Dark Matter Mapping

What if 90% of your furniture was invisible? You would have to think of some pretty creative ways to find it. Personally, I would drape sheets over everything in my house, great for Halloween time.

Unfortunately, it would be pretty difficult to cover all of the invisible matter in the universe with blankets, they just aren’t big enough. From what astronomers have discovered, as much as 90% of what makes up the universe is completely “invisible.” In other words, it does not radiate any signatures that can be detected in the electromagnetic spectrum by current technology [1].

The good news is that astronomers have created a few extremely clever ways of guessing the general mass and location of all of this dark matter.

Individual galaxies are always evolving because of the mutual gravitational pull of their galactic neighbors. But we know that the gravity caused by visible mass alone is not enough to stretch across the large distances between them. The gravity added by invisible dark matter is the major factor as we watch many galaxies growing, shrinking, transforming, and colliding. The paths that they take allow astronomers to find the gravitational forces at work on them. From these forces, we can calculate the mass of dark matter that the galaxies must contain to sustain their motions [2].

Another way of searching for dark matter involves examining the x-rays released by large dust clouds. X-rays are only detectable because dark matter between their sources and where they are detected. induce lensing. Gravitational lensing refers to a phenomenon where electromagnetic wave, like x-rays, are pulled slightly towards a large mass which gives a curve to their path. Because the path the rays follow can be approximated, any curves give away the location of large masses, like dark matter. The amount of dark matter can be estimated based on the size and shape of the curve. So far, matter found using this technique accounts for 20 to 30% of a galaxy cluster’s total gravitating mass [3,4].

A similar way to detect dark matter involves spotting rings or arcs around clusters of galaxies called “Einstein rings”. These rings are also caused by gravitational lensing, however, scientists look for waves in the visible light spectrum as opposed to x-rays. In order to form a ring, or even a partial ring, the two objects must be almost perfectly aligned in relation to the observation point. The light from the hidden object is then stretched around the foreground object forming the light ring seen in the image below [5]. How well the ring is defined can be useful in estimating the total mass of the foreground galaxy [6].

Image made up from several images taken with the DECam camera on the Blanco 4m telescope at the Cerro Tololo Observatory in Chile.

It’s important to find out as much about where dark matter is located as possible. Future space missions can take advantage of these bodies of mass to slingshot spacecrafts into deep space, but you don’t want any surprises with billion dollar equipment.

References:

1 http://www.indiana.edu/~geol105/images/gaia_chapter_1/dark_matter_in_the_universe.htm
2 http://www.indiana.edu/~geol105/images/gaia_chapter_1/dark_matter_in_the_universe.htm
3 http://www.indiana.edu/~geol105/images/gaia_chapter_1/dark_matter_in_the_universe.htm
4 https://arxiv.org/pdf/1504.05254v3.pdf
5 https://www.space.com/33095-nearly-perfect-einstein-ring-discovered-image.html
6 http://www.indiana.edu/~geol105/images/gaia_chapter_1/dark_matter_in_the_universe.htm

The H-Word: Herpes

You’re not feeling too hot. You’ve had cold and flu symptoms over the last few days, and suddenly those pesky blisters re-appear around your lips: cold sores. While the name might imply it’s the result of that nasty cold, cold sores stem from another virus entirely.

Herpes.

Structure HSV-1 of shown above. This image in particular is the most detailed rendering of the virus to-date. Courtesy of UCLA.

Growing up, you always heard the disease referenced alongside common STIs like chlamydia, syphilis, and gonorrhea - amongst others. However, there’s a critical distinctinction to be made with herpes: it’s incurable.

The other thing is, though, it’s incredibly common.

The herpes disease is caused by infection with the Herpes simplex virus (HSV), which comes in two varieties known as HSV-1 and HSV-2. The remarkable thing is, 67% of the world under age 50 is infected with HSV-1, while over 11% are infected with HSV-2.

Even developed countries like the United States has HSV infection rates of approximately 50%. If you see someone with blisters around their lips, it’s probably a HSV infection flaring up.

Yet, the only symptom for the majority of people are those pesky cold sores.

HSV has been able to cause rampant, but subtle infections. The virus spreads through oral-oral contact, especially by individuals with active cold sores. After infection, HSV lies dormant within neurons, where it evades the immune system and only occasionally pops out through neuronal axons leading to the skin.

HSV itself is part of a family of viruses known as herpesviridae, which includes viruses responsible for commonplace diseases like chickenpox, shingles, or mono. The underlying characteristic of this family are lifelong, latent infections without cure. In fact, the name herpes is derived from the Greek word herpein, or to creep.

Symptoms caused by these viruses, if any, either are occasional and mild (as seen with HSV), or involve acute, isolated periods of illness (as seen with chickenpox and mono).

It’s a very successful family in terms of infection rates, but not everyone is aware of just how successful herpes is.

HSV is already known to function as an STI, causing genital herpes with certain infections. However, recent studies have begun to suggest HSV infection as having a role in the development of Alzheimer’s disease, which is a form of progressive dementia where growing plaques within the brain leads to eventual loss of function and death.

As a result, spreading awareness and educating people about just how common this infection can be is critical.

Image showing the various levels of plaque accumulation of beta amyloid within brains. Alzheimer’s patients have particularly high, progressing levels of accumulation believed to contribute to loss of function. Image courtesy of Zephyr/Science Source

The association of HSV and Alzheimer’s was first proposed around 1980, where it was largely disregarded due to controversy. However, a recent study published in 2018 establishes a definite association between HSV infections and its disruption of several neuronal pathways that contribute to Alzheimer’s disease.

As a result, what was merely a common, pesky infection might have severe implications for one’s long-term health. Alzheimer’s is similarly incredibly common, and cannot be cured or treated. Finding a way to reduce its rate of occurrence is critical, and the answer itself may lie within further studying the herpes infection.

References:

1. https://www.sciencedirect.com/science/article/pii/S0896627318304215?via%3Dihub

2. https://www.nytimes.com/2018/06/21/health/alzheimers-virus-herpes.html

3. http://www.who.int/news-room/fact-sheets/detail/herpes-simplex-virus

Plant Communication: Silent but Not Invisible

If plants had a language, what would it sound like? For years, the concept of plant communication was fairly nonexistent, and hypotheses about trees sending each other electrical signals as they were being cut down were considered lunatic at best [1]. The botanical world has largely been viewed as a silent one, but the past few years of research have finally unveiled the buzz of constant communication between plants, all unheard by human ears.

As it turns out, plants need to ‘talk’ to each other for many of the same reasons humans have developed verbal and body language: to coexist successfully, express physiological needs, and cooperate in protecting the overall community. Only recent advancements in technology have allowed humans to gain insight into this unheard conversation – and now we can see it as well. Scientists have managed to visually prove that plants warn each other of impending dangers, negotiate with their nearest neighbors, and send messages throughout their populations when necessary.

For example, a curious phenomenon called ‘crown shyness’ refers to the learned behavior of plants, especially large trees, to redirect and divert growth when their leaves begin to brush up against the leaves of surrounding vegetation [1]. It’s almost the botanical equivalent of body language. More common, however, are chemical signals that spread throughout the body of one plant and then to those closest to it. Roots of one plant exude organic compounds into the soil that then pass into nearby plants through their roots, giving neighbors information on each other’s well-being. When tested on corn seedlings, researchers found that seedlings would direct growth away from plants whose roots were emanating chemical signals of distress in an effort to avoid the same stressors, and would also rely on these signals to reorient themselves if they sensed they were growing too close to each other [2].

The ability of plants to communicate with each other is crucial in defending against external threats like herbivory, chemical pollution, and even lumberjacks. Scientists had previously inferred that plants could warn each other of danger after one individual was attacked, but molecular technology has recently provided a remarkable visual representation of how the process actually works [3]. When a plant is attacked – say, by an herbivorous caterpillar – the site of the wound triggers a release of glutamate (a neurotransmitter that is also found in animals), which causes a change in calcium ion (Ca2+) concentration that spreads throughout the plant in minutes. The electrical signal then jumps to other surrounding plants, resulting in a chain reaction [4]. In cases such as an attack from a voracious caterpillar, this rapid alert system is useful because it allows the undamaged leaves to quickly mount a defense response, which usually involves the production of hormones that make the leaves toxic or unappetizing [3].

This entire process occurs silently and is virtually undetectable – or was, until scientists created a mutated species of Arabidopsis in which calcium concentrations could be seen under fluorescent light [4]. The final effect (seen in image) is a visually stunning reminder of the secret signals that lie beneath the surface.

References:

1. The Guardian. Plants ‘talk to’ each other through their roots. https://www.theguardian.com/science/2018/may/02/plants-talk-to-each-other-through-their-roots (accessed October 24, 2018).

2. Elhakeem, A.; Markovic, D.; Broberg, A.; Anten, N.P.R.; Ninkovic, V. Aboveground mechanical stimuli affect belowground plant-plant communication. PLoS ONE 2018, 13(5): e0195646.

3. Interesting Engineering. New Discoveries Made in How Plants Warn Each Other of Danger. https://interestingengineering.com/new-discoveries-made-in-how-plants-warn-each-other-of-danger (accessed October 24, 2018).

4. Toyota, M.; Spencer, D.; Sawai-Toyota, S.; Jiaqi, W.; Zhang, T.; Koo, A.J.; Howe, G.A.; Gilroy, S. Glutamate triggers long-distance, calcium-based plant defense signaling. Science. 2018, 361(6407), 1112-1115.

The Benefits of Exercise on Cognitive Ability

Health and fitness is something valued in society and seen as a priority. We see the need to stay active and push our bodies to perform moves never done before, such as running a marathon or lifting one more rep. The habit of exercise can keep us moving, but when things become stressful and overwhelming, very few of us will choose the gym over work or studying.  Instead, the majority of us delve further into our activities, which not only generates even more stress, but also makes us so exhausted that we can hardly imagine exercising. While this undivided attention on work seems to maximize efficiency, research shows that exercise can actually improve concentration.

Instead of toiling for seven hours straight on a task and succumbing to distractions, such as mindless snacking, taking an exercise break can actually help you stay focused. According to Ben Martynoga of The Guardian, studies on the effects of after-school sports classes on school children reveal that when the students got healthier, their their cognitive abilities also improved. Effective exercise doesn’t even have to be a full hour running or in the gym-- just 10 minutes of movement can reap similar results [1]. In other words, while it may seem counterintuitive to take a break from a hard task (instead of finishing it all at once), a small break for activity can actually improve concentration and increase your productivity.

When stress is high, exercise also comes in as a handy tool to decrease stress and improve mood. We’ve all heard of the “runner’s high,” but how real is it? The Mayo Clinic has found that  exercise helps increase the brain’s natural feel-good drug: endorphins. While the term “runner’s high” is more common, all forms of exercise can help you feel the mood-boosting benefits [2]. Staying physically active during times of hard-work helps relieve feelings of stress and anxiety.

While the short-term effects of exercise on cognitive ability are clear, there are numerous long-term benefits of exercise that improve not only physical health, but also brain health. Harvard Health Publishing states that a consistent, moderately intense exercise improves memory by stimulating the release of the chemical brain-derived neurotrophic factor (BDNF), which rewires our neural circuits to fire better [3].

Ultimately, the effects and benefits of exercise are far-reaching. There’s no doubt as to why we should value physical activity in our lives: not only does it improve our physical health, but it also enhances our cognitive ability and performance. Consistently exercising--even through busy times--provides us with countless advantages. In fact, exercising  during those harderdays can make them a whole lot better for us too.

References:

1. Ben Martynoga. How physical exercise makes your brain work better. https://www.theguardian.com/education/2016/jun/18/how-physical-exercise-makes-your-brain-work-better (accessed 27 October 2018).\

2. Mayo Clinic. Exercise and stress: Get moving to manage stress. https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/exercise-and-stress/art-20044469 (accessed 27 October 2018)

3. Harvard Health Publishing. Regular exercise releases brain chemicals key for memory, concentration, and mental sharpness. https://www.health.harvard.edu/press_releases/regular-exercise-releases-brain-chemicals-key-for-memory-concentration-and-mental-sharpness (accessed 27 October 2018)

ASMR: Genuine or Placebo?

Autonomous Sensory Meridian Response, more commonly known as ASMR, refers to the sensations felt in response to auditory stimuli, which can range from whispering to ambient noises such as tapping. The sensations caused by ASMR often resemble calming tingles along the scalp and spine that radiate throughout the entire body. If you’ve ever experienced shivers along your spine while listening to music or observing an aesthetic scene, you have likely experienced a similar feeling to ASMR.  

Though the name may sound scientific, ASMR is not by nature a scientific concept, owing its origins to people’s personal experiences [1]. Does that mean ASMR is just a placebo? A study published in PLOS One disagrees, asserting that ASMR is a reliable and psychologically sound phenomenon that may have therapeutic benefits for mental and physical health [3].  The first experiment conducted by these scientists demonstrated that ASMR videos increased the “pleasant-effect” for people who experience ASMR and the second concluded that ASMR is associated with high skin conductance and a reduced heart rate. The effects discovered by this study are consistent with people’s self-reported experiences with ASMR, which include tingling sensations (skin conductance) and a calming feeling (reduced heart rate). Furthermore, this calming feeling explains why one of the most common uses of ASMR is by people having trouble falling asleep, as majority of online searches for ASMR occur after 10 pm [5]. One of my own friends often has trouble falling asleep and listens to ASMR almost every night to help him relax before bed. While this study does explore some of the feelings associated with ASMR, it still leaves a question unexplored: it is possible for everyone to experience ASMR?

If you’re like me and have not personally experienced ASMR, you might justifiably be skeptical of this phenomenon. However, there is still no complete answer to the previous question about ASMR being universal, with not enough data to support either side of the argument. Two aspects of ASMR however are important to consider—triggers and sensitivity. Just like how our tastes in music vary widely, ASMR triggers are not universal, with different people experiencing ASMR through differing means. Furthermore, people tend to have a varying sensitivity towards these triggers, ranging from a fleeting pleasant sensation to an intense stimulating experience. It is difficult to make a conclusive judgement on the legitimacy of ASMR due to these inconsistencies in ASMR’s impact on people.

In conclusion, ASMR, while still being somewhat ambiguous, has exploded in popularity recently across social media platforms such as YouTube. Whether or not you think ASMR is real, millions of people around the world do, and it is in our best interests to further study this sensation to potentially learn more about its beneficial uses. If you have never tried ASMR, I would encourage you to give it a shot and see if you too can experience this mysterious feeling.

References:

1. “ASMR Science - Is There Any Science behind ASMR?” The ASMR Lab, www.asmrlab.com/asmr-science/.

2. Barratt EL, Davis NJ. (2015) Autonomous Sensory Meridian Response (ASMR): a flow-like mental state. PeerJ 3:e851 https://doi.org/10.7717/peerj.851

3. University of Sheffield. "Brain tingles: First study of its kind reveals physiological benefits of ASMR." ScienceDaily. ScienceDaily, 21 June 2018. <www.sciencedaily.com/releases/2018/06/180621101334.htm>.

4. More than a feeling: Autonomous sensory meridian response (ASMR) is characterized by reliable changes in affect and physiology 

5. Poerio GL, Blakey E, Hostler TJ, Veltri T (2018) More than a feeling: Autonomous sensory meridian response (ASMR) is characterized by reliable changes in affect and physiology. PLOS ONE 13(6): e0196645. https://doi.org/10.1371/journal.pone.0196645