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.

Researchers Explain How Rotifers Thrive Despite Forgoing Sex

Bdelloid rotifers haven’t had sex for at least thirty million years. Most asexual animals are doomed to extinction. The excellent show, Science Friday, looks at the extraordinary adaptations that allow rotifers to thrive sex-free.

For millions of years, the rotifers have reproduced asexually, flying in the face of an idea known as the Red Queen Hypothesis, which states that without the advantage of sexual reproduction, more-rapidly evolving parasites and predators will eventually doom the asexual species. Now, the researchers studying the tiny organism say that its ability to dry up and blow away to greener pastures may have given the rotifers a hidden tactical edge in this evolutionary war.

The webcast provides a nice overview of the research. Every week Science Friday provides many such interesting reviews of recent scientific research.

What Are Rotifers?

Rotifers are small, mostly freshwater animals, and are amongst the smallest members of the Metazoa — that group of multicellular animals which includes humans, and whose bodies are organized into systems of organs.
Most rotifers are about 0.5mm in length or less, and their bodies have a total of around a thousand cells. This means that their organ systems are a greatly simplified distillation of the organ systems found in the bodies of the higher animals.

A typical rotifer might have a brain of perhaps fifteen cells with associated nerves and ganglia, a stomach of much the same number, an excretory system of only a dozen or so cells, and a similarly fundamental reproductive system. They have no circulatory system. It is an anomaly that despite their complexity, many rotifers are much smaller than common single-celled organisms whose world they share.
…
they are able to survive long periods — even perhaps hundreds of years — in a dried or frozen state, and will resume normal behaviour when rehydrated or thawed.
Secondly, they exhibit what biologists call cell constancy — they grow in size not by cell division, but by increase in the size of the cells which they already have.

$100,000 Lemelson-MIT Award for Sustainability

[Sadly the video was made private so I removed it. It is disappointing how often people fail to follow decade old usability advice to make internet urls permanent]

According to the United Nations, more than 40 percent of Africans live in poverty, subsisting on less than US$1 a day. As co-founder and CEO of the nonprofit social enterprise KickStart, Fisher develops and markets moneymaking tools such as low-cost, human-powered irrigation pumps that improve the lives of small-scale rural farmers – the majority of the poor in sub-Saharan Africa.

“These poor rural farmers have one asset: a small plot of land; and one basic skill: farming. The best business they can pursue is irrigated farming,” Fisher explained. “Once they employ irrigation, the farmers can grow and sell high-value crops, like fruits and vegetables. They can grow year-round and reap four or five harvests, instead of waiting for the rain to grow a staple crop once or twice a year.”

Engineering Majors Hold 8 of Top 10 Highest Paid Majors

In August, employers responding to a NACE survey reported plans to trim their college hiring, hiring 7% for 2010 graduates from 2009. In addition, just 29% of those employers said they would increase their starting salary offers for the Class of 2010.

Most, but not all majors, experienced salary decreases. In fact, as a group, graduates with computer-related degrees (computer programming, computer science, computer systems analysis, and information sciences/systems) posted a 6.1% increase – the highest increase reported, which pushed their average up from $56,128 to $59,570. Among those earning a computer science degree, the average rose 4.8% to $61,205.

As a whole, engineering graduates also fared well. Their average salary offer as a group is up by 1.2% to $59,245. Although that increase is modest, engineering majors account for eight of 10 top-paid bachelor’s degrees in the Winter 2010 Salary Survey.

Major	Average Salary Offer
Petroleum Engineering	$86,220
Chemical Engineering	$65,142
Mining & Minteral Engineering (incl. geological)	$64,552
Computer Science	$61,205
Computer Engineering	$60,879
Electrical/Electronics & Communications Engineering	$59,074
Mechanical Engineering	$58,392
Industrial/Manufacturing Engineering	$57,734
Aerospace/Aeronautical/Astronautical Engineering	$57,231
Information Sciences & Systems	$54,038

Crow Using a Sequence of Three Tools

This crow was the first animal observed using 3 tools in the correct sequence, without explicit training.

Slime Mold and Engineers Design Similar Solution

Slime Mold Grows Network Just Like Tokyo Rail System

Talented and dedicated engineers spent countless hours designing Japan’s rail system to be one of the world’s most efficient. Could have just asked a slime mold.

When presented with oat flakes arranged in the pattern of Japanese cities around Tokyo, brainless, single-celled slime molds construct networks of nutrient-channeling tubes that are strikingly similar to the layout of the Japanese rail system, researchers from Japan and England report Jan. 22 in Science. A new model based on the simple rules of the slime mold’s behavior may lead to the design of more efficient, adaptable networks, the team contends.
…
The yellow slime mold Physarum polycephalum grows as a single cell that is big enough to be seen with the naked eye. When it encounters numerous food sources separated in space, the slime mold cell surrounds the food and creates tunnels to distribute the nutrients. In the experiment, researchers led by Toshiyuki Nakagaki, of Hokkaido University in Sapporo, Japan, placed oat flakes (a slime mold delicacy) in a pattern that mimicked the way cities are scattered around Tokyo, then set the slime mold loose.
…
Initially, the slime mold dispersed evenly around the oat flakes, exploring its new territory. But within hours, the slime mold began to refine its pattern, strengthening the tunnels between oat flakes while the other links gradually disappeared. After about a day, the slime mold had constructed a network of interconnected nutrient-ferrying tubes. Its design looked almost identical to that of the rail system surrounding Tokyo, with a larger number of strong, resilient tunnels connecting centrally located oats. “There is a remarkable degree of overlap between the two systems,” Fricker says.

Bewick’s Swan Divorce

photo of Sarindi and Sarind (by Colin Butters)

Experts stunned by swan ‘divorce’ at Slimbridge wetland

It is only the second time in more than 40 years that a “separation” has been recorded at the centre. Staff have described the new couplings as “bizarre”. It is not unheard of for the birds, which usually mate for life, to find a new mate but it tends to be because one of the pair has died, they said.

During the past four decades 4,000 pairs of Bewick’s swans have been studied at Slimbridge, with only one previous couple moving on to find new partners.
…
First suspicions of the rare event were raised when male swan Sarindi turned up in the annual migration from Arctic Russia without his partner of two years Saruni and with a new female – newly-named Sarind – in tow.

The pair’s arrival led conservationists to fear the worst for Saruni. But shortly afterwards Saruni arrived at the wetlands site – also with a new mate, Surune.
…
As for why they may have split, she said: “Failure to breed could be a possible reason, as they had been together for a couple of years but had never brought back a cygnet, but it is difficult to say for sure.”

Bewick’s swans are the smallest and rarest of the three species found in the UK and each individual can be identified by their unique bill pattern.

Apple’s iPad

Steve Jobs introduces the Apple iPad. A touch screen tablet with wireless internet connectivity and a touch screen keyboard (when desired).

Unique Dolphin Strategy for Hunting Fish

A pod of bottle-nose dolphins off the coast of Florida have developed a hunting technique unknown in other dolphins. One swims in a circle stirring up mud and then the dolphins wait to catch fish that jump out of the water to escape the contracting circle of muddy water.

Electric Wind

photo of William Kamkwamba on his windmill from his blog.

I have written about William Kamkwamba before: Inspirational Engineer – Home Engineering: Windmill for Electricity. And along with the post, Make the World Better, donated to his cause. His new book, The Boy Who Harnessed the Wind, is quite enjoyable and provides an interesting view of how he persevered. His talk of the famine, not being able to afford school and putting together a windmill using scrape parts and a few books from the library (donated by the American government – much better foreign aid than all the military weapons that are often counted as aid) is inspirational. And should help many sitting in luxury understand the privileged lives they lead.

“I’d become very interested in how things worked, yet never thought of this as science. In addition to radios, I’d also become fascinated by how cards worked, especially how petrol operated an engine. How does this happen? I thought? Well, that’s easy to find out – just ask someone with a car… But no one could tell me… Really how can you drive a truck and not know how it works?” (page 66)

“Using Energy, and this book has since changed my life… All I needed was a windmill, and then I could have lights. No more kerosene lamps that burned out eyes… I could stay awake at night reading instead of going to bed at seven with the rest of Malawi. But most important, a windmill could also rotate a pump for water and irrigation.” (page 158)

William set out to demonstrate his windmill for the first time to a skeptical crowd saying (page 193)

“Let’s see how crazy this boy really is.”… “Look,” someone said. “He’s made light!”… “Electric wind!” I shouted. “I told you I wasn’t mad!”

I like how the story shows how long, hard work, reading, experimenting and learning is what allowed William to success (page 194-5)

For the next month, about thirty people showed up each day to stare at the light. “How did you manage such a thing?” They asked. “Hard work and lots of research,” I’d say, trying not to sound too smug…
[to William’s father] “What an intelligent boy. Where did he get such ideas?”
“He’s been reading lots of books. Maybe from there?”
“They teach this in school?”
“He was forced to drop. He did this on his own.”

The diagram demonstrated twenty-four volts being transformed to two hundred forty. I knew voltage increased with each turn of wire. The diagram showed the primary coil to have two hundred turns, while the secondary had two thousand. A bunch of mathematical equations were below the diagram – I assumed they explained how I could make my own conversions – but instead I just wrapped like mad and hoped it would work. (page 200)

Soon I was attacking every idea with its own experiment. Over the next year, there was hardly a moment when I wasn’t planning or devising some new scheme. And though the windmill and radio transmitter had both been successes, I couldn’t say the same for a few other experiments. (page 215)

William is now attending the African Leadership Academy in South Africa, with an amazing group of classmates. See how you can support the Moving Windmills Projects.

Siftable Modular Computers

Pretty cool. I must admit I don’t really see how this would function outside of specifically designed situation. I can imagine it could be very cool for education, especially of young kids. Siftables act in concert to form a single interface: users physically manipulate them – piling, grouping, sorting – to interact with digital information and media. David Merrill and Jeevan Kalanithi originally created Siftables at the MIT Media Lab and have formed a company to commercialize the product and have received a grant from NSF to continue the work.