May 10, 2013
After 17 years underground, billions of cicadas are ready to emerge and see sunlight for the first time. They will blanket the East Coast until around mid-June, buzzing like jackhammers in harmony as they search for a mate. Since 1996, the periodical insects, which belong to a group called Brood II, have lived as nymphs two feet deep in the soil, feeding on nothing but the liquid they suck out of tree roots. Once they crawl up to the surface, they molt, mate, lay eggs and die within a month.
Scientists are still trying to determine how periodical cicadas know when to emerge. But in the last 17 years, researchers have made some other important discoveries about other insects, some of whom also enjoy swarming the United States. Here are 17 news items about the bugs’ brethren since 1996.
1. British researchers figured out how insects fly. In 1996, scientists at the University of Cambridge solved the mystery of how many winged insects can produce more lift than can be explained by aerodynamic properties. The team unleashed hawkmoths into a wind tunnel with smoke and then took high-speed photos of the insects in flight. By studying how the smoke moved around the moths’ wings, researchers were able to determine that flying insects create whirling spirals of air above the front edges of their wings, providing more lift.
2. Cuba claimed that the United States brought an insect infestation to the island. In 1997, Cuban authorities accused the U.S. of staging a biological attack the previous year by using a crop-duster to spread insects over the island. But what really happened? An American commercial airliner had flown over the country and released smoke to signal its location, an event that coincided with bug infestations on Cuba’s potato plantations.
3. A plague of crickets ravaged the Midwest. In 2001, hordes of crickets descended upon Utah, infesting more than 1.5 million acres in 18 of the state’s 29 counties. The damaged wreaked on the
ironically named Beehive State’s crops totaled nearly $25 million. Michael O. Leavitt, Utah’s governor at the time, declared the infestation a n emergency and sought help from the U.S. Department of Agriculture in combating the little critters.
4. Scientists uncovered an entire new order of insects. In 2002, entomologists discovered a group of inch-long wingless creatures that comprised a new order, a taxonomic rank used in the classification of organisms. The first to be identified in 88 years at that time, the order, dubbed Mantophasmatodea, consists of insects with features similar to praying mantises. The finding became the 31st known insect order.
5. A swarm of butterflies, thought to be one single species, turned out to be 10 of them. In 2004, researchers used DNA barcoding technology to study the Astraptes fulgerator butterfly, whose habitat ranges from Texas to northern Argentina. What they found was remarkable: an insect that was thought to be one species was actually 10 different species. The species’ habitats overlapped, but the butterflies never bred with its doppelganger neighbors.
6. Researchers pinpointed the world’s oldest known insect fossil. Until 2004, a 400 million-year-old set of tiny insect jaws—originally found in a block of chert along with a well-preserved and well-studied fossil springtail—lay untouched for almost a century in a drawer at the Natural History Museum in London. The rediscovery and subsequent study of the specimen meant that true insects appeared 10 million to 20 million years earlier than once thought. The researchers believe these ancient insects were capable of flight, which would mean the tiny creatures took to the skies 170 millions years ago, before flying dinosaurs.
7. Brood X invaded the East Coast. In 2004, another group of cicadas known as Brood X emerged after 17 years underground. The bugs’ motto? Strength in numbers. This class is the largest of the periodical insects, including three different species of cicada.
8. America’s bee population started to plummet. By spring of 2007, more than a quarter of the country’s 2.4 million honeybee colonies had mysteriously vanished. Something prevented the bees from returning to their hives, and scientists weren’t sure why, but they gave it a name: colony-collapse disorder. According to a recent report by the U.S. Department of Agriculture, the phenomenon continues to plague apiaries across the country, and no cause has been determined.
9. Gypsy moths destroyed thousands of trees in New Jersey. In 2007, gypsy moths ravaged more than 320,000 acres of forest in the Garden State. One of North America’s most devastating forest pests, the insect feeds on the leaves of trees, stripping branches bare. Agricultural officials said the infestation was the worst of its kind since 1990.
10. Scientists figured out how to extract DNA from preserved insect specimens. In 2009, researchers removed a barrier from the study of early insects, a practice that often left ancient specimens destroyed. In the past, too much tinkering around with tiny specimens meant that the samples often became contaminated or eventually deteriorated. The scientists soaked nearly 200-year-old preserved beetles in a special solution for 16 hours, a process that allowed them to then carefully extract DNA from the bugs without damaging them.
11. Hundreds of ancient insect species were found lodged in one chunk of amber. In 2010, a team of international researchers discovered 700 new species of prehistoric insects inside a block of 50-million-year-old amber in India. The finding signaled to scientists that the area was much more biologically diverse than previously thought.
12. The first truly amphibious insects were discovered. In 2011, a study reported that 11 species of caterpillar with the ability to live underwater indefinitely were found in freshwater streams in Hawaii. The twist? The same insects studied were land-dwellers too.
13. Scientists discovered a cockroach with more than just a spring in its step. In 2011, a new species of cockroach, for whom jumping and hopping accounts for 71 percent of movement, was found in South Africa. Saltoblattella montistabularis can cover a distance 50 times its body length with each hop. Dubbed the leaproach, the insect relies on its powerful hind legs, which are twice the length of its other limbs and make up 10 percent of its body weight, to propel it forward in high-speed bursts.
14. Japanese scientists documented radiation-induced mutations in butterflies. When a massive earthquake and tsunami severely damaged the Fukushima nuclear power plant in 2011, dangerous radioactive materials were spewed into the air and waterways. The following year, Japanese researchers said they observed dented eyes and stunted wings in local butterflies, mutations they believe were a result of radiation exposure.
15. The East Coast suffered a stink bug epidemic. In the summer of 2011, growing numbers of stink bugs prompted the Environmental Protection Agency to issue an emergency ruling that would allow farmers to use lethal insecticides. The insects had invaded crops of apples, cherries, pears and peaches from Virginia to New Jersey.
16. The world’s largest insect was discovered in New Zealand. Scientist Mark Moffett, known as Doctor Bugs, discovered the world’s largest insect, a surprisingly friendly female Weta bug, while traveling in New Zealand in 2011. The massive creature has a wingspan of seven inches and weighs three times as much as a mouse. Here’s a video of the bug eating a carrot out of Moffett’s hand.
17. A fly found in Thailand was determined to be the smallest in the world. Discovered in 2012, the fly, named Euryplatea nanaknihali, is 15 times smaller than a house fly and tinier than a grain of salt. But don’t let the miniature bugs fool you: they feed on tiny ants by burrowing into the larger insects’ head casings, eventually decapitating them.
April 4, 2013
What can’t a 3D printer build? The number of possible answers to this question has shrunk exponentially in recent years, as the high-tech machines continue to churn out solid object after object from computer designs.
The last few months alone saw countless new products and prototypes spanning an array of industries, from football cleats and pens to steel rocket parts and guns. Last month, the technology helped replace 75 percent of a person’s damaged skull, and this week it restored a man’s face after he lost half of it to cancer four years ago.
Today, a new study suggests 3D-printed material could one day mimic the behavior of cells in human tissue. Graduate student Gabriel Villar and his colleagues at the University of Oxford developed tiny solids that behave as biological tissue would. The delicate material physically resembles brain and fat tissue, and has the consistency of soft rubber.
To create this material, a specially designed 3D printing machine followed a computer programmed diagram and ejected tens of thousands of individual
droplets according to a specified three-dimensional network. As seen in the video above, its nozzles moved in various angles to establish the position of each tiny bead. Each droplet weighs in at about one picoliter—that’s one trillionth of a liter—a unit used to measure the size of droplets of inkjet printers, whose nozzle technology works much the same way to consolidate tiny dots of liquid into complete images and words on paper.
The droplets of liquid contained biochemicals found in tissue cells. Coated in lipids—fats and oils—the tiny aqueous compartments stuck together, forming a cohesive and self-supporting shape, with each bead partitioned by a thin, single membrane similar to the lipid bilayers that protect our cells.
The shapes that the printed droplets formed remained stable for several weeks. If researchers shook the material slightly, droplets could become displaced, but only temporarily. The engineered tissue quickly sprung back into its original shape, a level of elasticity the researchers say is comparable to soft tissue cells in humans. The intricate latticework of a network’s lipid bilayers appeared to hold the “cells” together.
In some of the droplet networks, the 3D printer built pores into the lipid membrane. The holes mimicked protein channels inside the barriers that protect real cells, filtering molecules important for cell function in and out. The researchers injected into the pores a type of molecule important for cell-to-cell communication, one that delivers signals to numerous cells so that they function
together as a group. While the 3D-printed material couldn’t exactly replicate how cells propagate signals, researchers say the movement of the molecule through defined pathways resembled the electrical communication of neurons in brain tissue
Water readily permeated the network’s membranes, even when pores were not built into its structure. The droplets swelled and shrank by the process of osmosis, trying to establish equilibrium between the amount of water they contained and the amount surrounding them on the outside. The movement of water was enough to lift the droplets against gravity, pulling and folding them, imitating muscle-like activity in human tissue.
The researchers hope that these droplet networks could be programmed to release drugs following a physiological signal. Printed cells could someday also be integrated into damaged or failing tissue, providing extra scaffolding or even replacing malfunctioning cells, perhaps even supplanting some of the 1.5 million tissue transplants that take place in the United States each year. The potential seems greatest for brain tissue transplants, as medical engineers are currently trying to grow brain cells in the lab to treat progressive diseases like Huntington’s disease, which slowly destroys nerve cells.
Whether it’s growing human tissue or entire ears, 3D printing technology is in full swing in the field of medicine, and countless researchers will no doubt jump on the bandwagon in the coming years.
March 18, 2013
Some scientists investigate the universe’s biggest mysteries, like the Higgs boson, the mysterious particle that endows all other subatomic particles with mass.
Other researchers look into questions that are, well, a bit humbler—like the age-old puzzle of whether roosters simply crow when they see light of any kind, or if they truly know to crow when the morning sun arrives.
Lofty or not, it’s the goal of science to answer all questions that arise from the natural world, from roosters to bosons and everything in between. And a new study by Japanese researchers published today in Current Biology resolves the rooster question once and for all: The birds truly do have an inner circadian rhythm that tells when to crow.
The research team, from Nagoya University, investigated via a fairly straightforward route: They put several groups of four roosters in a room for weeks at a time, turned the lights off, and let a video camera running. Although roosters can occasionally crow at any time of day, the majority of their crowing was like clockwork, peaking in frequency at time intervals roughly 24 hours apart—the time their bodies knew to be morning based on the sunlight they’d last seen before entering the experiment.
This consistency continued for about 2 weeks, then gradually began to die out. The roosters were left in the room for 4 weeks in total, and during the second half of the experiment, their crowing began occurring less regularly, at any time of day, suggesting that they do need to see the sun on a regular basis for their circadian rhythms to function properly.
In the experiment’s second part, the researchers also subjected the roosters to alternating periods of 12 hours of light and 12 hours of darkness, while using bright flashes of light and the recorded crowing of roosters (since crowing is known to be contagious) to induce crowing at different times of day. When they activated these stimuli near at or near the dawn of the roosters’ 12-hour day, crowing rates increased significantly. At other times of day, though, exposing them to sudden flashes of light or playing the sound of crowing had virtually no effect, showing that the underlying circadian cycle played a role in the birds’ response to the stimuli.
Of course, many people who live in close proximity to roosters note that they often crow in response to a random light source turning on, like a car’s headlights, no matter what time of day it is. While this may be true, the experiment shows that the odds of a rooster responding to a car’s headlights depend on how close the current time is to dawn—at some level, the rooster’s body knows whether it should be crowing or not, and responding to artificial stimuli based on this rhythm.
For the research team, all this is merely a prelude to their bigger, more complex questions: Why do roosters have a biological clock that controls crowing in the first place, and how does it work? They see the simple crowing patterns of the rooster as an entry point into better understanding the vocalizations of a range of animals. “We still do not know why a dog says ‘bow-wow’ and a cat says ‘meow,’” Takashi Yoshimura, one of the co-authors, said in a press statement. “We are interested in the mechanism of this genetically controlled behavior and believe that chickens provide an excellent model.”
February 21, 2013
3D printing is big news: During his State of the Union speech, President Obama called for the launch of manufacturing hubs centered around 3D printing, while earlier this week, we saw the birth of one of the most playful applications of the technology yet, the 3D Doodler, which lets you draw solid plastic objects in 3 dimensions.
Yesterday, Cornell doctors and engineers presented a rather different use of the technology: a lifelike artificial ear made of living cells, built using 3D printing technology. Their product, described in a paper published in PLOS ONE, is designed to help children born with congenital defects that leave them with underdeveloped outer ears, such as microtia.
The prosthesis—which could replace previously used artificial materials with styrofoam-like textures, or the use of cartilage tissue harvested from a patient’s ribcage—is the result of a multistep process.
First, the researchers make a digital 3D representation of a patient’s ear. For their prototype, they scanned healthy pediatric ears, but theoretically, they might someday be able to scan an intact ear on the other side of a patient’s head—if their microtia has only affected one of their ears—and reverse the digital image, enabling them to create an exact replica of the healthy ear.
Next, they use a 3D printer to produce a solid plastic mold the exact shape of the ear and fill it with a high-density collagen gel, which they describe as having a consistency similar to Jell-O.
After printing, the researchers introduce cartilage cells into the collagen matrix. For the prototype, they used cartilage samples harvested from cows, but they could presumably use cells from cartilage elsewhere on the patient’s own body in practice.
Over the course of a few days in a petri dish filled with nutrients, the cartilage cells reproduce and begin to replace the collagen. Afterward, the ear can be surgically attached to a human and covered with skin, where the the cartilage cells continue to replace the collagen.
So far, the team has only implanted the artificial ears underneath the skin on the backs of lab rats. After 3 months attached to the rats, the cartilage cells had replaced all the collagen and filled in the entire ear, and the prosthetic retained its original shape and size.
In a press statement, co-author Jason Spector said that using a patient’s own cells would greatly reduce the chance of the body rejecting the implant after surgery. Lawrence Bonassar, another co-author, noted that in addition to congenital defects, the prosthesis could also be valuable for those who lose their outer ear as a result of cancer or an accident. If used for a child with microtia, the ear won’t grow along with the head over time, so the researchers recommend waiting to implant one of their prostheses until the patient is 5 or 6 years old, when ears have normally grown to more than 80 percent of their adult size.
The biggest advantage of the new technology over existing methods is the fact that the production process is customizable, so it could someday produce remarkably realistic-looking ears for each patient on a rapid timescale. The researchers have actually sped up the process since conducting the experiments included in the study, developing the ability to directly print the ear using the collagen as an “ink” and skip making the mold.
There are still a few problems to tackle, though. Right now, they don’t have the means to harvest and cultivate enough of a pediatric patient’s own cartilage to build an ear, which is why they used samples from cows. Additionally, future tests are needed to prove that surgical implantation is safe for humans. The team says they plan to address these issues and could be working on the first implant of such an ear in a human as soon as 2016.
February 18, 2013
No one knows for sure how many individual pages are on the web, but right now, it’s estimated that there are more than 14 billion.
Recently, though, Hungarian physicist Albert-László discovered something surprising about this massive number: Like actors in Hollywood connected by Kevin Bacon, from every single one of these pages you can navigate to any other in 19 clicks or less.
published noted yesterday in Philosophical Transactions of the Royal Society (Correction: initially made way back in 1999), involved a simulated model of the web that he created to better understand its structure. He discovered that of the roughly 1 trillion web documents in existence—the aforementioned 14 billion-plus pages, along with every image, video or other file hosted on every single one of them—the vast majority are poorly connected, linked to perhaps just a few other pages or documents.
Distributed across the entire web, though, are a minority of pages—search engines, indexes and aggregators—that are very highly connected and can be used to move from area of the web to another. These nodes serve as the “Kevin Bacons” of the web, allowing users to navigate from most areas to most others in less than 19 clicks.
Barabási credits this “small world” of the web to human nature—the fact that we tend to group into communities, whether in real life or the virtual world. The pages of the web aren’t linked randomly, he says: They’re organized in an interconnected hierarchy of organizational themes, including region, country and subject area.
Interestingly, this means that no matter how large the web grows, the same interconnectedness will rule. Barabási analyzed the network looking at a variety of levels—examining anywhere from a tiny slice to the full 1 trillion documents—and found that regardless of scale, the same 19-click-or-less rule applied.
This arrangement, though, reveals cybersecurity risks. Barabási writes that knocking out a relatively small number of the crucial nodes that connect the web could isolate various pages and make it impossible to move from one to another. Of course, these vital nodes are among the most robustly protected parts of the web, but the findings still underline the significance of a few key pages.
To get an idea of what this interconnected massive network actually looks like, head over to the Opte Project, an endeavor started by Barrett Lyon in 2003 to create publicly available visualizations of the web. In the map above, for example, red lines represent links between web pages in Asia, green for Europe, the Middle East and Africa, blue for North America, yellow for Latin America and white for unknown IP addresses. Although the most recent visualization is several years old, Lyon reports that he’s currently working on a new version of the project that will be released soon.