Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

New Understanding of Human DNA

Very interesting Genetic breakthrough that reveals the differences between humans (bozo website broke the link – poor usability):

The discovery has astonished scientists studying the human genome – the genetic recipe of man. Until now it was believed the variation between people was due largely to differences in the sequences of the individual ” letters” of the genome.

It now appears much of the variation is explained instead by people having multiple copies of some key genes that make up the human genome.

Until now it was assumed that the human genome, or “book of life”, is largely the same for everyone, save for a few spelling differences in some of the words. Instead, the findings suggest that the book contains entire sentences, paragraphs or even whole pages that are repeated any number of times.

Fascinating information that I must admit I am still trying to grok.

The studies published today have found that instead of having just two copies of each gene – one from each parent – people can carry many copies, but just how many can vary between one person and the next.

The studies suggest variations in the number of copies of genes is normal and healthy. But the scientists also believe many diseases may be triggered by an abnormal loss or gain in the copies of some key genes.

It will be very interesting to see how this understanding develops.

Related: Humans show major DNA differences – We’re more different than thought, genome map reveals – Old Viruses Resurrected Through DNA – National Geographic overview of human genetics – Scientists crack 40-year-old DNA puzzle – Where Bacteria Get Their Genes

Be Thankful for Marine Algae

photo of seaweed - algae

The Most Important Organism?

It is estimated that between 70% and 80% of the oxygen in the atmosphere is produced by marine plants . Nearly all marine plants are single celled, photosynthetic algae. Yup, that’s right, good ol’ scum on the pond…green gak…..slip slimein’ away. Even marine seaweed is many times colonial algae. They are a bunch of single cells trying to look like a big plant (see seaweed photo), but they are really individuals.

We need marine algae a whole lot more than they need us. Think about it….70% to 80% of all the oxygen we breathe comes from algae!

Photo: “Seaweed are not plants, but are algae. Not only does algae provide much of the Earth’s oxygen, they also are the base for almost all marine life.”

Related: Ginko Cells Host Alga – How Bacteria Nearly Destroyed All Life – Student Algae Bio-fuel Project

The Best Science Books

An interesting post from John Dupuis discusses several lists of the best and worst science books. Some of the best books from the lists, based on importance, what strikes my mood right now, what I enjoyed… (those I list could easily change on another day):

Please share your favorite science books.

Related: our science and engineering book page – 2005 Science book gift suggestions (from the list above The Selfish Gene, Chaos, A Brief History of Time and The Mismeasure of Man are likely the best gifts for the widest audiences).

Science Saves Driver from Ticket

Driver beats fine with schoolboy science:

“The photographs show the back of my car and the white lines at the side of the road. The second photograph shows that it was taken 0.5 seconds later by which time I had moved five white lines along.”

He remembered from school you could calculate speed if you had the correct distance and time. He said he looked on the internet and found an official website stating that lines on the motorway are spaced two metres apart.

“That meant I had driven 10 meters in 0.5 seconds or 20 meters per second. That works out at precisely 44.8mph.”

Are Our Vegtables Less Nutritious?

Grandma’s Veggies May Have Been More Nutritious:

“Of the 13 nutrients that we were able to study, we found statistically reliable declines in six of the 13,” he says. Levels of other nutrients stayed roughly constant over the years.

But a big word of caution: USDA nutritionist Joanne Holden says those 1950 numbers may not be trustworthy. For one thing, measurement techniques have changed, possibly changing the results. In addition, she says, no one knows whether the vegetables measured in 1950 were an accurate sample of the American diet.

100 Innovations for 2006

Popular Science has selected the Best of What’s New. Previous posts talk about some of these, such as: One Laptop Per Child, New Soccer Ball, Grand Canyon Skywalk. And they discuss other breakthroughs like: Memory Spot, Sony Reader. They seem to be stretching a bit to reach 100 – still there are some cool items and it is a fun read. And where are some others: Lifestraw, Lego Mindstorm, Re-engineered Wheelchair…

Related: Inventions of the Year

Lifestraw

Lifestraw is an excellent example of an engineered appropriate technology solution.

At any given moment, about half of the world’s poor are suffering from waterborne diseases, of which over 6,000 – mainly children – die each day by consuming unsafe drinking water.

Today, more than one billion people of the world’s population are without access to safe water, causing lack of safe water supply to rob hundreds of women and girls of dignity, energy and time.

Safe water interventions, therefore, have vast potential to transform the lives of millions, especially in crucial areas such as poverty eradication, environmental upgradation, quality of life, child development and gender equality.

Lifestraw is a filter solution that allows water to be purified for about 6 months (before needing to be replaced) at a cost of just $3.50.

Related: Smokeless Stove Uses 80% Less Fuel – Clean Water Filter – New straw to kill disease as you drink – Safe Water Through Play – Millennium Development Goals

Far Eastern Leopard – Rarest Big Cat

World’s Rarest Big Cat Captured:

The team, led by biologists from the New York-based Wildlife Conservation Society, caught the 100-pound (45-kilogram) male in a snare last week while studying Siberian tigers in the Russian Far East, 20 miles (32 kilometers) from the Chinese border.

The chance capture gave biologists a priceless opportunity to study the elusive feline, and Melody Roelke (below), a specialist in big-cat genetics with the U.S. National Institutes of Health, wasn’t shy about getting a closer look.
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Among the scientists’ main concerns is whether Far Eastern leopards, also known as Amur leopards, can continue to sustain their tiny, isolated population, or whether disease and inbreeding may eventually wipe out the cats.

Related: Jaguars Back in the Southwest USA – Big Cats in America – Tabby Cat and a Black Bear

What is an Extremophile?

What is an Extremophile?

An extremophile is an organism that thrives under “extreme” conditions. The term frequently refers to prokaryotes and is sometimes used interchangeably with Archaea.
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The term extremophile is relatively anthropocentric. We judge habitats based on what would be considered “extreme” for human existence. Many organisms, for example, consider oxygen to be poisonous.

The site includes interesting photos and details on all sorts of extremophiles: Anaerobe (don’t require oxygen) – Endolith (live inside rocks) – Thermophile (enjoy over 40 °C).

Related: Types of Microbes – Life Untouched by the Sun