Internal representations of smell in the Drosophila brain

Recent advances in sensory neuroscience using Drosophila olfaction as a model system have revealed brain maps representing the external world. Once we understand how the brain's built-in capability generates the internal olfactory maps, we can then elaborate how the brain computes and makes decision to elicit complex behaviors. Here, we review current progress in mapping Drosophila olfactory circuits and discuss their relationships with innate olfactory behaviors

The Parameters 4-(12,6,6) and Related t-Designs

It is shown that a 4-(12,6,6) design, if it exists, must be rigid. The intimate relationship of such a design with 4-(12,5,4) designs and 5-(12,6,3) designs is presented and exploited. In this endeavor we found: (i) 30 nonisomorphic 4-(12,5,4) designs; (ii) all cyclic 3-(11,5,6) designs; (iii) all 5-(12,6,3) designs preserved by an element of order three fixing no points and no blocks; and (iv) all 5-(12,6,3) designs preserved by an element of order two fixing 2 points. 1 Introduction A simple t\Gamma(v; k; ) design is a pair (X; D) where X is a v-element set of points and D is a collection of distinct k-element subsets of X called blocks such that: for all T ae X, jT j = t, jfK 2 D : T ae Kgj = . For v 12, 4-(12,6,6) is the only parameter case for which existence is unsettled. It is known that necessary conditions for the existence of a t\Gamma(v; k; ) design are that for each 0 i t / v \Gamma i t \Gamma i ! j 0 (modulo / k \Gamma i t \Gamma i ! ): Given integers 0 t ..