Amazon Holiday Deals

Tuesday, July 21, 2015

Sea-Cloaked Mystery With Trillions of Clues

An image of two fish in the family Gonostomati...
An image of two fish in the family Gonostomatidae: the Elongated bristlemouth, Gonostoma elongatum (top) and Bonapartia pedaliota (bottom). From Oceanic Ichthyology by G. Brown Goode and Tarleton H. Bean, published 1896. (Photo credit: Wikipedia)

Habitats on land-rain forests, steppes, woodlands, deserts, alpine meadows, all well explored over the centuries-make up less than 1 percent of the planet’s biosphere. Why so little? The band of life is narrow. Fertile soil goes down only about a meter, and even the tallest trees stretch up only about 90 meters.

Water, however, is a different story. It covers more than 70 percent of the earth’s surface and goes down kilometers. Scientists put the ocean’s share of the biosphere at more than 99 percent. Fishermen know its surface waters and explorers its depths. But in general, compared with land, the ocean is unfamiliar.

Which helps explain why scientists have only recently come to realize that the bristlemouth, a fish of the middle depths that glows in the dark and can open its mouth extraordinarily wide, baring needlelike fangs, is the most numerous vertebrate on the earth.

“They’re everywhere,” Bruce H.Robison, a senior marine biologists at the Monterey Bay Aquarium Research Institute in California, said of the bony little fish. “Everybody agrees. It’s the most abundant on the planet.”

By human standards, the brute is tiny, smaller than a finger. But this strange little fish makes up for its diminutive size with staggering numbers, as well as a behavioral trick or two.

It starts life as a male and, in some cases, switches to a female. Scientists call it protandrous, a male-first hermaphrodite.

John C. Avise, the author of “Hermaphroditism, “said the adult male bristlemouth tended to be smaller than the female and had a better developed sense of smell, apparently to find mates in the darkness.

“They occupy an environment that’s hard to access,” Dr. Avise said of the fish, so there is “precious little information” about their behavior.

Though the portrait of the bristlemouth is incomplete, scientists know enough to assert that it far outstrips all other contenders for the title of most common vertebrate on the planet. Ichthyologists put the likely figure for bristlemouths at hundreds of trillions –and perhaps quadrillions, or thousands of trillions.

“No other animal gets close,” said Peter C. Davison, a fish scientist at the Farallon Institute for Advanced Ecosystem Research, in Petaluma, Calif. “There are as much as a dozen per square meter of ocean.”

The bristlemouths are a rapacious family of fishes that include the wildly successful genus Cyclothone-Greek for “circular,” in apparent reference to the creature’s gaping mouth. They are also known as roundmouths.

The genus has 13 species, such as the shadow bristlemouth. The main distinguishing features are subtle differences in the fins and luminous organs. All members wield bristlelike teeth. Over all, the fish are 2.5 to 7.5 centimeters in length, tan to black in color, and at times display a kind of ghostly translucence.

The first hints of the fish’s ubiquity came during the voyage of the H.M.S. Challenger, a British ship that sailed the globe from 1872 to 1876 and helped lay the foundations of oceanography. It lowered nets at dozens of sites and hauled up the creatures from as deep as five kilometers.

The first scientist to view the animals in their dark habitat was William Beebe. In the early 1930s, Mr. Beebe, a senior explorer of what is now the Wildlife Conservation Society, plunged into the depths off Bermuda in a spherical submersible, gazed through its porthole- and saw aliens.

“Numberless little creatures “raced through his light beam, he wrote in his 1934 book, “Half Mile Down.” They turned out to be bristlemouths. A color plate in the book shows a group with jaws wide open while chasing a school of copepods, tiny crustaceans with long antennas.

Oceans textbooks from the 1970s to the 1990s said little about Cyclothones. Then came a new wave of research, centering on careful trawls of the deep ocean with a new generation of nets in which the mesh was much finer. No matter how far the nets plunged, up came vast numbers of bristlemouths.

Dr. Robison said bristlemouths have very small eyes that in the dim habitat seemed to play little or no role in finding prey. Instead, the fish apparently relies on sense organs that can detect movement and vibration in the surrounding water.

And the rows of glowing dots on the bristlemouth’s abdomen? Dr. Robison said they appeared to be camouflage that helped the creature hide from predators by matching the surrounding light.

It has taken roughly a century and a half, but science has finally come to know the bristlemouth fairly well, even if questions remain. Not so other creatures of the deep. If the tortuous route to identifying the dominant fish is any indication, it will take longer still to learn about the uncommon forms of life that roam the depths.

“We keep seeing lots of different critters we haven’t seen before,” Dr. Robison said of voyages in the Monterey Canyon, a deep gorge in California’s coastal seabed, and beyond. He added, “The deeper you go, the stranger things get.”

Taken from TODAY Saturday Edition, The New York Times International Weekly, July 11, 2015

Monday, July 13, 2015

Ebola Nearly Claimed His Life, Then It Hid in His Eye

Satellite image of Sierra Leone
Satellite image of Sierra Leone (Photo credit: Wikipedia)

ATLANTA - When Dr. Ian Crozier was released from Emory University Hospital in October after a long, brutal fight with Ebola that nearly ended his life, his medical team thought he was cured. But less than two months later, he was back at the hospital with fading sight, intense pain and soaring pressure in his left eye.

Test results were chilling: The inside of Dr. Crozier’s eye was teeming with Ebola.

His doctors were amazed. Months had passed since he became ill while working in an Ebola treatment ward in Sierra Leone as a volunteer for the World Health Organization. By the time he left Emory, his blood was Ebola-free.

Almost nothing was known about the ability of Ebola to lurk inside the eye, but despite the infection, Dr. Crozier’s tears and the surface of his eye were virus-free, so he posed no risk to anyone who had casual contact with him.

More than a year after the epidemic in West Africa was recognized, doctors are still learning about Ebola and Lingering effects on survivors. Now, however, with at least 10,000 survivors in Guinea, Liberia and Sierra Leone, patterns are emerging.

Dr. Crozier, 44, calls himself a poster child for “post-Ebola syndrome.” Besides eye trouble, he has had debilitating joint and muscle pain, deep fatigue and hearing loss.

At ELWA Hospital in Monrovia, Liberia, run by the missionary group SIM, Dr.John Fankhauser, the medical director, said such ailments were the most common physical problems among the hundred or so people attending a special clinic for Ebola survivors.

In Sierra Leone, the picture is much the same, according to Dr. John S. Schieffelin, a physician from the Tulane University School of Medicine in New Orleans who volunteered there. He said a well-organized survivor group met regularly in Kenema.

“The main problems they’re telling me about are lots of body and joint pains, chronic headaches and women who stopped having menstrual periods, and for some it’s been several months,” Dr. Schieffelin said.” There’s quite a bit of vision problems.”

The inside of the eye is mostly shielded from the immune system to prevent vision damage. The barriers are not fully understood, but they include tightly packed cells in minute blood vessels that keep out certain cells, along with unique biological properties that inhibit the immune system. But this “immune privilege” can sometimes turn the inner eye into a sanctuary for viruses.

The question was whether Dr. Crozier’s sight could be saved. Severe inflammation suggested that the barriers that normally protect the eye from the immune system had been breached. So what was damaging Dr. Crozier’s eye? The virus, the inflammation or both?

The usual treatment for inflammation is steroids. But they can make an infection worse.

“What if it unleashed the virus?” Dr. Crozier said. “We were on a tightrope.”

Though Dr. Crozier was the patient, he was also part of his own medical team, and his focus on the scientific details helped counter his mounting fear that he was going blind. As he and his physicians struggled to balance treating the inflammation with fighting the infection, his eyesight continued to deteriorate.

He also had significant hearing loss on the same side. “The whole left side of your life is gone, “he said. “It was a very dark and depressing time.”

The biggest shock came when he glanced in the mirror one morning and saw that his eye color had changed from bright blue to a vivid green.

“It was like an assault,” he said. “It was so personal.”

Dr. Jay Varkey, an infectious-disease specialist who had handled much of Dr. Crozier’s care, got special permission from the United States Food and Drug Administration to use an experimental antiviral drug taken in pill form. (The doctors declined to name it.)

At first, there seemed to be no effect. But a week or so later, Dr. Crozier realized that if he turned his head this way and that, he could find “portals” through the obstructions in his eye.

His sight returned in a few months, and his eye turned blue again.

Was it the antiviral drug? He cannot be sure, but he think so.

Dr. Varkey said, “I think the cure was Ian’s own immune system.” He said he suspected the treatments had reduced Dr. Crozier’s symptoms and helped preserve his sight long enough for his immune system to kick in and clear out the virus-just as supportive care during the worst phase of his initial illness had kept him alive until his natural defenses could take over.

Dr. Crozier believes information from his case may help prevent blindness in Ebola survivors in West Africa. In April, he headed to Liberia with Dr. Steven Yeh, an ophthalmologist, and several other Emory physicians to see patients who had recovered from Ebola and examine their eyes.

“Maybe we can change the natural history of the disease for survivors,” Dr. Crozier said. “I want to start that conversation.”

Taken from TODAY Saturday Edition, The New York Times International Weekly, May 23, 2015

Tuesday, July 7, 2015

When the Mind’s Eye Is Blind, It’s Hard to Picture an Image

English: Main regions of the vertebrate brain,...
English: Main regions of the vertebrate brain, shown for a shark and a human brain (the human brain is sliced along the midline). The two brains are not on the same scale. (Photo credit: Wikipedia)

In 2005, a 65-year-old retired building inspector paid a visit to the neurologist Adam Zeman at the University of Exeter Medical School in England. After a minor surgical procedure, the man-whom Dr. Zeman and his colleagues refer to as MX-had suddenly realized he could not conjure images in his mind.

Dr. Zeman could not find the condition in medical literature. He was intrigued. For decades, scientists had debated how the mind’s eye works, and how much we rely on it to store memories and to make plans for the future.

MX agreed to a series of exams. He proved to have a good memory for a man of his age, and he performed well on problem-solving tests. His only unusual mental feature was an inability to form mental images.

Dr. Zeman then scanned MX’s brain as he performed certain tasks. First, MX looked at faces of famous people and named them. The scientists found that certain regions of his brain became active, the same ones that become active in other people who look at faces.

Then the scientists showed names to MX and asked him to picture their faces. In normal brains, some of those face-recognition regions again become active. In MX’s brain, none did.

Yet MX could answer questions that would seem to require a working mind’s eye. He could tell the scientists the color of Tony Blair’s eyes, for example, and name the letters of the alphabet that have low-hanging tails, like g and j. These tests suggested his brain used some alternate strategy to solve visual problems.

Since then, scientists have surveyed other people who say they cannot summon mental images-as if their mind’s eye were blind. Many of the survey respondents differed from MX in an important way. While he originally had a mind’s eye, they never did.

Reported in the journal Cortex, the condition has received a name: aphantasia, based on the Greek word phantasia, which Aristotle used to describe the power that presents imagery to our minds.

If aphantasia is real, it is possible that injury causes some cases while others begin at birth.

Thomas Ebeyer, a 25-year-old Canadian student, discovered his condition four years ago while talking with a girlfriend. He was shocked that she could remember what a friend had been wearing a year before. She replied that she could see a picture of it in her mind.

“I had no idea what she was talking about,” he said. He was then surprised to discover that everyone he knew could summon images to their minds.

Like many other survey subjects, he could count his windows without picturing his house.

It’s weird and hard to explain,” he said. “I know the facts. I know where the windows are.”

Dr. Zeman is trying to ascertain how common aphantasia is. He has sent the questionnaire to thousands of people and wants to hear from more. He can be reached at

Taken from TODAY Saturday Edition, The New York Times International Weekly, July 4, 2015