Dissolved concentrations of four forms of arsenic: arsenite, arsenate, monomethylarsenic, and dimethylarsenic, were measured in the Patuxent River Estuary near Benedict, Maryland, over two annual cycles. In each year, total arsenic concentrations peaked in the summer, in lateJuly and August, while minimum concentrations occurred in winter. Except in late winter, arsenate was a predominant form ...

Identifying the authorship either of an anonymous or a doubtful document constitutes a cornerstone for automatic forensic applications. Moreover, it is a challenging task for both humans and computers. Clustering documents according to the linguistic style of the authors who wrote them has been a task little studied by the research community. In order to address this problem, PAN Evaluation Fra...

Groups of the Guatemalan black howler monkey (Alouatta pigra) in a fragmented northern Guatemalan cloud forest in the Sierra Yalijux were analyzed for group composition and size using an ornithological census technique. Audio and visual records were combined to estimate each group’s home range size. The 361 observations in 2002 estimated 50 individuals in seven groups. Two home range classes we...

Artificial Intelligence is rapidly leaving its academic home and moving into the marketplace. There are few precedents for an arcane academic subject becoming commercialized so rapidly. But, genetic engineering, which recently burst forth from academia to become the foundation for the hot new biotechnology industry, provides useful insights into the rites of passage awaiting the commercializat,...

Recent technology advances in computer game industries demand a development of high-level artificial intelligence. This trend motivates the International Game Developers’ Association to develop a special interest group (SIG) in artificial intelligence (IGDA 2003) and the roundtable of ‘AI in Computer Games’ at the Game Developers Conference (GDC 2003). According to the IGDA SIG, high-level arti...

Coleoptera and Heteroptera associated with aquatic environments were studied at Berisso, near Rio de La Plata estuary (Buenos Aires Province, Argentina). Four waterbodies were characterized and compared: artificial pond, shallow pool, stream and artificial channel. Sampling was done twice a month, with a round sieve, for 12 months (April 1999 to April 2000). Sampling was quantified using a disc...

What has evolved in the ca 3.5 billion years of biological evolution on earth? A first answer which may spring to mind is your favorite organism, be it elephant, fly, slime mold, microbe or man. Other answers might be the stunning apparent diversity of lifeforms, or the greatly enhanced energy cycling at the earth surface. Or all this may be simplified to characterizing what has evolved as ’com...

Caterpillars of the spring brood of Nemoria arizonaria develop into mimics of the oak catkins upon which they feed. Caterpillars from the summer brood emerge after the catkins have fallen and they develop instead into mimics of oak twigs. This developmental polymorphism may be triggered by the concentration of defensive secondary compounds in the larval diet: all caterpillars raised on catkins,...

A decentralized control strategy for a robot swarm is presented, where each robot try to form a regular tetrahedron with its three neighbors. The proposed method is based on virtual spring and demands minimum local information. Four neighboring robots can form a regular tetrahedron formation regardless of their initial positions. A neighbor selection procedure is used to extend the strategy In ...

We developed a simple interactive simulation tool that applies the simulated breeding method to evolve populations of Reynolds’ Boids system. A user manually evolves swarm behaviors of artificial agents by repeatedly selecting his/her preferred behavior as a parent of the next generation. We used this tool as part of teaching materials of the course “Mathematical Modeling and Simulation” offere...