Sturcture of the Goldstone Bosons

The feasibility of measuring the pion and kaon structure functions has been investigated. A high luminosity electron-proton collider would make these measurements feasible. Also, it appears feasible to measure these structure functions in a nuclear medium. Simulations using the RAPGAP Monte Carlo of a possible pion structure function measurement are presented.Comment: To appear in the proceedings of the Second Workshop on Physics with an Electron Polarized Light-Ion Collider, 14-16 Sept 2000, Cambridge, Ma 6 pages, 5 figures, late

Water, women and local social organization in the Western Kenya highlands

Safe water is widely recognized as both a fundamental human need and a key input into economic activity. Across the developing world, the typical approach to addressing these needs is to segregate supplies of water for domestic use from water for large-scale agricultural production. In that arrangement, the goal of domestic water supply is to provide small amounts of clean safe water for direct consumption, cleaning, bathing and sanitation, while the goal of agricultural water supply is to provide large amounts of lower quality water for irrigated agriculture. A new third use of water is now being given more attention by researchers: small amounts of water employed in selected household enterprises. This third use may be particularly important for women. There is a potential, therefore, that provision of modest amounts of water to smallholder farmers can enhance household economic production, save labor time for women and girls, and improve family health. This paper adds to the merger literature on the multiple values of improved water supplies – improved health, time savings, and small-scale production for individual farmers and collectives – for the case of a rural community in the western highlands of Kenya. With minimum external support, two groups in this community have managed to install and operate systems of spring protection and piped water to their members’ homesteads. A third group is in the process of replicating this success. The experience of this community also illustrates some of the challenges that must be faced for a community to effectively selforganize the investment and maintenance of a community-based water scheme. There are challenges of finance, gender relations, conflicts over scarce water supplies, group leadership, enforcement of community bi-laws, and policy. Data from a census of springs in the same area show that successful collective action for water management is unusual, but certainly not unique, in this region of Kenya. Although women emerge as the main beneficiaries of improved water management in the community, their substantial contributions are largely hidden behind social norms regarding gender roles and relations. Research methods need to carefully triangulate information sources in order to clarify the very substantial and active roles performed by women.Length: 21p.WomenGenderWater supplyWater rightsHealthCollective actionParticipatory management

Compact Radio Cores in Seyfert Galaxies

We have observed a sample of 157 Seyfert galaxies with a 275 km baseline radio interferometer to search for compact, high brightness temperature radio emission from the active nucleus. We obtain the surprising result that compact radio cores are much more common in Seyfert 2 than in Seyfert 1 galaxies, which at first seems to be inconsistent with orientation unification schemes. We propose a model, involving optical depth effects in the narrow-line region, which can reconcile our result with the standard unified scheme. (Accepted for publication in ApJ 1994 Sep 10)Comment: 21 pages and 7 figures, uuencoded tar-compressed postscript files, ATP18

Gene regulatory factors of the sea urchin embryo. II. Two dissimilar proteins, P3A1 and P3A2, bind to the same target sites that are required for early territorial gene expression

Previous work demonstrated that a negative regulatory interaction mediated by factor(s) termed 'P3A' is required for correct territory-specific gene expression in the sea urchin embryo. A probe derived from a P3A target site in the skeletogenic SM50 gene of Strongylocentrotus purpuratus was used to isolate a cDNA clone coding for a factor that binds specifically to this site. This factor, called P3A1, contains two sequence elements that belong to the Zn finger class of DNA-binding motifs, and in these regions is most closely similar to the Drosophila hunchback factor. The P3A1 factor also binds to a similar target sequence in a second gene, CyIIIa, expressed in embryonic aboral ectoderm. Another sea urchin embryo protein factor, P3A2, has been isolated by affinity chromatography and cloned, as described in Calzone et al. Development 112, 335-350 (1991). P3A2 footprints the same target sites in the SM50 and CyIIIa genes as does P3A1, but lacks the Zn finger sequence motifs and in amino acid sequence is almost entirely dissimilar to P3A1. A deletion analysis of P3A2 delimited the DNA-binding region, revealing that five specific amino acids in the first P3A1 finger region and four in the second P3A1 finger region are also present in equivalent positions in P3A2. The P3A1 and P3A2 factors could function as regulatory antagonists, having evolved similar target specificities from dissimilar DNA-binding domains

Coherent Control of Trapped Bosons

We investigate the quantum behavior of a mesoscopic two-boson system produced by number-squeezing ultracold gases of alkali metal atoms. The quantum Poincare maps of the wavefunctions are affected by chaos in those regions of the phase space where the classical dynamics produces features that are comparable to hbar. We also investigate the possibility for quantum control in the dynamics of excitations in these systems. Controlled excitations are mediated by pulsed signals that cause Stimulated Raman Adiabatic passage (STIRAP) from the ground state to a state of higher energy. The dynamics of this transition is affected by chaos caused by the pulses in certain regions of the phase space. A transition to chaos can thus provide a method of controlling STIRAP.Comment: 17 figures, Appended a paragraph on section 1 and explained details behind the hamiltonian on section