Category Archives: Uncategorized

Eat with your… Environment?

We have all heard about eating with our eyes first, but no one ever talks about how our environment affects our meals. Mother Nature Network (MNN) indicate that your environment plays big factor in your perception of food. Whether it’s lighting, furniture, or noise, they all play a role.

Figure 1 – Chocolate Ice Cream Retrived from: HandletheHeat

This study published in October 2019 explored temporal changes in how chocolate ice cream was perceived when eaten at different locations. Each participant had their electrophysisological properties, emotions, and temporal changes in flavour monitored, with 5 minute breaks inbetween each measurement. The participants were randomly assigned different environments such as a university study area, a bus stop, a cafe, or a sensory testing laboratory.

Figure 2 – The 4 locations in which tests were conducted. A – Sensory testing laboratory B – University study area C – Bus stop D – Cafe Retrieved from: Figure 2 of Xu et al.

Electrophysiological Responses

3 electrophysiological responses were measured, including skin conductance (SC), blood volume pulse (BVP), and heart rate (HR). They found that SC and HR was significantly influenced by different environments. Using the Tukey-Kramer test, they found that eating chocolate ice cream in the study space compared to the laboratory significantly increases SC (F(3,156) = 3.149, p < 0.05). Furthermore, the HR was significantly lower after consumption in the study area compared to a bus stop (F(3,156) = 2.673, p < 0.05).

Figure 3 – Electrophysiological response measurements. n= 160 (50 males/110 females) Retrieved from: Figure 10 Xu et al.

Emotional Response

In a pilot study, the emotional responses were reported among 97 individuals. Positive emotions were noted such as happiness, cheerfulness, and joy. In addition, negative emotions were noted as well, such as tenseness, unhappiness, and anxiousness. Using a Cochran Q-test, they found that a significant number of negative emotions were associated with the bus stop compared to the other 3 environments. Furthermore, a significant number of positive emotions were expressed after consuming chocolate ice cream at a cafe or university compared to a bus stop.

Figure 4 – Both positive and negative emotions associated with eating chocolate ice cream in 4 different environments. Data adapted from: Xu et al.

Taste

The dominance of different attributes were measured and converted to a percentage of time it spent as a dominant factor. Sweetness the dominant attribute across all environments (46% lab, 33% university, 48% cafe, 38% bus stop). Interestingly, the dominance of sweetness subsided overtime, and other attributes became dominant. Other factors such as creaminess, roastedness, and bitterness was noted as well. At the bus stop, bitterness became the most dominant factor after sweetness, while the other 3 locations reported either creaminess, cocoa, or vanilla flavours were dominant.

How do I improve my next meal?

Next time you’re at the dinner table, try some of these tricks to improve the taste of your meal. By listening to higher pitched music, sour and sweet flavours are highlighted, while lower pitched music enhances bitter flavours. Even something as simple as the way food is arranged on the plate will impact its flavour.

-Jackson Kuan

LEGO: Is it more than just a kids toy?

With everyone staying at home due to recent events, a common struggle is finding ways to pass the time. You remember having a box of LEGO bricks lying around, but you think to yourself “Building with LEGO? Nah, that’s just a kid’s toy!”. However, LEGO bricks are more than just a construction toy, they are also a technological marvel both in manufacturing and function.

The LEGO group first patented their iconic LEGO brick design in 1958 in Billund, Denmark. Modern LEGO bricks are made of ABS plastic, a copolymer of acrylonitrile, 1,3-butadiene and styrene, which is formed into its distinct brick-like shape using the injection molding process.  The molds are designed to produce LEGO pieces accurate to up to five-thousandth of a millimeter (0.005 mm), which is around half the thickness of a human hair. This results in a piece defect rate of 0.0018%. In other words, the LEGO manufacturing process produces 18 defective pieces out of every 1 million total pieces produced.

Left to right: Structures of styrene, acrylonitrile and 1,3-butadiene, the main components that make up the plastic used to make LEGO bricks. Source: Sigma-Aldrich

LEGO bricks have become an iconic construction toy due to the endless building possibilities they present. LEGO bricks are connected together through round nubs on top of the brick, known as studs, to tube-based cavities on the bottom of the brick. For instance, six LEGO bricks that are two studs wide by four studs long, commonly referred to as a 2×4 brick, can be combined in 915,103,765 unique ways. This number was determined computationally by mathematics professor  Søren Eilers from the University of Copenhagen in 2005.

(Photo credit: Mark Rubinchik)

Although a LEGO brick may seem like a simple piece of plastic, there is a lot more to it than meets the eye. Next time you’re looking for something to do, why not pull out some LEGO and see how many combinations you can make!

-Mark Rubinchik

Vaccination and Herd Immunity

Herd immunity is often generated through vaccination or widespread infection. For the current Covid-19 pandemic, many scientists and experts advocate social distancing to avoid overwhelming hospitals while buying more time for the inventions of vaccines and treatments. Why is vaccination favored by scientists and medical experts than a widespread infection? How is herd immunity achieved through vaccination?

What is herd immunity?

Herd immunity refers to a means of protecting a whole community from disease by immunizing a critical portion of its populace. Vaccination protects the vaccinated person but also the people who are not immunized. However, to achieve herd immunity, we need a certain percentage of people in a community to be vaccinated.

Herd immunity, the result of a high immunization rate. Source: The National Institute of Allergy and Infectious Disease (NIAID)

To reach the herd immunity threshold, different vaccination coverages which depend on the basic reproduction number (Ro) are required. Vaccination coverage is the estimated percentage of people who have received specific vaccines. For example, measles, a highly contagious virus, has a Ro value between 12 and 18. This high Ro value calls for a high vaccine coverage which is 92-94%. In other words, to reach the herd immunity threshold, at least 92% of the population needs to be vaccinated.

The higher the vaccine coverage the better…

Does it mean that measles will die out as long as 92% of the population is vaccinated against measles? The answer is no. Dr. Plans-Rubio, an epidemiology expert in Europe, found a significant negative correlation (P<0.05) between the incidence of measles in 2017–2018 in different countries of the European Union and measles vaccination coverage with herd immunity levels in the target measles vaccination population during 2015–2017. According to Dr. Plans-Rubio, low percentages of measles vaccination coverage with two doses of vaccine and the resulting low herd immunity levels explained measles incidence and persistence of measles in the European Union in 2017-2018. To eliminate the measles virus in the European Union, W.H.O must improve routine measles vaccination coverage and conduct supplementary measles vaccination campaigns.

Linear correlation coefficient p
Coverage with two doses of measles vaccine − 0.533 0.003
Coverage with one dose of measles vaccine 0.523 0.004
Coverage with first dose of measles vaccine − 0.332 0.079
Coverage with second dose of measles vaccine − 0.559 0.002
Prevalence of individuals with vaccine-induced measles protection (Iv) − 0.580 0.001
Herd immunity gap (94.5 − Iv)a − 0.580 0.001

(Table source: European Journal of Clinical Microbiology & Infectious Diseases)

Relating to Covid-19 pandemic

Without measles vaccines, we would not have lowered the mortality rate of measles and reached herd immunity in most countries. The novel coronavirus, similar to measles, is also contagious. To lower the mortality rate of Covid-19 and reach herd immunity, the corresponding vaccine is required. Hence, every single one of us should practice social distancing to avoid overwhelming our healthcare system while scientists strive to invent the corresponding vaccine.

 

Reference:

Plans-Rubio Pedro. Low percentages of measles vaccination coverage with two doses of vaccine and low herd immunity levels explain measles incidence and persistence of measles in the European Union in 2017–2018. European Journal of Clinical Microbiology & Infectious Diseases, 2019; 38, 1719-1729. DOI: https://link-springer-com.ezproxy.library.ubc.ca/article/10.1007%2Fs10096-019-03604-0#Sec2

-Pricia

Global Warming Continues to Climb: The Pressure of Heat Stress Rises Just as Quickly

Every year the days continue to get hotter and it’s becoming very noticeable and soon it will become unbearable. As time moves forward, the effects of global warming continue to only get worse. With CO2 levels rising with no sign of slowing down, global average temperatures will rise with it. First introduced in 1975 by Wally Broecker, it has been noted that average global temperatures have rapidly been increasing since the early 1900s. Eventually the temperatures will become more than simply uncomfortable and will reach hazardous levels.

Figure 1: History of global surface temperature since 1880. Source

According to this research published in the journal Environmental Research Letters by Li et al. the result of increasing temperatures will result in an increase in cases of heat stress. Worst case scenario It could affect more than 1.2 billion people annually by 2100. That is potentially 4 times the number of people affected by heat stress presently.“Every bit of global warming makes hot, humid days more frequent and intense. In New York City, for example, the hottest, most humid day in a typical year already occurs about 11 times more frequently than it would have in the 19th century,” said lead author Dawei Li

Heat stress is caused by the body’s inability to cool down properly through sweating. This can cause body temperatures to rise rapidly with high temperatures damaging the brain and other vital organs. Various forms of heat stress include (in order from mild to extreme conditions): heat rash, heat cramps, heat exhaustion, and heat stroke. Without emergency treatment, heatstroke can cause permanent disability or even death.

Figure 2: Projected changes in global average temperature under four emission pathways. Source

Annual exposure to extreme heat and humidity are projected to affect areas currently home to about 500 million people if the planet heats 1.5°C and nearly 800 million with 2°C. The planet has already warmed by about 1.2°C above late 19th century levels.

An estimated 1.2 billion people would be affected with 3°C of warming, as expected by the end of this century under current conditions.

-Adrian Emata

Biodegradable, what does it really mean?

Plastic pollution is one of the major issues effecting the marine environment today.

A study published on February 13 2015 by Science investigated the input of plastic into the oceans from land. Using worldwide data, the study estimated that 192 coastal countries generated 275 million metric tons (MT) of plastic waste in 2010 alone, with 4.8-12.7 million MT of that waste entering the ocean.

Marine debris that was washed ashore covers a beach on Laysan Island in the Hawaiian Islands National Wildlife Refuge. (Susan White/USFWS)

What is bioplastic?

Bioplastics are plastics that are partially made of biological materials like wheat, maize, and tapioca.  Being made of biological material does not mean that bioplastics can be broken down by fungi and bacteria. Essentially, being bioplastic does not necessarily mean that the material is truly biodegradable.

Examples of non-biodegradable bioplastics include bio-based Polyethylene terephthalate and Polyethylene which make up everyday items such as bottles and carry bags.

There are bioplastics that can degrade in the environment, given specific conditions. For example, Kale et al. published a study in 2007 that investigated the biodegradation of polylactide bottles. The study found these bottles degrade after 30 days when buried in soil, at relatively high temperatures.

What is biodegradable plastic?

The definition of biodegradable is the break down of substances into inorganic materials, such as water and oxygen.

“This word ‘biodegradable’ has become very attractive to people trying to make quick bucks on it,” explains Ramani Narayan, a professor of Chemical and Biochemical Engineering at Michigan State University, who helped develop biodegradable corn-based plastic.

Typically, companies make plastics that degrade into smaller particles faster and then claim that they are ‘biodegradable’ says Narayan. Figure 2 shows the relative rates of degradation of various materials. Even though they are claimed to be biodegradable, they still take large amounts of time to degrade into smaller particles – which are no better for the environment.

Figure 2: Image depicting the relative rates of degradation for various materials. Obtained from creative commons.

Why does this matter?

The general public does not know the difference between bioplastics and biodegradable plastics. They also do not know that companies use the term ‘biodegradable’ lightly – and just because plastics claim to be biodegradable does not mean they actually are. This would cause people to assume that using and disposing of bio- and biodegradable plastics is safe for the environment, when that is not the case.

This discarded plastic would eventually find its way into the ocean, further increasing the plastic pollution in the marine environment. Plastic debris in the ocean is known to increase the rate of ingestion, suffocation and entanglement of hundreds of marine species – often resulting in death.

It is important to know the distinction between bio- and biodegradable when using plastics, such that they can be disposed/recycled in the appropriate manner.

The easiest solution would be to minimize your plastic use entirely, to reduce the rate of plastics entering the ocean and reduce the endangering of wildlife.

 

-Chantell Jansz

What is N95? ——The knowledge about face masks

Facing the outbreak of the new coronavirus, all kinds of face masks were sold out in the blink of an eye. More and more people seem to start to realize the importance of face masks.  But, do face masks really work? and how they work?

The answer largely depends on what type of face mask you are wearing.

Classification of Face Masks

According to the design of the face masks, the general ranking of the protective ability is (high to low): N95 masks> surgical masks> ordinary medical masks> ordinary cotton masks. But in the case of the new coronavirus, the most effective type of face masks are medical-surgical masks and masks filtering 95% or more of non-oily particles, such as N95, KN95, DS2, FFP2, etc. At present, China’s medical face masks are mainly divided into three types: medical protective masks with the highest protection level, medical-surgical masks commonly used in invasive operating environments such as operating rooms, and ordinary disposable medical masks.

 

How Face Masks Work?

Usually, medical face masks are made of non-woven fabrics, and its raw materials are mainly Polypropylene. And polypropylene layers are arranged to form an SMS structure.

SMS structure makes face masks capable to block floating particles while allowing airflow in and out the face masks. In this structure, the key material that brings the virus filtering effect is a high density, electrostatic layer lies in the middle: melt-blown non-woven fabric. When small particles like viruses get close to the melt-blown nonwoven fabric, it will be immediately captured by the electrostatic field and adsorbed on the surface of the non-woven fabric, and therefore prevent the virus gets into the body.
Yicheng Zhu

Calculating Decay Rates for Double-Proton Emission

Double-proton emission has motivated great interests in nuclear and radiochemistry due to its extremely rare occurrence. This decay mode first appeared only as a prediction from theories on nucleon pairing; it involves the simultaneous emission of two protons in proton-very-rich nuclei, where competing single-proton emission is quantum-mechanically forbidden. Since 2002, double proton-emission was observed in experiments, but they still lacked a coherent and accurate theoretical framework.

Double-Proton Emission (made with blender/photoshop)

The group of researchers led by M. Goncalves have recently calculated the decay rate for double-proton emission, filling the missing theoretical gap. The rate of decay is fundamental to the quantification of nuclear reactions; theoretical decay rates from this research will provide the basis for future double-proton reaction designs.

Nucleons are massive and inert to physical conditions, thus nuclear reactions are only quantified statistically using special relativity and quantum mechanics. To tackle this, the researchers used the effective liquid drop model, widely used in alpha decay and cold fission calculations. This model assumes that nucleons interact with each other like particles in a droplet of water.

Liquid Drop Model
(Source:People’s University, Bhopal)

From known values of mass excess, coulomb’s barrier, and dimensional parameters, the researchers calculated the double-proton emission half-life for nuclides mass below 70u. The log of half-life is then plotted against parameter q, derived from the decay energy of each nuclide.

The available experimental double-proton emission half-lives for 16Ne, 19Mg, 45Fe, 48Ni, 54Zn and 67Kr are then plotted on the graph. The experimental values matched closely with the theoretical calculations, except 16Ne; a possible explanation for the deviation may be its mass number away from nuclear magic numbers.

When not using a log variable, the differences between experimental and

theoretical values seem significant. Nevertheless, in the field of nuclear science, this scale of difference is already near-perfection; even the best models such as SEME shows a deviation above 4-times for nuclear binding energy calculations.

Is the World Set to Run Out of Cobalt?

Cobalt is an important part of most batteries, and our global supply is running low. The demand of cobalt in the next 10 years is expected to increase by roughly 300%, and a team of researchers from the Massachusetts Institute of Technology decided to investigate exactly how much of a problem this increased demand could be.

Lithium-ion batteries, such as the ones found in electric cars and most smart phones, require a cathode for the battery to operate, and cobalt is the most common choice due to having a high energy density compared to its competitors. The study focuses on the amount of cobalt we are mining and processing now compared to how much we will need by 2030. By their estimates, the world may require 450 k tonnes per year in cobalt.

Values interpolated from research data. Source: Fu et al.

The researchers employed a methodology of analyzing market trends in the sales of electric cars, which account for roughly 60% of all cobalt use. To determine the amounts of cobalt production, they surveyed mining companies to determine the amount of cobalt being produced in cobalt mines, and as a by-product in non-cobalt mines. With these values as their main metrics, they made projections for the next decade with the hopes of seeing if, and when, our cobalt might run short.

 

The methodology is not perfect, however; it is a forecast and not a guaranteed trend. Thus, the data presented is largely extrapolated and estimated from general trends. But the goal of the paper was not to draw exact conclusion. Their goal was to investigate how sustainable this resource is in the short term.

 

The main take-away from their paper are that end-of-life reclamation of cobalt-reliant materials is going to start being more and more necessary. So even with all of our new technologies, the message of sustainability stays the same: Reduce, Reuse, Recycle!

Griffin Bare

Revolution of Orthopedic Surgery – Bioactive Glass Composite Pore-forming Strategy

The use of adhesives to replace traditional invasive internal fixation tools (such as steel plates and nails) will revolutionize orthopedic surgery. The ideal bone cement should be able to immediately fix the fracture site, while providing a space and microenvironment suitable for bone cell growth and promoting fracture healing.

Cyanoacrylate (commonly known as universal glue) is currently the only medical glue with excellent instant adhesive strength and biocompatibility, but its polymerization product is non-degradable and cannot support the growth of new bone tissue through the adhesive layer, which hinders Because of bone healing, it cannot yet be used as a bone cement.

Recently, with the support of the Ministry of Science and Technology, the National Natural Science Foundation of China, and the Chinese Academy of Sciences, Qiu Dong’s group at the has proposed a bioactive glass composite pore-forming strategy to help cyanoacrylate bonding Agents are used for internal fixation of fractures to promote fracture healing. Bioactive glass has excellent osteoconductivity, osteoinduction, and can promote the regeneration of bone tissue.

To prove that the bioactive pore‐forming adhesive is not only strong and instant bonded but also facilitates cell ingrowth and displays excellent bioactivity, they conducted bone‐fracture healing experiments. In the experiment, the bioactive pore‐forming adhesive (PSC1/PEG4/OCA5) was compared with commercial adhesive (OCA) and pore‐forming adhesive (PEG5/OCA5) by applying all to a circular bone piece which was fixed within freshly formed cranial fractures in a group of mice.

Figure 1. The scheme of a mouse cranial fracture with the craniotomy location (Source)

The stability of the circular bone piece and bone healing effect were evaluated at 12 weeks post‐operation. The ratio of bone volume (BV) within the circular gap over the total volume (TV) within the circular gap was quantified as shown in the figure 2 below. After 12 weeks, BV/TV of the PSC1/PEG4/OCA5 group was 0.76 ± 0.06, which was significantly higher than that of the PEG5/OCA5 group (0.47 ± 0.10), the OCA group (0.40 ± 0.06), and the group with no adhesive treatment (0.26 ± 0.05). These findings supported that the adhesive with pores for bone ingrowth was crucial for new bone formation.

Figure 2. quantitative analysis of new bone formation (Source)

ARS (Alizarin Red S) can detect calcium which is a characteristic evidence to bone‐like structures. As shown in Figure 3, the Ca content in the bioactive pore‐forming adhesive (OD = 0.084 ± 0.008) was around two-fold higher than those in the merely pore‐forming adhesive (OD = 0.046 ± 0.004) and CA adhesive (OD = 0.041 ± 0.001). As a result, these findings were consistent with the statement that the PSC BG can promote osteogenic differentiation that is of importance for bone regeneration.

Figure 3. The optical density of eluents from ARS‐stained adhesives (Source)

The bioactive bone cement has good clinical transformation prospects and can provide new ideas and methods for clinical fracture treatment. At the same time, the above-mentioned composite pore-forming strategy can also be used for substances other than bioactive glass to increase matrix materials and functions. Material compatibility.

 

-Xinyue Yang

Posted on Mar.2nd, 2020

Deep Brain Stimulation on Patients with Parkinson Disease

Deep Brain Stimulation (DBS) is a form of neurological stimulation and is used as a form of treatment for those suffering from Parkinson’s Diesease (PD). PD is a neurodegenerative brain disorder which hinders dopaminergic neurons, resulting in impaired mobility. DBS involves a surgical process of implanting a small battery operated device and a electrodes into the brain.

Figure 1 – Deep Brain Stimulation Retrieved from – GAPS

This study published in August 2006 highlights the efficacy of DBS. 156 patients were randomly paired (78 pairs) and were subjected to different treatments. One was subjected to treatment from pharmaceuticals and the other underwent DBS. To test the efficacy of DBS, the patients’ quality of life was assessed using the Parkinson’s Disease Questionaire (PDQ-39). Additionally, numerous symptoms associated with PD were measured using the Unified Parkinson’s Disease Rating Scale, part III (UPDRS-III).

Efficacy of DBS

Out of the 78 pairs of patients, the patient who underwent DBS in 50 of the pairs saw an improvement in their PDQ-39 and UPDRS-III scores compared to their partner who was only provided with pharmaceutical drugs.

Figure 2 – How DBS and Pharmaceuticals affected the PDQ-39 and UPDRS-III scores in patients immediately after treatment. In 50 of the 78 pairs, those who underwent DBS showed improvement in their scores compared to their partners who took medication. Data from Deuschl et al.

Furthermore, the patients were assessed again in six months. Those who underwent DBS saw a 25% increase (a lower score) to their PDQ-39 score, while there we no significant changes to those who took medication.

Figure 3 – PDQ-39 Scores immediately after treatment (baseline), and 6 months after treatment. Error Bars represent standard deviation. Data adapted from Table 3 of Deuschl et al.

Benefit of DBS Compared to Medication on Treating Depression

There are additional benefits of DBS on other aspects of PD. This study published in March of 2005 highlights how DBS is able to treat depression, which is a symptom associated with PD. Patients who were treated by DBS noted a decrease in depression-like symptoms 1 month after treatment, and up to 1 year. In contrast, medication can only treat depression in the short-term.

Figure 4 – A visual interpretation of depression Retrieved from – ConsumerReport

So why is DBS better than Prescription Medication?

The results of both studies indicate that DBS is capable to treating PD with a higher efficacy compared to medication. Additionally, medication is kept constant and can be used to treat one specific issue. In contrast, the strength of DBS can be altered (stronger/weaker pulses) to treat different symptoms that may arise. Consequently, DBS results in long-term benefits, while medication is only able to provide short-term benefits.

-Jackson Kuan