22 research outputs found
Polarization observables of the gamma d --> PiNN reaction in the Delta(1232)-resonance region
Polarization observables of the three charge states of the pion for the
reaction with polarized photon beam and/or oriented
deuteron target are evaluated over the whole (1232)-resonance region
adopting a nonrelativistic model based on time-ordered perturbation theory.
Results for the -meson spectra, linear photon asymmetry, vector and tensor
target asymmetries are presented. Particular attention is given, for the first
time, to double polarization asymmetries for which we present results for
and . We found that all other double
polarization asymmetries of photon and deuteron target are vanished.Comment: 17 Pages, 8 Figures, accepted for publication in Int. J. Mod. Phys.
Considerations on rescattering effects for threshold photo- and electro-production of on deuteron
We show that for the S-state -production in processes and the rescattering effects due to the
transition: (or are cancelled
out due to the Pauli principle. The large values for these effects predicted in
the past may result from the fact that the spin structure of the corresponding
matrix element and the necessary antisymmetrization induced by the presence of
identical protons (or neutrons) in the intermediate state was not taken into
account accurately. One of the important consequences of these considerations
is that photo- and electro-production on deuteron near threshold can
bring direct information about elementary neutron amplitudes.Comment: Add a new sectio
Rescattering effects in coherent pion production on the deuteron
We present a calculation for coherent pion production on the deuteron in which rescattering corrections are included to all orders. These rescattering contributions are computed by solving the Faddeev equations for the πNN system. The corrections turn out to be fairly unimportant in the numerical description of the cross section in the resonance region. However, the inclusion of rescattering in the multipoles for pion production on a single nucleon has a large effect on the cross section for pion production on the deuteron. We also study the effect of the neutron contribution on the observables for pion production on the deuteron
Fragment-Based Screening in Tandem with Phenotypic Screening Provides Novel Antiparasitic Hits
Methods to discover biologically active small molecules include target-based and phenotypic screening approaches. One of the main difficulties in drug discovery is elucidating and exploiting the relationship between drug activity at the protein target and disease modification, a phenotypic endpoint. Fragment-based drug discovery is a target-based approach that typically involves the screening of a relatively small number of fragment-like (molecular weight <300) molecules that efficiently cover chemical space. Here, we report a fragment screening on TbrPDEB1, an essential cyclic nucleotide phosphodiesterase (PDE) from Trypanosoma brucei, and human PDE4D, an off-target, in a workflow in which fragment hits and a series of close analogs are subsequently screened for antiparasitic activity in a phenotypic panel. The phenotypic panel contained T. brucei, Trypanosoma cruzi, Leishmania infantum, and Plasmodium falciparum, the causative agents of human African trypanosomiasis (sleeping sickness), Chagas disease, leishmaniasis, and malaria, respectively, as well as MRC-5 human lung cells. This hybrid screening workflow has resulted in the discovery of various benzhydryl ethers with antiprotozoal activity and low toxicity, representing interesting starting points for further antiparasitic optimization
The Management of New Office Technology: Choice, Control and Social Structure in the Insurance Industry
Amongst the growing literature on the technical and social aspects of microelectronics in work organizations, a considerable portion has direct or indirect pertinence to the question of managerial practice. That segment of the literature relating to new office technology is perhaps especially conscious of this angle — not least because this sphere of innovation has a clear bearing on the managerial role itself.
Drawing both on theoretical issues extracted from this literature, and on empirical studies in three insurance companies, it is argued that while control is of crucial long-term importance in shaping the general direction of organizational change using new technology, there are sound sociological reasons why the path which is beaten out in that direction remains a far from straight one. Moreover, while differences in organizational practice between these organizations are found to exist, these appear to be associated only indirectly with the diverse levels of technological sophistication