Liquid Smoke From Rice Hulls

A couple of tons for the foodflavoring market is not going to do much for the 136.000,000 tons of hulls. Butreducing it to 20,000,000 tons of easily packaged biochar is a wonderfulidea.  One could even charge the productwith urea to remove all doubt regarding its value in soil remediation.

At a treatment level of aroundtwo tons per acre it becomes possible to thus treat ten million acres with biochar.  In ten years we would expect tosee that much land at least to be fully charged with a five to ten percentbiochar load.  Since even one suchtreatment is highly beneficial, much more land can be generally treated.

Rice hulls actually lendthemselves to the biochar process since their size is regular with plenty offine structure.  Thus a commercial fertilizervendor should take up the task of commercializing this.

'Liquid smoke' from rice shows potential health benefits

by Staff Writers

Washington DC (SPX) May 13, 2011

http://www.seeddaily.com/reports/Liquid_smoke_from_rice_shows_potential_health_benefits_999.html

Liquid smoke flavoring made from hickory and other wood - a mainstay flavoringand anti-bacterial agent for the prepared food industryandhome kitchens - may get a competitor that seems to be packed with antioxidant,antiallergenic and anti-inflammatory substances, according to a new study inACS' Journal of Agricultural and Food Chemistry. It is the first analysis ofliquid smoke produced from rice hulls, the hard, inedible coverings of ricegrains.

Mendel Friedman, Seok Hyun Nam and colleagues explain that wood fromtrees is typically used to produce liquid smoke, added to meat and other foodsfor a smoky taste. But other types of plants can also be burned to make thepopular seasoning. Rice is a prime candidate, with 680 millions tons producedworldwide each year.

Hulls account for 136 million tons of that amount and often go towaste. The researchers wondered rice hulls could be put to good use in a liquidform as a food flavoring,and did the first studies needed to determine if rice hullsmoke is safe enough for food use.

The scientists found that liquid smoke from rice hulls may behealthful. Their tests on laboratory cell cultures found that liquid rice hullsmoke worked as an antioxidant that could help fight off diseases. It alsohelped prevent inflammation, which is associated with many different healthproblems did not trigger an allergic response.

"New food usesof a major agricultural byproduct may benefit the environment, farmers, andconsumers," the report stated. "However, it is necessary todemonstrate that rice hull smoke is safe. The present study was designed tocontribute to this assessment."

The authors acknowledge funding from the Rural DevelopmentAdministration, Republic of Korea.

Parkinson's Vulnerability Discovered

I never understood that actualnerve cells based in the spinal column send axons all the way out to end oflimbs.  Thus the steps between the brain andthe ends are potentially very few. 

Thus any thing that inhibits theirfunctioning actually losses information quickly as we are not dealing with adistributed network, but a directed network. Here we explore protocols to induce the same symptoms and as should beobvious, we can select for substances that overcome this problem.

We are still early days but weare surely now much closer to a real answer to this riddle and perhaps we willsee the day when this disease no longer quiets so many voices.

Unique Vulnerability Found in Cells Hit by Parkinson's

Released: 5/12/2011 3:50 PM EDT 

Source: WashingtonUniversity in St. Louis

http://www.newswise.com/articles/view/576782/?sc=dwhn

Newswise — New data offer hints to why Parkinson’s disease soselectively harms brain cells that produce the chemical dopamine, sayresearchers at Washington University School of Medicine in St. Louis.

Dopamine is involved in brain cell communications including the signalsthat control movement. As Parkinson’s kills the dopamine-producing cells,patients begin to develop tremors, problems moving and other symptoms.

The new research shows that a drug known to damage dopamine-producingnerve cells and mimic Parkinson’s disease does so by rapidly damagingcellular energy generators called mitochondria. This damage impairs the abilityof mitochondria to circulate around the cell as they normally would. As aresult, axons, the extended arms nerve cells use to send messages, wither; afew days later, the body or main portion of the cell also dies.

“Much of the research into Parkinson’s disease treatments is focused onsaving the bodies of these cells, but our results suggest that keeping axonshealthy also is essential,”says Karen O’Malley, PhD, of WashingtonUniversity Schoolof Medicine in St. Louis.“When axons die back, dopamine is no longer delivered to the neurons thatneed it. The cell body also has fewer connections to other cells, and it needsthose connections to survive.”

The results were published May 11 in The Journal of Neuroscience.

Many processes and facilities for cellular maintenance are in the bodyof the nerve cell, and their products sometimes have to travel a significantdistance to reach the axon’s end.

“If you think, for example, about one of your peripheral nerves, thecell body is located in the spinal column, but some of the axons extend as faras your big toe,” says O’Malley, professor of neurobiology. “That’s like thecell body sits in an office in St. Louis and theend of the axon is in Chicago.”

O’Malley compares the axon’s system for transporting supplies to arailroad. Mitochondria are part of the railroad’s cargo. They supply the energythat allows the axon to do its work.

For the study, O’Malley gave cultured mouse nerve cells a toxin calledMPP+ that causes Parkinson’s-like symptoms.

“MPP+ is a derivative of a synthetic form of heroin developed inCalifornia in the early 1980s,” O’Malley says. “It came to scientists’attention when teenage abusers of the drug went to the hospital with Parkinson’sdisease symptoms.”

O’Malley found that the toxin stopped the movement of mitochondria inthe axon in 30 minutes. The railroad still functioned, shipping other cargo tothe end of the axon. But most mitochondria either stopped moving or were headedfor the cell body instead of the axon.

O’Malley suspected that this meant the mitochondria were damaged by thechanges caused by the toxin and being shipped back to the cell body for repair.Additional tests supported this theory, showing that the mitochondria had losttheir ability to maintain their membrane potential, a measure of mitochondrialfitness.

The specificity of this toxin for dopamine-producing cells isreinforced by the finding that other types of nerve cells did not have problemstransporting mitochondria after toxin exposure. In a comparison betweendifferent nerve cell types, O’Malley found mitochondria in dopamine-producingnerve cells are smaller in size and travel three times slower. But she can’tyet definitively say that these distinctions play a role in the problems causedby the toxin.

Scientists screened several compounds to see if they could block thetoxin's effects. Only two antioxidants worked, glutathione and N-acetylcysteine. The latter compound has already been shown to be effective in animalmodels of Parkinson’s disease and is used as a treatment for other disorders inpatients.

O’Malley is currently studying whether two genes linked to Parkinson’sdisease affect mitochondria damaged by the toxin.

“We’re going to continue to look for specific differences in thesecells that might help scientists develop better treatments,” O’Malley says.

###

Kim-Han JS, Antenor-Dorsey JA, O’Malley KL. The Parkinsonian mimetic,MPP+, specifically impairs mitochondrial transport in dopamine axons. TheJournal of Neuroscience, May 11, 2011.

Funding from the National Institutes of Health (NIH), the NationalInstitutes of Health Neuroscience Blueprint Core Grant and the Bakewell FamilyFoundation supported this research.

Washington UniversitySchool of Medicine’s 2,100 employedand volunteer faculty physicians also are the medical staff of Barnes-Jewishand St. LouisChildren’s hospitals. The School of Medicine is one of theleading medical research, teaching and patient care institutions in the nation,currently ranked fourth in the nation by U.S. News & World Report. Throughits affiliations with Barnes-Jewish and St. LouisChildren’s hospitals, the School of Medicine is linked toBJC HealthCare.

Human Lung Stem Cells Confirmed

This is an indication that stemcells can be extracted from any organ and then used to rebuild that sameorgan.  Sooner or later we are going toget there.  Obviously, the most pressingorgan is the heart, but lung tissue and kidneys are not far behind.

I suspect that this next fiveyears will see effective tissue replacement been made available for allorgans.  It is really happening that fastand I see little reason to pull my punches on this.  All the initial promise of stem cells is nowemerging as our shill and understanding improves.

Simply ending lung disease willbe a boon as the cost of care is typically catastrophic.  It could even be done on a piece by piecebasis which is likely barbaric but still a possibility.

One of the unstated outcomes ofthe present revolution in medical knowledge is that costly chronic conditions areclose to disappearing and saving huge amounts of cash presently spent tosupport its victims.

Human lung stem cell discovered

by Staff Writers

Boston MA(SPX) May 13, 2011

http://www.spacedaily.com/reports/Human_lung_stem_cell_discovered_999.html

For the first time, researchers at Brigham and Women's Hospital (BWH) haveidentified a human lung stem cell that is self-renewing and capable of formingand integrating multiple biological structures of the lung includingbronchioles, alveoli and pulmonary vessels. This research is published in thethe New England Journal of Medicine.

"This research describes, for the first time, a true human lungstem cell. The discovery of this stem cell has the potential to offer those whosuffer from chronic lung diseases a totally novel treatment option byregenerating or repairing damaged areas of the lung," said Piero Anversa,MD, director of the Center for Regenerative Medicineat Brigham and Women's Hospital and corresponding author.

Using lung tissue from surgical samples, researchers identified andisolated the human lung stem cell and tested the functionality of the stem cellboth in vitro and in vivo. Once the stem cell was isolated, researchersdemonstrated in vitro that the cell was capable of dividing both into newstem cells andalso into cells that would grow into various types of lung tissue.

Next, researchers injected the stem cell into mice with damaged lungs.The injected stem cells differentiated into new bronchioles, alveoli and pulmonaryvessel cells which not only formed new lung tissue, but also integratedstructurally to the existing lung tissue in the mice.

The researchers define this cell as truly "stem"because it fulfills the three categories necessary to fall under stem cellcategorization: first, the cell renews itself; second, it forms into manydifferent types of lung cells; and third, it is transmissible, meaning thatafter a mouse was injected with the stem cells and responded by generating newtissue, researchers were then able to isolate the stem cell in the treatedmouse, and use that cell in a new mouse with the same results.

"These are the critical first steps in developing clinicaltreatments for those with lung disease for which no therapies exist. Furtherresearch is needed, but we are excited about the impact this discovery couldhave on our ability to regenerate or recreate new lung tissues to replacedamaged areas of the lungs," said Joseph Loscalzo, MD, PhD, chair of theDepartment of Medicine at BWH and co-author.

Robot Images from Great Pyramid

I did not even know that thisprogram was on, but it is certainly welcome to see new data.

Beyond that I have difficultyassociating the word tunnel with a passage that is twenty centimeters squareand the word door with an end block.  Ithas fed speculation from the beginning.

I have come to the conclusionthat the great pyramid needs to be taken down block by block and thenreassembled block by block and then fully restored with casing stones.  It would take about ten years and around acouple of billion dollars, but is well within our capabilities.  If that works out well, we can finish therest of the complex.

Once done, we will have all theknowledge that is possible to winkle out and it will be a rather profitable touristattraction for the next 5000 years.

At present we have reason tobelieve that this complex went up in the Early Bronze age a millennia beforeKhufu and represented the culmination of a civilization that dominated the NileDelta and the Mediterranean littoral we know as Libya.  That civilization succumbed in 1159 BC, butwe now know that it extended in time intro the deep past.

Critically, it had a deepmathematical and astronomical tradition. The Great Pyramid was the culmination of that tradition and I suspectthat all these odd structures represent the physical expression of keyrelationships.  Suddenly a twentycentimeter square shaft is no longer strange.

First images from Great Pyramid's chamber of secrets

25 May 2011 by Rowan Hooper

http://www.newscientist.com/article/mg21028144.500-first-images-from-great-pyramids-chamber-of-secrets.html

THEY might be ancient graffiti tags left by a worker or symbols ofreligious significance. A robot has sent back the first images of markingson the wall of a tiny chamber in the Great Pyramid of Giza in Egyptthat have not been seen for 4500 years. It has also helped settle thecontroversy about the only metal known to exist in the pyramid, and shows a"door" that could lead to another hidden chamber.

The pyramid is thought to have been built as a tomb for the pharaohKhufu, and is the last of the seven wonders of the ancient world stillstanding. It contains three main chambers: the Queen's Chamber, the GrandGallery and the King's Chamber, which has two air shafts connecting it with theoutside world. Strangely, though, there are two tunnels, about 20 centimetresby 20 centimetres, that extend from the north and south walls of the Queen'sChamber and stop at stone doors before they reach the outside of the pyramid (seediagram).

The function of these tunnels and doors is unknown, but some believethat one or both could lead to a secret chamber. Zahi Hawass, Egypt'sMinister of State for Antiquities Affairs, describes the doors as the lastgreat mystery of the pyramid.

Several attempts have been made to explore the tunnels using robots. In1993, a robot crawled some 63 metres up the tunnel in the south wall anddiscovered what appeared to be a small stone door set with metal pins. Metal isnot part of any other known structure in the pyramid, and the discovery ignitedspeculation that the pins were door handles, keys or even parts of a powersupply constructed by aliens.

Then in 2002 anotherrobot drilled through the stone block and filmed a small chamberbacked by a large blocking stone, but little else. Now a robot designed byengineer Rob Richardson from the University of Leeds, UK, andcolleagues, and named Djedi after the magician that Khufu consulted when heplanned his tomb, has crawled up the tunnel carrying a bendy "microsnake" camera that can see around corners.

Images sent back by the camera have revealed hieroglyphswritten in red paint and lines in the stone that could be marks leftby stone masons when the chamber was being carved (Annales Du Service desAntiquités De L'Égypte, vol 84, ISBN: 978-977-704-184-3). "If thesehieroglyphs could be deciphered they could help Egyptologists work out whythese mysterious shafts were built," says Richardson.

"Red-painted numbers and graffiti are very common around Giza," says Peter Der Manuelian, an Egyptologist at Harvard Universityand director of the Giza Archives at the Museum of Fine Arts, Boston. "They are often masons' orwork-gangs' marks, denoting numbers, dates or even the names of thegangs."

As the camera can see around corners, the backof the stone door has been observed for the first time, scotching themore fanciful theories about the metal pins, says camera-designer ShaunWhitehead of the exploration company Scoutek, based in Melton Mowbray, UK. "Our newpictures from behind the pins show that they end in small, beautifully madeloops, indicating that they were more likely ornamental rather than electricalconnections."

Whitehead, who worked in collaboration with Dassault Systèmes inVélizy-Villacoublay, France, adds: "Also, the back of the 'door' ispolished so it must have been important. It doesn't look like it was a roughpiece of stone used to stop debris getting into the shaft."

KateSpence, an Egyptologist at the University of Cambridge who was not involvedin the study, suspects that since the narrow tunnels can serve no practicalpurpose, they are almost certainly symbolic. "The metal pins look likesymbolic door handles, and the shafts from the Queen's Chamber are orientednorth-south, not east-west, so I strongly suspect that their function issymbolic and relates to the stars, not the sun," she says.

While the King's Chamber originally contained Khufu's sarcophagus andpossibly his mummy, the Queen's Chamber probably didn't contain the remains ofa queen: Khufu's wives were interred in three smaller pyramids of their own.Instead, Spence speculates that the Queen's Chamber may have contained a"ka" statue of the pharaoh. In this interpretation the shafts werebuilt to allow Khufu's ka, or spirit, to cross to the afterlife.

As for the second "door" at the rear of the chamber, which isrough and unfinished, Spence thinks it is simply the end of the shaft."It's most likely to be a backing stone - there won't be another chamberbehind it, it makes no sense," she says. "However, it's fascinatingfrom a symbolic point of view, and this sort of work will allow us to get atthe intention behind the construction of the pyramid."

Hawass, director of the Djedi project, says that no other pyramid isknown to have a tunnel and doorway like this, which, he says, suggests therecould be a hidden room. "The King's Chamber may have been a dummy room,since the most important thing in the mind of the ancient Egyptians was to hidethe burial chamber," he says. "We have a story that the magicianDjedi met Khufu, who was searching for the god Thoth so he could find thesecret of hiding his pyramid. Based on that maybe there is something hidden inthe pyramid."

Hoyle State Calculated

The real story is that the Hoylestate has finally been calculated and we can expect a much tightened upunderstanding of the sequence of nuclear fusion producing our universe.  The rest of it is a bit of a stretch.  The only guess was that it existed and thatappears answered now the only way that was plausible.  A good news day for theorists.

We are slowly policing up a lotof atomic theory now and with the like of the Rossi Focardi reactor, this areamay again become hot.

Particle theory we can ignore fornow.

Fundamental question on how life started solved

by Staff Writers

Bonn, Germany (SPX) May 10, 2011

http://www.spacedaily.com/reports/Fundamental_question_on_how_life_started_solved_999.html

For carbon, the basis of life, to be able to form in the stars, a certain stateof the carbon nucleus plays an essential role. In cooperation with UScolleagues, physicists from the Universityof Bonn and Ruhr-Universitat Bochum have been able tocalculate this legendary carbon nucleus, solving a problem that has keptscience guessing for more than 50 years. The researchers published theirresults in the coming issue of the scientific journal Physical Review Letters.

"Attempts to calculate the Hoyle state have been unsuccessfulsince 1954," said Professor Dr. Ulf-G. Meissner (Helmholtz-Institut furStrahlen- und Kernphysik der Universitat Bonn).

"But now, we have done it!" The Hoyle state is an energy-richform of the carbon nucleus. It is the mountain pass over which all roads fromone valley to the next lead: From the three nuclei of helium gas tothe much larger carbon nucleus. This fusion reaction takes place in the hotinterior of heavy stars. If the Hoyle state did not exist, only very littlecarbon or other higher elements such as oxygen, nitrogen and iron could haveformed. Without this type of carbon nucleus, life probably also would not havebeen possible.

The search for the "slave transmitter"

The Hoyle state had been verified by experiments as early as 1954, butcalculating it always failed. For this form of carbon consists of onlythree, very loosely linked helium nuclei -more of a cloudy diffuse carbon nucleus. And it does not occurindividually, only together with other forms of carbon. "This is as if youwanted to analyze a radio signal whose main transmitter and several slavetransmitters are interfering with each other," explained Prof. Dr. EvgenyEpelbaum (Institute of Theoretical Physics IIat Ruhr-Universitat Bochum).

The main transmitter is the stable carbon nucleus from which humans -among others - are made. "But we are interested in one of the unstable,energy-rich carbon nuclei; so we have to separate the weaker radio transmittersomehow from the dominant signal by means of a noise filter."

What made this possible was a new, improved calculating approach theresearchers used that allowed calculating the forces between severalnuclear particles moreprecisely than ever. And in JUGENE, the supercomputer at ForschungszentrumJulich, a suitable tool was found. It took JUGENE almost a week of calculating.The results matched the experimental data so well that the researchers can becertain that they have indeed calculated the Hoyle state.

More about how the Universe came into existence

"Now we can analyze thisexciting and essential form of the carbon nucleus in every detail,"explained Prof. Meissner. "We will determine how big it is, and what itsstructure is. And it also means that we can now take a very close look at theentire chain of how elements are formed."

In future, this may even allow answering philosophical questions using science.For decades, the Hoyle state was a prime example for the theory that naturalconstants must have precisely their experimentally determined values, and notany different ones, since otherwise we would not be here to observe theUniverse (the anthropic principle).

"For the Hoyle state this means that it must have exactly theamount of energy it has, or else, we would not exist," said Prof.Meissner. "Now we can calculate whether - in a changed world with otherparameters - the Hoyle state would indeed have a different energy whencomparing the mass of three helium nuclei." If this is so, this wouldconfirm the anthropic principle.

The study was jointly conducted by the University of Bonn,Ruhr-Universita

Pacific Colonization Single Pulse Eight Centuries Ago

What is missing in thesediscussions is the forgotten fact that communication remained two way.  Thus the existence of a new island able toabsorb two thousand new settlers found its way back and this triggered a massmigration.  The success of that migrationthen triggered active exploration in all directions from the new island and thatquickly led to the discovery of New Zealand and others.

The same thing took place and allthese outliers were quickly colonized with sufficient manpower to allow full populationsin three centuries as happened.

My point is that the island discoveriestriggered an inflow of population that abrogated any need to wait fro naturalgrowth to encourage further expansion. It could all have happened over one man’s lifetime.

Pacificcolonisation one big 'pulse'

TOM HUNT

Last updated 05:00 29/12/2010

http://www.stuff.co.nz/national/4498668/Pacific-colonisation-one-big-pulse

Academics are calling for a rewrite of Pacific history after newresearch indicating the immigration wave that colonised islands around New Zealandis out by about 400 years.

Academics are calling for a rewrite of Pacific history after newresearch indicating the immigration wave that colonised islands around New Zealand isout by about 400 years.

An historian says the peer-reviewed and published findings could callinto question the notion of Maori as indigenous people.

The findings showed that islands such as Easter and Marquesas, as wellas Hawaii, were settled hundreds of yearslater than thought, about the same time as New Zealand, researchers said.

The research – led by Janet Wilmshurst from New Zealand's LandcareResearch, and Atholl Anderson, from the Australian National University – showeda rate of dispersal "unprecedented in oceanic prehistory", DrWilmshurst said. It also showed human impact on the islands – through fire,introduced predators and hunting – was faster than earlier believed.

"Whereas species declines were thought to have occurred over athousand years or more, it now appears that in most cases several hundred yearswas all it took."

Published in the Proceedings of the NationalAcademy of Sciences in the United States,the findings came from analysis of 1400 radiocarbon dates from 47 islands –more than 10 times the number of radiocarbon dates of previous studies.

They show Polynesians migrated from Samoa to the Society Islands aboutAD1050, four centuries later than had been thought.

About two centuries later, they colonised other islands, including New Zealand,in one major "pulse". Dr Anderson said possible reasons for leavingthe islands were rapid population growth, technical innovation in sailingboats, climate change and environmental disaster.

Existing models of human colonisation, ecological change and historicallinguistics for the region now required substantial revision, he said.

The timing of the colonisation of the South Pacific had previously beenpoorly understood, with no definite timeline for colonisation in most islandgroups, excluding New Zealand.

Auckland University of Technology history professor Paul Moon said thefindings could have implications for the Waitangi Tribunal because claims,using oral history, had Maori colonisation out by hundreds of years.

"If Maori reached New Zealand waters just 300 years before thefirst Europeans, some people might also start to reconsider the idea of Maoribeing indigenous. It could be interpreted as a different type of `indigenous'from the sort that applies to peoples who inhabited countries exclusively forthousands of years."

Professor Anderson dismissed Dr Moon's claim as"exaggerated", saying the most widely regarded figure for Maorisettlement had already been about 1250.

"Dr Moon's argument that occupation of only hundreds of yearscould disqualify Maori from claiming indigeneity is illogical, since they werethe first people here."

Richard Walter, an Otago University expert in the archaeology of NewZealand colonisation, backed the new findings and also dismissed Dr Moon'ssuggestions.

Monsoon Intensity Linked to Northern Climate

This helps provide a longerhistory of climate shifts that took place in the tropics and some sense of theduration.  The follow up is to complete asimilar mapping to cover the whole of the regions indicated in much finerresolution.  Even better, is to try toavoid conclusions until we have such data.

What is clear is that the variationis comparable to today’s extremes without I assume any reliance on humanactivity although that may turn out to be wrong even back one thousand years.  At most though, we simply do not know.

It is pleasing to see that detailis been slowly provided and a 2500 year span is meaningful whereas a fivehundred year span is only enough to pick up a single trend or two.

Climate Record Suggesting Severe Tropical Droughts asNorthern Temperatures Rise

by Staff Writers

Pittsburgh PA (SPX) May 12, 2011

http://www.terradaily.com/reports/Climate_Record_Suggesting_Severe_Tropical_Droughts_as_Northern_Temperatures_Rise_999.html

A 2,300-year climate record University of Pittsburgh researchersrecovered from an Andes Mountains lake reveals that as temperatures in theNorthern Hemisphere rise, the planet's densely populated tropical regions willmost likely experience severe water shortages as the crucial summer monsoonsbecome drier. The Pitt team found that equatorial regions of South America already are receiving less rainfall than atany point in the past millennium.

The researchers report in the Proceedings of the NationalAcademy of Sciences (PNAS) that anearly 6-foot-long sediment core fromLaguna Pumacocha in Perucontains the most detailed geochemical record of tropical climate fluctuationsyet uncovered. The core shows pronounced dry and wet phases of the SouthAmerican summer monsoons and corresponds with existing geological data ofprecipitation changes in the surrounding regions.

Paired with these sources, the sediment record illustrated thatrainfall during the South American summer monsoon has dropped sharply since1900-exhibiting the greatest shift in precipitation since around 300 BCE-whilethe Northern Hemisphere has experienced warmer temperatures.

"This model suggests that tropical regions are dry to a point wewould not have predicted," Abbott said. "If the monsoons that are socritical to the water supply intropical areas continue to diminish at this pace, it will have devastatingimplications for the water resources of a huge swath of the planet."

The sediment core shows regular fluctuations in rainfall from 300 BCEto 900 CE, with notably heavy precipitation around 550. Beginning in 900,however, a severe drought set in for the next three centuries, with the driestperiod falling between 1000 and 1040.

This period correlates with the well-known demise of regional NativeAmerican populations, Abbott explained, including the Tiwanaku and Wari thatinhabited present-day Boliva, Chile, and Peru.

After 1300, monsoons increasingly drenched the South American tropics.The wettest period of the past 2,300 years lasted from roughly 1500 to the1750s during the time span known as the Little Ice Age,a period of cooler global temperatures.

Around 1820, a dry cycle crept in briefly, but quickly gave way to awet phase before the rain began waning again in 1900. By July 2007, when thesediment core was collected, there had been a steep, steady increase in dryconditions to a high pointnot surpassed since 1000.

To create a climate record from the sediment core, the team analyzedthe ratio of the oxygen isotope delta-O-18 in each annual layer of lake-bedmud.

This ratio has a negative relationship with rainfall: Levels ofdelta-O-18 are low during the wetter seasons and high when monsoon rain islight. The team found that the rainfall history suggested by the lake corematched that established by delta-O-18 analyses from CascayungaCave in the Peruvian lowlands and theQuelccaya Ice Cap locatedhigh in the Andes.

The Pumacocha core followed the climatological narrative of thesesources between the years 980 and 2006, but provided much more detail, Abbottsaid.

The team then established a connection between rainfall and NorthernHemisphere temperatures by comparing their core to the movement of theIntertropical Convergence Zone (ITCZ),a balmy strip of thunderstorms near the equator where winds from the Northernand Southern Hemispheres meet.

Abbott and his colleagues concluded that warm Northern temperaturessuch as those currently recorded lure the ITCZ-the main source ofmonsoons-north and ultimately reduce the rainfall on which tropical areas rely.

The historical presence of the ITCZ has been gauged by measuring thetitanium concentrations of sea sediment, according to the PNAS report. Highlevels of titanium in the Cariaco Basin north of Venezuela show that the ITCZlingered in the upper climes at the same time the South American monsoon was atits driest, between 900 and 1100.

On the other hand, the wettest period at Pumacocha-between 1400 and1820, which coincided with the Little Ice Age-correlates with the ITCZ'ssojourn to far south of the equator as Northern Hemisphere temperatures cooled.

Study coauthor Mark Abbott, a professor of geology and planetaryscience in Pitt's School of Arts and Sciences whoalso codesigned the project, said that he and his colleagues did not anticipatethe rapid decrease in 20th-century rainfall that they observed. Abbott workedwith lead author and recent Pitt graduate Broxton Bird; Don Rodbell, studycodesigner and a geology professor at Union College in Schenectady, N.Y.;recent Pitt graduate Nathan Stansell; Pitt professor of geology and planetaryscience Mike Rosenmeier; and Mathias Vuille, a professor of atmospheric andenvironmental science at the State University of New York at Albany. Both Birdand Stansell received their PhD degrees in geology from Pitt in 2009.