Algebraic-eikonal approach to medium energy proton scattering from odd-mass nuclei

We extend the algebraic-eikonal approach to medium energy proton scattering from odd-mass nuclei by combining the eikonal approximation for the scattering with a description of odd-mass nuclei in terms of the interacting boson-fermion model. We derive closed expressions for the transition matrix elements for one of the dynamical symmetries and discuss the interplay between collective and single-particle degrees of freedom in an application to elastic and inelastic proton scattering from $^{195}$Pt.Comment: latex, 14 pages, 4 figures uuencoded, to be published in Physical Review

Incipient Resistance of Helicoverpa punctigera to the Cry2Ab Bt Toxin in Bollgard II® Cotton

Combinations of dissimilar insecticidal proteins (“pyramids”) within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt) transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the intended function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not ‘bullet proof’ and that rapid evolution to Bt toxins in the Cry2 class is possible

Increased Resistance of Bt Aspens to Phratora vitellinae (Coleoptera) Leads to Increased Plant Growth under Experimental Conditions

One main aim with genetic modification (GM) of trees is to produce plants that are resistant to various types of pests. The effectiveness of GM-introduced toxins against specific pest species on trees has been shown in the laboratory. However, few attempts have been made to determine if the production of these toxins and reduced herbivory will translate into increased tree productivity. We established an experiment with two lines of potted aspens (Populus tremula×Populus tremuloides) which express Bt (Bacillus thuringiensis) toxins and the isogenic wildtype (Wt) in the lab. The goal was to explore how experimentally controlled levels of a targeted leaf beetle Phratora vitellinae (Coleoptera; Chrysomelidae) influenced leaf damage severity, leaf beetle performance and the growth of aspen. Four patterns emerged. Firstly, we found clear evidence that Bt toxins reduce leaf damage. The damage on the Bt lines was significantly lower than for the Wt line in high and low herbivory treatment, respectively. Secondly, Bt toxins had a significant negative effect on leaf beetle survival. Thirdly, the significant decrease in height of the Wt line with increasing herbivory and the relative increase in height of one of the Bt lines compared with the Wt line in the presence of herbivores suggest that this also might translate into increased biomass production of Bt trees. This realized benefit was context-dependent and is likely to be manifested only if herbivore pressure is sufficiently high. However, these herbivore induced patterns did not translate into significant affect on biomass, instead one Bt line overall produced less biomass than the Wt. Fourthly, compiled results suggest that the growth reduction in one Bt line as indicated here is likely due to events in the transformation process and that a hypothesized cost of producing Bt toxins is of subordinate significance

Strategies to Target Tumor Immunosuppression

The tumor microenvironment is currently in the spotlight of cancer immunology research as a key factor impacting tumor development and progression. While antigen-specific immune responses play a crucial role in tumor rejection, the tumor hampers these immune responses by creating an immunosuppressive microenvironment. Recently, major progress has been achieved in the field of cancer immunotherapy, and several groundbreaking clinical trials demonstrated the potency of such therapeutic interventions in patients. Yet, the responses greatly vary among individuals. This calls for the rational design of more efficacious cancer immunotherapeutic interventions that take into consideration the “immune signature” of the tumor. Multimodality treatment regimens that aim to enhance intratumoral homing and activation of antigen-specific immune effector cells, while simultaneously targeting tumor immunosuppression, are pivotal for potent antitumor immunity

Medium energy hadron scattering from nuclei

The Glauber approximation for medium energy scattering of hadronic projectiles from nuclei is combined with the interacting boson model of nuclei to produce a transition matrix for elastic and inelastic scattering in algebraic form which includes coupling to all the intermediate states. We present closed form analytic expresions for the transition matrix elements for the three dynamical symmetries of the interacting boson model; that is for, a spherical quadrupole vibrator, a ..gamma.. unstable rotor, and both prolate and oblate axially symmetric rotors. We give examples of application of this formalism to proton scattering from /sup 154/Sm and /sup 154/Gd. 27 refs., 5 figs., 1 tab

Interacting boson model and medium energy probes

Medium energy electron and proton scattering are used to determine the quadrupole form factors for the Interacting Boson Model of Nuclei. 12 refs., 3 figs