Did You Know That YOU Are An Ecosystem?
The National Human Genome Research Institute (NHGRI), which is a part of the National Institutes of Health has been studying the various microbes that live in and on people.
Before you run for the soap, let's start at the beginning. Depending on who you ask, our bodies are made up of 50 to 75 trillion cells. However, within the body of a healthy adult, microbial cells are estimated to outnumber human cells by a factor of ten to one. Additionally, these bacterial life forms-- collectively called the human microbiome--possess at least 100 times as many genes as the 20,000 or so in the human genome. (OK, creeping you out, yet?)
Many of these bacteria are what biologists call commensals, that is helpful rather than harmful organisms. For instance, the crook of your elbow is a special ecosystem that provides a bountiful home to six tribes of bacteria. Even after you wash, there are still 1 million bacteria living on every square centimeter.
Dr. Julia A. Segre of NHGRI, suggests that there are at least 20 different niches for bacteria, and maybe many more, on the human skin, each with a characteristic set of favored commensals. The types of bacteria she found in the inner elbow are quite different from those that another researcher identified a few inches away, on the inner forearm.
In fact, human beings depend on their microbiome for various essential services, including digestion. As such, perhaps we need to begin thinking about ourselves as a superorganism consisting of our own cells and those of all of our commensal bacteria.
Oh, about those bacteria on your inner elbow. Notice how the skin there is usually quite soft? The six tribes of bacteria that live there moisturize your skin by processing the raw fats that your skin produces.
Sources:
The New York TImes: www.nytimes.com
http://nihroadmap.nih.gov/hmp/
Asimov, Isaac. The Human Body
So if we're superorganisms, do we get to wear cool capes?- Editors.
And Speaking of Cells...
Janet Iwasa, Szostak Laboratory, Harvard Medical
School and Massachusetts General Hospital.
Above is a three-dimensional view of a model protocell approximately 100 nanometers in diameter. The protocell's fatty acid membrane allows nutrients and DNA building blocks to enter the cell and participate in non-enzymatic copying of the cell's DNA. The newly formed strands of DNA remain in the protocell.
In an effort to understand the origins of life on Earth, a team of researchers at Harvard University have modeled in the laboratory a primitive cell, or protocell, that is capable of building, copying and containing DNA.
Since there are no physical records of what the first primitive cells on Earth looked like, or how they grew and divided, the research team's protocell project offers a useful way to learn about how Earth's earliest cells may have interacted with their environment approximately 3.5 billion years ago.
The protocell's fatty acid membrane allows chemical compounds, including the building blocks of DNA, to enter into the cell without the assistance of the protein channels and pumps required by today's highly developed cell membranes. Also unlike modern cells, the protocell does not use enzymes for copying its DNA.
Some scientists have proposed that ancient hydrothermal vents may have been sites where prebiotic molecules--molecules made before the origin of life, such as fatty acids and amino acids--were formed. The below animation shows a theoretical scenario in which fatty acids are formed on the surface of minerals deep underground, and then brought to the surface by the eruption of a geyser.
Janet Iwasa, Szostak Laboratory, Harvard Medical School
and Massachusetts General Hospital
When fatty acids are in an watery environment, they spontaneously arrange so that their water-loving (hydrophilic), "heads" interact with the surrounding water molecules and their water-fearing (hydrophobic) "tails" are shielded from the water, resulting in the formation of tiny spheres of fatty acids called micelles.
Depending upon chemical concentrations and the acidity or alkalinity of their environment, these micelles can convert into layered membrane sheets or enclosed vesicles. Researchers commonly use vesicles to model the cellular membranes of protocells. A second animation created by Iwasa (below) shows how vesicles may have been formed.
When the team started its work, the researchers were not sure that the building blocks required for copying the protocell's genetic material would be able to enter the cell.
"By showing that this can happen, and indeed happen quite efficiently, we have come a little closer to our goal of making a functional protocell that, in the right environment, is able to grow and divide on its own," said research team leader Jack W. Szostak of the Harvard Medical School.
Source: The National Science Foundation: www.nsf.gov
Starve a Cold, Shake a Virus?
It seems that one day, scientists may be able to destroy viruses through vibration. All objects have resonant frequencies at which they naturally oscillate. Pluck a guitar string and it will vibrate at its resonant frequency.
Resonating can have quite powerful results. A famous, catastrophic example is the Tacoma Narrows Bridge collapse in the 1940's. A wind rocked the bridge back and forth at one of its resonant frequencies causing the bridge to come apart.
It seems that viruses are susceptible to the same kind of mechanical collapse. An experimental group led by K. T. Tsen from Arizona State University have recently shown that pulses of laser light can induce destructive vibrations in virus shells.
Physicist Otto Sankey of Arizona State University says that, "If (a virus) shell can be compromised (by mechanical vibrations), the virus can be inactivated."
Once perfected as a therapy, the virus-killing resonances would not harm normal cells because they have resonant frequencies much lower than those of viruses.
Source:
http://www.livescience.com/health/080205-virus-shattering.html
Biology or Physics?
Here is an entertaining, interactive quiz called "Biology or Physics?" http://www.srcf.ucam.org/~lj237/BoP/ When you click on the site, you'll see a group of photographs. The idea is to figure out whether the pictures are of something biological or not.
Watch the doors! Next stop, Davy Jones' Locker!
Retired New York City subway cars are being used to turn a stretch of barren ocean floor into a bountiful sea oasis complete with grasses, mussels and fish such as sea bass and blackfish. Red Bird Reef, named for the old style "Red Bird" subway cars being used in its construction, lies in Delaware's coastal waters about 80 feet underwater.
“They’re basically luxury condominiums for fish,” Jeff Tinsman, artificial reef program manager for the Delaware Department of Natural Resources and Environmental Control, said as one of 48 of the 19-ton retirees from New York City sank toward the ocean floor.
The summer flounder and bass communities have filled the subway cars so well that Mr. Tinsman is trying to expand the reef's housing capacity. He is having trouble, however, because other states, seeing Delaware’s successes, have started competing for the subway cars, which New York City provides free.
The area of the new reef, has seen a 400-fold increase in the amount of marine food per square foot in the last seven years, according to Delaware state data.
Slideshow
Source: The New York TImes: www.nytimes.com
Coming Together and Picking Up!
Recently more than 10,000 volunteers across Oregon, joined their neighbors, family and friends for an annual "Down By The Riverside" event. Presented by the Oregon Lottery and organised by SOLV – Stop Oregon Litter and Vandalism, the day brings together community members, students, public agencies and businesses to celebrate and improve the region's watersheds, proving that when people get together, things get done!
This year, more than 300 projects took place in every corner of the state. Volunteers removed an impressive 125,000 pounds of trash! Helpers also cleared nearly 80,000 pounds of invasive plants and natural debris along the waterways – which is as much as can fill up over sixty trash cans!
Watershed enhancement projects included removing non-native vegetation, building trails, planting shrubs and seeds, enhancing butterfly gardens, removing debris from lakes and rivers and cleaning up litter. All the projects were designed to help improve cities, parks, and green spaces. Many sites offered snacks, nature walks or a BBQ; some even included boats and divers. One-third of the projects were organized for or by school children participating in service-learning activities; more than 5,700 students participated in this year’s event. These meaningful community-based projects added real-world relevance to the students' classroom lessons.
"Down By The Riverside is one of the most significant statewide watershed improvement projects in the nation," said Sara Ryan, SOLV program coordinator. “It originated after the floods of 1996, when Oregonians gathered to clean up the debris that had washed downstream and onto the floodplains. In the subsequent 13 years, this cleanup event has inspired thousands to join together and work elbow-to-elbow family, friends, and even complete strangers, to make an incredible difference in our communities,” she noted. "This event is SOLV’s largest and the largest of its kind in the United States and each year continues to grow in size and scope.”
Source: www.solv.org
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