. Desai, a board-certified dermatologist at University of Texas Southwestern Medical Center. 

Figure 1: Blue-black discoloration from long-term usage of hydroquinone-containing products. Source: Taylor & Francis Online  

Recently, optometrists at two corneal clinics in the UK had diagnosed three patients with corneal degeneration – a condition which leads to a loss of vision overtime, most likely from using hydroquinone-containing products for the past 3 to 15 years.

Corticosteroid, the most popular topical steroid for skin-inflammation conditions, also has a very potent bleaching effect. Chronic misuse of corticosteroid over an extended period of time at any dosage results in steroid dependent reactions – rashes, increased skin sensitivity to sunlight, and infections occur when a patient discontinues using topical steroid. 

Figure 2: Topical Steroid Dependent Face (TSDF). Source: CNN

Mercury, another dominating ingredient in many unregulated skin-lightening products which inhibits the production of skin pigmentation to reveal a lighter complexion. And in a note from the Pan American Health Organization, the well-documented list of associated risks from mercury poisoning does not look so pretty. 

Prolonged exposure to mercury ranges from organ failures such as kidney, liver, brain, and eyes, to psychological issues such as psychosis, depression, anxiety, and early-childhood development issues. 

Moreover, the determining factors when assessing a patient’s health on the severity of mercury exposure include the product’s concentration, period of exposure, other compounds changing mercury’s chemical properties, etc.

Due to the complex nature of these different coexisting factors, indicative symptoms of mercury poisoning may not manifest in the same way, raising another problem for proper diagnoses.

While exposure to mercury from skin-lightening products is mainly through skin absorption, inhalation of mercury vapors is not off-limit. In other words, users of mercury-containing products put not only themselves at risk of mercury poisoning, but also the whole household. 

Skin lightening, or skin bleaching, refers to the practice of lightening skin tone by reducing skin’s natural pigments. Dermatologists may prescribe patients products containing these active ingredients at low concentration to treat certain pigmentary conditions and post-inflammatory hyperpigmentation. Due to potential adverse complications, many countries either banned or strictly regulate these ingredients. 

Not surprisingly, most toxic skin-lightening products remain accessible and promoted on many social media platforms or in local markets. Some even go undercovered by purposely mislabelling the ingredient list by omitting toxic ingredients or using counterfeit labels. 

So how should buyers go on from here?

“Consumers should always check the ingredients of their skin creams, be suspicious of very low prices which are likely to indicate the lotion is fake and potentially harmful, and never use a product containing hydroquinone”, said Simon Blackburn, chairman of Local Government Association’s Safer and Stronger Communities 

 

A Breakthrough in Nuclear Fusion

On December 5th 2022, scientists at the Lawrence Livermore National Laboratory (LLNL) in the United States successfully created the reaction that powers the sun – nuclear fusion ignition – for the first time in human history.

The announcement was made by the US Department of Energy on December 13th. Described as a “historic, first-of-its-kind” achievement, the event has excited the scientific community because of its potential as a clean energy source. 

Inside the LLNL’s National Ignition Facility, where the experiment took place. Credit: LLNL

To achieve ignition, the scientists had constructed “the world’s most energetic laser”, consisting of 192 powerful laser beams. This laser was used on a small canister containing the compounds deuterium and tritium, causing the compounds to fuse together. The reaction generated 3.15 megajoules of energy from an input of 2.05 megajoules, a markup of 54%. 

After over 60 years since researchers first began to study nuclear fusion, this result finally proved that controlled fusion that produces more energy than it consumes is possible.

Depiction of fusion: deuterium(D) and tritium(T) fuse to form the larger Helium(He) and release energy. Credit: US Department of Energy

Nuclear fusion is the process that allows the Sun to emit vast amounts of energy in the form of light and heat. It involves the joining of two atoms of a lighter element to form a heavier one, releasing energy in the process.

Compared to nuclear fission, which is how nuclear power plants generate energy, fusion is much more powerful. It is also much cleaner as it does not produce radioactive materials as a byproduct.

Because of this, many believe that nuclear fusion is a promising avenue for sustainable and eco-friendly energy in the future. However, there is still a long way to go until fusion can be viable for commercial use.

When asked to comment on the time needed, Kim Budil, the director of the LLNL, stated that “It’s probably two or three decades. Scaling from where we are today to what you would require for a power-generating plant is a pretty significant challenge.”

Director Kim Budil at the announcement of the achievement of ignition on December 13th, 2022. Credit: Mary Calvert/REUTERS

For the 8000 engineers, physicists, and chemists at the LLNL, this event is just the first step. Researchers will have to find ways to conduct nuclear fusion that are faster and cheaper, while also generating much more power. According to Budil, “What we need now is a scientific and investment strategy that allows us to make progress on all of these fronts simultaneously… [because] we need gain of a few hundred [megajoules] to make an energy system.”

Despite the many challenges ahead, Tim Luce, one of the leaders of the international fusion research project ITER, remains hopeful. “A result like this will bring increased interest in the progress of all types of fusion, so it should have a positive impact on fusion research in general,” he states.