Monday, February 8, 2016

Zika virus raises issues of both abortion rights and disability rights

Women in 2015 protest a bill in North Carolina to increase restrictions for women seeking abortions.

Chloe Angyal writes in the Huffington Post about how the Zika virus may put abortion rights and disability rights on a collision course (although the causal connection between Zika and birth defects has not been established). Below is an excerpt from the article:

"While abortion rights advocates might well point to Zika-linked microcephaly as evidence that the U.S. needs to liberalize abortion laws, disability rights advocates might argue otherwise. On the issue of abortion, the feminist and disability rights movement often come into uncomfortable conflict as they struggle to accommodate both the rights of a woman to control her own fertility and the rights of people with disabilities to exist.

"Now, with the threat of Zika-linked fetal abnormalities looming, that fault line could well crack open, and at least one thought leader in disability rights is concerned by the hastiness with which calls for loosened abortion restrictions are being made.

"There are clear parallels between the experiences of women and those of people with disabilities (not to mention overlaps between the two groups), noted Rosemarie Garland-Thomson, a professor of English at Emory University and a pioneer of the discipline of disability studies. Through much of history, she said, able-bodied women were not allowed to control their own reproduction.

“'There’s a long, deep and troubling history of women’s reproduction being taken over by men and by a variety of other cultural institutions,' she told HuffPost. Likewise, people with disabilities have long been subject to reproductive coercion, from the abandonment of newborns with disabilities to mandatory sterilization of women with disabilities. They have, said Garland-Thomson, 'been eugenically eliminated from the world through selective abortion and other biomedical practices.' 

"Both groups have similar histories of subjugation, particularly around medical decision-making. And on the issue of access to abortion, particularly in the age of prenatal fetal testing, those histories collide."

Read the whole article in the Huffington Post.

Related:
Why we stare at those with disabilities

Image: Thinkstockphoto.com

Friday, January 29, 2016

Not all psychopaths are criminals: Some of their traits are tied to success

Tom Skeyhill made grandiose claims about his combat experience during the World War I battle of Gallipoli.

By Emory psychologist Scott Lilienfeld and Emory Ph.D. candidate Ashley Watts

Tom Skeyhill was an acclaimed Australian war hero, known as “the blind solider-poet.” During the monumental World War I battle of Gallipoli, he was a flag signaler, among the most dangerous of all positions. After being blinded when a bomb shell detonated at his feet, he was transferred out.

After the war he penned a popular book of poetry about his combat experience. He toured Australia and the United States, reciting his poetry to rapt audiences. President Theodore Roosevelt appeared on stage with him and said, “I am prouder to be on the stage with Tom Skeyhill than with any other man I know.” His blindness suddenly disappeared following a medical procedure in America.

But, according to biographer Jeff Brownrigg, Skeyhill wasn’t what he seemed. The poet had, in fact, faked his blindness to escape danger.

That’s not all. After a drunken performance, he blamed his slurred speech on an unverifiable war injury. He claimed to have met Lenin and Mussolini (there is no evidence that he did), and spoke of his extensive battle experience at Gallipoli, when he had been there for only eight days.



You have to be pretty bold to spin those kinds of self-aggrandizing lies and to carry it off as long as Skeyhill did. Although he never received a formal psychological examination (at least to our knowledge), we suspect that most contemporary researchers would have little trouble recognizing him as a classic case of psychopathic personality, or psychopathy. What’s more, Skeyhill embodied many elements of a controversial condition sometimes called successful psychopathy.

Despite the popular perception, most psychopaths aren’t coldblooded or psychotic killers. Many of them live successfully among the rest of us, using their personality traits to get what they want in life, often at the expense of others.

Psychopathy is not easily defined, but most psychologists view it as a personality disorder characterized by superficial charm conjoined with profound dishonesty, callousness, guiltlessness and poor impulse control. According to some estimates, psychopathy is found in about one percent of the general population, and for reasons that are poorly understood, most psychopaths are male.

That number probably doesn’t capture the full number of people with some degree of psychopathy. Data suggest that psychopathic traits lie on a continuum, so some individuals possess marked psychopathic traits but don’t fulfill the criteria for full-blown psychopathy.

Not surprisingly, psychopathic individuals are more likely than other people to commit crimes. They almost always understand that their actions are morally wrong – it just doesn’t bother them. Contrary to popular belief, only a minority are violent.

Read the whole story in The Conversation. 

Related:
Psychopathic boldness tied to presidential success

Tuesday, January 26, 2016

Tuvan throat singing gives voice to a unique way of life

On Friday, Emory will host a free performance by the Alash Tuvan throat singers, masters of a unique musical tradition. The trio includes, from left: Ayan-ool Sam, Bady-Dorzhu Ondar and Ayan Shirizhik. 

By Carol Clark

The first time that Emory anthropologist Paul Hooper went to Tuva, in 2013, it didn’t take long to make friends – including members of the famed Tuvan throat-singing ensemble, Alash. The Anthropology department is hosting Alash in a free concert at the Emory Performing Arts Studio on Friday, January 29 at 7 pm.

Hooper had traveled to the small Republic of Tuva in Russia, on the southern edge of Siberia on the border of Mongolia, to research nomadic herding economics. “I drove in over the mountains and started meeting people pretty quickly,” he recalls.

Within a few days, he was invited to a local barbecue on the outskirts of the capital city of Kyzyl. He and other guests mingled by a yurt, in a high mountain landscape of pine and birch forests. “We ate some really delicious goat, roasted over an open fire,” Hooper says, “and washed it down with araga, the local wine, which is fermented cow’s milk that has been distilled into a clear liquid. Araga is also delicious – it tastes like saki with some parmesan cheese melted into it.”

But the best thing about the party was the entertainment by some of the fellow guests, the Alash throat singers. “I was awestruck, having just arrived a few days earlier and here I was meeting the country’s super stars,” Hooper says. “The Alash members perform internationally and they are like ambassadors to the outside world because they’ve traveled much more than most Tuvans.”

They played handmade instruments and emitted low, droning voices that vibrated into high-pitched, harmonic whistling. “It’s incredible because each singer can generate two or three harmonizing tones at once,” Hooper says. “When you have three guys who are doing this together, and they are all masters at it, they create a musical landscape that is almost extraterrestrial in terms of the sensation it gives you. There is nothing like sitting on a high mountain peak and getting to hear Tuvan throat singing.”

Tuva, tucked into the mountains, remained relatively isolated during the era of the Soviet Union. “It was a refuge for this form of folk music that developed separately from other musical traditions and has grown into a fine performance art,” Hooper says. “Throat singing is now Tuva’s biggest export, in a way."

Fans of “The Big Bang Theory” may be familiar with Tuvan throat singing since it’s a hobby of Sheldon Cooper. But Sheldon falls far short of the masters of the art, Alash.

Hooper hosted Alash for an Emory concert once before, during their 2014 U.S. tour, so Friday will be a return performance, and a reunion of friends.

“They’re wonderful guys, incredibly hospitable,” Hooper says of the trio. “They’ve each invited me to stay with their families in yurts in the countryside. I went to Tuva to learn about nomadic herding, but throat singing is such a beautiful, unique tradition, and Alash is so welcoming, that I couldn’t help but get wrapped up in the musical side of the country as well.”

Friday, January 22, 2016

Zika virus 'a game-changer' for mosquito-borne diseases

The Aedes aegypti mosquito, which transmits Zika, as well as the dengue and chikungunya viruses. “Mosquito control is not considered ‘sexy’ science, like developing a new drug or a vaccine,” says Emory disease ecologist Uriel Kitron, “but more attention and resources need to be devoted to it.”

By Carol Clark

The Zika virus, unlike other mosquito-borne viruses such as dengue, is relatively unknown and unstudied. That is set to change since Zika, now spreading through Latin America and the Caribbean, has been associated with an alarming rise in babies born in Brazil with abnormally small heads and brain defects – a condition called microcephaly.

“This is a huge public health emergency and horrible on many levels,” says Uriel Kitron, chair of Emory’s Department of Environmental Sciences and an expert in vector-borne diseases, which are transmitted by mosquitoes, ticks or other organisms. “The microcephaly cases are a personal tragedy for the families whose babies are affected. They will need much care and support, some of them for decades. The costs to the public health system will be enormous, and Brazil was already experiencing an economic crisis.”

For the past several years, Kitron has collaborated with Brazilian scientists and health officials to study the dengue virus, which is spread by the same mosquito species, Aedes aegypti, as Zika. The focus of that collaboration is now shifting to Zika. Kitron will return to Salvador, the capital of the Brazilian state of Bahia, in February to support the country’s research strategies and control efforts for the outbreak.

“Dengue is a very serious disease, but it doesn’t usually kill people,” Kitron says. “Zika is a game-changer. It appears that this virus may pass through a woman’s placenta and impact her unborn child. That’s about as scary as it gets.”

Since the Zika outbreak began in northeastern Brazil last spring, an estimated 500,000 to 1.5 million people have been infected. The resulting illness only lasts a few days. The symptoms, including a rash, joint pains, inflammation of the eyes and fever, tend to be less debilitating than those of dengue. As many as 80 percent of infected people may be asymptomatic.

It was not until months after Zika cases showed up in Brazil that a spike in microcephaly births was tied to women infected during pregnancy. More than 3,500 microcephaly cases have been reported since October in Brazil, compared to around 150 cases in 2014.

While Zika’s connection to microcephaly has yet to be definitively proven, the presence of the virus has been found in the bodies of five of the newborns that died with the condition and in the placentas of two women who miscarried babies with microcephaly.

The Centers for Disease Control and Prevention has warned pregnant women not to travel unnecessarily to more than a dozen countries currently experiencing an outbreak of Zika virus, as well as Puerto Rico. The governments of Brazil, El Salvador and Columbia, meanwhile, are urging women to delay any plans of pregnancy.

“People are worried that Zika may also have other, more subtle, effects on fetuses besides microcephaly,” Kitron says. “We just don’t know that much about Zika. It has not been studied extensively in the lab and field data is also limited.”

So far, the few known cases of Zika in the U.S. mainland are linked to people who had traveled abroad and were likely infected by mosquitos elsewhere. If Zika follows the same patters as dengue fever, however, states like Texas, Florida and Hawaii could experience small outbreaks transmitted by mosquitoes during the summer months.

The Zika virus is named after an isolated forest in Uganda where it was discovered in a monkey in 1947. Only a handful of human cases were known until 2007 when it popped up in the Yap Islands of the southwestern Pacific Ocean, sickening thousands of people. In 2013 Zika appeared in French Polynesia and the following year in other islands of the South Pacific.

Although Zika outbreaks have coincided with a slightly increased rate of Gillian-Barre’s Syndrome, none of the previous outbreaks were associated with a spike in microcephaly births.

The Brazilian Zika outbreak, first identified in May, is the largest ever. The cases are centered in the northeastern states of Paraiba, Pernambuco and Bahia. Zika quickly spread in the region, since the population had never been exposed to the virus, making it highly susceptible. Given the high rate of infection, herd immunity may delay future outbreaks for several years, Kitron says.

Zika cases were initially confused with chikungunya, another virus transmitted by the Aedes aegypti mosquito that was introduced to Brazil and other parts of Latin America and the Caribbean in 2014.

Zika, chikungunya and dengue viruses are all now circulating in Brazil. They cause similar symptoms, complicating clinical identification during outbreaks. And no treatments or vaccines exist for any of the three viruses, making mosquito control vital.

“Mosquito control is not considered ‘sexy’ science, like developing a new drug or a vaccine,” Kitron says, “but more attention and resources need to be devoted to it.”

Aedes aegypti are like “the roaches” of the mosquito world, perfectly adapted to living with humans, especially in urban environments, says Gonzalo Vazquez-Prokopec, another disease ecologist in Emory’s Department of Environmental Sciences who studies vector-borne diseases.

Vazquez-Prokopec specializes in spatial analysis of disease transmission patterns and has several research projects for dengue fever ongoing in Latin America. He is traveling to the Brazilian capital of Brasilia in February to assist the country’s vector control team as they continue to battle the outbreak through mosquito control.

While mosquitoes that carry malaria only feed during the evening, the Aedes aegypti feeds almost exclusively on humans and bites primarily during the daytime.

“Killing mosquitoes is labor-intensive and expensive if you do it well, and it can be difficult to get funding for it,” Vazquez-Prokopec says. “Now we have three viruses – dengue, chikungunya and Zika – being spread by Aedes aegypti, so that greatly increases the cost-effectiveness of doing high-quality, thorough mosquito control.”

Related:
How the dengue virus makes a home in the city
Human mobility data may help curb urban epidemics

Tuesday, January 19, 2016

Cells talk to their neighbors before making a move

Cells trade information with adjoining cells and, like the telephone game, the original message becomes garbled the further it travels down the line.

By Carol Clark

To decide whether and where to move in the body, cells must read chemical signals in their environment. Individual cells do not act alone during this process, two new studies on mouse mammary tissue show. Instead, the cells make decisions collectively after exchanging information about the chemical messages they are receiving.

“Cells talk to nearby cells and compare notes before they make a move,” says Ilya Nemenman, a theoretical biophysicist at Emory University and a co-author of both studies, published by the Proceedings of the National Academy of Sciences (PNAS). The co-authors also include scientists from Johns Hopkins, Yale and Purdue.

The researchers discovered that the cell communication process works similarly to a message relay in the telephone game. “Each cell only talks to its neighbor,” Nemenman explains. “A cell in position one only talks to a cell in position two. So position one needs to communicate with position two in order to get information from the cell in position three.”

And like the telephone game – where a line of people whisper a message to the person next to them – the original message starts to become distorted as it travels down the line. The researchers found that, for the cells in their experiments, the message begins to get garbled after passing through about four cells, by a factor of about three.

“We built a mathematical model for this linear relay of cellular information and derived a formula for its best possible accuracy,” Nemenman says. “Directed cell migration is important in processes from cancer to the development of organs and tissues. Other researchers can apply our model beyond the mouse mammary gland and analyze similar phenomena in a wide variety of healthy and diseased systems.”

Since at least the 1970s, and pivotal work by Howard Berg and Ed Purcell, scientists have been trying to understand in detail how cells decide to take an action based on chemical cues. Every cell in a body has the same genome but they can do different things and go in different directions because they measure different chemical signals in their environment. Those chemical signals are made up of molecules that randomly move around.

“Cells can sense not just the precise concentration of a chemical signal, but concentration differences,” Nemenman says. “That’s very important because in order to know which direction to move, a cell has to know in which direction the concentration of the chemical signal is higher. Cells sense this gradient and it gives them a reference for the direction in which to move and grow.”

Berg and Purcell understood the best possible margin of error – the detection limit – for such gradient sensing. During the subsequent 30 years, researchers have established that many different cells, in many different organisms, work at this detection limit. Living cells can sense chemicals better than any man-made device.

It was not known, however, that cells can sense signals and make movement decisions collectively.

“Previous research has typically focused on cultured cells,” Nemenman says. “And when you culture cells, the first thing to go away is cell-to-cell interaction. The cells are no longer a functioning tissue, but a culture of individual cells, so it’s difficult to study many collective effects.”

The first PNAS paper drew from three-dimensional micro-fluidic techniques from the Yale University lab of Andre Levchenko, a biomedical engineer who studies how cells navigate; research on mouse mammary tissue at the Johns Hopkins lab of Andrew Ewald, a biologist focused on the cellular mechanisms of cancer; and the quantification methods of Nemenman, who studies the physics of biological systems, and Andrew Mugler, a former post-doctoral fellow in Nemenman’s lab at Emory who now has his own research group at Purdue.

The 3D micro fluidics allowed the researchers to experiment with functional organoids, or clumps of cells. The method does not disrupt the interaction of the cells. The results showed that epidermal growth factor, or EGF, is the signal that these cells track, and that the cells were not making decisions about which way to move as individuals, but collectively.

“The clumps of cells, working collectively, could detect insanely small differences in concentration gradients – such as 498 molecules of EGF versus 502 molecules – on different sides of one cell,” Nemenman says. “That accuracy is way better than the best possible margin of error determined by Berg and Purcell of about plus or minus 20. Even at these small concentration gradients, the organoids start reshaping and moving toward the higher concentration. These cells are not just optimal gradient detectors. They seem super optimal, defying the laws of nature.”

Collective cell communication boosts their detection accuracy, turning a line of about four cells into a single, super-accurate measurement unit.

In the second PNAS paper, Nemenman, Mugler and Levchenko looked at the limits to the cells’ precision of collective gradient sensing not just spatially, but over time. “We hypothesized that if the cells kept on communicating with one another over hours or days, and kept on accumulating information, that might expand the accuracy further than four cells across,” Nemenman says. “Surprisingly, however, this was not the case. We found that there is always a limit of how far information can travel without being garbled in these cellular systems.”

Together, the two papers offer a detailed model for collective cellular gradient sensing, verified by experiments in mouse mammary organoids. The collective model expands the classic Berg-Purcell results for the best accuracy of an individual cell, which stood for almost forty years. The new formula quantifies the additional advantages and limitations on the accuracy coming from the cells working collectively.

 “Our findings are not just intellectually important. They provide new ways to study many normal and abnormal developmental processes,” Nemenman says.

Related:
Biology may not be so complex after all
Biochemical cell signals quantified for the first time
Biophysicists take small step in quest for 'robot scientist'