Chameleon Magnets: Ability to Switch Magnets 'On' or 'Off' Could Revolutionize Computing

Theoretical physicist Igor Zutic has been exploring ways to use magnets to revolutionize computing (Credit: Image courtesy of University at Buffalo)

Science Daily  — What causes a magnet to be a magnet, and how can we control a magnet's behavior? These are the questions that University at Buffalo researcher Igor Zutic, a theoretical physicist, has been exploring over many years.

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He is one of many scientists who believe that magnets could revolutionize computing, forming the basis of high-capacity and low-energy memory, data storage and data transfer devices.

In a recent commentary in Science, Zutic and fellow UB physicist John Cerne, who studies magnetism experimentally, discuss an exciting advancement: A study by Japanese scientists showing that it is possible to turn a material's magnetism on and off at room temperature.

A material's magnetism is determined by a property all electrons possess: something called "spin." Electrons can have an "up" or "down" spin, and a material is magnetic when most of its electrons possess the same spin. Individual spins are akin to tiny bar magnets, which have north and south poles.

In the Japanese study, which also appears in the current issue of Science, a team led by researchers at Tohoku University added cobalt to titanium dioxide, a nonmagnetic semiconductor, to create a new material that, like a chameleon, can transform from a paramagnet (a nonmagnetic material) to a ferromagnet (a magnetic material) at room temperature.

To achieve change, the researchers applied an electric voltage to the material, exposing the material to extra electrons. As Zutic and Cerne explain in their commentary, these additional electrons -- called "carriers" -- are mobile and convey information between fixed cobalt ions that causes the spins of the cobalt electrons to align in one direction.

In an interview, Zutic calls the ability to switch a magnet "on" or "off" revolutionary. He explains the promise of magnet- or spin-based computing technology -- called "spintronics" -- by contrasting it with conventional electronics.

Modern, electronic gadgets record and read data as a blueprint of ones and zeros that are represented, in circuits, by the presence or absence of electrons. Processing information requires moving electrons, which consumes energy and produces heat.

Spintronic gadgets, in contrast, store and process data by exploiting electrons' "up" and "down" spins, which can stand for the ones and zeros devices read. Future energy-saving improvements in data processing could include devices that process information by "flipping" spin instead of shuttling electrons around.

In their Science commentary, Zutic and Cerne write that chameleon magnets could "help us make more versatile transistors and bring us closer to the seamless integration of memory and logic by providing smart hardware that can be dynamically reprogrammed for optimal performance of a specific task."

"Large applied magnetic fields can enforce the spin alignment in semiconductor transistors," they write. "With chameleon magnets, such alignment would be tunable and would require no magnetic field and could revolutionize the role ferromagnets play in technology."

In an interview, Zutic says that applying an electric voltage to a semiconductor injected with cobalt or other magnetic impurities may be just one way of creating a chameleon magnet.

Applying heat or light to such a material could have a similar effect, freeing electrons that can then convey information about spin alignment between ions, he says.

The so-far elusive heat-based chameleon magnets were first proposed by Zutic in 2002. With his colleagues, Andre Petukhov of the South Dakota School of Mines and Technology, and Steven Erwin of the Naval Research Laboratory, he elucidated the behavior of such magnets in a 2007 paper.

The concept of nonmagnetic materials becoming magnetic as they heat up is counterintuitive, Zutic says. Scientists had long assumed that orderly, magnetic materials would lose their neat, spin alignments when heated -- just as orderly, crystalline ice melts into disorderly water as temperatures rise.

The carrier electrons, however, are the key. Because heating a material introduces additional carriers that can cause nearby electrons to adopt aligned spins, heating chameleon materials -- up to a certain temperature -- should actually cause them to become magnetic, Zutic explains. His research on magnetism is funded by the Department of Energy, Office of Naval Research, Air Force Office of Scientific Research and the National Science Foundation

Significant Role Played by Oceans in Ancient Global Cooling

ScienceDaily — Thirty-eight million years ago, tropical jungles thrived in what are now the cornfields of the American Midwest and furry marsupials wandered temperate forests in what is now the frozen Antarctic. The temperature differences of that era, known as the late Eocene, between the equator and Antarctica, were only half of what they are today. A debate has long been raging in the scientific community on what changes in our global climate system led to such a major shift from the more tropical, greenhouse climate of the Eocene to the modern and much cooler climates of today.

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New research published in the journal Science, led by Rensselaer Polytechnic Institute scientist Miriam Katz, is providing some of the strongest evidence to date that the Antarctic Circumpolar Current (ACC) played a key role in the major shift in the global climate that began approximately 38 million years ago. The research provides the first evidence that early ACC formation played a vital role in the formation of the modern ocean structure.

The paper, titled "Impact of Antarctic Circumpolar Current development on late Paleogene ocean structure," is published in the May 27, 2011, issue of Science.

"What we have found is that the evolution of the Antarctic Circumpolar Current influenced global ocean circulation much earlier than previous studies have shown," said Katz, who is assistant professor of earth and environmental science at Rensselaer. "This finding is particularly significant because it places the impact of initial shallow ACC circulation in the same interval when the climate began its long-term shift to cooler temperatures."

There has been a debate over the past 40 years on what role the Antarctic Circumpolar Current had in the underlying cooling trend on Earth. Previous research has placed the development of the deep ACC (greater than 2,000 meters water depth) in the late Oligocene (approximately 23-25 million years ago). This is well after the global cooling pattern had been established. With this research, Katz and her colleagues used information from ocean sediments to place the global impact of the ACC to approximately 30 million years ago, when it was still just a shallow current.

Oceans and global temperatures are closely linked. Warmer ocean waters result in warmer air temperatures and vice versa. In the more tropical environs of the Eocene, ocean circulation was much weaker and currents were more diffuse. As a result, heat was more evenly distributed around the world. This resulted in fairly mild oceans and temperatures worldwide, according to Katz. Today, ocean temperatures vary considerably and redistribute warm and cold water around the globe in significant ways.

"As the global ocean currents were formed and strengthened, the redistribution of heat likely played a significant role in the overall cooling of the Earth," Katz said.

And no current is more significant than the ACC. Often referred to as the "Mixmaster" of the ocean, the ACC thermally isolates Antarctica by preventing warm surface waters from subtropical gyres to pass through its current. The ACC instead redirects some of that warm surface water back up toward the North Atlantic, creating the Antarctic Intermediate Water. This blocking of heat enabled the formation and preservation of the Antarctic ice sheets, according to Katz. And it is this circumpolar circulation that Katz's research concludes was responsible for the development of our modern four-layer ocean current and heat distribution system.

To come to her conclusions, Katz looked at the uptake of different elemental isotopes in the skeletons of small organisms found in ocean sediments. The organisms, known as benthic foraminifera, are found in extremely long cores of sediments drilled from the bottom of the ocean floor.

During their lifetime, foraminifera incorporate certain elements and elemental isotopes depending on environmental conditions. By analyzing the ratios of different isotopes and elements, the researchers are able to reconstruct the past environmental conditions that surrounded the foraminifera during their life. Specifically, they looked at isotopes of oxygen and carbon, along with ratios of magnesium versus calcium. More detailed information on Katz's isotopic analysis methods can be found at http://green.rpi.edu/archives/fossils/index.html.

Analysis of these isotopes from sediment cores extracted directly off the North American Atlantic coast showed the earliest evidence for the Antarctic Intermediate Waters, which circulates strictly as a direct consequence of the ACC. This finding is the first evidence of the effects of shallow ACC formation. The findings place development of the ACC's global impact much closer to the time that Antarctica separated from South America. It had previously been thought that the currents moving through this new continental gateway could not be strong enough at such shallow depths to affect global ocean circulation.

Katz points out that the larger cooling trend addressed in the paper has been punctuated by many short, but often significant, episodes of global warming. Such ancient episodes of warming are another significant aspect of her research program, and play an important role in understanding the modern warming of the climate occurring on the planet.

"By reconstructing the climates of the past, we can provide a science-based means to explore or predict possible system responses to the current climate change," Katz said.

Katz is joined in the research by Benjamin Cramer of Theiss Research; J.R. Toggweiler of Geophysical Fluid Dynamics Lab/NOAA; Chengjie Liu of ExxonMobil Exploration Co.; Bridget Wade of University of Leeds; and Gar Esmay, Kenneth Miller, Yair Rosenthal, and James Wright of Rutgers University

Scientists Argue Against Conclusion That Bacteria Consumed Deepwater Horizon Methane

Fire boat response crews battle the blazing remnants of the off shore oil rig Deepwater Horizon April 21, 2010. (Credit: U.S. Coast Guard photo)

ScienceDaily (May 29, 2011) — A technical comment published in the May 27 edition of the journal Science casts doubt on a widely publicized study that concluded that a bacterial bloom in the Gulf of Mexico consumed the methane discharged from the Deepwater Horizon well.

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The debate has implications for the Gulf of Mexico ecosystem as well as for predictions of the effect of global warming, said marine scientist and lead author Samantha Joye, University of Georgia Athletic Association Professor in Arts and Sciences.

Based on methane and oxygen distributions measured at 207 stations in the Gulf of Mexico, a study published in the January 21, 2011 edition of Science concluded that "nearly all" of the methane released from the well was consumed in the water column within approximately 120 days of the release. In the current paper inScience, Joye and co-authors from 12 other institutions make the case that uncertainties in the hydrocarbon discharge from the blowout, oxygen depletion fueled by processes other than methane consumption, a problematic interpretation of genetic data and shortcomings of the model used by the authors of the January study challenge the attribution of low oxygen zones to the oxidation of methane gas.

"Our goal is to understand what happened to the methane released from the Macondo discharge and in the larger framework, to better understand the factors that regulate microbial methane consumption following large-scale gas releases," said Joye, a professor in the UGA Franklin College of Arts and Sciences. "I believe there is still a lot to learn about the environmental factors that regulate methane consumption in the Gulf's waters and elsewhere."

Joye and her co-authors note that low levels of oxygen are known to occur in the Gulf of Mexico because of bacterial consumption of carbon inputs from the Mississippi River as well as the bacterial consumption of hydrocarbons that naturally seep from the seafloor. The researchers point out that given the uncertainty in oxygen and methane budgets, strong supporting evidence is required to attribute oxygen depletion to methane removal; however, a study published in the October 8, 2010 edition of Science showed low measured rates of methane consumption by bacteria. Joye and her co-authors note that samples from the control stations and the low-oxygen stations that were analyzed for unique genetic markers in the January 2011 study showed no significant difference in the abundance of methane consuming bacteria. Joye and her colleagues also argue that the model the study used neglected important factors that affect the transport and biodegradation of methane, and that it only provided a tentative match of the observational data.

Methane is a potent greenhouse gas, and understanding the fate of the methane released from the Deepwater Horizon well has implications for the entire planet, since global warming is likely to accelerate the release of methane that is currently trapped in hydrates on the seafloor. Based on the conclusion that bacteria had rapidly consumed the methane released from the Deepwater Horizon well, the January 2011 Science paper suggested that methane released from the oceans may not be likely to amplify an already warming climate.

Joye and her colleagues note that several other studies have found that considerable amounts of methane released from natural deep-sea vents are not consumed by microbes. The most vulnerable store of methane hydrates is not in the Gulf of Mexico, they also point out, but in the deposits that underlie the shallow waters of the Arctic.

"A range of data exists that shows a significant release of methane seeping out at the seafloor to the atmosphere, indicating that the microbial biofilter is not as effective," Joye said. "Importantly for the future of the planet, there is even less evidence for a strong biofilter of methane hydrate destabilized in the shallow Arctic settings."

Joye's co-authors include Ira Leifer, University of California, Santa Barbara; Ian MacDonald, Jeffery Chanton and Joel Kostka, Florida State University; Christof Meile, University of Georgia; Andreas Teske, University of North Carolina, Chapel Hill; Ludmila Chistoserdova and Evan Solomon, University of Washington, Seattle; Richard Coffin, U.S. Naval Research Laboratory; David Hollander, University of South Florida; Miriam Kastner, Scripps Institution of Oceanography, University of California, San Diego; Joseph Montoya, Georgia Institute of Technology; Gregor Rehder, Leibniz Institute for Baltic Sea Research; Tina Treude, Leibniz Institute of Marine Sciences and; Tracy Villareal, University of Texas at Austin.

Teasing Apart Galaxy Collisions: Spitzer Photo Atlas of Galactic 'Train Wrecks'

This montage shows three examples of colliding galaxies from a new photo atlas of galactic "train wrecks." The new images combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted. The panel at far left shows NGC 470 (top) and NGC 474 (bottom); at top right are NGC 3448 and UGC 6016; at bottom right are NGC 935 and IC 1801. In this representative-color image, far-ultraviolet light from GALEX is blue, 3.6-micron light from Spitzer is cyan, 4.5-micron light from Spitzer is green, and red shows light at 5.8 and 8 microns from Spitzer. (Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA)

ScienceDaily  — Five billion years from now, our Milky Way galaxy will collide with the Andromeda galaxy. This will mark a moment of both destruction and creation. The galaxies will lose their separate identities as they merge into one. At the same time, cosmic clouds of gas and dust will smash together, triggering the birth of new stars.

To understand our past and imagine our future, we must understand what happens when galaxies collide. But since galaxy collisions take place over millions to billions of years, we can't watch a single collision from start to finish. Instead, we must study a variety of colliding galaxies at different stages. By combining recent data from two space telescopes, astronomers are gaining fresh insights into the collision process.

"We've assembled an atlas of galactic 'train wrecks' from start to finish. This atlas is the first step in reading the story of how galaxies form, grow, and evolve," said lead author Lauranne Lanz of the Harvard-Smithsonian Center for Astrophysics (CfA).

Lanz presented her findings May 25 at the 218th meeting of the American Astronomical Society.

The new images combine observations from NASA's Spitzer Space Telescope, which observes infrared light, and NASA's Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because different components of a galaxy are highlighted.

GALEX's ultraviolet data captures the emission from hot young stars. Spitzer sees the infrared emission from warm dust heated by those stars, as well as from stellar surfaces. Therefore, GALEX's ultraviolet data and Spitzer's infrared data highlight areas where stars are forming most rapidly, and together permit a more complete census of the new stars.

In general, galaxy collisions spark star formation. However, some interacting galaxies produce fewer new stars than others. Lanz and her colleagues want to figure out what differences in physical processes cause these varying outcomes. Their findings will also help guide computer simulations of galaxy collisions.

"We're working with the theorists to give our understanding a reality check," said Lanz. "Our understanding will really be tested in five billion years, when the Milky Way experiences its own collision."

Lanz's co-authors are Nicola Brassington (Univ. of Hertfordshire, UK); Andreas Zezas (Univ. of Crete, Greece, and CfA); Howard Smith and Matt Ashby (CfA); Christopher Klein (UC Berkeley); and Patrik Jonsson, Lars Hernquist, and 

Biological Computers: Genetically Modified Cells Communicate Like Electronic Circuits

Genetically modified cells can be made to communicate with each other as if they were electronic circuits. (Credit: University of Gothenburg

 

ScienceDaily  — Genetically modified cells can be made to communicate with each other as if they were electronic circuits. Using yeast cells, a group of researchers at the University of Gothenburg, Sweden, has taken a groundbreaking step towards being able to build complex systems in the future where the body's own cells help to keep us healthy. The study was presented recently in an article in the scientific journal Nature.

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"Even though engineered cells can't do the same job as a real computer, our study paves the way for building complex constructions from these cells," says Kentaro Furukawa at the University of Gothenburg's Department of Cell- and Molecular Biology, one of the researchers behind the study. "In the future we expect that it will be possible to use similar cell-to-cell communication systems in the human body to detect changes in the state of health, to help fight illness at an early stage, or to act as biosensors to detect pollutants in connection with our ability to break down toxic substances in the environment."

Combining biology and technology

Synthetic biology is a relatively new area of research. One application is the design of biological systems that are not found in nature. For example, researchers have successfully constructed a number of different artificial connections within genetically modified cells, such as circuit breakers, oscillators and sensors.

Some of these artificial networks could be used for industrial or medical applications. Despite the huge potential for these artificial connections, there have been many technical limitations to date, mainly because the artificial systems in individual cells rarely work as expected, which has a major impact on the results.

Biotechnology challenges the world of computers

Using yeast cells, the research team at the University of Gothenburg has now produced synthetic circuits based on gene-regulated communication between cells. The yeast cells have been modified genetically so that they sense their surroundings on the basis of set criteria and then send signals to other yeast cells by secreting molecules. The various cells can thus be combined like bricks of Lego to produce more complicated circuits. Using a construction of yeast cells with different genetic modifications, it is possible to carry out more complicated "electronic" functions than would be the case with just one type of cells.

The University of Gothenburg research team is headed by professor Stefan Hohmann, and also comprises Kentaro Furukawa and Jimmy Kjellén.

The article Distributed biological computation with multicellular engineered networks, published in the scientific journal Natureon 8 December, was the result of a partnership with two Spanish research teams at Universitat Pompeu Fabra in Barcelona. The work forms part of the EU CELLCOMPUT 

Biological Circuits for Synthetic Biology

Berkeley Lab researchers are using RNA molecules to engineer genetic networks – analogous to microcircuits - into E. coli. (Credit: Image courtesy 

Science Daily — "If you don't like the news, go out and make some of your own," said Wes "Scoop" Nisker. Taking a page from the book of San Francisco radio legend Scoop Nisker, biologists who find themselves dissatisfied with the microbes nature has provided are going out and making some of their own. Members of the fast-growing "synthetic biology" research community are designing and constructing novel organisms and biologically-inspired systems -- or redesigning existing organisms and systems -- to solve problems that natural systems cannot. The range of potential applications for synthetic biological systems runs broad and deep, and includes such profoundly important ventures as the microbial-based production of advanced biofuels and inexpensive versions of critical therapeutic drugs.

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Synthetic biology, however, is still a relatively new scientific field plagued with the trial and error inefficiencies that hamper most technologies in their early stages of development. To help address these problems, synthetic biologists aim to create biological circuits that can be used for the safer and more efficient construction of increasingly complex functions in microorganisms. A central component of such circuits is RNA, the multipurpose workhorse molecule of biology.

"A widespread natural ability to sense small molecules and regulate genes has made the RNA molecule an important tool for synthetic biology in applications as diverse as environmental sensing and metabolic engineering," says Adam Arkin, a computational biologist with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab), where he serves as director of the Physical Biosciences Division. Arkin is also a professor at the University of California (UC) Berkeley where he directs the Synthetic Biology Institute, a partnership between UC Berkeley and Berkeley Lab.

In his multiple capacities, Arkin is leading a major effort to use RNA molecules for the engineering of programmable genetic networks. In recent years, scientists have learned that the behavior of cells is often governed by multiple different genes working together in networked teams that are regulated through RNA-based mechanisms. Synthetic biologists have been using RNA regulatory mechanisms to program genetic networks in cells to achieve specific results. However, to date these programming efforts have required proteins to propagate RNA regulatory signals. This can pose problems because one of the primary goals of synthetic biology is to create families of standard genetic parts that can be combined to create biological circuits with behaviors that are to some extent predictable. Proteins can be difficult to design and predict. They also add a layer of complexity to biological circuits that can delay and slow the dynamics of the circuit's responses.

"We're now able to eliminate the protein requirement and directly propagate regulatory signals as RNA molecules," Arkin says.

Working with their own variations of RNA transcription attenuators -- nucleotide sequences that under a specific set of conditions will stop the RNA transcription process -- Arkin and his colleagues engineered a system in which these independent attenuators can be configured to sense RNA input and synthesize RNA output signals. These variant RNA attenuators can also be configured to regulate multiple genes in the same cell and -- through the controlled expression of these genes -- perform logic operations.

"We have demonstrated the ability to construct with minimal changes orthogonal variants of natural RNA transcription attenuators that function more or less homogeneously in a single regulatory system, and we have shown that the composition of this system is predictable," Arkin says. "This is the first time that the three regulatory features of our system, which are all properties featured in a semiconductor transistor, have been captured in a single biological molecule."

A paper describing this breakthrough appears in theProceedings of the National Academy of Science (PNAS).

The success of Arkin and his colleagues was based on their making use of an element in the bacterial plasmid (Staphylococcus aureus) known as pT181. The element in pT181 was an antisense RNA-mediated transcription attenuation mechanism that controls the plasmid's copy number. Plasmids are molecules of DNA that serve as a standard tool of synthetic biology for, among other applications, encoding RNA molecules. Antisense RNA consists of non-coding nucleotide sequences that are used to regulate genetic elements and activities, including transcription. Since the plasmid pT181 antisense-RNA-mediated transcription attenuation mechanism works through RNA-to-RNA interactions, Arkin and his colleagues could use it to create attenuator variants that would independently regulate the transcription activity of multiple targets in the same cell -- in this case, in Escherichia coli, one of the most popular bacteria for synthetic biology applications.

"It is very advantageous to have independent regulatory units that control processes such as transcription because the assembly of these units into genetic networks follows a simple rule of composition," Arkin says.

While acknowledging the excellent work done on other RNA-based regulatory mechanisms that can each perform some portion of the control functions required for a genetic network, Arkin believes that the attenuator variants he and his colleagues engineered provide the simplest route to achieving all of the required control functions within a single regulatory mechanism.

"Furthermore," he says, "these previous efforts were fundamentally dependent on molecular interactions through space between two or more regulatory subunits to create a network. Our approach, which relies on the processive transcription process, is more reliable."

Arkin and his colleagues say their results provide synthetic biologists with a versatile new set of RNA-based transcriptional regulators that could change how future genetic networks are designed and constructed. Their engineering strategy for constructing orthogonal variants from natural RNA system should also be applicable to other gene regulatory mechanisms, and should add to the growing synthetic biology repertoire.

"Although RNA has less overall functionality than proteins, its nucleic acid-based polymer physics make mechanisms based on RNA simpler and easier to engineer and evolve," Arkin says. "With our RNA regulatory system and other work in progress, we're on our way to developing the first complete and scalable biological design system. Ultimately, our goal is to create a tool revolution in synthetic biology similar to the revolution that led to the success of major integrated circuit design and deployment."

Much of this research was supported by was supported by the Synthetic Biology Engineering Research Center (SynBERC) 

Ocean Acidification Will Likely Reduce Diversity, Resiliency in Coral Reef Ecosystems

A new study of Papua New Guinea's "champagne reefs" in Nature Climate Change by the University of Miami, the Australian Institute of Marine Science and the Max-Planck Institute for Marine Microbiology in Germany concludes that ocean acidification, along with increased ocean temperatures, will likely severely reduce the diversity and resilience of coral reef ecosystems within this century. These reefs provide sobering illustrations of how coral reefs may look in 100 years if ocean acidification conditions continue to worsen. (Credit: Katharina Fabricius/Australian 

ScienceDaily— A new study from University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science scientists Chris Langdon, Remy Okazaki and Nancy Muehllehner and colleagues from the Australian Institute of Marine Science and the Max-Planck Institute for Marine Microbiology in Germany concludes that ocean acidification, along with increased ocean temperatures, will likely severely reduce the diversity and resilience of coral reef ecosystems within this century.

The research team studied three natural volcanic CO₂ seeps in Papua New Guinea to better understand how ocean acidification will impact coral reefs ecosystem diversity. The study details the effects of long-term exposure to high levels of carbon dioxide and low pH on Indo-Pacific coral reefs, a condition that is projected to occur by the end of the century as increased human-made CO₂ emissions alter the current pH level of seawater, turning the oceans acidic.

"These 'champagne reefs' are natural analogs of how coral reefs may look in 100 years if ocean acidification conditions continue to get worse," said Langdon, UM Rosenstiel School professor and co-principal investigator of the study.

The study shows shifts in the composition of coral species and reductions in biodiversity and recruitment on the reef as pH declined from 8.1 to 7.8. The team also reports that reef development would cease at a pH below 7.7. The IPCC 4th Assessment Report estimates that by the end of the century, ocean pH will decline from the current level of 8.1 to 7.8, due to rising atmospheric CO₂ concentrations.

"The seeps are probably the closest we can come to simulating the effect of human-made CO₂ emissions on a coral reef," said Langdon. "They allow us to see the end result of the complex interactions between species under acidic ocean conditions."

The reefs detailed in this study have healthy reefs nearby to supply larvae to replenish the reefs. If pH was low throughout the region -- as projected for year 2100 -- then there would not be any healthy reefs to reseed damaged ones, according to Langdon.

The research was funded by the Australian Institute of Marine Science, the University of Miami, and the Max-Planck Institute of Marine Microbiology through the Bioacid Project 

பாண்டிச் செல்வி

அது ஒரு மென்பொருள் ஆய்வகம் , அன்று வளாகத்தேர்வில் தேர்வாகிவந்த புதியவர்களால் வண்ணமயமாகியிருந்தது. ஒரிருவருடம் பணியாற்றிய அனுபவமுள்ளவர்கள் புதியவர்களுக்கு பயிற்சியளிக்க பணிக்கப்பட்டிருந்தனர். இப்படித்தான் அகிலனிடம் வந்துசேர்ந்தாள் செல்வி. அகிலன்..ஐந்துஇலக்கத்தின் உச்சத்தில் சம்பளம்வாங்கும் இன்றையதலைமுறை. தோற்றப்பொலிவும் காந்தப்பேச்சும் என யாரையும் கவர்ந்துவிடுவான். ஒருவாரம் கடந்தபின்னும் செல்வியிடம் அவன் வித்தைகள் எதுவும் எடுபடவில்லை. அந்தவார இறுதியில் புதியவர்களுக்கான வரவேற்பு விருந்து..மாமல்லபுரம் கடற்கரை கேளிக்கைவிடுதியில் .  இரண்டிரண்டாய் ..கூட்டங்கூட்டமாய் என பேச்சு சுவாரசியமாய்  ஓடிக்கொண்டிருந்தது.தோழிகளுடன் செல்வியும் பேசிக்கொண்டிருந்தாள். அவளைக்கவனித்த அகிலனுக்கு, அவளிடமிருந்து  கண்ணை எடுக்கவே மனமில்லை  . அந்த மாநிறமும் திராவிடமுகமும் அவனைக்கட்டியிழுத்தது.  "செல்வி வாயேன்..கடற்கரைப்பக்கம் போய்டுவருவோம் " , என்று அவளை அழைத்துப்போனான். வேலை..படிப்பு நண்பர்கள்..என்று ஏதேதோ பேசினாலும் அகிலன் மனம் பேச்சில்ஒட்டவில்லை. மெதுவாக அவள் இடையில் கைபோட்டுவளைத்தான். தீப்பட்டதுபோல உதறிஎழுந்தவள் ஆவேசமாய்  , " ஏய் என்னனு நெனைச்ச என்னை ? , நான் மதுரைக்காரியாக்கும் ..போன நிமிசத்துவரைக்கும் கையில கருக்கருவா புடிச்சி புல்லறுத்துக்கிட்டிருந்தவ . இதெல்லாம் எங்கிட்ட வச்சிக்காத ஆஞ்சிப்புடுவேன்ஆஞ்சி " , என்று கத்திச்செல்ல.. ஆடிப்போனான் அகிலன். "கடவுளே..என்னா பொண்ணுடா இவ , கட்டினா இவளைத்தான் கட்டணும் " ..உறுதிகொண்ட அகிலன் வேகமாய் அவளைத்தொடர்ந்து ஓடினான் ...செல்வி செல்வி என்று கத்தியவாறே...!   பெண்ணின் பெருந்தக்க யாவுள கற்பெனும்  திண்மை உண்டாகப் பெறின்.   கற்பெனும் திண்மை மெய்க்காதலையும் பெற்றுத்தரும்.                       நட்புடன்..யாழினி..

Following Your Nature

Following Your Nature

"If you do not act according to My direction and do not fight, then you will be falsely directed. By your nature, you will have to be engaged in warfare." (Lord Krishna, Bhagavad-gita, 18. 59)

Lord Krishna, the Supreme Personality of Godhead, is not only the Supreme Lord for the entire earth’s population, including even the animal kingdom, but He can quickly and capably assume any and all important roles. Even when unexpectedly thrust into the role of spiritual master, or guru, He is more than up for the challenge. On one particular occasion, His disciple was perplexed in thought, unable to decide on the proper course of action. Technically, the student had made up his mind to follow a certain path, but since this decision was based on his own nature, a mindset temporarily sidetracked from the divine consciousness, he wasn’t sure of himself. To find the answer, he turned to his dear friend, his charioteer for an upcoming battle. Yet this was no ordinary servant; it was Krishna Himself kindly taking a subordinate role to help out His cousin, the glorious warrior known the world over for his fighting ability. When presenting His subsequent talk, which would later become famous as the Bhagavad-gita, or the Song of God, Shri Krishna not only pointed to the authoritative statements of the Vedas, a scriptural tradition which He personally instituted at the beginning of creation, but He also used cutting logic to get His points across.

The checkmate scenario presented to Arjuna, the doubtful warrior, made the proper course of action to take obvious beyond a doubt. The scene for the talk was a battlefield which saw millions of soldiers huddled together to start the greatest war the world had ever seen. Arjuna was fighting for the Pandavas, the side deemed the “good guys”. They had the rightful claim to the throne of the city of Hastinapura, but due to the backhanded methods employed by the competing Kurus headed by Duryodhana, the Pandavas were put into all sorts of difficulty and denied their chance to rule. After all diplomatic efforts were exhausted, the battle to end all battles was ready to commence. There was one slight problem, though. Arjuna became faint of heart, not wanting to kill his family members and spiritual guides fighting for the opposing army. He was all set to drop his weapons and retire to the woods. Indeed, he had convinced himself of the validity of this plan of action based on his own logic and understanding. His nature was that of a chivalrous fighter, but Arjuna temporarily lost sight of the proper goal in life and the duties assigned to him.

“Sanjaya said: Arjuna, having thus spoken on the battlefield, cast aside his bow and arrows and sat down on the chariot, his mind overwhelmed with grief.” (Bg. 1.46)

Lord Krishna kindly stepped in after being sought out for advice from Arjuna. Though the noble soldier was ready to quit, he still could be convinced otherwise with persuasive words coming from a proper authority figure. Therefore Arjuna accepted Krishna as his spiritual master, the guru to guide him down the right path, one that would eliminate the mental distresses he was feeling and keep him committed to dharma, or religiosity. Krishna started by presenting the basic truths of spiritual life: that the living entity is not the body, and that the spirit soul goes through the cycle of reincarnation perpetually until pure God consciousness is achieved. The desires on the mind at the time of death indicate what type of body will be assumed in the future. One who takes on the spiritual consciousness, wherein all thoughts are directed at the Supreme Personality of Godhead, will naturally think of God at the time of death. Therefore they will receive a spiritual form in the next life.

The difference between a spiritual body and a material one can best be understood by studying the natures of the two realms. Though we see much variety around us in terms of manifestations, there are really only two places to reside, one spiritual and one material. The material world is populated with individual spirit souls, who are by constitution meant to reside in the imperishable land, and gross matter, which is inanimate and incapable of any force or motion without instigation from spirit. Since the manifestations of matter can come in varying mixtures of the three modes of nature: goodness, passion and ignorance, there is immense variety in the phenomenal world. The variations are so great than the human brain, which is the most advanced in terms of its potential for acquiring intelligence, has not even the slightest idea of the full breadth and scope of the material creation. There are too many planets to count, with each one inhabited by different life forms. Just as the human being is not the only species on earth, the other planets in the countless universes have living entities which have different bodily makeups. Some jivas, or living entities, have bodies composed almost completely of fire, while others even have forms made mostly of air.

“Those who study the Vedas and drink the soma juice, seeking the heavenly planets, worship Me indirectly. They take birth on the planet of Indra, where they enjoy godly delights.” (Lord Krishna, Bg. 9.20)

The Christian tradition has saints and angels, who are both deemed heavenly and majestic figures. According to Vedic information, such life forms are not at all difficult to comprehend. After all, with a slight adjustment in material makeup, you can have one body that is extremely powerful and another that is totally weak. If an individual is pious during one lifetime, they get promotion to a higher planetary system in the next. Since the heavenly realm allows for increased sense gratification, a body commensurate with the properties of the land is required. Therefore there can be so many heavenly species, each with their own unique brand of abilities. The Vedas cap the list of total species at 8,400,000.

There is a dividing line, however, between the material and spiritual worlds. On the surface, the spiritual sky isn’t all that different from the phenomenal world. Matter is also found there, but it is of a different quality. Gross matter in the mundane world is known as prakriti, and in the spiritual world it is known as daivi prakriti. Ordinary matter is dull and lifeless, and thus considered separate from the individual occupying and associating with it. But in the spiritual land, there is no difference between the bodily forms and their owners. Daivi prakriti is eternal, so the living entities who are encased in such matter remain tied to their bodies without the need for exiting. What leads to the different natures of matter in the two realms is the desire of the living entities. The jivas in the spiritual sky all want to serve Krishna or one of His personal Vishnu forms. In the material land, they all want to serve their own senses. Indeed, as soon as the desire is shifted in earnest towards pleasing Krishna, elevation to the spiritual sky is guaranteed.

Lord Krishna very nicely explained these high concepts to Arjuna to enlighten him. Spiritual teachers can give instructions and just tell their disciples what to do and what to avoid, but it is much more beneficial to the student if straight information can be imparted first. If the disciple then comes to the proper conclusion on their own, after having been given all the facts, their dedication to the resolved upon path will be a lot stronger. It’s similar to how when arguing with people it is better to ask them roundabout questions, getting them to agree with certain points in the beginning to lead them to the ultimate conclusion, rather than getting into their face and telling them that they’re stupid or wrong.

As the final instruction, the checkmate position that would remove all doubt from Arjuna’s mind, Krishna told his dear friend that if he didn’t fight because of the faulty concoctions of dharma he had made, he would be following his own nature anyway. Krishna essentially presented Arjuna with the choice that all jivas residing in the material world have. We can either follow Krishna’s instructions and carry out our prescribed duties, or we can follow our own nature. Arjuna’s bodily makeup was that of a fighter, a member of the warrior caste. Even if he didn’t listen to Krishna, he was not suited for any other business except fighting. On the other hand, if he followed Krishna’s advice, he could use his natural tendencies for the right purpose.

Krishna’s instruction provides the basic formula for achieving success in the precious human form of life. In the absence of Krishna consciousness, the mind will wander and come up with conclusions that it is not wholly convinced of. The nature belonging to a particular form of body develops from the beginning of life. It is seen that famous athletes were inclined towards their particular sport at the youngest possible age. This means that their body types were conducive to performing a particular activity. Lord Krishna says that the natures of human beings fall into one of four general categories, or varnas. There is the class of intelligent men, or brahmanas, the administrators and warriors, or kshatriyas, the merchants and businessmen, orvaishyas, and the laborers, or shudras. One should follow his nature and not try to forcefully take to the life of another class. The corresponding varna can be determined by a spiritual master during the person’s youth, thereby allowing for proper training to be received.

By giving up, Arjuna wanted to take to the life of a brahmana, who is peaceful and nonviolent. But Arjuna was not suited for this lifestyle. Society needs brave people to protect the innocent. We can praise equality movements all we want, but at the end of the day, we see caste divisions in virtually every sphere. Even when walking into a supermarket there are class distinctions. There is the customer and the cashier. Both parties are not equal in their positions nor in their work. Without proper authorization or training, the customer is not allowed to become a cashier. For starters, they wouldn’t know how to operate the registers, and secondly their inclination would be to not pay any money for the goods being purchased. The cashier has the opposite interest; their goal is to collect money for the owner of the establishment. Therefore the class distinctions in this one particular scenario must be adhered to; otherwise there will be disharmony.

By default, the jiva will follow the nature belonging to the particular body it has assumed. But from Arjuna’s example, we see that if one’s nature isn’t coupled to the Supreme Consciousness, intelligence can get easily clouded and lead the person astray. Even if he didn’t listen to Krishna, Arjuna would eventually have to fight. He wasn’t cut out for becoming a mendicant and begging for a living. He was born to fight against those deserving punishment. If he gave up prior to the war he had every right to fight in, he would have to suffer greatly later on. Similarly, the jiva who simply follows his nature guided by the material elements assumed at the time of birth will have to suffer periodically.

When direction is taken from Krishna, the same nature becomes purified because it can be used towards furthering the ultimate goal of attaining Krishna consciousness. Arjuna would go on to heed Krishna’s advice and fight valiantly, without any attachment to the result. He used his inherent qualities for the right purpose, and subsequently his thoughts never deviated from the lotus feet of the Supreme Lord, who is so attractive that He captivates the hearts and minds of people from all spheres of society, including those following spiritual traditions besides the Vedas. Indeed, all forms of religion are meant to bring about a deep and unbreakable bond of affection towards the Supreme Spirit. Who better to bring about that attachment than the all-attractive Krishna, the most wonderful and beautiful form of Godhead to behold?

The question may be raised as to how to determine the proper course of action for ourselves. Who will guide us when we don’t know what to do? What if we can’t find a spiritual master to approach? This certainly does present a problem, as our natures can’t be guided in the proper direction without some sort of input from a higher authority. Yet there is one quality that we all share, that of a deep, loving attachment for the Supreme Lord found within the heart. The Supersoul, or Paramatma, is God’s expansion residing within the hearts of every living entity. Therefore knowledge can also be acquired from within. The act of chanting, “Hare Krishna Hare Krishna, Krishna Krishna, Hare Hare, Hare Rama Hare Rama, Rama Rama, Hare Hare”, is universally appealing, as it is in line with everyone’s inherent qualities. Chanting this sacred formula forms the bedrock of the discipline known as bhakti-yoga, or devotional service. Even in the absence of a personally present spiritual guide, simply chanting this mantra day in and day out can bring about a spiritual awakening, a connection with the divine consciousness in the form of the Supersoul within the heart.

Without adherence to bhakti, we will be forced to follow our own material nature, which has proven to be faulty so many times. If it weren’t, we would never be in any doubt. We would never hesitate or make mistakes. The choice is ours: we can follow the path that’s already led to so much heartache, grief and doubt, or we can simply surrender unto Krishna and be guided on the proper path. Either way, we’ll have to follow some nature, so we might as well side with the one connected to Krishna. Arjuna did, and he was eternally benefitted for it.