A computer program for grain-size data

The computer program presented here seeks to improve estimation of statistical parameters for grain-size data by use of interpolated values. Interpolation is made by fitting a series of overlapping parabolas to the data, and follows the method of Snyder (1961). The values are used in moment formulas to compute standard statistical measures. Skewness and kurtosis are reduced by the interpolation data, and extreme positive values of kurtosis tend to be greatly reduced. The program also picks major modes, the median, and sediment type .The United States Geological Survey under Contract USGS-14-08-0001-835

King Vultures (Sarcoramphus papa) follow jaguar in the Serranía de la Cerbatana, Venezuela

I collected data over six field seasons (34 ½ wks) between 1994-2000 at Hato Las Nieves in northwestern Bolívar state, Venezuela. A mean of 6.4 King Vultures (Sarcoramphus papa) ± 4.9 SD (range = 2-15) searched in flight for jaguar (Panthera onca) or remains of kills and were present at or seen going directly to kills. Jaguarrelated activities took place on 27 of the 162 days on which the vultures were not feeding on livestock carcasses. On 16 days only vultures presumed to be local to the area (n = 2-4 adults, 1 young) were involved. The presence of a jaguar was confirmed by tracks and/or known kills on livestock. Vulture behaviours were correlated with dates and locations of tracks and kills as well as with direction of travel of tracks. After sighting a jaguar, King Vultures perched to monitor the feline, or showed prolonged circling overhead, and then focused searching to specific areas, indicating they knew the routes it used and the areas most likely to have kills. Searching often alternated, from one day to the next or from morning to afternoon, with monitoring the ranch refuse dump, feeding on remains of former carcasses or foraging in palm stands. King Vultures also monitored large terrestrial mammals that were potential big-cat prey, especially white-tailed deer (Odocoileus virginianus), often when a jaguar was or had been present. A small number (n = 1-8) of American Black Vultures (Coragyps atratus) and/or Turkey Vultures (Cathartes aura ruficollis), the only other Cathartidae in the area, joined the King Vultures in searching on only 9 days and did not go into the mountains with them. Searching for jaguar and/or kills along the presumed travel routes of the feline was mainly a King Vulture activity, but the smaller vulture species were present (n = 26 and 10 birds, respectively) at kills within the valley. Few published data are available on the use of big-cat kills by vultures in the Neotropics, and further study is needed on the proportion of such kills, notably those of jaguar, in the food supply of King Vultures.Vulture News Vol. 57 2007: pp. 4-1

Another drug bites the dust: A review on the mechanisms of antimalarial drug resistance and current preventative intervention

Malaria is a disease transmitted to humans through female mosquito bites. The disease is caused by a parasite that advances through a complex life cycle composed of unique stages depending on its changing host environments. Millions of people, primarily inhabitants of Africa and Southeast Asia, succumb to the disease every year. In the past few decades, there has been a rise in resistance to current antimalarial therapies, sounding the alarm for intervention. Chloroquine, sulfadoxine-pyrimethamine, and artemisinin-based combination therapies are among the most potent pharmacological tools against the parasite, but mutations in P. falciparum have begun to disarm these drugs. This review summarizes mechanisms of action for various antimalarial drugs and carefully examines the genetic mutations in Plasmodium falciparum conferring drug resistance