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.

Vampire Moth Discovered

Entomologist Jennifer Zaspel at the University of Florida in Gainesville said the discovery suggests the moth population could be on an “evolutionary trajectory” away from other C. thalictri populations.

In January, she will compare the Russian population’s DNA to that of other populations and other species to confirm her suspicions. “Based on geography, based on behavior, and based on a phenotypic variation we saw in the wing pattern, we can speculate that this represents something different, something new,” Zaspel said.
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Only male moths exhibit blood feeding, she noted, raising the possibility that as in some species of butterflies and other moths, the Russian moths do it to pass on salt to females during copulation.

“There is no evidence it prolongs the life of the male, or anything like that,” she said. “So we suspect that it is probably going to the female.” The sexual gift, she said, would provide a nutritional boost to young larvae that feed on leaf-rich, but sodium-poor, diets.

Dean Kamen: Stirling Engines

Dean Kamen: part man, part machine

Conceived in Scotland almost 200 years ago, the Stirling [engine] is a marvel of thermo-dynamics that could help to replace the internal combustion engine – in theory it can turn any source of heat into electricity, in silence and with 100 per cent efficiency. But corporations including Phillips, Ford and Nasa have devoted decades of research, and millions of dollars, to developing the engine, and all retired defeated, having failed to find a way of turning the theoretical principles of the engine into a workable everyday application. Kamen, nevertheless, has spent the past 10 years and, he estimates, up to $40 million working on the problem.

Now he and his engineers have built and tested a range of Stirling engines suitable for mass production that can be run on anything from jet fuel to cow dung. The one in the boot of the small blue car is designed to extend its range and constantly recharge its batteries to make a new kind of hybrid vehicle: one fit for the roads of the 21st century. A Stirling-electric hybrid, Kamen tells me, can travel farther and more efficiently than conventional electric cars; it generates enough power to run energy-hungry devices such as heaters and defrosters that are essential for drivers who, unlike those he calls the ‘tofu heads’ of California, must cope with a cold climate; and even using petrol, the engine runs far cleaner than petrol-electric hybrids such as Toyota’s Prius.

However, Kamen confesses, his new creation isn’t quite finished yet: ‘The Stirling engine’s not hooked up. Which really pisses me off.’

But it could work?

‘It will work,’ he says. ‘Trust me.’

Common Cold Alters the Activity of Genes

Scientists Come Closer to Unlocking Secrets of Common Cold

Canadian and U.S. researchers have found that the human rhinovirus, long blamed for causing the common cold, doesn’t actually cause those annoying sniffles, sneezes, and coughs.

Instead, the ubiquitous virus alters the activity of genes in the body, which then results in the misery that afflicts most people every year or so, according to a study in the first November issue of the American Journal of Respiratory and Critical Care Medicine.
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Human rhinovirus (HRV) causes some 30 percent to 50 percent of common colds and can also worsen more serious conditions, such as asthma.
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A “microarray analysis” of DNA showed no genetic changes eight hours after infection. But, after two days, about 6,500 genes had been affected, either with heightened activity or dampened activity.

The genes most affected by the presence of the virus were ones that make antiviral proteins and pro-inflammatory chemicals that contribute to airway inflammation, the researchers said.

Read: Learning How Viruses Evade the Immune System – Gene Carnival – Black Raspberries Alter Hundreds of Genes Slowing Cancer – Study Finds No Measurable Benefit to Flu Shots

The Life of the Queen Bee

A common mistake amongst non apiarists is the assumed fact that the queen directly controls the hive. Effectively, however, her duty is as an egg making machine. She can lay bout two thousand eggs a day in the spring. This amounts to more than her own weight in eggs each day. Surrounded continuously by workers, she needs for nothing. They give her food and take her waste away. They will also collect a pheromone which they then distribute to stop workers from starting queen cells.
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This very close up [follow link] of a queen bee shows one of its greatest – and smallest – enemies. The bee mite is an external parasite that attacks honey bees. It attaches itself to the bee’s body and sucks out its hemolymph. This is the blood analogue that is used by bees as they have an open circulatory system. Unfortunately the mite is more than just a pain in the neck. It can spread a host of viruses, including “Deformed Wing Virus” and the arrival of mites in a colony can often spell its demise. Scientists believe that the mite may contribute to the Colony Collapse Disorder (otherwise known as CCD) that is spreading throughout the United States.

Monitor-Merrimac Memorial Bridge-Tunnel

photo of Hampton Roads Virginia Bridge-Tunnel

Now that is some cool engineering: a bridge that becomes a tunnel. The Monitor-Merrimac Memorial Bridge-Tunnel is a 4.6 miles (7.4 km) crossing for Interstate 664 in Hampton Roads, Virginia, USA. It is a four-lane bridge-tunnel composed of bridges, trestles, man-made islands, and tunnels under a portion of the Hampton Roads harbor where the James, Nansemond, and Elizabeth Rivers come together in the southeastern portion of Virginia.

If you like this post, please look at our other popular posts, and consider adding our blog feed to your blog reader. Posts such as: Bacteriophages: The Most Common Life-Like Form on Earth, Robot Finds Lost Shoppers and Provides Directions and The Engineer That Made Your Cat a Photographer

It was completed in 1992, after 7 years of construction, at a cost $400 million, and it includes a four-lane tunnel that is 4,800 feet (1,463 m) long, two man-made portal islands, and 3.2 miles (5.1 km) of twin trestle.

Photos by Virginia Department of Transportation. Details from wikipedia. Google satellite view of the bridge-tunnel.

Waste from Gut Bacteria Helps Host Control Weight

A single molecule in the intestinal wall, activated by the waste products from gut bacteria, plays a large role in controlling whether the host animals are lean or fatty, a research team, including scientists from UT Southwestern Medical Center, has found in a mouse study.

When activated, the molecule slows the movement of food through the intestine, allowing the animal to absorb more nutrients and thus gain weight. Without this signal, the animals weigh less.

The study shows that the host can use bacterial byproducts not only as a source of nutrients, but also as chemical signals to regulate body functions. It also points the way to a potential method of controlling weight, the researchers said.

“It’s quite possible that blocking this receptor molecule in the intestine might fight a certain kind of obesity by blocking absorption of energy from the gut,” said Dr. Masashi Yanagisawa, professor of molecular genetics at UT Southwestern and a senior co-author of the study, Proceedings of the National Academy of Sciences, open access: Effects of the gut microbiota on host adiposity are modulated by the short-chain fatty-acid binding G protein-coupled receptor, Gpr41.

Humans, like other animals, have a large and varied population of beneficial bacteria that live in the intestines. The bacteria break up large molecules that the host cannot digest. The host in turn absorbs many of the resulting small molecules for energy and nutrients.

In the Big Fat Lie I mentioned some related ideas:

It also makes perfect sense that our bodies evolved to store energy for worse times (and some of us have bodies better at doing that). Now we are in a new environment where (at least for many people alive today) finding enough calories is not going to be a problem so it would be nice if we could tell our bodies to get less efficient at storing fat

This research seems to be looking for a similar way to attack the obesity epidemic: reduce the efficiency of our bodies converting potential energy in the food we eat to energy we use or store. If we can make that part of the solution that will be nice. So far the reduction in our activity and increase in food intake have not been getting good results. And efforts to increase (from our current low levels) activity and reduce food intake have not been very effective.
Continue reading →

Plants can Signal Microbial Friends for Help

When under attack, plants can signal microbial friends for help

Researchers at the University of Delaware have discovered that when the leaf of a plant is under attack by a pathogen, it can send out an S.O.S. to the roots for help, and the roots will respond by secreting an acid that brings beneficial bacteria to the rescue.
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In a series of laboratory experiments, the scientists infected the leaves of the small flowering plant Arabidopsis thaliana with a pathogenic bacterium, Pseudomonas syringae. Within a few days, the leaves of the infected plants began yellowing and showing other symptoms of disease.

However, the infected plants whose roots had been inoculated with the beneficial microbe Bacillus subtilis were perfectly healthy. Farmers often add B. subtilis to the soil to boost plant immunity. It forms a protective biofilm around plant roots and also has antimicrobial properties, according to Bais.

Using molecular biological tools, the scientists detected the transmission of a long-distance signal, a “call for help,” from the leaves to the roots in the plants that had Bacillus in the soil. The roots responded by secreting a carbon-rich chemical–malic acid.

All plants biosynthesize malic acid, Bais explains, but only under specific conditions and for a specific purpose–in this case, the chemical was actively secreted to attract Bacillus. Magnified images of the roots and leaves showed the ratcheted-up defense response provided by the beneficial microorganisms.
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“Plants can’t move from where they are, so the only way they can accrue good neighbors is through chemistry,” Bais notes.

Huge Tomb Uncovered in Rome

‘Gladiator’ tomb is found in Rome

The tomb of a general thought to have been an inspiration for the main character in the Oscar-winning film Gladiator has been unearthed in Rome.
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The tomb was discovered along the northbound Via Flaminia where construction work has been taking place. Many marble columns, inscriptions and decorations have been beautifully preserved thanks to the mud caused by a centuries-old flood of the River Tiber. It is “the most important ancient Roman monument to come to light for 20 or 30 years”, said senior archaeologist Daniela Rossi.

Workers renovating a rugby stadium have uncovered a vast complex of tombs that mimic the houses, blocks and streets of a real city… Meanwhile, archaeologists restoring imperial residences in the heart of ancient Rome are also reported to have found what they believe to be the underground passageway where the Emperor Caligula was murdered by his guards…

Problems Programming Math

Arithmetic Is Hard – To Get Right by Mark Sofroniou

I’ve been working on arithmetic in Mathematica for more than 12 years. You might think that’s silly; after all, how hard can arithmetic be?
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The standard “schoolbook” algorithms are pretty easy. But they’re inefficient and often unnecessarily inaccurate. So people like me have done a huge amount of work to find algorithms that are more efficient and accurate. And the problem is that these algorithms are inevitably more complicated, and one has to be very careful to avoid insidious bugs.

Take multiplying integers, for example. The standard “schoolbook” long-multiplication algorithm uses n^2 multiplications to multiply two n-digit numbers. But many of these multiplications are actually redundant, and we now know clever algorithms that take n^1.58, n log n, or even fewer multiplications for large n. So this means that if one wants to do a million-digit multiplication, Mathematica can do it in a fraction of a second using these algorithms–while it would take at least a few minutes using standard long multiplication.
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It’s not easy to get reliable numerical computation, and it’s not something one can “bolt on” after the fact. It’s something one has to build in from the beginning, as we’ve done in Mathematica for nearly 20 years.

Reducing Poverty

photo of Rita Bashnet

Today is blog action day, which this year is focused on poverty. We have highlighted various uses of appropriate technology, many of which help those in poverty improve their lives. Such as: Water Pump Merry-go-Round and Smokeless Stove Uses 80% Less Fuel.

I am also very interested in using micro loans to help entrepreneur improve their lives – I have written about Kiva before. Kiva fellows are funded by Kiva (fellows are unpaid) to go to spend time in the countries Kiva facilitates loans for working with the local partners. This post is about Rita Bashnet (in photo) an entrepreneur from Nepal:

Field visits are by far the best part about being a Kiva Fellow. You’re given the opportunity to hop on a motorbike, hike up a village trail, and actually see the impact of a Kiva loan firsthand.
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Five years ago, Ms. Rita took her first loan of NRs. 10,000 (USD $150) and purchased some extra seed and fertilizer in the hopes of expanding her small vegetable patch. With the profits from this initial investment and a second loan from Patan Business and Professional Women (they offer a graduated loan program), she then purchased her first dairy cow.
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After hearing about a program that subsidized the installation of methane gas storage tanks, Ms. Rita took another loan and applied for the program. With this new system, she is now able to capture the valuable gas released from her cow’s waste in a simple controlled-release storage tank. Today she no longer purchases gas from the city and can even sell some during times of shortage.
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Ms. Rita exemplifies the potential of microfinance. A combination of access to capital and strategic investment has allowed her and her family to drastically improve their economic situation in a short five years.

Great story, and exactly my hope for using capitalism to improve the standard of living for people around the globe.

If you haven’t loaned money through Kiva, please consider it now. If you do (or already have a Kiva page), send me your Kiva lender link and I will add it to Curious Cat Kivans. I would love to add more of our readers to that page.