In November, two teams of scientists published methods of generating embryonic-like stem cells without destroying an embryo, a finding which could quell the ethical controversy surrounding stem cell research. The two independent research teams, headed by James Thomson of the University of Wisconsin-Madison and Shinya Yamanaka of Kyoto University in […]
Within one second of the detonation, a 20 pounds per square inch (psi) overpressure will be generated out to a distance of 0.4 miles from the Empire State Building. Everything in this circle is utterly demolished. Those within this circle will be exposed to sudden pressure effects that destroys lungs and ear drums, shrapnel from nearby objects, and a thermal emission of such intensity that immediate death results.
Fluorescent imaging depends on the physical principles behind the scattering of light. In a typical ﬂuorescent microscope, a laser, usually of argon, shines through a sample at a wavelength of 488 nm. The sample, in turn, ﬂuoresces according to how it was stained. Certain cells, and often even speciﬁc cellular structures, can be resolved, which results in a ﬂuorescent image that is reﬂected into an optical lens or screen for visual analysis.
The overuse of antibiotics has led to the evolution of resistant strains of bacteria. Strains now exist that elude even the strongest antibacterial agents. The World Health Organization estimates that two million people in the United States are infected with antibiotic- resistant bacteria, resulting in the deaths of 14,000 each year. Once an indispensable weapon in the ﬁght against disease, antibiotics have ushered in a new public health threat.