What shapes a bone? Diet and genetics dictate adult jaw shape

ScienceDaily (Aug. 5, 2011) — Researchers at Johns Hopkins found that use over time and not just genetics informs the structure of jaw bones in human populations. The researchers say these findings may be used to predict the diet of an ancient population, even if little evidence exists in the fossil record. It can also make it easier for scientists to pinpoint the genetic relationship between fossils.

Their results were published online June 23 in the American Journal of Physical Anthropology.

"Our research aimed to see how much of the mandible's -- or jaw bone's -- shape is plastic, a response to environmental influences, such as diet, and how much is genetic. We used archaeological jaw bones from two different regions to answer that question," explains Megan Holmes, graduate student at the Johns Hopkins Center for Functional Anatomy and Evolution, and lead author of the paper. "Before we can make inferences about what the shape of a bone tells us, like what environment the individual lived in, who it's related to or what it ate, we have to understand what creates that shape. The idea that function influences the shape of jaw bones is great for the archeological record in terms of discovering the diet of a population, and it's also really useful for reconstructing the fossil record -- finding which fossils are related to which, and how."

The group chose to study the Arikara and Point Hope American Indian populations, since they were genetically isolated from other groups and ate different diets. They investigated bones from the regions dating back to the 1600s and 1700s, times for which the diets are known from other records. The Point Hope population in Alaska ate a "hard" diet that included tough dried meat. They also used their teeth for a variety of nonfood-related tasks, such as stripping leather. The Arikara, from the Dakota area of the United States, ate a softer diet, which consisted of farming supplemented with light hunting.

The researchers precisely measured jaw bones from 63 members of the Point Hope population and 42 individuals from the Arikara population using an X-ray gun as well as calipers, and they used those measurements to extrapolate the proportions of the entire jaw. "The jaw bones were similar in children before they were old enough to start chewing, but different in adulthood, which implies that this divergence is likely a functional result of their diet and the use of their jaw, rather than genetics," says Holmes.

The changes to the jaw bones were explained using a theory drawn from engineering, which directly relates the geometry of a bone to the stresses put on it during use. The team was able to investigate very specific parts of the jaw bones and relate them to specific dietary habits. In the Point Hope population, for example, they found round, wide jaw bones -- a result of having to exert more force to chew a harder diet. The Arikara, on the other hand, did not show this expansion, which they attributed to the lighter chewing requirement of a softer diet.

"Genetics creates a blueprint of the bone, but a lot of things influence the bone's construction," says Holmes. "Mechanical pressure from muscle stress and strain from day-to-day activities can remodel the bone's surface and internal structure. Knowing how much the shape of a mandible we find is related to diet and how much genetically connects it to fossils found elsewhere can really help us parse out the family tree."

This study was funded by the Johns Hopkins Center of Functional Anatomy and Evolution.

Christopher B. Ruff, Ph.D., also of the Johns Hopkins University School of Medicine's Center of Functional Anatomy and Evolution, was the faculty advisor and co-author of the study.

What shapes a bone? Diet and genetics dictate adult jaw shape

Did past climate change encourage tree-killing fungi?

The researchers do not rule out the possibility that today's changing climate could cause a similar increase in pathogenic soil bacteria that could devastate forests already stressed by a warming climate and pollution.

The study, available online Aug. 5, will be published in the September 2011 print edition of the journal Geology of the Geological Society of America.

The death of the forests -- primarily composed of conifers, which are distant relatives of today's pines and firs -- was part of the largest extinction of life on Earth, which occurred when today's continents were part of one supercontinent, Pangaea. The so-called Permian extinction likely was triggered by immense volcanic eruptions in what is now Siberia. The huge amounts of gas and dust thrown into the atmosphere altered global climate, and some 95 percent of marine organisms and 70 percent of land organisms eventually went extinct.

The scientists claim that thread-like or filamentous microfossils commonly preserved in Permian rock are relatives of a group of fungi, Rhizoctonia, that today is known for members that attack and kill plants.

"Modern Rhizoctonia include some of the most ubiquitous plant pathogens, causing root, stem and foliar diseases in a wide variety of plants," said coauthor Cindy Looy, UC Berkeley assistant professor of integrative biology. "Based on patterns of present-day forest decline, it is likely that fungal disease has been an essential accessory in woodland destabilization, accelerating widespread tree mortality during the end-Permian crisis."

The conifer forests, which covered the semi-arid equatorial region of Pangaea, were eventually replaced by lycopods -- four foot-tall relatives of today's diminutive club mosses -- as well as by seed ferns (pteridosperms). The conifers didn't recover for another 4 to 5 million years.

Looy and her colleagues -- Henk Visscher of the Laboratory of Palaeobotany and Palynology at Utrecht University in the Netherlands and Mark Sephton of the Impacts and Astromaterials Research Centre at Imperial College, London -- caution that today's changing climate could also lead to increased activity of pathogenic soil microbes that could accelerate the death of trees already stressed by higher temperatures and drought.

"Pathogenic fungi are important elements of all forest ecosystems," said Visscher. "When an entire forest becomes weakened by environmental stress factors, onslaught of damaging fungal diseases can result in large-scale tissue death and tree mortality."

The researchers dispute the conclusion of other researchers who claim that the thread-like microfossils are the remains of algae. Furthermore, while the researchers previously thought that Reduviasporonites were fungi that took advantage of dying forests, they now believe the fungi actively helped destroy the forests.

"Previously, mass occurrences of Reduviasporonites had been ascribed to wood-rotting fungi living off an excessive abundance of dead wood," said Looy, a paleobotanist who focuses on pollen and spores as keys to understanding past plant communities. "However, the notion that the microfossils represent Rhizoctonia-like resting structures suggest a much more active role for fungi in the ecological crisis:"

The researchers' conclusion comes largely from the fact that they have found living fungi in the genus Rhizoctonia that have a dormant or resting stage during their life cycles in which they look nearly identical to Reduviasporonites.

"One of our problems was that the microfossils didn't resemble the hyphae of known fungi," Looy said. "Buta few years ago, we realized that we were looking in the wrong direction; that we should have been looking at fungal resting structures, not normal hyphae."

Fungi typically spread by means of thread-like hyphae, which can form immense underground networks of mycelia, especially in forests where the fungi live in a symbiotic relationship with tree roots. Each filament is a chain of cells with hard walls made of chitin, the same substance that insects use for their exoskeleton.

When these hyphae branch and intertwine, they may form resting structures known assclerotia. Sclerotia of modern soil-borne fungi such as Rhizoctonia look nearly identical to the disc-shaped structures found among the Reduviasporonites microfossils. Sclerotia are energy storage structures that can help fungi survive extreme conditions.

The team concluded that the loss of trees and the roots that hold soil in place led to severe topsoil erosion, which carried the sclerotia to the sea.

The researchers acknowledge that conifer forests probably suffered from other environmental stresses as a result of the long-term volcanic eruptions, which spewed carbon dioxide and methane into the atmosphere and likely destroyed some of Earth's protective ozone layer. Nevertheless, they wrote in their paper, "… whatever (the) sequence of events that triggered ecosystem destabilization on land, the aggressiveness of soil-borne pathogenic fungi must have been an integral factor involved in Late Permian forest decline worldwide."

The work was funded by Utrecht University, Imperial College London and the University of California, Berkeley.

Did past climate change encourage tree-killing fungi?

Discovery points way to graphene circuits: Materials scientists find new way to control electronic properties of graphene 'alloys'

Graphene's stock shot sky-high last year when the nanomaterial attracted the Nobel Prize in physics. Graphene is a layer of carbon atoms that is just one atom thick. When stacked atop one another, graphene sheets form graphite, the material found in pencils the world over. Thanks to the tools of nanotechnology, scientists today can make, manipulate and study graphene with ease. Its unique properties make it ideal for creating faster, more energy-efficient computers and other nanoelectronic devices.

But there are hurdles. To make tiny circuits out of graphene, engineers need to find ways to create intricate patterns of graphene that are separated by a similarly thin nonconductive material. One possible solution is "white graphene," one-atom-thick sheets of boron and nitrogen that are physically similar to graphene but are electrically nonconductive.

In a new paper in the journal Nano Letters, Rice materials scientist Boris Yakobson and colleagues describe a discovery that could make it possible for nanoelectronic designers to use well-understood chemical procedures to precisely control the electronic properties of "alloys" that contain both white and black graphene.

"We found there was a direct relationship between the useful properties of the final product and the chemical conditions that exist while it is being made," Yakobson said. "If more boron is available during chemical synthesis, that leads to alloys with a certain type of geometric arrangement of atoms. The beauty of the finding is that we can precisely predict the electronic properties of the final product based solely upon the conditions -- technically speaking, the so-called 'chemical potential' -- during synthesis."

Yakobson said it took about one year for him and his students to understand exactly the distribution of energy transferred between each atom of carbon, boron and nitrogen during the formation of the "alloys." This precise level of understanding of the "bonding energies" between atoms, and how it is assigned to particular edges and interfaces, was vital to developing a direct link from synthesis to morphology and to useful product.

With interest in graphene running high, Yakobson said, the new study has garnered attention far and wide. Graduate student Yuanyue Liu, the study's lead co-author, is part of a five-student delegation that just returned from a weeklong visit to Tsinghua University in Beijing. Yakobson said the visit was part of an ongoing collaboration between Tsinghua researchers and colleagues in Rice's George R. Brown School of Engineering.

Rice postdoctoral fellow Somnath Bhowmick also co-authored the paper. The research was funded by the Department of Energy and the Office of Naval Research, and the computational resources were supported by the National Institute for Computational Sciences and the National Science Foundation.

Discovery points way to graphene circuits: Materials scientists find new way to control electronic properties of graphene 'alloys'

NASA's Juno spacecraft launches to Jupiter

Juno's detailed study of the largest planet in our solar system will help reveal Jupiter's origin and evolution. As the archetype of giant gas planets, Jupiter can help scientists understand the origin of our solar system and learn more about planetary systems around other stars.

"Today, with the launch of the Juno spacecraft, NASA began a journey to yet another new frontier," NASA Administrator Charles Bolden said. "The future of exploration includes cutting-edge science like this to help us better understand our solar system and an ever-increasing array of challenging destinations."

After Juno's launch aboard an Atlas V rocket, mission controllers now await telemetry from the spacecraft indicating it has achieved its proper orientation, and that its massive solar arrays, the biggest on any NASA deep-space probe, have deployed and are generating power.

"We are on our way, and early indications show we are on our planned trajectory," said Jan Chodas, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We will know more about Juno's status in a couple hours after its radios are energized and the signal is acquired by the Deep Space Network antennas at Canberra."

Juno will cover the distance from Earth to the moon (about 250,000 miles or 402,336 kilometers) in less than one day's time. It will take another five years and 1,740 million miles (2,800 million kilometers) to complete the journey to Jupiter. The spacecraft will orbit the planet's poles 33 times and use its collection of eight science instruments to probe beneath the gas giant's obscuring cloud cover to learn more about its origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.

With four large moons and many smaller moons, Jupiter forms its own miniature solar system. Its composition resembles that of a star, and if it had been about 80 times more massive, the planet could have become a star instead.

"Jupiter is the Rosetta Stone of our solar system," said Scott Bolton, Juno's principal investigator from the Southwest Research Institute in San Antonio. "It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined, and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary -- to interpret what Jupiter has to say."

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

The NASA Deep Space Network -- or DSN -- is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. JPL is a division of the California Institute of Technology in Pasadena.

For more information about Juno, visit http://www.nasa.gov/juno and http://missionjuno.swri.edu .

NASA's Juno spacecraft launches to Jupiter

IBM, Watson, Palmisano, Research IBM CEO: How to live to be 100

MOUNTAIN VIEW, Calif. – In a speech commemorating IBM's 100^th anniversary, chief executive Samuel J. Palmisano said companies need to deliver value, collaborate broadly and embrace change to survive the long haul.

Only a handful companies have lasted as long as Big Blue. Just two of the top 25 U.S. industrial firms of 1900 remained when IBM turned 50 in 1961, and only six of the top 25 Fortune 500 companies of that year remain in business today.

"We're off to the best year in 100 years and our stock is at a 100-year high even after the sell off today," said Palmisano in a talk at the Computer History Museum Thursday night.

Linking research and development is one key to success, said the IBM CEO. "You have to turn discovery into profits, that’s the fundamental role of a company," he said.

In an era of crowd-sourcing, Palmisano lobbied for the importance of basic research as fundamental to success. "Today we need deep science more than ever, serious highly institutionalized research and collaborations that are multidisciplinary," he said.

"Competition is a wonderful stimulant, but it's not sufficient," Palmisano said. "The wild West of competition needs to be complemented with collaboration even between competitors," he added.

The IBM executive quoted a 1962 speech by Thomas Watson Jr. highlighting another key pillar of success.

A company must be prepared to change everything about itself except its core beliefs, Watson said. That means companies should never define themselves by a product, technology or a business model, but only by their corporate values, said Palmisano, only the ninth chief executive in IBM's history.

IBM has not always embraced change boldly, the CEO said. "In the '90's we held on to the mainframe business model long after it was obsolete," he said.

When it finally did jettison the "old mainframe model of entitlement" it meant slashing the IBM workforce from 412,000 to 214,000 people. "That’s structural change," said Palmisano.

"We're back to 426,000 people today, so there's life after a change of business model," he said. Indeed, "in our last quarter our mainframe business was up 50 percent, so it's hardly dead," he added.

More recently IBM jettisoned its hard disk drive and PC businesses when they became commodities, selling them to Japan's Hitachi and China's Lenovo respectively. "The key is don’t get wedded to your successes in a business model or technology," he said.

Not all of IBM's history was glamorous or high tech. The company sold clocks and cheese slicers in 1914. "We had one hell of a cheese slicer," Palmisano quipped.

It also had bombs like the PC Junior and OS/2 operating system.

"We haven’t been known as a marketing company," said Palmisano. "There's an old joke that IBM products aren’t launched, they just escape from the lab," he said.

"We have another principle that’s called 'Sam wants his money back,'" he joked.

For example, the artificial intelligence researchers that got millions to build the Watson system that beat human contestants in "Jeopardy" are gearing up to make their return on that investment. Their work will be productized next year for applications in finance and a physician's assistant, he said.

IBM, Watson, Palmisano, Research IBM CEO: How to live to be 100

Tzu-Yin Chiu, David Wang, Richard Chang, Hua Hong, SMIC, TSMC CEO, semiconductor, foundry SMIC appoints TSMC veteran as CEO

LONDON – Foundry chip company Semiconductor Manufacturing International Corp. has appointed Tzu-Yin Chiu as CEO with immediate effect. The appointment of Chiu should resolve uncertainties that began as a result of the death of former chairman Jiang Shang Zhou.

Trading in shares in SMIC (Shanghai, China) ceased at the company's request on June 30, after SMIC reported the death of its chairman and that the company's president and CEO David Wang had failed to win re-election to its board of directors. In July Wenyi Zhang was appointed chairman of the board of directors and interim CEO.

The incoming Chiu, aged 55, has a prestigious academic record and 27 years of experience in the semiconductor foundry business. However, Chiu could be set to have a difficult start at SMIC as the foundry industry is widely tipped to be about to go into an oversupply situation. This usually affects smaller foundries, such as SMIC sooner and longer than it does market leader Taiwan Semiconductor Manufacturing Co. Ltd.

Chiu has experience of both companies having begun his foundry career at TSMC and spent four years at SMIC between 2001 and 2005. SMIC was founded in 2000 by Richard Chang.

Chiu earned his bachelor's degree in electrical and system's Engineering at Rensselaer Polytechnic Institute in New York and M.A. and Ph.D. degrees in electrical engineering and computer science at the University of California at Berkeley. He received an EMBA degree from Columbia University in New York and began his professional career as a research scientist at AT&T Bell Laboratories in Murray Hill, New Jersey, where he rose to become the department head for high-speed electronics research.

Chiu then joined Taiwan Semiconductor Manufacturing Co. Ltd. as senior director of fab operations. Chiu subsequently joined SMIC and served as senior vice president of operations from 2001 to 2005. He was chief operating officer at Hua Hong International Management Shanghai Co. Ltd. to 2007 and president and COO of Silterra Malaysia Sdn. Bhd from 2007 to 2009. Chiu was president and CEO of Shanghai Hua Hong NEC Electronics Co. Ltd. from 2009 to 2011.

Chiu also served as an independent director of Actions Semiconductor Co. Ltd. from 2005 to 2009. He holds ten semiconductor technology patents, and has published more than thirty technical articles.   

Related links and articles:

SMIC appoints chair, acting CEO

SMIC trading halted after chairman's death

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SMIC to invest $1 billion in Wuhan fab

Datang pumps cash into SMIC, TSMC declines


Tzu-Yin Chiu, David Wang, Richard Chang, Hua Hong, SMIC, TSMC CEO, semiconductor, foundry SMIC appoints TSMC veteran as CEO