The spin structure functions g1 and g2 have been calculated in the resonance region and for small and intermediate momentum transfer. The calculation is based on a gauge-invariant and unitary model for one-pion photoand electroproduction. The predictions of the model agree with the asymmetries and the spin sturcture functions recently measured at SLAC, and the first moments of the calculated sp...

I review new results on s-channel helicity nonconservation (SCHNC) in diffractive DIS. I discuss how by virtue of unitarity diffractive DIS gives rise to spin structure functions which were believed to vanish at x ≪ 1. These include tensor polarization of sea quarks in the deuteron, strong breaking of the Wandzura-Wilczek relation and demise of the Burkhardt-Cottingham sum rule. The invited tal...

The image of the complement of a hyperplane arrangement under a monomial map can be tropicalized combinatorially using matroid theory. We apply this to classical moduli spaces that are associated with complex reflection arrangements. Starting from modular curves, we visit the Segre cubic, the Igusa quartic, and moduli of marked del Pezzo surfaces of degrees 2 and 3. Our primary example is the B...

We show that the Politzer theorem on the equations of motion implies approximate constraints on the quark correlator. These, in turn, restrict considerably, for sufficiently large Q 2 , the number of independent distribution functions that characterize the internal structure of the nucleon, and of independent fragmentation functions. This result leads us to suggesting an alternative method for ...

The knowledge of cytodynamics in the respiratory tract is still in its infancy. Since Bertalanffy and Leblond (1953) described their findings in a study of the alveolar macrophage cells in the lung of the albino rat, few investigations have been reported in the literature (Koburg, 1962; Spencer and Shorter, 1962; Meyer zum Gottesberge and Koburg, 1963; and Shorter, Titus, and Divertie, 1964b), ...