What drives countercyclical volatility? A large literature has documented that many economic variables are more disperse in recessions, but this could either occur because shocks get bigger or because …rms respond more to shocks which are the same size. Existing evidence that the dispersion of endogenous variables rises in recessions cannot tell us which of volatility or responsiveness is getti...

I show that the cross-sectional standard deviation of individual price changes in the BLS CPI database is countercyclical and comoves strongly with the frequency of price adjustments. Standard Ss models with only …rst moment shocks cannot explain these facts. Adding a second moment (‘uncertainty’) shock improves the model …t signi…cantly. Furthermore, it implies a strongly procyclical sensitivi...

The legume pod borer, Maruca vitrata (Lepidoptera: Crambidae; syn. M. testulalis), is a serious pantropical insect pest of grain legumes. Comparative studies of M. vitrata female sex pheromone components in two different geographic populations in China, Wuhan and Huazhou, confirmed that (E,E)-10,12-hexadecadienal (E10,E12-16:Ald) and (E)-10-hexadecenal (E10-16:Ald) were present in variable rati...

We study the fermionic extension of the E10/K(E10) coset model and its relation to eleven-dimensional supergravity. Finite-dimensional spinor representations of the compact subgroup K(E10) of E10(R) are studied and the supergravity equations are rewritten using the resulting algebraic variables. The canonical bosonic and fermionic constraints are also analysed in this way, and the compatibility...

A formal “small tension” expansion of D=11 supergravity near a spacelike singularity is shown to be equivalent, at least up to 30th order in height, to a null geodesic motion in the infinite dimensional coset space E10/K(E10), where K(E10) is the maximal compact subgroup of the hyperbolic KacMoody group E10(R). For the proof we make use of a novel decomposition of E10 into irreducible represent...