Imaging cytoplasmic cAMP in mouse brainstem neurons

Background  

cAMP is an ubiquitous second messenger mediating various neuronal functions, often as a consequence of increased intracellular Ca²⁺ levels. While imaging of calcium is commonly used in neuroscience applications, probing for cAMP levels has not yet been performed in living vertebrate neuronal tissue before.     

Production of cumulative protons in high-energy hadron-nucleus and nucleus-nucleus interactions

Under conditions of 4π coverage, the production of cumulative protons in π ^?C, pC, ⁴HeC, and CC collisions at high energies is studied on the basis of a large statistical sample. The behavior of inclusive cross sections for cumulative-proton production versus the cumulative number β is found to be universal in the sense that it is independent of the type projectile and primary energy. It is established that the mean number of cumulative protons is also independent of the projectile type and primary energy.     

Stable isotopic studies of earthworm feeding ecology in tropical ecosystems of Puerto Rico

Feeding strategies of earthworms and their influence on soil processes are often inferred from morphological, behavioral and physiological traits. We used (13)C and (15)N natural abundance in earthworms, soils and plants to explore patterns of resource utilization by different species of earthworms in three tropical ecosystems in Puerto Rico. In a high altitude dwarf forest, native earthworms Trigaster longissimus and Estherella sp. showed less (15)N enrichment ((15)N = 3-6 per thousand) than exotic Pontoscolex corethrurus ((15)N =7-9 per thousand) indicating different food sources or stronger isotopic discrimination by the latter. Conversely, in a lower altitude tabonuco forest, Estherella sp. and P. corethrurus overlapped completely in (15)N enrichment ((15)N = 6-9 per thousand), suggesting the potential for interspecific competition for N resources. A tabonuco forest converted to pasture contained only P. corethrurus which were less enriched in (15)N than those in the forest sites, but more highly enriched in (13)C suggesting assimilation of C from the predominant C(4) grass. These results support the utility of stable isotopes to delineate resource partitioning and potential competitive interactions among earthworm species. Copyright 1999 John Wiley & Sons, Ltd.     

Breakup of an oxygen nucleus to light fragments of mass number in the range A ? 4 in 16Op interactions at a momentum of 3.25 GeV/c per nucleon

New experimental data on the correlations of the yields of ⁴He and ²H nuclei in semi-inclusive reactions involving by the production of ³He and ³H mirror nuclei in ¹⁶Op collisions at a momentum of 3.25 GeV/c per nucleon are presented. The mean multiplicities of protons and neutrons appearing as fragments are found to be independent of the number of associated deuterons, this indicating that a considerable part of these fragments originate from the breakup of the alpha-particle clusters forming the oxygen nucleus.     

Fragmentation of relativistic oxygen nuclei in interactions with a proton

The data on investigation of inelastic interactions of ¹⁶O nuclei in a hydrogen bubble chamber at an incident momentum of 3.25 A GeV/c are presented. Separate characteristics as fragments isotope composition and topological cross-sections of fragmentation channels are given. The processes of formation of light fragments and unstable nuclei, and the break-up of the ¹⁶O nucleus into multicharge fragments are investigated. A comparison between the experimental data and the calculations of the cascade fragmentation evaporation model (CFEM) is made. The observed singularities of the interactions point out the important role of the nucleus α-cluster structure in the formation of the final products. Received: 9 January 2001 / Accepted: 13 June 2001     

Contribution of excited nuclei 12C* to the channel of three-alpha-particle production in 16Op collisions at a momentum of 3.25 GeV/c per nucleon

Physics of Atomic Nuclei - A phenomenological analysis of the channel involving the production of three alpha particles in collisions of relativistic oxygen nuclei with protons is performed for the...     

Production of multibaryon clusters in hadron-nucleus collisions at high energies

The results obtained by analyzing the production of multibaryon clusters in π ⁻C and p ²⁰Ne interactions at momenta of 40 and 300 GeV/c, respectively, are presented.