Self-esteem across a life span can be like riding a roller coaster, starting with an inflated sense of self-approval in late childhood, dropping precipitously in adolescence and then rising steadily through adulthood only to plummet to the lowest point in late old age, according to a new study in the journal Psychology and Aging.
Scientists have shown, for the first time, that changes in a large-scale climate system can synchronize population fluctuations in multiple mammal species across a continent-scale region. The study, to be published in the 14 November 2002 issue of the journal Nature, compares long-term data on the climate system known as the North Atlantic Oscillation with long-term data from Greenland on the population dynamics of caribou and muskoxen, which are large mammals adapted to breeding in the Arctic.
Second-hand tobacco smoke threatens the health of 21 million American children ? 35 percent of everyone age 17 and younger ? who live in homes where residents or visitors smoke once a week or more, according to a study published Nov. 13 by researchers from RAND and UCLA. The study is the most thorough ever conducted of youths’ exposure to environmental second-hand tobacco smoke at home. It found that 19 million American children ? 28 percent of everyone in the United States 17 and younger ? are exposed to tobacco smoke at home on a daily basis.
Routine monitoring of volcanic activity on Jupiter’s moon Io has turned up the largest eruption to date on Io’s surface or in the solar system. The eruption took place in February 2001, though image analysis was only recently completed by a team of University of California, Berkeley, astronomers. Their results are published in the November issue of the planetary sciences journal Icarus. “The Surt eruption appears to cover an area of 1,900 square kilometers, which is larger than the city of Los Angeles and even larger than the entire city of London,” said the lead researcher. “The total amount of energy being released by the eruption is amazingly high, with the thermal output from this one eruption almost matching the total amount of energy emitted by all of the rest of Io, other volcanoes included.”
This image from the Chandra X-ray Observatory has given scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 75 miles above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms. X-rays from the Sun impact oxygen atoms, knock electrons out of the inner parts of their electron clouds, and excite the atoms to a higher energy level in the process. The atoms almost immediately return to their lower energy state and may emit a fluorescent X-ray in this process with an energy characteristic of the atom involved ? oxygen in this case. A similar process involving ultraviolet light produces the visible light from fluorescent lamps.
Scientists have recreated a temperature not seen since the first microsecond of the birth of the universe and found that the event did not unfold quite the way they expected. The interaction of energy, matter, and the strong nuclear force in the ultra-hot experiments conducted at the Relativistic Heavy Ion Collider (RHIC) was thought to be well understood, but a lengthy investigation has revealed that physicists are missing something in their model of how the universe works.
Surgeons in Philadelphia say they are finding success by combining light-based cancer therapy with surgery to treat patients with advanced lung cancer that has spread within the chest. While the number of patients treated to date is small, many patients are living three to four times longer than did those patients who did not receive the therapy. In photodynamic therapy (PDT), a nontoxic photosensitizing agent, photofrin, is injected into the bloodstream and absorbed by cells all over the body. These compounds tend to concentrate more in cancer cells than in normal cells. When the compound is exposed to a certain wavelength of light, it absorbs the light energy and produces a form of oxygen that kills the cells. The damage occurs only where the light is shined. In the study, each patient is given chemotherapy until the cancer stops responding, meaning the disease begins to grow again. If the cancer has not spread beyond the chest, the patient then receives photofrin 24 hours prior to surgery to remove the tumor. During surgery, he or she receives an appropriate dose of light therapy. Of the 16 patients evaluated to date, at least one-half have lived more than 23 months, which is between three and four times the usual time.
A chance observation of high-energy electrons emanating from a tiny region of space where the sun and Earth’s magnetic fields intertwine provides the first solid evidence that a process called magnetic reconnection accelerates electrons to near the speed of light in the Earth’s magnetosphere and perhaps throughout the universe where magnetic fields entangle.
Buildings built according to federal design criteria to be able to withstand earthquakes may not be able to survive the effects of explosions from bombs small enough to be carried by a terrorist, Penn State researchers have found.
The ecological importance of phytoplankton, microscopic plants that free-float through the world’s oceans, is well known. Among their key roles, the one-celled organisms are the major source of sustenance for animal life in the seas. Now, researchers at Scripps Institution of Oceanography in San Diego say that phytoplankton exert a significant and previously uncalculated influence on Earth’s climate.
The 2002 outbreak of phocine distemper virus, or PDV, in European harbor seals may reduce the population by more than half and that future outbreaks with similar characteristics would significantly increase the risk of population declines. Their findings are the first epidemiological data reported on the 2002 outbreak, which is still underway, and may help predict the recurrence of the outbreaks and the impact on the long-term growth and survival of the European harbor seal population.
How do 30,000 genes in our DNA work together to form a large part of who we are? How do one hundred billion neurons operate in our brain? The huge number of factors involved makes such complex networks hard to crack. Now, a study published in the October 25 issue of Science uncovers a strategy for finding the organizing principles of virtually any network ? from neural networks to ecological food webs or the Internet.
U.S. government scientists have demonstrated that a miniature positron emission tomography (PET) scanner, known as microPET, and the chemical markers used in traditional PET scanning are sensitive enough to pick up subtle differences in neurochemistry between known genetic variants of mice. This “proof-of-principle” experiment “opens up a whole new, non-invasive way to study and follow transgenic or genetically engineered strains of mice that serve as animal models for human neurological diseases, such as Parkinson’s and Alzheimer’s disease or psychiatric diseases such as substance abuse, depression, and anxiety disorders,” said Panayotis (Peter) Thanos, lead author of the study.
A California physicist will announce plans for the first known attempt to push a spacecraft into the Earth’s orbit with energy beamed up from the ground. The satellite will be called the Cosmos Sail, the first solar-sail craft to orbit Earth. The physics team developed the sail with researchers from the Jet Propulsion Laboratory. Made from lightweight layers of aluminized mylar, the sail will allow a craft to be propelled from low orbit to high orbit and ultimately into interplanetary space, driven by microwave energy, similar to the way wind pushes a sailboat across the sea.