Humans were already recycling 13,000 years ago, burnt artifacts show

ScienceDaily (Sep. 20, 2012) — A study at the Universitat Rovira i Virgili and the Catalan Institute of Human Paleoecology and Social Evolution (IPHES) reveals that humans from the Upper Palaeolithic Age recycled their stone artefacts to be put to other uses. The study is based on burnt artefacts found in the Molí del Salt site in Tarragona, Spain.

The recycling of stone tools during Prehistoric times has hardly been dealt with due to the difficulties in verifying such practices in archaeological records. Nonetheless, it is possible to find some evidence, as demonstrated in a study published in the 'Journal of Archaeological Science'.

"In order to identify the recycling, it is necessary to differentiate the two stages of the manipulation sequence of an object: the moment before it is altered and the moment after. The two are separated by an interval in which the artefact has undergone some form of alteration. This is the first time a systematic study of this type has been performed," as explained to SINC by Manuel Vaquero, researcher at the Universitat Rovira i Virgili.

The archaeologists found a high percentage of burnt remains in the Molí del Salt site (Tarragona), which date back to the end of the Upper Palaeolithic Age some 13,000 years ago. The expert ensures that "we chose these burnt artefacts because they can tell us in a very simple way whether they have been modified after being exposed to fire."

The results indicate that the recycling of tools was normal during the Upper Palaeolithic Age. However, this practice is not documented in the same way as other types of artefacts. The use of recycled tools was more common for domestic activities and seems to be associated with immediate needs.

Recycling domestic tools

Recycling is linked to expedited behaviour, which means simply shaped and quickly available tools as and when the need arises. Tools used for hunting, like projectile points for instance, were almost never made from recycled artefacts. In contrast, double artefacts (those that combine two tools within the same item) were recycled more often.

"This indicates that a large part of these tools were not conceived from the outset as double artefacts but a single tool was made first and a second was added later when the artefact was recycled," outlines the researcher. The history of the artefacts and the sequence of changes that they have undergone over time are fundamental in understanding their final morphology.

According to Vaquero, "in terms of the objects, this is mostly important from a cultural value point of view, especially in periods like the Upper Palaeolithic Age, in which it is thought that the sharper the object the sharper the mind."

Sustainable practices with natural resources

Recycling could have been determinant in hunter-gatherer populations during the Palaeolithic Age if we consider the behaviour of current indigenous populations nowadays.

"It bears economic importance too, since it would have increased the availability of lithic resources, especially during times of scarcity. In addition, it is a relevant factor for interpreting sites because they become not just places to live but also places of resource provision," states the researcher.

Reusing resources meant that these humans did not have to move around to find raw materials to make their tools, a task that could have taken them far away from camp. "They would simply take an artefact abandoned by those groups who previously inhabited the site."

Vaquero and the team believe that this practice needs to be borne in mind when analysing the site. "Those populating these areas could have moved objects from where they were originally located. They even could have dug up or removed sediments in search of tools," highlights the researcher.

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The above story is reprinted from materials provided by Plataforma SINC, via AlphaGalileo.

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Journal Reference:

1. Manuel Vaquero, Susana Alonso, Sergio García-Catalán, Angélica García-Hernández, Bruno Gómez de Soler, David Rettig, María Soto. Temporal nature and recycling of Upper Paleolithic artifacts: the burned tools from the Molí del Salt site (Vimbodí i Poblet, northeastern Spain). Journal of Archaeological Science, 2012; 39 (8): 2785 DOI: 10.1016/j.jas.2012.04.024

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20 Sep, 2012

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Olympic Games in Rio 2016: Mathematical formula can predict medal haul, including impact of home advantage

ScienceDaily (Sep. 19, 2012) — Team GB is only likely to clock up 46 medals in the Olympic Games in Rio in 2016, say researchers who used a mathematical formula three years ago to predict performance for London 2012, and came up with a medal haul of 63.

In the end, Team GB won 65 medals in London, so the prediction was only out by two.

The formula, published in the British Journal of Sports Medicine, is based on all cities and countries that have hosted the Olympic Games since World War II and the number of medals awarded to competitors from each country.

The approach, known as logit regression, takes into account medal tallies achieved before, during, and after hosting the Games, and includes the impact of home advantage.

The formula suggests that the odds of winning medals when hosting the Games, roughly doubles (2.05). So looking at the average tally for Britain's athletes since World War II produces a figure of 31, which when multiplied by 2.05, indicates 63.5 medals.

Home advantage has little or no influence on sports that are objectively judged, such as athletics, swimming and weightlifting. But it does seem to have a role in sports that are either subjectively judged such as boxing, equestrian/dressage and gymnastics, or those which rely on subjective decisions, such as team games, say the authors.

Team GB made 13 medal gains in subjectively assessed sports in London 2012, compared with Beijing in 2008, but only a five medal gain in objectively assessed sports.

"Anecdotal evidence suggests that the crowd had a positive effect on athletes to raise their performance, but also, based on these results, crowds appear to have had an important effect on influencing officials to favour the home based performers, and hence increase their medal winning capacity," write the authors.

Historically the medal haul has dropped off in hosting nations by the time of the next Games, the figures show.

The formula reduces the odds of winning medals to 1.46 without the home advantage, so multiplying that by 31 gives a total medal haul for Team GB of 45 or 46 medals in Rio in 2016, roughly the same as the tally in Beijing in 2008.

Funding will clearly be important in helping to temper this decline, say the authors, who note Prime Minister David Cameron's pledge to maintain funding for elite sports, but add that "the current and projected economic situation presents some stern challenges."

The authors emphasise that Team GB's accomplishments were "a testament to the achievements of athletes and their coaches" and a "source of delight and pride for spectators."

But they add: "However, it seems unlikely that even maintained funding can make up for the benefits of a partisan London crowd."

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The above story is reprinted from materials provided by BMJ-British Medical Journal.

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Journal Reference:

1. Alan M Nevill, Nigel J Balmer, Edward M Winter. Congratulations to team GB, but why should we be so surprised? Olympic medal count can be predicted using logit regression models that include 'home advantage'. British Journal of Sports Medicine, 2012; DOI: 10.1136/bjsports-2012-091719

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20 Sep, 2012

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Invasive 'Rasberry Crazy Ant' in Texas now identified species

ScienceDaily (Sep. 19, 2012) — The Rasberry Crazy Ant is an invasive ant that was first noticed infesting areas around Houston, Texas ten years ago, but its species identity has remained undetermined until now.

In a paper published Sept. 19 in the open access journal PLOS ONE, a research team led by John LaPolla from Towson University in Maryland identifies the species as Nylanderia fulva. Identifying the species should help control this emerging pest, the authors write.

They also conclude that the species, whose common name comes from exterminator Tom Rasberry who first noticed the ants, is distributed more widely than previously thought and has likely invaded all Gulf Coast states.

"This study demonstrates the invaluable role that taxonomy, an often underappreciated discipline, plays in our understanding of emerging pests. Now that we know just what species the Rasberry Crazy Ant really is, we can better understand its biology to improve control of this invasive species," says LaPolla.

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1. Dietrich Gotzek, Seán G. Brady, Robert J. Kallal, John S. LaPolla. The Importance of Using Multiple Approaches for Identifying Emerging Invasive Species: The Case of the Rasberry Crazy Ant in the United States. PLoS ONE, 2012; 7 (9): e45314 DOI: 10.1371/journal.pone.0045314

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20 Sep, 2012

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Obese children have less sensitive taste-buds than those of normal weight

ScienceDaily (Sep. 19, 2012) — Obese kids have less sensitive taste-buds than kids of normal weight, indicates research published online in the Archives of Disease in Childhood.

This blunted ability to distinguish all five tastes of bitter, sweet, salty, sour, and umami (savoury) may prompt them to eat larger quantities of food in a bid to register the same taste sensation, suggest the authors.

They base their findings on 94 normal weight and 99 obese children aged between 6 and 18, who were in good health and not taking any medications known to affect taste and smell.

The taste sensitivity of every child was tested using 22 "taste strips" placed on the tongue, to include each of the five taste sensations, at four different levels of intensity, plus two blank strips.

Each child was asked to refrain from eating or drinking anything other than water and not to chew gum for at least an hour before they took the two tests, which involved identifying the different tastes and their intensity.

The sum of all five taste sensations at the four different intensities allowed for a maximum score of 20, with scores ranging from two to 19.

Girls and older children were better at picking out the right tastes.

Overall, the children were best able to differentiate between sweet and salty, but found it hardest to distinguish between salty and sour, and between salty and umami.

And obese children found it significantly more difficult to identify the different taste sensations, scoring an average of 12.6 compared with an average of just over 14 clocked up by children of normal weight.

Obese children were significantly less likely to identify the individual taste sensations correctly, particularly salty, umami, and bitter.

And while both obese and normal weight children correctly identified all the differing levels of sweetness, obese kids rated three out of the four intensity levels lower than kids of normal weight.

Similarly, children of normal weight were better able to distinguish the different taste sensations, the older they were, but this trend was not seen among the obese children.

Exactly why people have differing taste perceptions is unclear, but genes, hormones, acculturation and exposure to different tastes early in life are all thought to play a part, say the authors.

But previous research indicates that heightened sensitivity to different taste sensations may help to reduce the amount of food eaten as less is required to get the same "taste hit."

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Journal Reference:

1. Johanna Overberg, Thomas Hummel, Heiko Krude, Susanna Wiegand. Differences in taste sensitivity between obese and non-obese children and adolescents. Archives of Disease in Childhood, 2012; DOI: 10.1136/archdischild-2011-301189

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20 Sep, 2012

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Clenching left hand could help athletes avoid choking under pressure

ScienceDaily (Sep. 19, 2012) — Some athletes may improve their performance under pressure simply by squeezing a ball or clenching their left hand before competition to activate certain parts of the brain, according to new research published by the American Psychological Association.

In three experiments with experienced soccer players, judo experts and badminton players, researchers in Germany tested the athletes' skills during practice and then in stressful competitions before a large crowd or video camera. Right-handed athletes who squeezed a ball in their left hand before competing were less likely to choke under pressure than right-handed players who squeezed a ball in their right hand. The study was published online in the Journal of Experimental Psychology: General.

For skilled athletes, many movements, such as kicking a soccer ball or completing a judo kick, become automatic with little conscious thought. When athletes under pressure don't perform well, they may be focusing too much on their own movements rather than relying on their motor skills developed through years of practice, said lead researcher Juergen Beckmann, PhD, chair of sport psychology at the Technical University of Munich in Germany.

"Rumination can interfere with concentration and performance of motor tasks. Athletes usually perform better when they trust their bodies rather than thinking too much about their own actions or what their coaches told them during practice," Beckmann said. "While it may seem counterintuitive, consciously trying to keep one's balance is likely to produce imbalance, as was seen in some sub-par performances by gymnasts during the Olympics in London."

Previous research has shown that rumination is associated with the brain's left hemisphere, while the right hemisphere is associated with superior performance in automated behaviors, such as those used by some athletes, the study notes. The right hemisphere controls movements of the left side of the body, and the left hemisphere controls the right side. The researchers theorized that squeezing a ball or clenching the left hand would activate the right hemisphere of the brain and reduce the likelihood of the athlete's choking under pressure. The study focused exclusively on right-handed athletes because some relationships between different parts of the brain aren't as well understood for left-handed people, according to the authors.

The research could have important implications outside athletics. Elderly people who are afraid of falling often focus too much on their movements, so right-handed elderly people may be able to improve their balance by clenching their left hand before walking or climbing stairs, Beckmann said.

"Many movements of the body can be impaired by attempts at consciously controlling them," he said. "This technique can be helpful for many situations and tasks."

In the first experiment, 30 semi-professional male soccer players took six penalty shots during a practice session. The next day, they attempted to make the same penalty shots in an auditorium packed with more than 300 university students waiting to see a televised soccer match between Germany and Austria. The players who squeezed a ball with their left hand performed as well under pressure as during practice, while players who squeezed a ball in their right hand missed more shots in the crowded auditorium.

Twenty judo experts (14 men and six women) took part in the second experiment. First, they performed a series of judo kicks into a sandbag during practice. During a second session, they were told that their kicks would be videotaped and evaluated by their coaches. The judo athletes who squeezed a ball with their left hand not only didn't choke under pressure, they performed better overall during the stressful competition than during practice, while those in the control group choked under pressure, the study found.

The final experiment featured 18 experienced badminton players (12 men and six women) who completed a series of practice serves. Then, they were divided into teams and competed against each other while being videotaped for evaluation by their coaches. Athletes who squeezed a ball in their left hand didn't choke under pressure, unlike the control group players who squeezed a ball in their right hand. A final phase of the experiment had the athletes just clench their left or right hand without a ball before competition, and players who clenched their left hand performed better than players who squeezed their right hand.

The ball-squeezing technique probably wouldn't help athletes whose performance is based on strength or stamina, such as weightlifters or marathon runners, the authors noted. The effects apply to athletes whose performance is based on accuracy and complex body movements, such as soccer players or golfers, they said.

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The above story is reprinted from materials provided by American Psychological Association (APA), via Newswise.

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Journal Reference:

1. Jürgen Beckmann, Peter Gröpel, Felix Ehrlenspiel. Preventing Motor Skill Failure Through Hemisphere-Specific Priming: Cases From Choking Under Pressure.. Journal of Experimental Psychology: General, 2012; DOI: 10.1037/a0029852

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20 Sep, 2012

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Protecting our harbors and ships with a robotic tuna fish

ScienceDaily (Sep. 19, 2012) — No question about it… they're very good at what they do. But they don't take well to orders, especially those to carry out inspection work in oily or dangerous environments, or in any kind of harsh environment, for that matter. Still, they're one of the fastest and most maneuverable creatures on the planet, having extraordinary abilities at both high and low speeds due to their streamlined bodies and a finely tuned muscular/sensory/control system.

This impressive creature is the humble tuna fish.

The Department of Homeland Security's (DHS) Science and Technology Directorate (S&T) is funding the development of an unmanned underwater vehicle designed to resemble a tuna, called the BIOSwimmer™. Why the tuna? Because the tuna has a natural body framework ideal for unmanned underwater vehicles (UUVs), solving some of the propulsion and maneuverability problems that plague conventional UUVs.

Inspired by the real tuna, BIOSwimmer™ is a UUV designed for high maneuverability in harsh environments, with a flexible aft section and appropriately placed sets of pectoral and other fins. For those cluttered and hard-to-reach underwater places where inspection is necessary, the tuna-inspired frame is an optimal design. It can inspect the interior voids of ships such as flooded bilges and tanks, and hard to reach external areas such as steerage, propulsion and sea chests. It can also inspect and protect harbors and piers, perform area searches and carry out other security missions.

Boston Engineering Corporation's Advanced Systems Group (ASG) in Waltham, Massachusetts, is developing the BIOSwimmer™ for Homeland Security's Science and Technology Directorate. "It's designed to support a variety of tactical missions and with its interchangeable sensor payloads and reconfigurable Operator Controls, and can be optimized on a per-mission basis," says the Director of ASG, Mike Rufo.

BIOSwimmer™ is battery-powered and designed for long-duration operation. Like other unmanned underwater vehicles, it uses an onboard computer suite for navigation, sensor processing, and communications. Its Operator Control Unit is laptop-based and provides intuitive control and simple, mission-defined versatility for the user. A unique aspect of this system is the internal components and external sensing which are designed for the challenging environment of constricted spaces and high viscosity fluids

"It's all about distilling the science," says David Taylor, program manager for the BIOSwimmer™ in S&T's Borders and Maritime Security Division. "It's called 'biomimetics.' We're using nature as a basis for design and engineering a system that works exceedingly well.

Tuna have had millions of years to develop their ability to move in the water with astounding efficiency. Hopefully we won't take that long."

Background

Biologically inspired robotics (biomimetic robotry) is a fairly new science that is gaining steam. There are now robotic lobsters, flies, geckos, moths, clams, dogs, and even a lamprey-like robot, all being designed to perform a variety of missions including surveillance and search and rescue. Robotics based on sinuous snakes and elephant trunks, for example, may be the ideal way to search for survivors inside the rubble of structures destroyed by explosions or natural disasters.

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20 Sep, 2012

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Blind people develop accurate mental map by playing 'video' game

ScienceDaily (Sep. 19, 2012) — Researchers have developed a new "video" game for blind people that can help them learn about a new space using only audio cues, as reported Sept. 19 in the open access journal PLOS ONE.

The system, developed by a team led by Lotfi Merabet of Harvard Medical School and Jaime Sánchez of the University of Chile, is called the Audiobased Environment Simulator and uses only audio-based cues to allow blind users to learn about the layout of a previously unfamiliar building.

After playing the game, participants were better able to navigate a real-world version of the space explored in the virtual reality environment, confirming that the spatial information learned in the game was accurate and transferrable.

"Learning through such interactive games represents an innovative and motivating way to improve crucial skills that allow blind individuals to remain functionally independent," says Merabet.

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1. Lotfi B. Merabet, Erin C. Connors, Mark A. Halko, Jaime Sánchez. Teaching the Blind to Find Their Way by Playing Video Games. PLoS ONE, 2012; 7 (9): e44958 DOI: 10.1371/journal.pone.0044958

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20 Sep, 2012

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People change moral position without even realizing it

ScienceDaily (Sep. 19, 2012) — Shortly after expressing a moral view about a difficult topic, people may easily endorse the opposite view and remain blind to the psychological mismatch, according to research published Sept. 19 in the open access journal PLOS ONE.

In the study, led by Lars Hall of Lund University, Sweden, participants were presented with a survey about moral issues, including foundational principles and current hot topics with moral implications. To complete the survey they had to flip over the first page of questions, which was displayed on a clipboard, and this is where the researchers implemented a design usually used in performance magic: the back of the clipboard had a patch of glue that caught the top layer of the questions, so when the page was flipped back over, an opposite version of the original questions was revealed but the answers remained unchanged. In other words, the participants' responses were opposite to their originally declared positions (For a video illustration of the experiment, see http://www.lucs.lu.se/cbq/).

The researchers then discussed the participants' answers with them, and found that many participants supported their reported answers, even though the responses were opposite to what the individual had originally intended to express. The authors write that "participants often constructed coherent and unequivocal arguments supporting the opposite of their original position," suggesting "a dramatic potential for flexibility in our moral attitudes."

Commenting on their results, Lars Hall says, "It could have significant impact on research that uses self-reported questionnaires. Either we would have to conclude that many participants hold no real attitudes about the topics we investigate, or that standard survey scales fail to capture the complexity of the attitudes people actually hold."

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1. Lars Hall, Petter Johansson, Thomas Strandberg. Lifting the Veil of Morality: Choice Blindness and Attitude Reversals on a Self-Transforming Survey. PLoS ONE, 2012; 7 (9): e45457 DOI: 10.1371/journal.pone.0045457

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20 Sep, 2012

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Ancient tooth may provide evidence of early human dentistry

ScienceDaily (Sep. 19, 2012) — Researchers may have uncovered new evidence of ancient dentistry in the form of a 6,500-year-old human jaw bone with a tooth showing traces of beeswax filling, as reported Sep. 19 in the open access journal PLOS ONE.

The researchers, led by Federico Bernardini and Claudio Tuniz of the Abdus Salam International Centre for Theoretical Physics in Italy in cooperation with Sincrotrone Trieste and other institutions, write that the beeswax was applied around the time of the individual's death, but cannot confirm whether it was shortly before or after. If it was before death, however, they write that it was likely intended to reduce pain and sensitivity from a vertical crack in the enamel and dentin layers of the tooth.

According to Tuniz, the severe wear of the tooth "is probably also due to its use in non-alimentary activities, possibly such as weaving, generally performed by Neolithic females."

Evidence of prehistoric dentistry is sparse, so this new specimen, found in Slovenia near Trieste, may help provide insight into early dental practices.

"This finding is perhaps the most ancient evidence of pre-historic dentistry in Europe and the earliest known direct example of therapeutic-palliative dental filling so far," says Bernardini.

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1. Federico Bernardini, Claudio Tuniz, Alfredo Coppa, Lucia Mancini, Diego Dreossi, Diane Eichert, Gianluca Turco, Matteo Biasotto, Filippo Terrasi, Nicola De Cesare, Quan Hua, Vladimir Levchenko. Beeswax as Dental Filling on a Neolithic Human Tooth. PLoS ONE, 2012; 7 (9): e44904 DOI: 10.1371/journal.pone.0044904

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20 Sep, 2012

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Odorant shape and vibration likely lead to olfaction satisfaction

ScienceDaily (Sep. 19, 2012) — A new study of the sense of smell lends support to a controversial theory of olfaction: Our noses can distinguish both the shape and the vibrational characteristics of odorant molecules.

The study, in the journal Physical Chemistry Chemical Physics, demonstrates the feasibility of the theory -- first proposed decades ago -- that the vibration of an odorant molecule's chemical bonds -- the wagging, stretching and rocking of the links between atoms -- contributes to our ability to distinguish one smelly thing from another.

"The theory goes that when the right odorant binds to its receptor, the odorant's molecular vibration allows electrons to transfer from one part of the receptor to another," said University of Illinois physics and Beckman Institute professor Klaus Schulten, who conducted the analysis with postdoctoral researcher Ilia Solov'yov and graduate student Po-Yao Chang. "This electron transfer appears to fine-tune the signal the receptor receives."

Many who study olfaction maintain that odorant receptors recognize only an odorant's shape and surface characteristics. They dismiss the idea that molecular vibration has anything to do with it, Schulten said. Likewise, some proponents of the vibrational theory think that molecular vibration only, and not shape, guides the sense of smell. Schulten and his colleagues belong to a "third camp" that sees evidence for both, he said.

The vibrational theory of olfaction is supported by studies showing that insects, humans and other animals can tell the difference between two versions of the same odorant molecule -- a normal one and an identical one with deuterium atoms substituted for each of the hydrogens. The deuterated and normal versions of the odorant have the same shape and surface characteristics, and yet humans and other animals can smell the difference, Schulten said.

"The question then is of course, for scientists, how does this happen?" he said.

To answer this question, Schulten turned to the work of a former colleague at Illinois, Rudolph Marcus, a chemist (now at the California Institute of Technology) who received the Nobel Prize in Chemistry in 1992 for his insights into electron transfer, one of the most basic forms of a chemical reaction.

"Marcus realized that when electrons are being exchanged between molecules the process is coupled to the vibrations of the molecules involved," Schulten said. Marcus focused primarily on the low-frequency "rumblings" that occur as a result of molecular vibration in large molecules, Schulten said.

Odorant molecules are generally quite small, however, with a lot of high-frequency, high-energy vibrations, Schulten said. Some scientists have theorized that these high-frequency vibrations can, when an odorant binds to the right receptor, enhance the likelihood that an electron will transfer from one part of the receptor to another, sending an electrical signal that contributes to the detection of that odor.

Prior to the new study, no one had analyzed the energetics of the system to see if the vibrations of the odorant molecules -- in the context of all the background vibrations that are part of the system -- could actually promote electron transfer within the receptor. Schulten and his colleagues are the first to conduct such an analysis, he said.

"You can actually carry out quantum chemical calculations that determine very precisely the vibration of the molecule as well as the ability to couple it to electron transfer," Schulten said. The calculations indicate that such an interaction is energetically feasible, he said.

Odorant receptors are embedded in membranes and so are more difficult to study than other proteins. But previous research indicates that some receptors are metalloproteins, and "the metals in the proteins are predesigned to transfer electrons," Schulten said. "We also see that there are other amino acid side groups that can accept an electron, so the electron can be transferred through the protein."

Like others before them, Schulten and his colleagues suggest that the odorant receptor contains both an electron donor and an electron acceptor, but that electron transfer occurs only when a specific odorant is bound to the receptor. The new calculations offer the first quantitative evidence that the odorant can in fact promote electron transfer.

Those who suggested that molecular vibration played a role in odorant recognition in previous studies "didn't know about Marcus' theory and they didn't do quantum chemical calculations," Schulten said. "They argued very much on principle (that it was possible). So we are saying now, yes, it is really possible even when you do the most complete and reliable calculations."

Video: http://www.youtube.com/watch?v=Oe5PW2KqImI

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The above story is reprinted from materials provided by University of Illinois at Urbana-Champaign.

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Journal Reference:

1. Ilia A. Solov'yov, Po-Yao Chang, Klaus Schulten. Vibrationally assisted electron transfer mechanism of olfaction: myth or reality? Physical Chemistry Chemical Physics, 2012; DOI: 10.1039/C2CP41436H

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

20 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/strange_science/~3/RJsO4o1Hpkc/120919135322.htm
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