Friday, August 22, 2014

70,000 Year-Old African Settlement Unearthed

During ongoing excavations in northern Sudan, Polish archaeologists from the Institute of Archaeology and Ethnology in Poznań, have discovered the remains of a settlement estimated to 70,000 years old. This find, according to the researchers, seems to contradict the previously held belief that the construction of permanent structures was associated with the so-called Great Exodus from Africa and occupation of the colder regions of Europe and Asia.

The site known as Affad 23, is currently the only one recorded in the Nile Valley which shows that early Homo sapiens built sizeable permanent structures, and had adapted well to the wetland environment.

This new evidence points to a much more advanced level of human development and adaptation in Africa during the Middle Palaeolithic.

Locating the “village”

“Discoveries in Affad are unique for the Middle Palaeolithic. Last season, we came across a few traces of light wooden structures. However, during the current research we were able to precisely locate the village and identify additional utility areas: a large flint workshop, and a space for cutting hunted animal carcasses, located at a distance” – explained project director Dr. Marta Osypińska.

The researchers are also working on a list of animal species that these early humans hunted. Despite the relatively simple flint tools produced using the Levallois technique, these humans were able to hunt both large, dangerous mammals such as hippos, elephants and buffalo, as well as small, nimble monkeys and cane rats (large rodents that inhabited the wetlands).

Palaeolithic hunters

This year, the researchers intended to precisely date the time period in which the Palaeolithic hunters lived here, using optically stimulated luminescence.

“At this stage we know that the Middle Palaeolithic settlement episode in Affad occurred at the end of the wet period, as indicated by environmental data, including the list of hunted animal species. But in the distant past of the land such ecological conditions occurred at least twice” about 75 millennia and about 25 millennia ago. Determining the time when people inhabited the river bank near today’s Affad is the most important objective of our project “- said prehistory expert Piotr Osypiński.

The Polish team is working with scientists from Oxford Brookes University, who are helping to analyse the geological history of the area. The results will help determine climatic and environmental conditions that prevailed in the Central Nile Valley during the late Pleistocene and hope to identify factors that contributed to the excellent state of preservation at the Affad 23 site.
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References:

Past Horizons. 2014. “70,000 Year-Old African Settlement Unearthed”. Past Horizons. Posted: July 20, 2014. Available online: http://www.pasthorizonspr.com/index.php/archives/07/2014/70000-year-old-african-settlement-unearthed

Thursday, August 21, 2014

Little too late: Pathogenic bacterium in 700-year-old skeleton identified

Researchers at the University of Warwick, working with Italian anthropologist Raffaella Bianucci and others, have recovered a genome of the bacterium Brucella melitensis from a 700-year-old skeleton found in the ruins of a Medieval Italian village.

Reporting this week in mBio, the online open-access journal of the American Society for Microbiology, Warwick Medical School's Professor Mark Pallen and his colleagues describe using a technique called shotgun metagenomics to sequence DNA from a calcified nodule from the pelvic region of a middle-aged male skeleton excavated from the settlement of Geridu in Sardinia, an island off the coast of Italy. Geridu is thought to have been abandoned in the late 14th century. Shotgun metagenomics allows scientists to sequence DNA without looking for a specific target.

From this sample, the researchers recovered the genome of Brucella melitensis, which causes an infection called brucellosis in livestock and humans. In humans, brucellosis is usually acquired by ingesting unpasteurized dairy products or from direct contact with infected animals. Symptoms include fevers, arthritis and swelling of the heart and liver. The disease is still found in the Mediterranean region.

"Normally when you think of calcified material in human or animal remains you think about tuberculosis, because that's the most common infection that leads to calcification," says Professor Pallen, PhD. "We were a bit surprised to get Brucella instead."

The skeleton contained 32 hardened nodules the size of a penny in the pelvic area, though Pallen says it's unclear if they originated in the pelvis, or higher up in the chest or other body part.

In additional experiments, the research team showed that the DNA fragments extracted had the appearance of aged DNA -- they were shorter than contemporary strands, and had characteristic mutations at the ends. They also found that the medieval Brucella strain, which they called Geridu-1, was closely related to a recent Brucella strain called Ether, identified in Italy in 1961, and two other Italian strains identified in 2006 and 2007.

Pallen and others have used shotgun metagenomics before to detect pathogens in contemporary and historical human material. Last summer, he and his colleagues published a report in the New England Journal of Medicine describing the recovery of tuberculosis genomes from the lung tissue of a 215-year-old mummy from Hungary. His team also has identified the outbreak strain genome using metagenomics on stool samples from a 2011 E. coli outbreak in Germany.

Pallen's team is now testing the technique on a range of additional samples, including historical material from Hungarian mummies; Egyptian mummies; a Korean mummy from the 16th or 17th century; and lung tissue from a French queen from the Merovingian dynasty, which ruled France from the 5th to 8th centuries; as well as contemporary sputum samples from the Gambia.

"Metagenomics stands ready to document past and present infections, shedding light on the emergence, evolution and spread of microbial pathogens," Pallen says. "We're cranking through all of these samples and we're hopeful that we're going to find new things."
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References:

Science Daily. 2014. “Little too late: Pathogenic bacterium in 700-year-old skeleton identified”. Science Daily. Posted: July 15, 2014. Available online: http://www.sciencedaily.com/releases/2014/07/140715085149.htm

Wednesday, August 20, 2014

Ötzi's non-human DNA: Opportunistic pathogen discovered in Iceman tissue biopsy

Ötzi's human genome was decoded from a hip bone sample taken from the 5,300 year old mummy. However the tiny sample weighing no more than 0.1 g provides so much more information. A team of scientists from EURAC in Bolzano/Bozen together with colleagues from the University of Vienna successfully analysed the non-human DNA in the sample. They found evidence for the presence of Treponema denticola, an opportunistic pathogen involved in the development of periodontal disease. Thus, by just looking at the DNA, the researchers could support a CT-based diagnosis made last year which indicated that the Iceman suffered from periodontitis. The results of the current study have recently been published in the online scientific journal PLOS ONE.

Much of what we know about Ötzi -- for example what he looked like or that he suffered from lactose intolerance -- stems from a tiny bone sample which allowed the decoding of his genetic make-up. Now, however, the team of scientists have examined more closely the part of the sample consisting of non-human DNA. "What is new is that we did not carry out a directed DNA analysis but rather investigated the whole spectrum of DNA to better understand which organisms are in this sample and what is their potential function," is how Frank Maixner, from the EURAC Institute for Mummies and the Iceman in Bozen/Bolzano, described the new approach which the team of scientists are now pursuing.

"This 'non-human' DNA mostly derives from bacteria normally living on and within our body. Only the interplay between certain bacteria or an imbalance within this bacterial community might cause certain diseases. Therefore it is highly important to reconstruct and understand the bacterial community composition by analysing this DNA mixture," said Thomas Rattei, Professor of Bioinformatics from the Department of Microbiology and Ecosystem Science at the University of Vienna.

Unexpectedly the team of scientists, specialists in both microbiology as well as bioinformatics, detected in the DNA mixture a sizeable presence of a particular bacterium: Treponema denticola, an opportunistic pathogen involved in the development of periodontitis. Thus this finding supports the computer tomography based diagnosis that the Iceman suffered from periodontitis. Even more surprising is that the analysis of a tiny bone sample can still, after 5,300 years, provide us with the information that this opportunistic pathogen seems to have been distributed via the bloodstream from the mouth to the hip bone. Furthermore, the investigations indicate that these members of the human commensal oral microflora were old bacteria which did not colonise the body after death.

Besides the opportunistic pathogen, the team of scientists led by Albert Zink -- head of the EURAC Institute for Mummies and the Iceman -- also detected Clostridia-like bacteria in the Iceman bone sample which are at present most presumably in a kind of dormant state. Under hermetically sealed, anaerobic conditions, however, these bacteria can re-grow and degrade tissue. This discovery may well play a significant part in the future conservation of the world-famous mummy. "This finding indicates that altered conditions for preserving the glacier mummy, for example when changing to a nitrogen-based atmosphere commonly used for objects of cultural value, will require additional micro-biological monitoring," explained the team of scientists who will now look closer at the microbiome of the Iceman.
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References:

Science Daily. 2014. “Ötzi's non-human DNA: Opportunistic pathogen discovered in Iceman tissue biopsy”. Science Daily. Posted: July 15, 2014. Available online: http://www.sciencedaily.com/releases/2014/07/140715085055.htm

Tuesday, August 19, 2014

Do women talk more than men? It's all about context

Use of sociometers shows that the extent that women are more talkative and collaborative than men depends on the situation

We've all heard the stereotype: Women like to talk. We bounce ideas off each other about everything from career moves to dinner plans. We hash out big decisions through our conversations with one another and work through our emotions with discussion.

At least, that's what "they" say. But is any of it actually true? A new study from Northeastern University professor David Lazer's lab says it isn't that simple.

Lazer, who researches social networks and holds joint appointments in the Department of Political Science and the College of Computer and Information Sciences, took a different approach. Using so- called "sociometers" – wearable devices roughly the size of smartphones – the researchers collected real- time data about the user's social interactions. Lazer's team was able to tease out a more accurate picture of the talkative- woman stereotype we're so familiar with—and they found that context plays a large role.

But can we really make such sweeping generalizations about the communication patterns of women versus those of men? The research is surprisingly thin considering the strength of the stereotype: Some studies say yes, women are more talkative than men. Others say there's no pattern at all. Still others say men are even bigger chatterboxes.

Perhaps all this contradiction comes from the difficulty of studying such a phenomenon. Most of these studies rely on either self- reported data, in which researchers gather information by asking subjects about their past conversational exploits, or observational data, in which researchers watch the interactions directly. But both of these approaches bring with them some hefty limitations. For one thing, our memories are not nearly as good as we like to think they are. Secondly, researchers can only observe so many people at once, meaning large data sets, which offer the most statistical power to detect differences, are hard to come by. Another challenge with direct observation is that subjects may act in a more affiliative manner in front of a researcher.

The research was published Tuesday in the journal Scientific Reports and represents one of the first academic papers to use sociometers to address this kind of question. The research team includes Jukka- Pekka Onnela, who previously worked in Lazer's lab and is now at the Harvard School of Public Health, as well as researchers at the MIT Media Laboratory and the Harvard Kennedy School.

For their study, Lazer's research team provided a group of men and women with sociometers and split them in two different social settings for a total of 12 hours. In the first setting, master's degree candidates were asked to complete an individual project, about which they were free to converse with one another for the duration of a 12- hour day. In the second setting, employees at a call- center in a major U.S. banking firm wore the sociometers during 12 one- hour lunch breaks with no designated task.

"In the one setting that is more collaborative we see the women choosing to work together, and when you work together you tend to talk more," said Lazer, who is also co- director of the NULab for Texts, Maps, and Networks, Northeastern's research- based center for digital humanities and computational social science. "So it's a very particular scenario that leads to more interactions. The real story here is there's an interplay between the setting and gender which created this difference."
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References:

EurekAlert. 2014. “Do women talk more than men? It's all about context”. EurekAlert. Posted: July 15, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-07/nu-dwt071514.php

Monday, August 18, 2014

Prehistoric 'bookkeeping' continued long after invention of writing

An archaeological dig in southeast Turkey has uncovered a large number of clay tokens that were used as records of trade until the advent of writing, or so it had been believed.

But the new find of tokens dates from a time when writing was commonplace – thousands of years after it was previously assumed this technology had become obsolete. Researchers compare it to the continued use of pens in the age of the word processor.

The tokens – small clay pieces in a range of simple shapes – are thought to have been used as a rudimentary bookkeeping system in prehistoric times.

One theory is that different types of tokens represented units of various commodities such as livestock and grain. These would be exchanged and later sealed in more clay as a permanent record of the trade – essentially, the world's first contract.

The system was used in the period leading up to around 3000 BC, at which point clay tablets filled with pictorial symbols drawn using triangular-tipped reeds begin to emerge: the birth of writing, and consequently history.

From this point on in the archaeological record, the tokens dwindle and then disappear, leading to the assumption that writing quickly supplanted the token system.

However, recent excavations at Ziyaret Tepe – the site of the ancient city Tušhan, a provincial capital of the Neo-Assyrian Empire – have unearthed a large quantity of tokens dating to the first millennium BC: two thousand years after 'cuneiform' – the earliest form of writing – emerged on clay tablets.

"Complex writing didn't stop the use of the abacus, just as the digital age hasn't wiped out pencils and pens," said Dr John MacGinnis from Cambridge's MacDonald Institute for Archaeological Research, who led the research.

"In fact, in a literate society there are multiple channels of recording information that can be complementary to each other. In this case both prehistoric clay tokens and cuneiform writing used together."

The tokens were discovered in the main administrative building in Tušhan's lower town, along with many cuneiform clay tablets as well as weights and clay sealings. Over 300 tokens were found in two rooms near the back of the building that MacGinnis describes as having the character of a 'delivery area', perhaps an ancient loading bay.

"We think one of two things happened here. You either have information about livestock coming through here, or flocks of animals themselves. Each farmer or herder would have a bag with tokens to represent their flock," said MacGinnis.

"The information is travelling through these rooms in token form, and ending up inscribed onto cuneiform tablets further down the line."

Archaeologists say that, while cuneiform writing was a more advanced accounting technology, by combining it with the flexibility of the tokens the ancient Assyrians created a record-keeping system of greater sophistication.

"The tokens provided a system of moveable numbers that allowed for stock to be moved and accounts to be modified and updated without committing to writing; a system that doesn't require everyone involved to be literate."

MacGinnis believes that the new evidence points to prehistoric tokens used in conjunction with cuneiform as an empire-wide 'admin' system stretching right across what is now Turkey, Syria and Iraq. In its day, roughly 900 to 600 BC, the Assyrian empire was the largest the world had ever seen.

Types of tokens ranged from basic spheres, discs and triangles to tokens that resemble oxhide and bull heads.

While the majority of the cuneiform tablets found with the tokens deal with grain trades, it's not yet known what the various tokens represent. The team say that some tokens likely stand for grain, as well as different types of livestock (such as goats and cattle), but – as they were in use at the height of the empire – tokens could have been used to represent commodities such as oil, wool and wine.

"One of my dreams is that one day we'll dig up the tablet of an accountant who was making a meticulous inventory of goods and systems, and we will be able to crack the token system's codes," said MacGinnis.

"The inventions of recording systems are milestones in the human journey, and any finds which contribute to the understanding of how they came about makes a basic contribution to mapping the progress of mankind," he said.
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References:

EurekAlert. 2014. “Prehistoric 'bookkeeping' continued long after invention of writing”. EurekAlert. Posted: July 13, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-07/uoc-pc071014.php

Sunday, August 17, 2014

Ancient Coins Found Buried in British Cave

Digging through a cave in central Britain, archaeologists uncovered 26 ancient gold and silver coins belonging to the Corieltauvi tribe, a group of people that lived in Britain before the Roman conquest. Archaeologists previously found collections of coins like these in other parts of Britain, but this is the first time they have ever been discovered buried in a cave. The discovery of the coins was a surprise, because they were found at a site called Reynard's Kitchen Cave, which is located outside the Corieltauvi's usual turf.

"It might be that we have a member of the tribe living beyond the boundary that is more usually associated with the territory," Rachael Hall, an archaeologist at the National Trust who led the excavation, told Live Science in an email.

Back in 2000, a group of almost 5,000 Corieltauvi coins were discovered in Leicestershire. This more recent find at Reynard's Kitchen Cave might be additional evidence that members of the tribe once hoarded coins. Hall and the team speculate that the coins were hidden to ensure they weren't stolen, and whoever buried them may have planned on returning to the site to dig the coins up again. The discovery included 20 Iron Age coins, three Roman coins and three coins from much later eras, according to a treasury report prepared by Ian Leins, curator of Iron Age and Roman coins at the British Museum. While the coins are not all from the same time period, Hall and the team of archaeologists said it's common to find collections of coins from different times, in the same way that, for example, U.S. coins from earlier decades are still circulating among newer coins.

Archaeologists are still unsure how Iron Age coins were used, but it is unlikely they were used as money to purchase items. They were more likely used as a means for storing wealth, given as gifts or offered as sacrifice. The three Roman coins discovered predate the Roman invasion, so archaeologists believe the coins may have been given as gifts.

A climber seeking shelter in the cave first discovered four of the coins, which prompted a full-scale excavation by the National Trust and Operation Nightingale, a group that helps injured military members recuperate by having them perform field archaeology.

The monetary value today of the coins discovered is around two thousand pounds (about $3,400 USD). The collection of coins officially qualifies as "treasure" under the United Kingdom's 1996 Treasure Act, which means it is valuable enough that it needs to be reported to authorities and offered up to museums.

Earlier excavation of Reynard's Kitchen Cave revealed animal bones and pieces of pottery. The coins will be put on display later this year at the Buxton Museum in Derbyshire.
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References:

Dickerson, Kelly. 2014. “Ancient Coins Found Buried in British Cave”. Live Science. Posted: July 11, 2014. Available online: http://www.livescience.com/46693-ancient-cave-coins-discovered.html

Saturday, August 16, 2014

Mobile phone bling may be a personal, but also cultural thing

Choosing mobile phone cases and customizing phones with charms and decorations may reveal a lot about a person's culture, as well as increase attachment to the devices, according to researchers. In a study on culture and mobile phone customization, researchers found that people from Eastern cultures tend to be more motivated to change the look and sound of their mobile phones than people in Western countries, said S. Shyam Sundar, Distinguished Professor of Communications and co-director of the Media Effects Research Laboratory, Penn State.

"People who live in collectivist cultures are often more other-directed," said Sundar. "They want to know how others might look at them and also look to others as a way of influencing their own behaviors."

The researchers gave American and South Korean students surveys on how they customized their mobile phones and asked them how they perceived their social identity and efforts to self-promote. Mobile phone accessories, which are big business South Korea, Japan and other Eastern countries, include physical items, such as charms, cases, bags and stickers, as well as functional additions, such as ringtones and screen wallpaper.

The surveys revealed that Koreans were more focused on how to fit into social situations, according to Sundar, who worked with Seoyeon Lee, a mobile user-interface and user-experience researcher at LG Electronics in Seoul. They also were more likely to look at the actions of others to give them cues on behavior. Americans, on the other hand, valued self-expression more and were less worried about how others perceived them. This could be why Americans customize less, while Koreans accessorize their phones to a greater degree.

People see their phones not as a tool, but as part of themselves, according to the researchers, who present their findings in an upcoming issue of Media Psychology that is now available online.

"The more you customize your phone for aesthetic reasons the more it reflects who you are," said Sundar. "You see your phone as your self."

While people who live in Eastern cultures, which are typically more collectivist than Western cultures, tend to be more expressive with their mobile phone customization than Westerners, both cultures become more attached to the devices after they are customized.

Technology companies may want to provide more ways for a consumer to customize products to enhance this feeling of attachment.

"Tools for aesthetic customization can enhance people's attachment to a device, regardless of culture," said Sundar. "In this study we looked at phones, but it could also apply to other information technology products that people use in public, such as iPads."

Market research may help these companies to better match their accessories to consumers, according to the researchers.

"This may differ from one county to another," said Lee. Phone manufacturers sell different designs, colors and accessories in different countries, she added.

The study also reinforces previous research that showed how people are becoming more connected with their mobile phones, according to Sundar.

"If you ask people what objects they want to make sure they have with them when they leave their house, usually their phone is in the top three, along with keys and money," Sundar said.

A total of 400 American students from a U.S. university and 205 Korean students from various South Korean universities were asked to fill out a survey with 112 questions. Approximately 49 of the respondents did not have any customization.
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References:

EurekAlert. 2014. “Mobile phone bling may be a personal, but also cultural thing”. EurekAlert. Posted: July 10, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-07/ps-mpb071014.php