Some of the oldest known corncobs, husks, stalks and tassels (male flowers), dating from 6,700 to 3,000 years ago were found at Paredones and Huaca Prieta, two mound sites on Peru’s arid northern coast. The research group, led by Tom Dillehay from Vanderbilt University and Duccio Bonavia from Peru’s Academia Nacional de la Historia, also found corn microfossils: starch grains and phytoliths. Characteristics of the cobs – the earliest ever discovered in South America – indicate that the sites’ ancient inhabitants ate corn several ways, including popcorn and flour corn. However, corn was still not an important part of their diet.

“Corn was first domesticated in Mexico nearly 9,000 years ago from a wild grass called teosinte,” said Piperno. “Our results show that only a few thousand years later corn arrived in South America where its evolution into different varieties that are now common in the Andean region began. This evidence further indicates that in many areas corn arrived before pots did and that early experimentation with corn as a food was not dependent on the presence of pottery.”

Understanding the subtle transformations in the characteristics of cobs and kernels that led to the hundreds of maize races known today, as well as where and when each of them developed, is a challenge. Corncobs and kernels were not well preserved in the humid tropical forests between Central and South America, including Panama – the primary dispersal routes for the crop after it first left Mexico about 8,000 years ago.

“These new and unique races of corn may have developed quickly in South America, where there was no chance that they would continue to be pollinated by wild teosinte,” said Piperno. “Because there is so little data available from other places for this time period, the wealth of morphological information about the cobs and other corn remains at this early date is very important for understanding how corn became the crop we know today.”

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a unit of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. Website: www.stri.si.edu

Contact: Beth King
kingb@si.edu
202-633-4700 x28216
Smithsonian Tropical Research Institute

Yun Zhang, Wen-Hui Lee and Xinwang Yang explain that scientists long have recognized frogs’ skin as a rich potential source of new antibiotics. Frogs live in warm, wet places where bacteria thrive and have adapted skin that secretes chemicals, known as peptides, to protect themselves from infections. Zhang’s group wanted to identify the specific antimicrobial peptides (AMPs), and the most potent to give scientists clues for developing new antibiotics.

They identified more than 700 of these substances from nine species of odorous frogs and concluded that the AMPs account for almost one-third of all AMPs found in the world, the greatest known diversity of these germ-killing chemicals. Interestingly, some of the AMPs have a dual action, killing bacteria directly and also activating the immune system to assist in the battle.

The authors acknowledge funding from the National Basic Research Program of China and The National Natural Science Foundation of China.

The American Chemical Society is a non-profit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Contact: Michael Bernstein
m_bernstein@acs.org
202-872-6042
American Chemical Society

The results could help explain the callous and impulsive anti-social behavior exhibited by some psychopaths.

The study showed that psychopaths have reduced connections between the ventromedial prefrontal cortex (vmPFC), the part of the brain responsible for sentiments such as empathy and guilt, and the amygdala, which mediates fear and anxiety. Two types of brain images were collected. Diffusion tensor images (DTI) showed reduced structural integrity in the white matter fibers connecting the two areas, while a second type of image that maps brain activity, a functional magnetic resonance image (fMRI), showed less coordinated activity between the vmPFC and the amygdala.

“This is the first study to show both structural and functional differences in the brains of people diagnosed with psychopathy,” says Michael Koenigs, assistant professor of psychiatry in the University of Wisconsin School of Medicine and Public Health. “Those two structures in the brain, which are believed to regulate emotion and social behavior, seem to not be communicating as they should.”

The study, which took place in a medium-security prison in Wisconsin, is a unique collaborative between three laboratories,

UW-Madison psychology Professor Joseph Newman has had a long term interest in studying and diagnosing those with psychopathy and has worked extensively in the Wisconsin corrections system. Dr. Kent Kiehl, of the University of New Mexico and the MIND Research Network, has a mobile MRI scanner that he brought to the prison and used to scan the prisoners’ brains. Koenigs and his graduate student, Julian Motzkin, led the analysis of the brain scans.

The study compared the brains of 20 prisoners with a diagnosis of psychopathy with the brains of 20 other prisoners who committed similar crimes but were not diagnosed with psychopathy.

“The combination of structural and functional abnormalities provides compelling evidence that the dysfunction observed in this crucial social-emotional circuitry is a stable characteristic of our psychopathic offenders,” Newman says. “I am optimistic that our ongoing collaborative work will shed more light on the source of this dysfunction and strategies for treating the problem.”

Newman notes that none of this work would be possible without the extraordinary support provided by the Wisconsin Department of Corrections, which he called “the silent partner in this research.” He says the DOC has demonstrated an unprecedented commitment to supporting research designed to facilitate the differential diagnosis and treatment of prisoners.

The study, published in the most recent Journal of Neuroscience, builds on earlier work by Newman and Koenigs that showed that psychopaths’ decision-making mirrors that of patients with known damage to their ventromedial prefrontal cortex (vmPFC). This bolsters evidence that problems in that part of the brain are connected to the disorder.

“The decision-making study showed indirectly what this study shows directly – that there is a specific brain abnormality associated with criminal psychopathy,” Koenigs adds.

Male spiders were provided with either a potential gift of a fly, or a worthless item, such as a cotton wool ball, a dry flower head, a prey leftover (previously eaten housefly), or no gift at all. All the gifts were approximately the same size, so the females would not be able to tell what the gift was without unwrapping it. Males that offered any gift were more likely to successfully mate than males without. However the length of time the females allowed males with worthless gifts to spend transferring sperm was shorter than those with edible gifts (and even shorter for those with no gift at all!).

It appears that both male and female spiders are apparently able to assess the value of the gift and modify their behavior accordingly. Not only did the female spiders end mating sooner with an inedible gift, but male death feigning (thanatosis), which is triggered by the female attempting to end mating and run away with the gift, occurred in half of the matings involving an edible gift, but only once with a worthless gift. Similarly males and females were sometimes seen fighting over edible gifts, but never for a worthless gift.

Maria Albo who led the research explained, “The evolution of male deceit involves a complex equation of costs and benefits. It costs the males to find and wrap a gift, but these costs can be reduced if the male does not have to first catch his gift, or gives one that has already been eaten. The benefit of the gift is longer mating, which leads to more sperm being transferred, and potentially a higher number of offspring. However, the females are wise to deception and terminate mating early for worthless gifts.”

She continued, “The final results show that the number of eggs hatching was lower if the female had not received a gift, but there was little difference between females who had received an edible or inedible gift. The success of cheating probably explains why both strategies have co-evolved and are maintained in the population.”

Contact: Dr Hilary Glover
hilary.glover@biomedcentral.com
44-020-319-22370
BioMed Central

“Looking for alien cities would be a long shot, but wouldn’t require extra resources. And if we succeed, it would change our perception of our place in the universe,” said Loeb.

As with other SETI methods, they rely on the assumption that aliens would use Earth-like technologies. This is reasonable because any intelligent life that evolved in the light from its nearest star is likely to have artificial illumination that switches on during the hours of darkness.

How easy would it be to spot a city on a distant planet? Clearly, this light will have to be distinguished from the glare from the parent star. Loeb and Turner suggest looking at the change in light from an exoplanet as it moves around its star.

As the planet orbits, it goes through phases similar to those of the Moon. When it’s in a dark phase, more artificial light from the night side would be visible from Earth than reflected light from the day side. So the total flux from a planet with city lighting will vary in a way that is measurably different from a planet that has no artificial lights.

Spotting this tiny signal would require future generations of telescopes. However, the technique could be tested closer to home, using objects at the edge of our solar system.

Loeb and Turner calculate that today’s best telescopes ought to be able to see the light generated by a Tokyo-sized metropolis at the distance of the Kuiper Belt – the region occupied by Pluto, Eris, and thousands of smaller icy bodies. So if there are any cities out there, we ought to be able to see them now. By looking, astronomers can hone the technique and be ready to apply it when the first Earth-sized worlds are found around distant stars in our galaxy.

“It’s very unlikely that there are alien cities on the edge of our solar system, but the principle of science is to find a method to check,” Turner said. “Before Galileo, it was conventional wisdom that heavier objects fall faster than light objects, but he tested the belief and found they actually fall at the same rate.”

As our technology has moved from radio and TV broadcasts to cable and fiber optics, we have become less detectable to aliens. If the same is true of extraterrestrial civilizations, then artificial lights might be the best way to spot them from afar.

Contact: Christine Pulliam
cpulliam@cfa.harvard.edu
617-495-7463
Harvard-Smithsonian Center for Astrophysics

By the end of the one year study, nearly 30 percent of the 100 participants achieved significant vision gains. About 60 percent showed at least some improvement. Significant gains were more likely in children who participated in Groups 3 or 4 of the four treatment regimens. Treatment Group 3 completed daily video game practice and Group 4 took the supplement citicoline, which is associated with improved brain function. Improvement was more likely in children younger than age 14 than in those 14 and older.

The prevailing wisdom has been that if amblyopia is not diagnosed and corrected before a child reaches school age, it is difficult or impossible to correct. But recently the United States-based Pediatric Eye Disease Investigation Group (PEDIG) reported significant vision gains in 27 percent of older children in a study funded by the National Eye Institute. This report motivated Dr. Ghosh to test new approaches to learn what might be particularly effective in this age group.

His study was divided into four treatment groups. Students in all groups followed a basic treatment plan that required them to wear eyeglasses that blocked the stronger eye for at least two hours a day, during which time they practiced exercises using the weaker eye. This “patching” technique is a standard amblyopia treatment that works by making the weaker eye work harder. Group one followed only the basic plan and served as the control group, while groups two, three and four received additional treatments:

• Group 2 took a supplement that contained micronutrients considered important to good vision
• Group 3 played at least one hour of video games daily using only the weaker eye
• Group 4 took the supplement citicoline, which is associated with improved brain function

Saurav Sen, a 16 year old graduate of Dr. Ghosh’s clinic, received a second chance to achieve good vision. At age 13 Sen began to experience serious vision problems, which negatively impacted his school work. Other doctors had told him it was too late to correct his amblyopia. He completed the regimen assigned to treatment Group 3.t

“Playing the shooting games while using just my weaker eye was hard at first, but after a few months I could win all game levels easily,” said Sen. “I’m very happy that I stuck with the program. My vision has improved a lot, so that I now have no trouble studying or taking exams. My tennis game also improved, and of course I’m now a pro PC gamer.”

“The cooperation of the patient is very important, maybe even crucial, to successful treatment of amblyopia,” said Dr. Ghosh. “We should never give up on our patients, even the older children, but instead offer them hope and treatment designed to help them achieve better vision.”

The 115th Annual Meeting of the American Academy of Ophthalmology is in session October 23 through 25 at the Orange County Convention Center in Orlando, Fla. It is the world’s largest, most comprehensive ophthalmic education conference. Approximately 25,000 attendees and more than 500 companies gather each year to showcase the latest in ophthalmic technology, products and services. To learn more about the place Where All of Ophthalmology Meets, visit www.aao.org/annual_meeting.

Note to media: Contact Media Relations to arrange interviews with experts.

About the American Academy of Ophthalmology

The American Academy of Ophthalmology is the world’s largest association of eye physicians and surgeons – Eye M.D.s – with more than 30,000 members worldwide. Eye health care is provided by the three “O’s” – ophthalmologists, optometrists, and opticians. It is the ophthalmologist, or Eye M.D., who can treat it all: eye diseases, infections and injuries, and perform eye surgery. For more information, visit www.aao.org. The Academy’s EyeSmart® public education program works to educate the public about the importance of eye health and to empower them to preserve their healthy vision, by providing the most trusted and medically accurate information about eye diseases, conditions and injuries. Visit www.geteyesmart.org to learn more.

Contact: Mary Wade
mwade@aao.org
510-725-5677
American Academy of Ophthalmology

While the findings lend some support to the stereotype on gender differences and humor – perhaps most vociferously and provocatively argued in recent memory by author Christopher Hitchens in his 2007 Vanity Fair article “Why Women Aren’t Funny” – they also undermine the standard explanations as to why. The standard explanations are usually variations on an evolutionary sexual-selection argument that likens a man’s humor to a peacock’s fancy tail or a deer’s rack of antlers, useful primarily for showing off and impressing potential mates.

Besides, said the study’s first author Laura Mickes, a postdoctoral researcher in the UC San Diego Department of Psychology and a Ph.D. graduate of the same department, “The differences we find between men’s and women’s ability to be funny are so small that they can’t account for the strength of the belief in the stereotype.”

Men edged out women by 0.11 points out of a theoretically possible perfect score of 5.0, while about 90 percent of both male and female study participants agreed with the stereotype that men are funnier.

The study, published in the journal Psychonomic Bulletin & Review, used a controlled version of The New Yorker cartoon caption contest to reach its conclusions.

Coauthors on the study are Nicholas Christenfeld, a UC San Diego professor of psychology, graduate students Drew Walker and Julian Parris, and Robert Mankoff, cartoon editor for The New Yorker.

Male prowess at the task of being funny on command, said Christenfeld, was “just at the edge of detectability,” and men scored better with other men than with women.

The study team ran two separate but related experiments. The first experiment had 16 undergraduate males and 16 undergraduate females writing captions alone in a quiet room for 20 New Yorker cartoons in 45 minutes, for a total of 640 captions. All were instructed to be as funny as they could be.

Though writing captions may not be the most “natural” way to be funny, Christenfeld and Mickes explained, it has several distinct advantages, including a level playing field to determine what people are capable of doing (as opposed to what they do in social settings and day-to-day life, which could be governed by other factors). It also helps eliminate the effect of bias in the humor ratings since it is harder to tell, despite writer V.S. Naipaul’s claims to the contrary, whether the writer is a man or a woman from written words alone.

The second phase of the first experiment had 34 male and 47 female undergraduates helping to rate the captions written earlier in a five-round knockout tournament: One cartoon image was displayed with two random and anonymous captions, and the raters chose the funnier of the two at their own pace. The process, with new captions each time, was repeated for all 32 captions for each cartoon. The 16 winning captions of round one were then randomly pitted against each other and so on. The number of rounds, from zero to five, that captions survived before being knocked out determined the writers’ average scores.

True to the conventional wisdom, men did better than women, but not by much: Male writers earned an average 0.11 more points than female writers. But what’s even more interesting, the researchers say, and what runs contrary to the standard explanations of why men might be funnier, is that men did better with other men: Female raters allocated only an average 0.06 more points to the male writers, while the male raters gave them a significantly higher average of 0.16 more points.

“Sad for the guys,” Christenfeld said, “who think that by being funny they will impress the ladies, but really just impress other men who want to impress the ladies.”

In a second, related experiment, the researchers tested memory and memory bias to see if men are credited with being funnier than they really are.

As expected, funny captions were remembered better than unfunny ones. The authors of funny captions were remembered better too. But humor was more often misremembered “as having sprung from men’s minds,” the researchers write. And, even more telling, Mickes said, when the study participants were guessing at authors’ gender, unfunny captions were more often misattributed to women and funny captions were more often misattributed to men.*

So if the study is right and men are just a skosh more funny, why might that be? In analyzing the content of the captions, the researchers noted that men used profanity and sexual humor a little more frequently (about 4 vs. 2 percent of the time), but that didn’t seem to account for the “win” since that style of caption didn’t necessarily do better, with either sex.

It could be that men see more opportunities to take a stab at humor, said Christenfeld. It could be that they try harder or more often.

As The New Yorker cartoon editor Mankoff observed on his blog in May, after film critic Roger Ebert won the caption contest on his 107th try: Nine of the top 10 most devoted entrants, or “überenterers,” are men. While fewer women win the actual contest, far fewer of them enter. When they do enter, though, their success rates are pretty impressive. Looking at contests #250 through #282, there are 32 winners, with 22 men and 10 women, Mankoff writes: “The 22 winning men entered an average of 70.22 contests, but the 10 women averaged 6.4 entries – and four of them won on their first attempt.”

It remains for further research to ferret out the reasons men might be the marginally funnier sex. In the meanwhile, the current paper had one other finding worth noting: When asked to predict their own performance on a scale of one to five, the men figured they’d get a 2.3, and the women, a more modest 1.5. That is, the difference in self-assessment was greater than the actual difference detected by the contest. “Male confidence, in this domain at least,” the researchers write, “does seem to outstrip male competence.”

*Mickes declined to make any funny comments because they’d be attributed to her male coauthors anyway.

Contact: Inga Kiderra
ikiderra@ucsd.edu
858-822-0661
University of California – San Diego

This research could lead to new tools for diagnosis and treatment, and have implications law enforcement and social media.

The words of psychopathic murderers match their personalities, which reflect selfishness, detachment from their crimes and emotional flatness, says Jeff Hancock, Cornell professor of computing and information science, and colleagues at the University of British Columbia in the journal Legal and Criminological Psychology.

Hancock and his colleagues analyzed stories told by 14 psychopathic male murderers held in Canadian prisons and compared them with 38 convicted murderers who were not diagnosed as psychopathic. Each subject was asked to describe his crime in detail. Their stories were taped, transcribed and subjected to computer analysis.

Psychopaths used more conjunctions like “because,” “since” or “so that,” implying that the crime “had to be done” to obtain a particular goal. They used twice as many words relating to physical needs, such as food, sex or money, while non-psychopaths used more words about social needs, including family, religion and spirituality. Unveiling their predatory nature in their own description, the psychopaths often included details of what they had to eat on the day of their crime.

Past as prologue: Psychopaths were more likely to use the past tense, suggesting a detachment from their crimes, say the researchers. They tended to be less fluent in their speech, using more “ums” and “uhs.” The exact reason for this is not clear, but the researchers speculate that the psychopath is trying harder to make a positive impression, needing to use more mental effort to frame the story.

“Previous work has looked at how psychopaths use language,” Hancock said. “Our paper is the first to show that you can use automated tools to detect the distinct speech patterns of psychopaths.” This can be valuable to clinical psychologists, he said, because the approach to treatment of psychopaths can be very different.

In addition to Hancock, co-authors were Michael T. Woodworth and Stephen Porter, from the University of British Columbia, “Hungry like the wolf: A word-pattern analysis of the language of psychopaths,” Legal and Criminological Psychology (online Sept. 14, 2011).

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University

Scholars at Brigham Young University studied 1,734 married couples across the country. Each couple completed a relationship evaluation, part of which asked how much they value “having money and lots of things.”

The researchers’ statistical analysis showed that couples who say money is not important to them score about 10 to 15 percent better on marriage stability and other measures of relationship quality than couples where one or both are materialistic.

“Couples where both spouses are materialistic were worse off on nearly every measure we looked at,” said Jason Carroll, a BYU professor of family life and lead author of the study. “There is a pervasive pattern in the data of eroding communication, poor conflict resolution and low responsiveness to each other.”

The findings will be published Oct. 13 in the Journal of Couple & Relationship Therapy.

For one in five couples in the study, both partners admitted a strong love of money. Though these couples were better off financially, money was often a bigger source of conflict for them.

“How these couples perceive their finances seems to be more important to their marital health than their actual financial situation,” Carroll said.

And despite their shared materialism, materialistic couples’ relationships were in poorer shape than couples who were mismatched and had just one materialist in the marriage.

The study’s overall findings were somewhat surprising to Carroll because materialism was only measured by self-evaluations.

“Sometimes people can deceive themselves about how important their relationships are to them,” Carroll said. “It’s helpful to step back and look at where you focus your time.”

Contact: Joe Hadfield
joe_hadfield@byu.edu
801-422-9206
Brigham Young University

The Siberian fossil provides new data for the long-lasting debate among scientists about the average duration of an insect species. It was originally estimated to be ca. 2-3 million years based on the available fossil record, but slowly accumulating data begin to show that such an estimate is an oversimplification of the problem. Recently, evolutionary trees dated using molecular clocks suggested that some insect species are rather young, originating during the Ice Ages, but others may have been able to survive the last 10-20 million years until today. The long-living species had to survive the massive changes of the Earth’s climate during the last millions of years – how they managed to do so is another question for scientists to address.

A large missing piece for the acceptance of long-living insects as a general phenomenon and for understanding the reasons for survival of the particular species is the scarcity of the fossils of such species. The reasons seem to be rather straightforward – the majority of the fossils bear too few details to allow a detailed comparison with living species, whose taxonomy is often based on the shape of male genitalia and other details. That is why the fossil discovered by the Czech-Russian-British team is so important: it bears enough details to allow its detailed comparison with the living species. Although the genitalia are not preserved in the fossil, the scientists were lucky that Helophorus beetles bear species-specific granulation on the pronotum which was readily seen on the fossil and allowed its reliable identification.

A life-style associated with an environment which remains stable over time, such as rotten wood, has been suggested as one of the possible ways in which long-living species may have survived from the past. The discovery of a long-living species of an aquatic beetle may indicate that temporary pools in which Helophorus sibiricus is mainly living today may be another example of such a stable environment – it is really not difficult to imagine that the conditions in a pool created in a modern grassland from the melting snow are very similar to those one would have found in such a pool 20 million years ago.

Original source: Fikáček M, Prokin A, Angus RB (2011) A long-living species of the hydrophiloid beetles: Helophorus sibiricus from the early Miocene deposits of Kartashevo (Siberia, Russia). ZooKeys 130: 239-254. doi: 10.3897/zookeys.130.1378

Contact: Martin Fikacek
mfikacek@gmail.com

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