Beaver functions

Function (affectionately known as the busy beaver function). This function says, given n, what is the longest non-inhnite output of any program of size n This is an incomputable function, but it can be shown to be computable given an oracle for... 

Houlihan, P. W. (1989). Scent mounding by beaver (Castor canadensis) functional and semiochemical aspects. M. Sc. Thesis, State University of New York, College of Environmental Science and Eorestry, Syracuse, New York. 

Castoreum of beaver (Castor canadensis) function, chemistry and biological activity of its components. In Chemical Signals in Vertebrates, vol. 6, ed. R. L. Doty, and D. Muller-Schwarze, pp. 457-464. New York Plenum. 

Beaver, K. A. Siegmund, A. C. Spear, K. L. Application of the Sulfonamide Functional Group as an Anchor for Solid Phase Organic Synthesis (SPOS), Tetrahedron Lett. 1996,37, 1145-1148. 

Ecological key(stone) species are species that play a major role in ecosystem performance, productivity, stability, and resilience. These species may also play an important role in ecosystem function (see below) and include 1) species that are critical determinants in trophic cascades, such as piscivorous fish and large herbivores and 2) species that are ecological engineers, that is, those that have a large influence on the physical properties of habitats such as rooted submerged macrophytes and beavers... 

Discuss the function of scent marking in the context of the beavers extensive investment in habitat modification. 

The biological functions of such plant secondary metabolites (PSMs) have been debated for a long time. They often have antimicrobial functions, but also serve as repellents and feeding inhibitors against herbivorous insects and vertebrates, notably birds and mammals. Animals have evolved many mechanisms to cope with phenolics in their diet. These start with food processing. For instance, beavers consume experimental sticks of the phenolics-rich witch hazel only after leaving them in the water for 2-3 days, apparently to leach out unpalatable compounds (Miiller-Schwarze et al. 2001). Many birds and mammals eat clay to adsorb phenolics so they never will be absorbed in the intestines. If they are taken up in the blood stream, such PSMs will eventually be rendered harmless by oxidation and other processes, followed by conjugation, in the liver. They then will be excreted in the urine. 

An artifact is an inclusion in some system, made by animals or man. Spider webs, bird nests, beaver dams, houses, books, machines, music, paintings, and language are artifacts. They may or may not be prostheaes, inventions which carry out some critical process essential to a living system. An artificial pacemaker for a human heart is an example of an artifact which can replace a pathological process with a healthy one. Insulin and thyroxine are replacement drugs which are human artifacts. Chemical, mechanical, or electronic artifacts have been constructed which carry out some functions of all levels of living systems. 

Sun, L. X., and Miiller-Schwarze, D., 1999, Chemical signals in the beaver one species, two secretions, many functions in Advances in Chemical Signals in Vertebrates, R. E. Johnston, D. Miiller-Schwarze, and P. W. Sorensen, eds., Kluwer Academic/Plenum Press, New York, pp. 281-288. 

Rosell, F. 2002, The function of scent marking in beaver (Castor fiber) territorial defence, PhD thesis, Norwegian University of Science and Technology, Trondheim, Norway. 

Sun, L. and Muller-Schwarze, D. 1999. Chemical signals in the beaver One species, two secretions, many functions This volume. 

Therefore, our theoretical calculations indicate that the exohedral functionalization of synthesized Tm3N C7g (Krause et al. 2005), Dy3N C7g (Popov et al. 2007) and Gd3N C7g (Beavers et al. 2009) might be stereoselectively produced over the [5,5] bonds. 

Flehmen (or lipcurl) is a response of male mammals primarily to female urine. It is seen primarily during the reproductive season and might function as a means of transport of chemicals to the vomeronasal organ (286). To elucidate the components of female urine which release the flehmen. Crump et al. (277) fractionated the urine of black-tailed deer Odocoileus hemionus columbianus and observed that behavioral responses disappeared completely before fractionation had reached the level of a single component. Similar results were found with beaver (287). 

---