Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on-line taxonomic database AlgaeBase (http://www.algaebase.org). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the va...

Psychological theories disagree on how we attribute emotions to people. A new neuroimaging study shows that such attributions involve a large number of abstract features, rather than a small set of emotion categories.

One of the basic issues that arises in functional genomics is the ability to predict the subcellular location of proteins that are deduced from gene and genome sequencing. In particular, one would like to be able to readily specify those proteins that are soluble and those that are inserted in a membrane. Traditional methods of distinguishing between these two locations have relied on extensive...

J. Makowsky and B. Zilber (2004) showed that many variations of graph colorings, called CP-colorings in the sequel, give rise to graph polynomials. This is true in particular for harmonious colorings, convex colorings, mcct-colorings, and rainbow colorings, and many more. N. Linial (1986) showed that the chromatic polynomial χ(G;X) is #P-hard to evaluate for all but three values X = 0, 1, 2, wh...

A Borel equivalence relation on a Polish space is countable if all of its equivalence classes are countable. Standard examples of countable Borel equivalence relations (on the space of subsets of the integers) that occur in recursion theory are: recursive isomorphism, Turing equivalence, arithmetic equivalence, etc. There is a canonical hierarchy of complexity of countable Borel equivalence rel...

Is this observation a true fact? Certainly it is easy to verify that no matter where you look among the numbers you find plenty of primes. From a scientific point of view you can do billions of experiments with your mathematical package and always find primes. It can be tested more often and more precisely than any law of physics. You can safely bet the family farm on this and still sleep sound...

Here we will show that T (s)− B2(s − 1) −1 can be continuously extended onto the line Re s = 1, (Th.1). This enables application of the powerful complex Tauberian theorem of Wiener and Ikehara (1931) and then almost immediately yields our main result, (Th.2). The ideas basic to our proof of Th.1 are plain: We are striving to exhibit a relation between T (s) and the Riemann Zeta function ζ(s); m...

The number of possible distinct names of reasonable length is necessarily finite, and with the heavy demand for new names in some areas of current English-speaking commerce it seems possible that the supply might approach exhaustion. Numbers of possibilities cannot be calculated exactly, because most wordforms theoretically allowed by English phonology are too clumsy to be usable. However, Mont...

Optimality Theory assumes the candidate set generated for any given input is of infinite cardinality. If all of the candidates in the candidate set were potential winners (optimal candidates under some ranking), then OT would have predicted an infinite typology— there would be infinitely many possible languages. However, Samek-Lodovici and Prince (1999) have shown that in standard OT (with only...

T microorganisms classified in the two prokaryotic domains of the tree of life, Bacteria and Archaea, possess immense metabolic diversity, and their activities are critical in processes ranging from sewage treatment to regulating the composition of the atmosphere. Especially in light of the rate of modern climate change, it is essential to understand how microbial communities affect ecosystem f...