Science Metropolis – Boston

The cylindrical sea squirt, Ciona intestinalis, also known as the sea vase, can regenerate any part of its body, including its brain. (Credit: Joseph Caputo/MBL)

Cut off one finger from a salamander and one will grow back. Cut off two and two will grow back. It sounds logical, but how the salamander always regenerates the right number of fingers is still a biological mystery.

The salamander isn’t the only animal with this regenerative ability. Take the sea squirt, Ciona intestinalis, a cylindrical marine creature about the size of a small cucumber that regularly loses its siphons, or feeding tubes, to hungry predators. At the base of each siphon are eight photoreceptors, cells used to detect light. Whenever the sea squirt experiences a violent loss at the siphon base, the number of photoreceptors that grow back is always eight.

Understanding the molecular pathway responsible for this phenomenon is a research objective for MBL investigator William R. Jeffery, a former director of the MBL Embryology course and professor of biology at the University of Maryland. “The question I’m interested in is not only what mechanisms are involved in regeneration, but how exact [photoreceptor] patterns are formed,” Jeffery says.

Following up on previous research, in which he experimentally induced variations in the number of photoreceptors that regenerate by manipulating the siphon’s diameter, this summer Jeffery will test the role of the Notch signaling pathway, a highly conserved molecular cascade that determines how an embryo forms. If Jeffery is on the right track, not only will he develop a model of regeneration in sea squirts, but in salamanders as well. Basic research on animal regeneration is a foundation for a major goal in medicine: Learning how to guide human stem cells to regenerate new tissues or organs.

Late stage midshipman larvae (about 30 days old and 20 mm length) attached to a rocky substrate. Credit: Margaret Marchaterre, Department of Neurobiology and Behavior, Cornell University

The 3rd installment of “At MBL,” Joseph Caputo’s experience as a science writing intern at the Marine Biological Laboratory in Woods Hole, Massachusetts. The following story originally appeared, along with more audio and video clips, on the Marine Biological Laboratory Website.

A male midshipman, a close relative of the toadfish, doesn’t need good looks to attract a mate – just a nice voice. After building a nest for his potential partner, he calls to nearby females by contracting his swim bladder, the air-filled sac fish use to maintain buoyancy. The sound he makes is not a song or a whistle, but a hum; more reminiscent of a long-winded foghorn than a ballad. Female midshipman find it very alluring, and they only approach a male’s nest if he makes this call.

In a paper published this week in Science, three Marine Biological Laboratory (MBL) visiting investigators show that the sophisticated neural circuitry that midshipman use to vocalize develops in a similar region of the central nervous system as the circuitry that allows a human to laugh or a frog to croak, evidence that the ability to make and respond to sound is an ancient part of the vertebrate success story. The research is presented by Andrew Bass of Cornell University, Edwin Gilland of Howard University College of Medicine, and Robert Baker of New York University Medical Center.

“Fish have all the same parts of the brain that you do,” says Bass, the paper’s lead author. The way our brains work is also similar. Just as we have neurons that coordinate when our larynx and tongue change shape to produce words, toadfish and midshipman orchestrate the movement of muscles attached to their swim bladder to produce grunts and hums.

Using larval toadfish and midshipman, the group traced the development of the connection from the animal’s vocal muscles to a cluster of neurons located in a compartment between the back of its brain and the front of its spinal cord. The same part of the brain in more complex vertebrates, such as humans, has a similar function, indicating that it was highly selected for during the course of evolution.

Scientists have known for decades that these fish make sounds, but they are not the only species whose hums, growls, and grunts have meaning. “There’s reason to suggest that the use of sound in social communication is widespread among fishes,” Bass says.

This research is an example of the growing field of evolutionary neurobiology, which aims to understand the evolution of behavior through neurobiology. According to Bass, fish are an incredibly successful group, making up nearly half of the living species of vertebrates, and vocal communication may be partly responsible. “The kind of work we’re doing contributes to answering questions as to why these animals are so successful,” Bass says. “We’re only touching the tip of the iceberg here.”

The majority of this research was completed at the MBL over the past five years, although the question of how fish communicate through sound first came to Bass as a graduate student studying the neurobiology of fish at the University of Michigan. In the summer of 1986, Bass, then a summer instructor at the MBL, met Robert Baker, who was also researching the neurobiology of fish calling. For years they discussed fish social behavior with the roots of the hypothesis tested in the Science paper first published in 1997 and the research to test that hypothesis beginning in 2003. “The whole project began at the MBL,” Bass says. “It’s where collaborations happen.”

Evolution guarantees this sea anemone doesn’t need a stress test. Credit: Norbert Bieberstein/istockphoto.com

Though the starlet sea anemone, a translucent marine creature as long as a credit card, may appear helpless, years of evolution have prepared it for any attack nature or humans have in store. Rather than spikes, teeth or claws, the soft anemone, a native to the coasts of New England, defends itself with its genes.

While humans stress about bees and mortgage payments, the anemone’s anxieties concern starvation, suffocation, pollution and coastal development.  Despite the laundry list, it is a thriving family of creatures. Cousins of the starlet sea anemone can be found over a range of temperatures and conditions. Their secret is a wide variety of stress-response genes, which define immediately against toxins, osmotic shock, illness and physical wounds.

This knowledge of the creature’s biology didn’t emerge through observational studies. Instead, it was made possible by the recently-acquired ability to compare genomes. By plugging DNA sequences from the sea anemone into a genetic database, John R. Finnerty, a biology professor at Boston University, compared genes known to have a role in stress-response with the genomes of related creatures. With this information he now has a few guesses as to how sea anemone’s evolved to be so resilient.

“[The starlet sea anemone] is known to harbor extensive genetic variation,” Finnerty writes in the paper. “This suggests that the natural dispersal ability of the animals may be quite limited, that local adaptation may be driving genetic differentiation, or a combination of both.”

Being that the anemone can survive most conditions, especially at the local level, Finnerty sees the creatures’ as canaries in the coal mine for salt marshes.  Meaning that if the anemones start to go, the area is in serious trouble.

His findings were pulished in the June issue of The Biological Bulletin, located at the Marine Biological Laboratory in Woods Hole, Massachusetts.

The invasive sea squirt Didemnum lahillei. Credit: USGS Woods Hole Science Center

The phrase invasive species is a relative term. Almost everything has been invasive at one point. The house sparrow that sits at your bird feeder – an unwanted gift from English sailors. The green seaweed that coats the Massachusetts seashore – an Atlantic hitchhiker.  A species is invasive when it can’t coexist with the native creatures, whether by stealing food or shelter.

With climate change on the loom, species are going to get a whole lot more invasive as they migrate to warmer or colder regions. This poses not only an environmental risk but a health risk as well, especially if the traveling critters happen to be mosquitoes, for instance. In a few centuries, the phrase “native species” could be obsolete.

New England has it’s own share of invasive creatures. Here’s a list of four in our backyard:

The Sea Squirt (Didemnum lahillei)

This tubular sea squirt, an underwater resident of the Pacific and Europe, has overtaken spots on the  seashore ranging from Maine to Connecticut. It first grabbed the attention Cape Cod residents in 2003, when the Boston Globe reported sea squirt colonies carpeting the water off Georges Bank, hindering scallop fishing.

Emerald Ash Borer (Agrilus planipennis)

This green beetle has been causing all sorts of havoc in the Middle States since turning up in Detroit in 2002. Originally from Asia, the bug has killed millions of ash trees, the main staple of its diet, and is heading for the Northeast. A few days ago, the Associated Press reported the use of a wasp to hunt and kill the pests, a quick and environmentally friendly solution to an agricultural disaster.

Norway Maple (Acer platanoides)

According to a member of EarthWorks, an ecological awareness organization located in Greater Boston, one familiar site on the streets of Boston is also an invasive species – the Norway maple.  The tree, a favorite for the streets of small towns and cities, easily wins the resource battle against native North American trees like the red maple or native oaks.  The article’s author advises against planting them in your yard.

Phragmites (Phragmites australis)

Anyone who has been to a salt marsh has seen these long reeds sticking out from the sand dunes. Their red stalks making an attractive backdrop against the blue water. But in areas full of protected plants like Sandy Neck Beach on Cape Cod, phragmites, native to Europe and Asia, can be a real nuisance. According to a WCAI report, residents and conservation organizations have to schedule regular “mowings” to keep these grasses at bay.

Psychologist Anne Fishel prepares dinner. Credit: Ginger Chappell

It’s Saturday evening and the smell of roast turkey fills Anne Fishel’s kitchen. Her husband Chris removes the turkey from the oven while Fishel prepares the traditional Passover matzoh ball soup. She dips her hand in water and then places it in a bowl with the sticky matzoh dough. She takes a handful of dough, molds it into the shape of ping pong balls, then boils them in chicken broth. Finally, Fishel serves her family, gathered around the dining room table.

Dinners are more than a Saturday family gathering for Fishel, a clinical psychologist, professor and director of the Family and Couples Therapy Program at Massachusetts General Hospital (MGH). She studies how family dinners contribute to children’s cognitive and personal development, as well as how they strengthen the bond between children and parents. As dinner is typically a daily routine, Fishel can observe a family’s dynamic and propose solutions tailored to their needs. “Dr. Fishel’s work outlines how the family dinner can serve as an invaluable tool in the assessment and treatment of families in any school of family therapy,” says David Rubin, a psychiatrist at Cornell Medical Center in New York.

For the past 25 years, Fishel has been treating couples and families as a clinical psychologist at her office in Newton Highlands, Massachusetts. She recently began taking a close look at dinner rituals, because meals are family routines that help a therapist understand important aspects of families and make interventions easier. “Patients feel more comfortable answering questions about their dinner than about their sex life or the family roles,” she says.

“Food experiences function not only as a means of physically nourishing a child, but also as a form of emotional nourishment,” says Laura Weisberg, a psychologist at Duke Medical Center in Durham, North Carolina and an expert in eating disorders. Family dinners, according to several psychological studies, show fascinating positive behavioral impacts on children of all ages. Lower rates of substance abuse, depression, pregnancy, alcoholism and eating disorders are just some examples of the long list of positive effects of family dinners. For vulnerable children, not having family meals on a regular basis “makes it easier to begin a pattern of skipping meals, or eating in unhealthy ways, which can then get out of control before the family has an opportunity to recognize it,” says Weisberg. This body of research is so impressive that Fishel almost wants to tell her patients, “Don’t waste your time in therapy-go home right now and cook a meal and eat it together. Here are some recipes, now go!”

Research about the impact of family meals to children’s language and literacy development also caught Fishel’s attention. Although both parents and pediatricians believe that reading is the best way to teach children new vocabulary words, a new study by Catherine Snow of the Harvard Education School in Cambridge, Massachusetts, shows that the best way to build a child’s vocabulary is through regular family meals. “The use of relatively sophisticated vocabulary at family mealtimes predicted children’s later vocabulary knowledge better than in other settings -book reading, toy play, or story telling,” says Snow, an expert on children’s language and literacy development.

To keep children at the table, Fishel proposes maximizing the pleasure of dinner time. Parents can engage younger kids by playing word games or guessing what ingredients are in a meal. In dealing with teenagers, Fishel suggests avoiding discussions that would bring conflict to dinner. Instead she encourages parents to discuss their daily experiences in an honest and self-disclosing way, inviting children to participate in the conversation. After all, dinners are family rituals, whose purpose is to “create a feeling of warm connection among its members,” Fishel says.

Fishel’s family meals are a synonym of joy and creativity, “something that connects everybody up,” she says. Her two college age sons are very demanding eaters, but “I like the way they push me to be creative and adventurous,” she says. Her favorite meals to prepare are those made with a lot of ingredients cooked together in a pot. She loves making soups, such as squash-apple-onion or swordfish stew with pine nuts, tomatoes and raisins. “These foods are very cozy and connected; the flavors are distinct like the different members of the family.” But, both the ingredients in the soup and the members of the family “are made better by being together,” she adds.

To read the full story by Staff Writer Aspasia Daskalopoulou, visit the Contributions page.

A quarter scale radio-controlled model of Glenn Curtiss’s June Bug takes to the air. Credit: Jeff Meredith

On June 21, 1908, Glenn Curtis made aerospace history with the first kilometer-long plane flight n his June Bug.  One-hundred years later, the Glenn H. Curtiss Museum in Hammondsport, New York, honored the event with a celebration including the flight of a quarter-scale radio-controlled model of the plane.

Designed and orchestrated by the Finger Lakes Air Pirates, a group that flies model helicopters, planes, and even lawn mowers (see below), the approximately 7-foot long replica made it’s trip as an audience of Independence Day visitors looked on.

With a sputter and a roar, the airplane took moments to reach it’s destination at the end of the field. The original flight was a little longer, when the June Bug, with it’s nearly 43 foot wingspan, flew over Stony Brook Farm, also in Hammondsport.

For the achievement, Curtiss, a contemporary of the Wright Brothers and Alexander Graham Bell, was awarded the Scientific American Trophy and, the Pilot’s License #1 by the Aero Club of America. As one onlooker remarked, Curtiss is one inventor that doesn’t get his due.

A remote-controlled flying lawnmower also part of the festivities. Credit: Jeff Meredith

Soft-bodied caterpillar robot prototype. Credit: Tufts University

Will the caterpillar inspire a new generation of military robots?  The U.S. Defense Advanced Research Projects Agency (DARPA) sees potential. The research and development arm of the Department of Defense, known for funding long term and risky scientific projects such as the stealth bomber and atomic clock, signed a $3.3 million contract with Tufts University last week to develop caterpillar-like chemical robots.

Caterpillars, like mice or octopi, can sneak through small crevices by flattening their bodies,   remerging moments later into their usual shape. The military wants unmanned robots to be able to do the same, except remerge 10 times larger, and ultimately biodegrade.  Normal metallic robots are too rigid to contort their shape this way, so DARPA is looking to use a Chembot, a robot made of a softer material like artificial silk, the expertise of David Kaplan, the chair of biomedical engineering at Tufts and one of the scientists awarded the contract.

DARPA posted its solitation for the project in March, which includes lengthy specifications for progress withing the first 18 to 24 months.  According to the document, if the scientists are to receive further funding, by the end of Phase I, they must:

“1. Demonstrate a ChemBot, approximately the size of a regulation softball, that can:
a) travel a distance of 5 meters at a speed of 0.25 meters/minute;
b) achieve a 10-fold reduction in its largest dimension; and
c) traverse through a 1 cm opening of arbitrary geometry and reconstitute its original size and shape, in 15 seconds.”

According to the press release, the robot design is inspired by the Tufts scientist’s findings on both the brain mechanics of the Manduca sexta caterpillar and the properties of large artificial molecules.

The Manduca sexta caterpillar, the Chembots’ inspiration. Credit: Tufts University

The Tufts Chembots will copy the Manduca’s  flexibility, climbing ability and scalability. (From hatching to the end of its larval stage, the caterpillar grows 10,000 fold in mass using the same number of muscles and motor neurons.)

Dr. Barry Trimmer, a Tufts neurobiologist also on the contract team, has been studying the nervous system and behavior of this caterpillar for almost two decades. The complete chembot is envisioned to have multiple hair-like sensors for temperature, pressure, chemical and audio/video, not to mention use wireless communication.

More updates on the project are to come in following months. But for now, it seems Nature can’t be faulted for bad design.

One of several polls presented by Science Debate 2008

The advocacy group Science Debate 2008 will make an excellent documentary subject someday. In just 8 months, the growing group of concerned citizens, (although journalists, scientists and university presidents aren’t exactly your average American…), have built an aggressive campaign requesting a simple chat between the presidential candidates about science. However, with the date of that proposed debate having passed, and the presidential elections edging closer, the group is trying plan B, written responses from Barack Obama and John McCain.

What’s shocking about Science Debate 2008 is how much it has had to prove to the United States that science is important, not just to the country’s progress but to its citizens. It’s polls generally show a majority agreement that science-related issues like education, health care, energy needs and climate change need to be at the forefront of the next election. Yet, still the candidates have not responded.

In conjunction with Scientists and Engineers for America, Science Debate 2008 published today a list of 14 questions covering the biggest scientific issues of our day. After 8 years of a president who openly attacked science, (Read Chris Mooney’s “The Republican War on Science” for more information), knowing how each candidate plans to handle predicted water shortages and stem cell research would be change we can depend on.

As important as where the president stands on these issues, is how your local politicians support science. The SEA Website also tracks how congressmen vote on important scientific issues. Democratic Senator John Kerry and Democratic Congressman Michael Capuano are listed for the 8th district of Massachusetts.

Science Metropolis supports Science Debate 2008. If you’d also like to get involved, visit their Website.

Ask and Answer: Which of the 14 questions are most important to you?

Wall-E dreams of holding hands. Credit: Pixar

Wall-E, the new Pixar/Disney film by Andrew Stanton (Finding Nemo), was not the action-packed fanfare of robotic mayhem I expected. I saw instead a touching and budding story of unrequited (robot) love backlit by an eerie vision of humanity.

Unlike other Disney films, there is no grand heroic motivation for Wall-E, our romantic lead. He doesn’t strive to be a fancier ‘bot, nor does he dream of exploring the cosmos. Rather he is timid, afraid of loud noises and large spaceships

When we meet Wall-E, he is the sole occupant on the remains of Earth, a place overcome by towers of trash, a fecund atmosphere, encased in satellite trash and utterly abandoned. (Hints to this decay are revealed in the flickering advertisements and billboards for the super-conglomerate “Big ‘n Large.”)

Every day Wall-E heads out alone to do his garbage compacting with his cockroach sidekick, collecting discarded items he finds interesting in his cooler, before heading back to his trinket-filled home. There he watches the love duet from “Hello Dolly!,” revealing his sole dream and endearing motivation-to hold hands with someone.

The story progresses when a spaceship descends to Earth to drop off Eve, a capsule-shaped, advanced female robot intent on a mysterious mission. Wall-E falls hard despite Eve’s immediate rejection (in the form of attempted vaporization). Wall-E, however, is utterly, completely entranced. Despite space mishaps, confrontations with other bots and personal danger, Wall-E is as single-minded in his affection as perhaps only a robot or someone in love can be. Throughout the rest of the movie he has no other wish, no greater desire, than to win over – and hold hands with – his dear Eve.

It’s impressive that the movie works entirely well with nearly no vocals from the two main characters, except for “Wallll-eeee” and “Eeeev-aaa” in varying tones of distress, vexation (on Eve’s part) and, eventually, adoration.

The background on which the love story plays out is as interesting as the robots themselves. Stanton’s vision for humanity in 700-plus years is not pretty. In his future, robots operate ubiquitously in the background, helping humans to such an extent they don’t really have to do anything except reach for the next processed meal

The film’s environments ebb and flow gracefully from the lone, sad Earth to a waltz over the empty, yet lovely dance floor of space. Juxtaposing robots with the human need to connect, touches on the notion that, all things aside, the simple act of holding a beloved’s hand can be worth jumping galaxies.

Story by Technology Review staff writer and Boston-based science journalist Kristina Grifantini.