Author Archives: curiouscat

Friday Fun: Bird Using Bait to Fish

In the webcast an Aukuu bird (Black-crowned Night Heron) fishes using bread as bait. They normally hunt by waiting at the side of a lake and fishing. This individual learned how to bait the fish with bread and improve the fishing results. It also passed on that method to other birds that learned how to use the bait method themselves.

Another bird using bait (with turtles trying to get the bait) and another bird using bait (with a stork trying to steal the fish). And another one. The videos seem to be different species of birds to me.

Waste Treatment Plants Result in Super Bacteria

Multiple antibiotic-resistant bacteria has emerged as one of the top public health issues worldwide in the last few decades as the overuse of antibiotics and other factors have caused bacteria to become resistant to common drugs. Chuanwu Xi‘s group chose to study Acinetobacter because it is a growing cause of hospital-acquired infections and because of its ability to acquire antibiotic resistance.

Xi said the problem isn’t that treatment plants don’t do a good job of cleaning the water—it’s that they simply aren’t equipped to remove all antibiotics and other pharmaceuticals entering the treatment plants.

The treatment process is fertile ground for the creation of superbugs because it encourages bacteria to grow and break down the organic matter. However, the good bacteria grow and replicate along with the bad. In the confined space, bacteria share resistant genetic materials, and remaining antibiotics and other stressors may select multi-drug resistant bacteria.

While scientists learn more about so-called superbugs, patients can do their part by not insisting on antibiotics for ailments that antibiotics don’t treat, such as a common cold or the flu, Xi said. Also, instead of flushing unused drugs, they should be saved and disposed of at designated collection sites so they don’t enter the sewer system.

The next step, said Xi, is to see how far downstream the superbugs survive and try to understand the link between aquatic and human superbugs. This study did not look past 100 yards.

Xi’s colleagues include visiting scholar Yongli Zhang; Carl Marrs, associate professor of public health; and Carl Simon, professor of mathematics.

Xi and colleagues found that while the total number of bacteria left in the final discharge effluent declined dramatically after treatment, the remaining bacteria was significantly more likely to resist multiple antibiotics than bacteria in water samples upstream. Some strains resisted as many as seven of eight antibiotics tested. The bacteria in samples taken 100 yards downstream also were more likely to resist multiple drugs than bacteria upstream.

Full press release

Historical Engineering: Hanging Flume

photo of hanging flume overlook in Colorado, by John Hunter, Creative Commons Attribution.

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While driving from Dinosaur National Monument to Mesa Verde National Park last year I passed the sight above with the remnants of a hanging flume. The Montrose Placer Mining Company built a 13 mile canal and flume to deliver water from the San Miguel River for gold mining operations. The last 5 miles of the flume clung to the wall of the canyon itself, running along the cliff face in the photo above (see more photos).

Constructed between 1888 and 1891, the 4 foot deep 5 foot 4 inch wide hanging flume carried 23,640,000 gallons of water in a 24 hour period. The mining operations used water and sluice boxes to separate the gold from lighter materials (dirt and gravel).

The technology was not yet available to pump the water directly from the river at the necessary volume and pressure to wash the gold from the gravel, therefore they constructed the flume to transport the water.

The Great Sunflower Project

photo of sunflower (Helianthus Annuus Taiyo)

Sunflower photo from WikiMedia – Helianthus Annuus ‘Taiyo’

The Great Sunflower Project provides a way for you to engage in the ongoing study of bees and colony collapse disorder. The study uses the annual Lemon Queen sunflowers (Helianthus annuus), that can be grown in a pot on a deck or patio or in a garden (and they will send you seeds).

How do bees make fruits and vegetables?

Bees help flowers make seeds and fruits. Bees go to flowers in your garden to find pollen (the powder on the flower) and nectar which is a sweet liquid. Flowers are really just big signs advertising to bees that there is pollen or nectar available – though sometimes a flower will cheat and have nothing! The markings on a flower guide the bee right into where the pollen or nectar is.

All flowers have pollen. Bees gather pollen to feed their babies which start as eggs and then grow into larvae. It’s the larvae that eat the pollen. Bees use the nectar for energy. When a bee goes to a flower in your garden to get nectar or pollen, they usually pick up pollen from the male part of the flower which is called an anther. When they travel to the next flower looking for food, they move some of that pollen to the female part of the next plant which is called a stigma. Most flowers need pollen to make seeds and fruits.

After landing on the female part, the stigma, the pollen grows down the stigma until it finds an unfertilized seed which is called an ovary. Inside the ovary, a cell from the pollen joins up with cells from the ovary and a seed is born! For many of our garden plants, the only way for them to start a new plant is by growing from a seed Fruits are just the parts of the plants that have the seeds. Some fruits are what we think of as fruits when we are in the grocery store like apples and oranges. Other fruits are vegetables like tomatoes and cucumbers and peppers.

Sun Missing It’s Spots

Image courtesy of SOHO, shows an image of the sun on July 19th 2000 and March 18th 2009.

Sun Oddly Quiet

The sun is the least active it’s been in decades and the dimmest in a hundred years. The lull is causing some scientists to recall the Little Ice Age, an unusual cold spell in Europe and North America, which lasted from about 1300 to 1850. The coldest period of the Little Ice Age, between 1645 and 1715, has been linked to a deep dip in solar storms known as the Maunder Minimum.
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Sunspots, which can be visible without a telescope, are dark regions that indicate intense magnetic activity on the sun’s surface. Such solar storms send bursts of charged particles hurtling toward Earth that can spark auroras, disrupt satellites, and even knock out electrical grids.

Graphene: Engineered Carbon

A material for all seasons

Graphene, a form of the element carbon that is just a single atom thick, had been identified as a theoretical possibility as early as 1947.
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Its unique electrical characteristics could make graphene the successor to silicon in a whole new generation of microchips, surmounting basic physical constraints limiting the further development of ever-smaller, ever-faster silicon chips.

But that’s only one of the material’s potential applications. Because of its single-atom thickness, pure graphene is transparent, and can be used to make transparent electrodes for light-based applications such as light-emitting diodes (LEDs) or improved solar cells.
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Graphene could also substitute for copper to make the electrical connections between computer chips and other electronic devices, providing much lower resistance and thus generating less heat. And it also has potential uses in quantum-based electronic devices that could enable a new generation of computation and processing.

“The field is really in its infancy,” says Michael Strano, associate professor of chemical engineering who has been investigating the chemical properties of graphene. “I don’t think there’s any other material like this.”

The mobility of electrons in graphene — a measure of how easily electrons can flow within it — is by far the highest of any known material. So is its strength, which is, pound for pound, 200 times that of steel. Yet like its cousin diamond, it is a remarkably simple material, composed of nothing but carbon atoms arranged in a simple, regular pattern.

“It’s the most extreme material you can think of,” says Palacios. “For many years, people thought it was an impossible material that couldn’t exist in nature, but people have been studying it from a theoretical point of view for more than 60 years.”

Global Installed Wind Power Now Over 1.5% of Global Electricity Demand

graph of global installed wind power capacity

Chart showing global installed wind energy capacity by Curious Cat Science and Engineering Blog, Creative Commons Attribution. Data from World Wind Energy Association, for installed Mega Watts of global wind power capacity.

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Globally 27,339 MW of capacity were added in 2008, bringing the total to 121,188 MW, a 29% increase. The graph shows the top 10 producers (with the exceptions of Denmark and Portugal) and includes Japan (which is 13th).

In 2007, Europe had for 61% of installed capacity and the USA 18%. At the end of 2008 Europe had 55% of installed capacity, North America 23%, Asia 20%, Australia 1.5%, Latin America .6% and Africa .5%. Country shares of global capacity at the end of 2008: USA 21%, Germany 20%, Spain 14%, China 10%, India 8% (those 5 countries account for 73% of global capacity).

USA capacity grew 50% in 2008, moving it into the global lead for the first time in a decade. China grew 107%, the 3rd year in a row it more than doubled capacity.

European Eels in Crisis After 95% Decline in Last 25 years

Eels in crisis after 95% decline in last 25 years

But the action the Environment Agency is about to take is upsetting those who rely on the eel for their livelihoods. A ban on exporting eels out of Europe – they are a popular dish in the far east – is proposed, along with a plan to severely limit the fishing season and the number of people who will be allowed licences.

It seems pretty obvious we have over-fished the oceans. Without effective regulation we will destroy the future of both the wildlife and our food source.

The eel remains one of the world’s most mysterious creatures. It is generally accepted that European eels – Anguilla anguilla – are born in the Sargasso Sea near Bermuda.

As leaf-like larvae, they are swept by the Gulf Stream towards Europe, a journey that may take a year. When the larvae reach the continental shelf they change into “glass eels” and in the spring begin to move through estuaries and into freshwater.

The animals develop pigmentation, at which point they are known as elvers and are similar in shape to the adult eel. Elvers continue to move upstream and again change colour to become brown or yellow eels.

When the fish reach full maturity – some can live to 40 and grow to 1m long – they migrate back to the ocean. Females are reported to carry as many as 10m eggs. They return to the Sargasso Sea, spawn and die.

Antigen Shift in Influenza Viruses

Antigenic shift is the process by which at least two different strains of a virus, (or different viruses), especially influenza, combine to form a new subtype having a mixture of the surface antigens of the two original strains.

Pigs can be infected with human, avian and swine influenza viruses. Because pigs are susceptible to all three they can be a breeding ground for antigenic shift (as in the recent case of H1N1 Flu – Swine Flu) allowing viruses to mix and create a new virus.

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Surgeon-engineer advances high-tech healing

Catherine Mohr, 40, is herself a rare creature. Part surgeon, part engineer, she designs instruments and procedures for laparoscopic, or minimally invasive, surgery as well as the surgery curriculum at Stanford University School of Medicine.
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The spider – better known as the DaVinci surgical robot – was created by the Sunnyvale company Intuitive Surgical Inc., where her husband, Paul Mohr, is an engineer and she is director of medical research. She designed the special surgical instruments that attach securely to the DaVinci’s strong, wristed arms, and has helped to design the next generation of the robot.

She also designed a procedure for using the robot for gastric-bypass surgery. Her paper on the procedure was published in 2006 in Obesity Surgery, a medical journal. “Someone who needs a gastric bypass has a thick abdominal wall,” Mohr explains. “It can take months for incisions to heal, so you want to do the operation through the smallest incision you can.”

The operation is also ergonomically challenging for the surgeon. “What you’re doing inside is very challenging, and you can’t stand terribly close because these patients are so large,” she says. “It seemed to me that this was something we should do with the robot.”

The surgeon uses controllers to drive the laparoscopic instruments held by the robot, and a screen to view the action. “You don’t cut what you can’t see,” she says.