In the dark

Reconstruction surgery rarely discussed with breast cancer patients

Reconstruction surgery rarely discussed with breast cancer patients Medical Studies/Trials Published: Sunday, 30-Dec-2007 Print - Reconstruction surgery rarely discussed with breast cancer patients Printer Friendly Email - Reconstruction surgery rarely discussed with breast cancer patients Email to a Friend A new study finds that most general surgeons do not discuss reconstruction with patients before surgical breast cancer treatment. The analysis shows that only one in three patients eligible for mastectomy or breast conserving surgery have such discussions. The study is published in the February 1, 2008 issue of CANCER, a peer-reviewed journal of the American Cancer Society. The option of breast reconstruction has increased treatment choices for women with breast cancer. Women with early stage disease who are not likely to need post-mastectomy radiation are considered eligible for reconstruction at the time of surgery. However, little is known about how often surgeons discuss breast reconstruction with patients. Led by Dr. Amy Alderman of the University of Michigan Medical Center, researchers surveyed a 1,178 women aged 79 years or younger who had undergone a surgical procedure for stage I, II, or III breast cancer between December 2001 to January 2003. The researchers found only 33 percent of patients had a general surgeon discuss breast reconstruction with them during the surgical decision-making process for their cancer. Surgeons were significantly more likely to have this discussion with younger, more educated patients. Patients who discussed reconstruction with their surgeon were more willing to consider having a mastectomy and were more than 4 times likely to undergo the surgery. The findings suggest that discussing reconstruction will impact women?s decisions regarding initial surgery for their breast cancer. According to the authors, these results have important implications for patient care and policy. "This research suggests that patients should be informed of all options in order to be educated consumers of healthcare and ensure maximal breast cancer treatment decision quality," they conclude. "Our results suggest a need for comprehensive breast cancer treatment decision aids, including information on initial surgery and other treatment options such as reconstruction." http://www.cancer.org

optical 'rogue waves'

Maritime folklore tells tales of giant "rogue waves" that can appear and disappear without warning in the open ocean. Also known as "freak waves," these ominous monsters have been described by mariners for ages and have even appeared prominently in many legendary literary works, from Homer's "Odyssey" to "Robinson Crusoe."

Once dismissed by scientists as fanciful sailors' stories akin to sea monsters and uncharted inlands, recent observations have shown that they are a real phenomenon, capable of destroying even large modern ships. However, this mysterious phenomenon has continued to elude researchers, as man-made rouge waves have not been reported in scientific literature — in water or in any other medium.

Now, researchers at the UCLA Henry Samueli School of Engineering and Applied Science have succeeded in creating and capturing rogue waves. In their experiments, they have discovered optical rogue waves — freak, brief pulses of intense light analogous to the infamous oceanic monsters — propagating through optical fiber. Their findings appear in the Dec. 13 issue of the journal Nature.

"Optical rogue waves bear a close connection to their oceanic cousins," said lead investigator Daniel Solli, a UCLA Engineering researcher. "Optical experiments may help to resolve the mystery of oceanic rogue waves, which are very difficult to study directly."

It is thought that rogue waves are a nonlinear, perhaps chaotic, phenomenon, able to develop suddenly from seemingly innocuous normal waves. While the study of rogue waves has focused on oceanic systems and water-based models, light waves traveling in optical fibers obey very similar mathematics to water waves traveling in the open ocean, making it easier to study them in a laboratory environment.

Still, detecting a rogue wave is like finding a needle in a haystack. The wave is a solitary event that occurs rarely, and, to make matters worse, the timing of its occurrence is entirely random. But using a novel detection method they developed, the UCLA research group was able to not only capture optical rogue waves but to measure their statistical properties as well.

They found that, similar to freak waves in the ocean, optical rogue waves obey "L-shaped" statistics - a type of distribution in which the heights of most waves are tightly clustered around a small value but where large outliers also occur. While these occurrences are rare, their probability is much larger than predicted by conventional (so-called normal or Gaussian) statistics.

"This discovery is the first observation of man-made rogue waves reported in scientific literature, but its implications go beyond just physics," said Bahram Jalali, UCLA professor of electrical engineering and the researcher group leader. "For example, rare but extreme events, popularly known as "black swans," also occur in financial markets with spectacular consequences. Our observations may help develop mathematical models that can identify the conditions that lead to such events."

Source: University of California - Los Angeles

Why Pregnant Women Don't Tip Over

Amitabh Avasthi for National Geographic News December 12, 2007

Wedge-shaped vertebrae in the lower back might be the key evolutionary adaptation that helps human females maintain a stable posture over the course of pregnancy. According to anthropologists, the human adaptation is unique among primates and may have arisen shortly after early humans started walking upright. "Bipedalism challenges stable postures, because the abdomen expands in front of the body as the baby grows," said Katherine Whitcome, an anthropologist at Harvard University. "This changes the mother's center of mass, which is a critical point in any three-dimensional body on which gravity acts." As this center of mass shifts forward, pregnant women have to lean back and change their gait to stay steady. This realigns the center of mass over the hips, knees, and ankles to correct the imbalance—but it creates another problem. "It generates loading on parts of the vertebral column that are not normally under such stress," Whitcome said. Joint Support To find out how pregnant women keep their balance without damaging their spines, Whitcome and her colleagues studied 19 pregnant females between the ages of 20 and 40. The team found that the key appears to be joints in the bony vertebrae that wrap protectively around the spinal cord. (These joints become heavily loaded whenever people lean back. But the size of the joints relative to the vertebrae in the lower back is much larger in women than in men. This suggests that the joints' larger surface area is an adaptation to bear more load. And the shape of the vertebrae in women tapers off toward the back, creating a wedge shape that further facilitates arching, Whitcome said. Women also have three such vertebrae, while men have just two. "These wedge-shaped vertebrae, when stacked together, form a natural curve and help reduce the shearing stress generated during pregnancy," said Whitcome, whose findings appear today in the journal Nature. Evolutionary Adaptation Whitcome and her colleagues suggest that the special vertebrae are unique evolutionary adaptations that helped the first ancestors of human women as they started walking upright. For example, the researchers have found the unusual spinal characteristics in lumbar vertebral columns from Australopithecus africanus fossils dating back nearly two million years . "The female characteristics, which are explained by the biomechanics of fetal load, are present in the fossil record, suggesting that these adaptations evolved very early in humans," Whitcome noted. Karen Rosenberg is an anthropologist at the University of Delaware who was not involved in the new study. She said that the feature would have been naturally selected in humans at about the same time that bipedalism evolved, nearly five million years ago. And John Fleagle, an anthropologist at Stony Brook University, commented that "there are lots of neat things about this paper." "It documents some striking features of the lumbar spine of female humans that seem rather clearly related to the demands of pregnancy." Scientists had previously known about male-female differences in the shape of the pelvis related to birthing, Fleagle added. But spinal differences between males and females had not been appreciated until now. "Like so many discoveries," he added, "this is one that causes you to slap your forehead and exclaim, Of course! Why hasn't anyone thought of this before?"

Crystal spectra

Light is shed on new fibre's potential to change technology

Light is shed on new fibre's potential to change technology

December 11, 2007 - Photonic crystal fibre's ability to create broad spectra of light, which will be the basis for important developments in technology, has been explained for the first time in an article in the leading science journal Nature-Photonics.

The fibre can change a pulse of light with a narrow range of wavelengths into a spectrum hundreds of times broader and ranging from visible light to the infra-red. This is called a supercontinuum.

This supercontinuum is one of the most exciting areas of applied physics today and the ability to create it easily will have a significant effect on technology.

This includes telecommunications, where optical systems hundreds of times more efficient than existing types will be created because signals can be transmitted and processed at many wavelengths simultaneously.

Supercontinua generated in photonic crystal fibres also help to create optical clocks which are so accurate that they lose or gain only a second every million years. Two physicists based in the US and Germany shared the Nobel Prize for Physics in 2005 for work in this area.

Despite these applications, the mechanism behind supercontinuum generation has remained unclear, which has stopped physicists from being even more precise in using it.

But researchers at the University of Bath have now discovered the reason for much of the broadening of the spectrum.

Dr Dmitry Skryabin and Dr Andrey Gorbach, of the Centre for Photonics and Photonic Materials in the Department of Physics, found that the generation of light across the entire visible spectrum was caused by an interaction between conventional pulse of lights and what are called solitons, special light waves that maintain their shape as they travel down the fibre.

The researchers found that the pulses of light sent down the fibre get struck behind the solitons as both pass down the fibre, because the solitons slow down as they move. This barrier caused by the solitons forces the light pulses to shorten their wavelength and so become bluer, just as the solitons' wavelength lengthens, becoming redder. This dual effect creates the broadened spectrum.

"One of the most startling effects of the photonic crystal fibre is its ability to create a strong bright spectrum of visible and infra red light from a very brief pulse of light," said Dr Skryabin.

"We have never fully understood exactly why this happens until our research showed how the pulse of light is slowed down and blocked by other activity in the fibre, forcing it to shorten its wavelength.

"Until now the creation and manipulation of the supercontinua in photonic crystal fibres have been done in an ad-hoc way without knowing exactly why different effects are observed. But now we should be able to be much more precise when using it."

Dr Skryabin believes that the interaction between light pulses and solitons has similarities with the way gravity acts on objects.

See Related Links for more on the research carried out in the Centre for Photonics and Photonic Materials.

The University of Bath