Halting Neotropical Deforestation: Do the Forest Principles Have What It Takes?

INTRODUCTION I crashed into the thick secondary growth, stopping suddenly to duck a certain branch in my path: a fat black bullet ant crawled along it with indifference, an attitude that would have quickly changed had I brushed up against him. I headed toward the large patch of Heliconia just to the right. We had earlier mapped out the clump, and finding it to contain seventeen flower clusters, it was one of the prize patches in the study plot. I took my spot ten paces from the outer clusters, started my stop watch, and waited with field book in hand. The Birds of Paradise were dripping nectar from their red fingertips. With such a gold mine, I did not have to wait long for a hummingbird. Like an Evinrude-powered flat bottom whizzing up a winding lagoon, the bird\u27s sound reached me before I saw him. He appeared from the back of the patch, taking a drink here, then there, then here again, then at some other spot, then there again and back to here. He did not sit and sip for long at each spot, but he did pause long enough for me to see him gleam green and deep violet. He was a red-footed plumeleteer, emerald green on the head, changing to dark purple through his body and on to his tail. His feet and straight bill were distinctively red. Without a doubt he owned this lucrative Heliconia patch. But then from my right came another whir. A ..

Self-dual quiver moduli and orientifold Donaldson-Thomas invariants

Motivated by the counting of BPS states in string theory with orientifolds, we study moduli spaces of self-dual representations of a quiver with contravariant involution. We develop Hall module techniques to compute the number of points over finite fields of moduli stacks of semistable self-dual representations. Wall-crossing formulas relating these counts for different choices of stability parameters recover the wall-crossing of orientifold BPS/Donaldson-Thomas invariants predicted in the physics literature. In finite type examples the wall-crossing formulas can be reformulated in terms of identities for quantum dilogarithms acting in representations of quantum tori.Comment: 24 pages. The factorization used to define orientifold DT invariants has been slightly revise

Beetles (Coleoptera: Histeridae and Scarabaeidae) from previously unsampled populations of pocket gopher burrows in Louisiana

Pocket gopher burrows (Rodentia: Geomyidae) were sampled from five previously unsampled localities in northern Louisiana to determine the associated faunal composition of Histeridae and Scarabaeidae (Coleoptera). Sampling produced four species of Histeridae and seven species of Scarabaeidae, all of which had been previously reported from Louisiana. The most commonly collected scarab beetle was Cryptoscatomaseter haldemani (Horn) followed by Geomyphilus insolitus (Brown). Onthophilus kirni Ross was the most commonly collected hister beetle