Orbital period change of Dimorphos due to the DART kinetic impact.

The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (β) was possible. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos.

Ammonia disinfection of animal feeds --laboratory study.

Animal feeds may be contaminated, accidentally or maliciously, with a number of zoonotic bacteria. Animal infections with these bacterial agents, whether or not they cause animal disease, may lead to human illnesses. Anhydrous ammonia was introduced on farms in developed countries as a high-nitrogen soil amendment, but later found use in enhancing crude protein in low-quality roughage fed to ruminants and in neutralizing mycotoxins in fungus-infested feed grains.

Abdominal wall endometrioma after cesarean section: a preventable complication.

The occurrence of abdominal wall scar endometrioma after cesarean section has been reported previously in the literature. However, steps to prevent this complication have not been delineated. A study was undertaken of six patients seen at our general surgical clinic, each of whom had presented with a painful mass at a previous cesarean section site.