30 Jun 2021

Forensics and Justice

 by Paula Johanson

The news in Canada this summer is troubling, with stories of unmarked graves on the sites of former Indian Residential Schools. Searches are being done on other former school sites, and in the United States as well. The little that was ever taught in public schools about the Residential School system is not enough, and people are looking to learn more.

Forensics is the science of examining physical evidence. There can be a forensic audit of paperwork and records, but forensic science is commonly used to study physical evidence of a crime.

Here are some books on forensic science  which you can request at your public library, or order online. If you take this list to a library or bookstore, they will help you get a copy. There are other books as well available on this topic, and referenced in the back of these books.

Forensic Science: In Pursuit of Justice written by Sci/Why's own member L.E. Carmichael

ISBN:  978-1624035616 Essential Library Publishing


This title presents the history of forensics. Vivid text details how early studies of toxic chemicals and firearm analysis led to modern scientific crime solving techniques. It also puts a spotlight on the brilliant scientists who made these advances possible. Useful sidebars, rich images, and a glossary help readers understand the science and its importance. Maps and diagrams provide context for critical discoveries in the field. Aligned to Common Core Standards and correlated to state standards. Essential Library is an imprint of Abdo Publishing.


Look on the author L.E. Carmichael's website at https://www.lecarmichael.ca/books/ and scroll down to find among covers for her many books, the covers for these books on forensics.

Forensics in the Real World by L.E. Carmichael

ISBN: 9781680784794



Fuzzy Forensics: DNA Fingerprinting Gets Wild by L.E. Carmichael



Focusing on forensic science to protect endangered animals, this book is winner of the 2014 Lane Anderson Award for exceptional children''s science writing. 


Discover Forensic Science by L.E. Carmichael



Bones Never Lie: How Forensics Help Solve History's Mysteries by Elizabeth MacLeod

ISBN: 978-1554514823 Annick Press


This book collects seven mysteries about historic royal figures whose deaths were under suspicious circumstances. Hard scientific facts about crime-solving techniques make this book highly recommended by Sci/Why author L.E. Carmichael.

25 Jun 2021

A Meromictic Treasure in Petroglyph Park

 by Nina Munteanu

 Looking for ancient treasure, I drove north from Peterborough to Petroglyph Park in the Great Lakes-St. Lawrence Lowlands Forest Region, a sought-after destination for its impressive ancient petroglyphs (rock carvings). Holes in the rock were considered entrances to the spirit world, situated directly beneath the surface (spirits prefer to live near water).

When I reached the park, I discovered that the glyphs were off-limits because of COVID. Disappointed, I looked to salvage my trip by hiking the 2 km loop trail to McGinnis Lake. The walk from the west day use parking lot took me through dense pine forest. Giant pines thrust high above me like columns of a sacred cathedral. Their deep green canopies swayed and creaked in the breeze as they strained toward the heavens in a low baritone hush. I passed pink granite outcrops in the soft limestone and found myself on a rocky promontory that overlooked the over 12 m deep lake. The 4.4 ha lake’s water was a deep blue-green jade colour rimmed by shallows of lighter green that graded to a cream colour. Rocks, logs and large shore debris hung precariously over the steep sides of the lake below me, covered in creamy marl.

On the opposite side of the jade-coloured lake—accessed by the east day use parking lot, the marl-covered shallows extended further out, creating a stunning visual colourscape that shifted from deep blue-green to yellow and cream.

The information sign on the promontory describes McGinnis Lake as a rare meromictic lake.

What a treasure! I’d studied meromictic lakes at university as a limnology student; I’d never actually seen one before. Until now. Meromictic lakes aren’t just rare; they are fascinating in the study of lake formation, type and function.

Many lakes in the northern temperate area of Canada are dimictic: they mix completely (holomixis) twice a year, once in the spring and once in the fall. In shallow lakes, warmed by the sun and mixed by the wind, wind-driven currents keep the water mixed all year round. In deeper lakes, the currents can’t compete with the active summer warming of the upper water mass and density differences develop between upper and lower waters. The lake stratifies into an upper epilimnion and lower hypolimnion, separated by a metalimnion or thermocline barrier. In the fall, with cooling, the density barrier breaks down and the wind-driven currents penetrate into the lower layers to thoroughly mix the lake to the bottom sediments (holomixis) in what’s called vernal turnover.

Unlike dimictic lakes, meromictic lakes experience incomplete vertical mixing of only the upper water mass during the circulation period (called meromixis). The upper water mass (mixolimnion) mixes twice yearly like a dimictic lake; however, below this upper mixing layer lies a salinity barrier known as a chemocline (where dissolved oxygen decreases markedly with depth) and beneath it lies the anoxic water mass known as the monimolimnion, which experiences a fairly constant temperature and higher salinity. The higher dissolved salt at the bottom—and greater associated water density—prevents wind-driven mixing of this bottom quiescent layer and accumulates hydrogen sulfide and methane.

Lake morphology—particularly the relationship of depth and surface area—contributes largely to whether a lake is meromictic and capable of preserving undisturbed laminated sediments. A meromictic lake may develop if it contains a deep hole in a shallow basin or is sheltered from the prevailing wind by tall vegetation or other barriers—like McGinnis Lake, which rests in a steep-sided limestone basin, sheltered from the winds by a dense pine forest. McGinnis Lake may have formed through karst erosion; it may also simply occupy a deep glacial trough. Because of the barrier and lack of mixing, any exchange of dissolved materials from the lower quiescent layer into the mixing layer occurs very slowly through eddy diffusion across the chemocline. This makes Lake McGinnis’s monimolimnion a nutrient sink and why it is, like most meromictic lakes, unproductive (oligotrophic).

This drawing shows how the lake is shallow at its edges and grows deeper in two places.

In summer, when McGinnis Lake is stratified, the top 6 m layer of McGinnis Lake reaches 20-22˚C and its middle 6-12 m layer is typically 7-12˚C. However, below the chemocline, the anoxic monimolimnion (below 12 m), stays a constant 5-6˚C year-round, and is a pinky-brown colour. Few organisms live in the oxygen-depleted monimolinion. An exception are the cyanobacteria (Cyanophyceae), autotrophic bacteria that can survive on hydrogen sulfide at the lake bottom and are responsible for lime depositing in lakes.

Brilliant Jade Colour
The intense jade colour of marl-based McGinnis Lake is partially explained by the presence of calcium carbonate (CaCO3) in the lake from marl—calcium carbonate and clay. The dominant carbonate mineral in most marls is calcite, along with other carbonate minerals such as aragonite, dolomite and siderite. Marl formation and settling is encouraged by bacteria, phytoplankton, and periphyton (attached algae) as temperatures increase in summer. The calcium carbonate—which is present in the limestone bedrock surrounding the lake—acts like a flocculent to clear the lake of the coloured, dissolved substances; as the brown hue is removed, blue and green light can penetrate into the deepest parts of the lake. The most brilliant jades can be seen when the microscopic algae thrive and when the suspended marl increases in volume in mid to late summer.

Presence of marl is also why the water-sunken trees and debris and the entire shoreline are covered in a milky cream-coloured floc—likely a combination of marl deposit and periphyton (attached encrusting and filamentous algae) that help deposit the marl. Examples may include stalked diatoms (Gomphonema) and blue-green alga Oedogonium. The periphyton secrete glycocalyx (fibrous meshwork of carbohydrates) and other mucilage secretions that coat the sediment particles and adsorb organics and other nutrients for their use. This is why the lake’s shallow shores are a dramatic cream-yellow colour and grade to a brilliant green then deep blue-green of deeper overlying waters. Marl are tiny white coloured crystals and as the water warms in the day, so does the volume of crystals in the water. As the summer progresses, the clear deep blue of McGinnis Lake may transform into lighter milkier turquoise with suspended calcium carbonate crystals.

Undisturbed Sediments & Varves
Because a meromictic lake’s bottom water layer doesn’t mix and is permanently anoxic (without oxygen), no burrowing benthic organisms are present to destroy the sediment layers (varves) laid down over time—mostly organics that don’t decay. Because of this, these varves provide an undisturbed history of biological succession and climate change of the last 10,000 years.

Here's a cutaway image of varves - layers of sediment

Undisturbed annual sediment laminations can provide accurate chronology, just like tree rings, over thousands of years, dating back to the late Pleistocene and Holocene 10,000 to 12,000 years ago. This is because sediment accumulation—just like tree growth—often follows a seasonal pattern. Annual accumulations of sediment may consist of a simple two-component couplet (summer vs. winter sedimentation). In summer increased photosynthesis causes settling of CaCO3; while in winter, when the lake is ice-covered, fine organic material and clay settles to the bottom.

This is a layer of diatoms in a varve

Varve couplets (summer-winter layers of a year) typically consist of a dark layer of organic sludge with algal filaments, iron sulfides, and clay that grades upward into a lacy network of diatom frustules and organic matter; this would be overlain by a light layer of diatom frustules and calcite that turns into pure calcite at the top. In summer, calcium carbonate and diatoms (algae with silica shells) accumulate on the bottom; in winter more fine organic matter and clay settle.

These shapes are tiny diatoms!

On my way home, I considered my fortune: I’d found a real ancient treasure after all, something
I hadn’t expected to see.

Anderson, Roger Y., Walter E. Dean, J. Platt Bradbury, and David Love. 1985. “Meromictic Lakes and Varved Lake Sediments in North America. USGS Bulletin 1607.

Burkholder, JoAnn M. 1996. “Interactions of Benthic Algae with Their substrata. B. The Edaphic Habit: Epipsammic and Epipelic Algae among Sands and Other Sediments. Algal Ecology: Freshwater Benthic Ecosystems, R. Jan Stevenson et al., editors. Academic Press. 753pp.

Cheek, Michael Ross. 1979. “Paleo-indicators of Meromixis.” M.Sc. Thesis, Brock University, St. Catherines, Ontario. 129pp.

Stewart, K.M., G.E. Likens. 2009. “Meromictic Lakes.” In: Encyclopedia of Inland Waters, G. E. Likens, editor-in-chief. Academic Press. 2250pp.

20 Jun 2021

Celebrating the (Banting and) Best Anniversary Ever!

 by Anne Munier

Leonard, a Toronto teenager, arrived at the hospital weak and pale, his hair falling out. Like everyone else who had Type 1 diabetes 100 years ago, he was dying.

People with Type 1 diabetes (let’s call if T1D for short) stop producing the hormone insulin. In fact, their immune system -- which should be busy fighting off diseases -- gets confused, and starts killing the body’s own insulin-producing cells!


Diagram credit: MyHealthDigest

That’s a big deal, because insulin moves food energy (glucose) out of our blood, and into our body’s cells. Without it, we don’t get much energy from food. Then sugar accumulates in our blood, eventually causing a lot of damage. T1D affects children mostly, and, back in the day, they would generally die within a few weeks or months of being diagnosed.

Symptoms of T1D include:
1. Having to pee more than usual, to flush out all that sugar. (Thousands of years ago doctors noticed that ants were attracted to the urine of T1D patients, because it was sweet. The ant trick helped to diagnose new patients!)
2. Being really thirsty (to replace all that lost fluid)
3. Not having much energy (no surprise there- food energy doesn’t get where it needs to go!)

Back to Leonard. At 14 years old, he weighed only weighed 65 pounds. That was partly due to the diabetes, but mostly it was because he was barely eating. A “starvation diet” was a cruel, but popular, T1D treatment, which could extend life by several months.

Leonard before and after treatment

But this story has a happy ending.

A small research team at the University of Toronto, led by Dr.’s Banting and Best, were removing and purifying bits of the pancreas (the organ where insulin is made) from dogs and cows. They thought that injecting this into diabetic patients might provide their bodies with the insulin they so desperately needed. Leonard was about to be their first human guinea pig.

Three heroes of diabetes treatment
(Dr. Best, lab dog 408, and Dr. Banting) -
University of Toronto

Their first try was a failure -- all that happened was that poor Leonard developed an allergic reaction. Undaunted, the researchers purified the extract some more, and tried again. This time the results were quick, and they were amazing. Leonard’s blood glucose went down to near-normal levels within a day. He brightened, became more active, and felt stronger. And survived!

After Leonard came other children -- 6 year old Teddy; Elizabeth, somehow still hanging on after 3 years of the starvation diet; Elsie, in a coma, revived by insulin. Insulin has since saved the lives of millions of people.

Letter to Dr. Banting from a much-
improved Teddy (U. of Toronto)

While the treatment has become more sophisticated, T1D troopers still inject themselves with insulin every day, and carefully control their food (especially carbohydrates). There’s still no cure -- yet.

About one in every 100 Canadians has T1D. Whether we realize it or not, we’ve all been impacted by insulin, because we all know and care about people whose lives it has saved.

All this to say: Happy 100th anniversary everyone!

11 Jun 2021

A Clownfish Comic

 by Raymond Nakamura

Finding Nemo maybe an entertaining animated movie about clownfish, but it is not exactly a nature documentary. A recent bit of science news  about clownfish stripes inspired me to make a little comic about them.

Unlike the movie, juvenile clownfish do not start out with all their stripes (or bars). They don’t even live with a parent. But they do live among sea anemones, which normally sting and eat other types of fish. Some species of clownfish can live with more than one species of sea anemone.



Stripes may be important for distinguishing individuals and species from each other.


A team of scientists under Professor Vincent Laudet have been studying clownfish in New Guinea.



They noticed that juvenile clownfish developed white bars more quickly when associated with the Giant Carpet Anemone than when they lived with the Magnificent Anemone.



Thyroid hormone is known to be important to triggering metamorphosis in frogs. 

The team sent juvenile clownfish from the two different anemones to Dr. Pauline Salis for analysis. 

Clownfish living on the Giant Carpet Anemone tended to have more thyroid hormone than those on the Magnificent Anemone. Furthermore, adding thyroid hormone to juvenile clownfish caused them to develop white bars more quickly. White bars depend on the development of pigment cells called iridophores. The development of iridophores in turn depends on a gene called Duox (which codes for the protein Dual Oxidase). And Duox was found to be more active in clownfish residents of the Giant Carpet Anemone. 


The scientists are not yet sure why clownfish develop at different rates in the two kinds of sea anemone.



What do you think?




This week's post is by our own Raymond Nakamura, Ph.D ! Check out his website at http://www.raymondsbrain.com

Raymond K. Nakamura writes, draws cartoons, and develops fun learning opportunities about science and Japanese Canadian history and culture, when he is not washing the dishes, walking the dog, or helping his daughter with homework.

He blogs and cartoons not only for Sci/Why but for Science World British Columbia and Science Borealis as well. He is the author of Peach Girl, a picture book that reimagines a Japanese folk tale, published by Pajama Press.



4 Jun 2021

Technology That Gives Us Superpowers

 by Elaine Kachala

It’s happening! We’re living through a Machine Revolution unlike anything before.

Science and technology have always shaped human civilization. But computers for our bodies and minds?

Our world is exploding with smart wearable devices. They have all the functions of a computer. They can store, retrieve, and process data. But they’re different from desktops or laptops, or hand-held devices because they’re intensely personal! Wearables live on us, in us, or close to us.

Smartwatches or activity trackers were once the most popular kind of wearable technology. But that’s changing with the next generation of devices. The “wrist” is history! We won’t be strapping wearables onto our wrists anymore. Our brains, skin, eyes, ears, and clothing are new ways to connect with technology. A couple of examples here barely scratch the surface of what’s happening. 


Photo credit: Northwestern University

Source: Rogers, J. https://news.northwestern.edu/stories/2016/11/researchers-develop-soft-microfluidic-lab-on-the-skin-for-sweat-analysis/&fj=1

Dr. John Rogers at Northwestern University developed a small electronic device. It captures and analyzes a person’s sweat. It wirelessly connects with a smartphone to help someone know if they’re becoming dehydrated.

Google’s Project JacquardTM took smart clothes to a new level. They partnered with Levis to launch a jacket with built-in sensors and conductive fabric. It can send signals to your smartphone. Tap your jacket to answer calls or play music! And, they’ve developed a smart tag that slips into any piece of clothing or object for connectivity. See https://atap.google.com/jacquard/#.

This brain-sensing headband by MuseTM helps people relax, meditate, focus, and sleep.


Photo: Elaine Kachala

This is my Muse, but here’s the website https://choosemuse.com/.


Sensors inside the headband detect and measure the activity of a person’s brain, along with sensors that track heart rate, breathing, and movement. Look closely, and you can see the soft gold patches on the fabric; those are the sensors. The pod at the top is the brain-sensing technology. The headband uses Bluetooth to connect to a smartphone. Once a person selects a program from the Muse app, the rest journey begins. After meditating, Muse uses algorithms to turn the brainwave activity into information about how well a person slept or relaxed, so they learn what works best.

Exoskeletons are like wearable robot suits. They apply robotics, mechanics, and electronics to support people with extra strength and endurance. For example, soldiers, firefighters, factory workers, and others can wear this suit to help them carry heavy loads or cross over rugged terrain. People with difficulty walking because of illnesses or injuries can wear them to move more easily. 

Computers are being infused into everything wearable. They can empower people to live better lives. And with advances in artificial intelligence, sensors, software, materials science, robotics, cloud computing, mobile networks, and the Internet of Things (IoT), wearables are getting smarter. 

These devices know a lot about us because they collect data about our body movements, location, heart rate, voice sounds, and more. They know how we feel and what we’re looking at. Wearables collect personal information that can put our privacy, safety, and security at risk. 

And, there are some bigger questions to think about too. Our minds and bodies are merging with computers. Can this human-machine evolution go too far? What if some people can afford wearables but others can’t?

Stay-tunned for my book called Super Power? The Wearable Tech Revolution. It will debut in Fall 2022 with Orca Book Publishers. The book explores how wearable electronics and robotics, virtual reality, and brain-computer interfaces are changing our lives and why designers, engineers, and scientists strive towards responsible design. For more info, please visit me at www.elainekachala.com