Bacterial biodegradation is the basis for the bioremediation of contaminated sites. The key to its success is the use of bacterial strains with high metabolic activity for target contaminants. The goal of this project is to understand the bacterial biodegradation of dinitrotoluene (DNT) by a novel marine bacterium, Pseudoxanthomonas sp. JA40. Isolated along with forty other bacterial species from contaminated Johnston Atoll sand in 2003, JA40 is hypothesized to degrade DNT because it evolved in an environment deficient of organic nitrogen sources but rich in polycyclic aromatic hydrocarbons (PAH's) and polychlorinated biphenyls (PCB's).
Instrumental magnitude photometry of the eclipsing binary star DE CVn in the U color band was carried out using the Lowell Observatory 31-inch telescope with the NURO CCD photometer. Deep and flat primary minima with steep ingress and egress confirm the hypothesis that the primary component of this binary system is a hot white dwarf. New, more precise ephemeris of the system based on these and other observations is presented.
Dust particles in a protoplanetary disk coagulate into larger bodies which eventually form planetesimals. When the dust particles stick together, they form fluffy aggregates which often have a self similar structure characterized by the fractal dimension. The fractal aggregates can couple more closely to the gas in the nebula, which decreases their relative velocities. Since some of the gas particles are ionized, the dust becomes charged due to collisions with free ions and electrons. These dust properties, relative velocity and charge, have a large effect on both the coagulation rate and the fractal dimension.
We use interferometric maps to investigate the statistical properties of the velocity fields traced by H2O masers in five galactic regions of star formation. In a previous work, Strelnitski et al. (2002) concluded that H2O masing spots in such regions appear to probe highly intermittent supersonic turbulence and demonstrated that the two-point velocity correlation functions for the line-of-sight components of velocity traced by the masers could be approximated by power laws, with the exponents near the classical Kolmogorov value of 1/3 expected for high-Reynolds number incompressible turbulence.
The Pediatric Exclusivity Act of 1997 was enacted to implement an additional six months of patent protection for a drug. As a result, if a manufacturer conducts studies of the drug on children, the drug company will be able to benefit by having an effective monopoly of the drug for an additional six months. While the aim of this provision was to increase the safety of drugs in the pediatric population, the pharmaceutical industry has been accused of exploiting the law for financial gain. The charge is that drug manufacturers are only using the act to gain an extended patent for its large selling drugs in order to profit at greater margins.
Effective conservation strategies require that agencies account for genetic diversity and its geographic distribution within threatened species. Unionid mussels are among the most endangered taxa in North America, with between 55% and 72% of species having some protected status, and many others declining rapidly. With so few populations of these mussels safe from anthropogenic impacts, it is vital that we study relatively undisturbed species to understand historical genetic distributions.