Scientists wrestle with possibility of second Zika-spreading mosquito
Sure, mosquitoes spread Zika virus. Scientists have already identified the yellow fever mosquito (Aedes aegypti) as a major spreader in the Americas of Zika and its risk of birth defects and possible paralysis. But Ae. aegypti may not be the only culprit. Recent evidence raises concerns that a relative, the Asian tiger mosquito (Ae. albopictus), might also play a role.
A Mexican lab, for instance, recently detected Zika virus for the first time in an Ae. albopictus collected in the Americas, the World Health Organization and Pan American Health Organization announced in April.
Just finding the virus in a mosquito doesn’t prove the species will spread the disease in a major way in the Americas, says Phil Lounibos of the University of Florida’s medical entomology lab in Vero Beach. But if Asian tiger mosquitoes do turn out to be important in driving the Zika outbreak northward in the Americas, researchers predict more people and more places could face disease risk, wrote
For Ae. aegypti, the evidence is clear that it readily transfers the Zika virus, the WHO declares. Ae. aegypti is a household cockroach of a species, thriving around people; it frequents human houses, bites (and bites repeatedly) during the day, and breeds in plant saucers and other minipools in yards.
Asian tiger mosquitoes also thrive around humans, and in many places, they have a taste for human blood.
They can spread Zika relatives such as dengue — in fact, Ae. albopictus has been responsible for at least modest outbreaks of viral disease on its own, as evidenced by surges of dengue cases in Hawaii and in southern China.
Researchers have their reasons for worrying that Ae. albopictus can transmit Zika as well. Lab work has shown that the virus can travel from blood in the mosquito gut to the salivary glands and then reproduce there vigorously enough to render future bites infectious (although recent lab tests find a low rate of virus transmission). And the mosquito is a major suspect in a 2007 Zika outbreak in Gabon.
These worrying factors, however, still leave a lot of uncertainty about whether Ae. albopictus will prove important in Zika’s sweep through the Americas. In general, Ae. albopictus isn’t as dedicated to biting humans as Ae. aegypti, says Michael Reiskind of North Carolina State University in Raleigh. And while Ae. albopictus’ range reaches much farther north than that of Ae. aegypti, the virus replicates more slowly in mosquitoes as temperatures drop.
Therefore, milder temperatures in northern mosquito seasons can render mosquitoes a bit less dangerous by dragging out the time between drinking virus-tainted blood and building up enough virus to pass it on.
Figuring out the role of Ae. albopictus in the current sweep of Zika through the Americas is critically important, says Lauren Gardner of the University of New South Wales in Sydney. Gardner specializes in analyzing how widespread human systems, such as transportation, affect the spread of disease.
In the May issue of Lancet Infectious Diseases, she and colleagues argue that adding Ae. albopictus as a second spreader of Zika virus makes a big difference in how the epidemic might play out worldwide. In North America for instance, with just Ae. aegypti as the major vector, the researchers predict a high risk of Zika virus spreading mostly in Florida, Louisiana and Texas. But having Ae. albopictus as a second important vector raises the specter of local mosquitoes spreading Zika in chillier places such as Canada.
Although Ae. albopictus is a competent vector in lab tests, the real world has so many more variables that actual outcomes are difficult to predict, Reiskind says. “Could albopictus spread Zika? Absolutely,” he says. “Will it?” That’s the question.
Mom’s voice activates different regions in children’s brains
Children’s brains are far more engaged by their mother’s voice than by voices of women they do not know, a new study from the Stanford University School of Medicine has found.
According to medicalexpress.com, brain regions that respond more strongly to the mother’s voice extend beyond auditory areas to include those involved in emotion and reward processing, social functions, detection of what is personally relevant and face recognition.
The study, which is the first to evaluate brain scans of children listening to their mothers’ voices, was published in the Proceedings of the National Academy of Sciences. The strength of connections between the brain regions activated by the voice of a child’s own mother predicted that child’s social communication abilities, the study also found.
“Many of our social, language and emotional processes are learned by listening to our mom’s voice,” said lead author Daniel Abrams, PhD, instructor in psychiatry and behavioral sciences. “But surprisingly little is known about how the brain organizes itself around this very important sound source. We didn’t realize that a mother’s voice would have such quick access to so many different brain systems.”
Decades of research have shown that children prefer their mother’s voices: In one classic study, one-day-old babies sucked harder on a pacifier when they heard the sound of their mom’s voice, as opposed to the voices of other women. However, the mechanism behind this preference had never been defined.
“Nobody had really looked at the brain circuits that might be engaged,” senior author Vinod Menon, PhD, professor of psychiatry and behavioral sciences, said. “We wanted to know: Is it just auditory and voice-selective areas that respond differently, or is it more broad in terms of engagement, emotional reactivity and detection of salient stimuli?”
The study examined 24 children aged seven to 12. All had IQs of at least 80, none had any developmental disorders, and all were being raised by their biological mothers. Parents answered a standard questionnaire about their child’s ability to interact and relate with others. And before the brain scans, each child’s mother was recorded saying three nonsense words.
“In this age range, where most children have good language skills, we didn’t want to use words that had meaning because that would have engaged a whole different set of circuitry in the brain,” said Menon, who is the Rachael L. and Walter F. Nichols, MD, professor.
Two mothers whose children were not being studied, and who had never met any of the children in the study, were also recorded saying the three nonsense words. These recordings were used as controls.
The children’s brains were scanned via magnetic resonance imaging while they listened to short clips of the nonsense-word recordings, some produced by their own mother and some by the control mothers. Even from very short clips, less than a second long, the children could identify their own mothers’ voices with greater than 97 percent accuracy.
The brain regions that were more engaged by the voices of the children’s own mothers than by the control voices included auditory regions, such as the primary auditory cortex; regions of the brain that handle emotions, such as the amygdala; brain regions that detect and assign value to rewarding stimuli, such as the mesolimbic reward pathway and medial prefrontal cortex; regions that process information about the self, including the default mode network; and areas involved in perceiving and processing the sight of faces.
“The extent of the regions that were engaged was really quite surprising,” Menon said.
“We know that hearing mother’s voice can be an important source of emotional comfort to children,” Abrams added. “Here, we’re showing the biological circuitry underlying that.”
Children whose brains showed a stronger degree of connection between all these regions when hearing their mom’s voice also had the strongest social communication ability, suggesting that increased brain connectivity between the regions is a neural fingerprint for greater social communication abilities in children.
An important new template
“This is an important new template for investigating social communication deficits in children with disorders such as autism,” Menon said. His team plans to conduct similar studies in children with autism, and is also in the process of investigating how adolescents respond to their mother’s voice to see whether the brain responses change as people mature into adulthood.
“Voice is one of the most important social communication cues,” Menon said. “It’s exciting to see that the echo of one’s mother’s voice lives on in so many brain systems.”
‘Smart leg’ makes engineering prize shortlist
A smart prosthetic leg is one of three finalists for the MacRobert Award, a major UK engineering prize.
Made by Basingstoke firm Blatchford, the Linx Limb uses a network of sensors to adapt to changing conditions by adjusting its robotic knee and foot, BBC wrote.
Also on the shortlist are Jaguar Land Rover, for building its own innovative engines, and Siemens Magnet Technology, for pushing the boundaries of MRI scanning.
The MacRobert Award, organized annually since 1969 by the Royal Academy of Engineering, will be presented for 2016 at a dinner on June 23.
Each of the three nominees would “have a positive impact on millions of people and bolster the UK economy”, said the Chair of the Judging Panel Dame Sue Ion.
“It’s often said that Britain doesn’t make anything anymore, but these three companies are proof that the opposite is true, and testament to the world-leading engineering innovation that happens here in the UK,” Dame Sue said.
“Each of this year’s finalists has taken a different approach to innovation ― from sustained incremental improvements to starting from scratch.”
The Linx system is the first ever prosthetic limb with integrated, robotic control of the knee and foot. The parts work together much like those of a human leg.
For example, it senses when the wearer comes to a standstill and locks up, allowing the person to relax.
When a patient is first fitted with the Linx, the calibration process is streamlined by software which records data about the patient’s walking style via a Bluetooth connection.
The prosthetic is expensive, but could save money in the long run by minimizing secondary problems such as back pain or falls.
“Blatchford has achieved a huge leap forward in making the knee and ankle joints work together as an integrated system, enabling it to adapt immediately to both the actions of the wearer and changes in the environment,” said Dr Frances Saunders, one of the MacRobert Award judges.
Siemens Magnet Technology, headquartered in Oxfordshire, developed the world’s first seven-Tesla (7T) MRI scanner. This figure quantifies the strength of the magnetic field used to peek inside the body; the previous standard was 3T.
That boost in power delivers much clearer pictures, improving the accuracy of scientific research as well as making diagnoses, from Alzheimer’s to multiple sclerosis, much more sensitive.
Scientists create ‘liquid wire’ material inspired by spiders’ capture silk
Why doesn’t a spider’s web sag in the wind or catapult flies back out like a trampoline? The answer, according to new research by an international team of scientists, lies in the physics behind a ‘hybrid’ material produced by spiders for their webs.
Pulling on a sticky thread in a garden spider’s orb web and letting it snap back reveals that the thread never sags but always stays taut — even when stretched to many times its original length. This is because any loose thread is immediately spooled inside the tiny droplets of watery glue that coat and surround the core gossamer fibers of the web’s capture spiral, phys.org reported.
The phenomenon was described in the journal PNAS by scientists from the University of Oxford, UK and the Université Pierre et Marie Curie, Paris, France.
The researchers studied the details of this ‘liquid wire’ technique in spiders’ webs and used it to create composite fibers in the laboratory which, just like the spider’s capture silk, extend like a solid and compress like a liquid. These novel insights may lead to new bio-inspired technology.
Professor Fritz Vollrath of the Oxford Silk Group in the Department of Zoology at Oxford University said: “The thousands of tiny droplets of glue that cover the capture spiral of the spider’s orb web do much more than make the silk sticky and catch the fly. Surprisingly, each drop packs enough punch in its watery skins to reel in loose bits of thread. And this winching behavior is used to excellent effect to keep the threads tight at all times, as we can all observe and test in the webs in our gardens.”
The novel properties observed and analyzed by the scientists rely on a subtle balance between fiber elasticity and droplet surface tension. Importantly, the team was also able to recreate this technique in the laboratory using oil droplets on a plastic filament. And this artificial system behaved just like the spider’s natural winch silk, with spools of filament reeling and unreeling inside the oil droplets as the thread extended and contracted.
Dr. Hervé Elettro, the first author and a doctoral researcher at Institut Jean Le Rond D’Alembert, Université Pierre et Marie Curie, Paris, said: “Spider silk has been known to be an extraordinary material for around 40 years, but it continues to amaze us. While the web is simply a high-tech trap from the spider’s point of view, its properties have a huge amount to offer the worlds of materials, engineering and medicine.
“Our bio-inspired hybrid threads could be manufactured from virtually any components. These new insights could lead to a wide range of applications, such as microfabrication of complex structures, reversible micro-motors, or self-tensioned stretchable systems.”
Artificial intelligence software
Physicists have revealed artificial intelligence software was used to run a complex experiment ― creating an extremely cold gas trapped in Bose-Einstein condensate, replicating the experiment that won the 2001 Nobel Prize.