7 research outputs found
Journal of Economic Entomology
No full textDrosophila suzukii (Matsumura) is a pest of small fruits and grapes in the United States and in its home range of Japan. Physiological and morphological laboratory testing was performed on six commonly grown wine grape varieties in Virginia. Skin thickness, penetration force, and ºBrix were analyzed to determine ovipositional preferences. Experiments were performed for three consecutive years from grapes collected at one Virginia vineyard. More eggs were laid in intact Viognier grapes than any other variety. Oviposition into intact grapes was not affected by skin thickness or ºBrix; however, oviposition increased when penetration force decreased. An ovipositional choice test determined no varietal preferences. Survivorship from egg to adulthood using uninjured and injured grapes was also assessed to determine varietal suitability as D. suzukii hosts, with more flies emerging from injured grapes than uninjured. However, D. suzukii adults did emerge from intact grapes and at higher percentages than previously recorded in other wine grape studies. All varieties had eggs oviposited into them when injured. Determining the time at which each grape variety became susceptible to oviposition was determined using a D. suzukii bioassay spanning 12 wk using grapes from the green pea stage until ripe. Susceptibility to D. suzukii oviposition was based upon ripening period and penetration force. Early ripening varieties may be more susceptible to D. suzukii oviposition in the field with later maturing, harder fleshed-varieties which may escape D. suzukii oviposition.Published versionThe lead author, Meredith Shrader, was my doctoral student
Development and Application of a Multimodal Coherent Raman Scattering Microscope
No full textA multimodal nonlinear optical microscope is a microscope capable of imaging in two or more nonlinear optical imaging modalities, such as second harmonic generation, third harmonic generation, two-photon excitation fluorescence, and coherent Raman imaging. These imaging modalities provide researchers with the means to image biological structures, responses, and chemical compositions, label-free, and are fast becoming invaluable tools of biomedical investigation. In the Lab for Laser Assisted Medical Physics and Engineering (LLAMPE), we seek to apply such microscopy for biomedical research and to demonstrate its utility in new areas. We also seek to demonstrate new technologies to improve performance, robustness, and general utility, and so we have built such a microscope and have been using it in various studies since construction. In this thesis I document my work in constructing a multimodal NLO micro- scope capable of coherent Raman imaging, along with two-photon fluorescence and second harmonic imaging. Use of a new detector technology for acquisition of coher- ent anti-Stokes Raman scattering signals is discussed and demonstrated for the first time. I then discuss specific applications that I have directly used this microscope for, including detecting mitochondrial activity in murine macrophages, and imaging the radiobiological response in irradiated breast cancer cells using stimulate Raman scattering microscopy. I finish with a discussion of ongoing work and future plans for improving the microscope, some of which are currently being implemented
Isospin dependence of electromagnetic transition strengths among an isobaric triplet
No full text© 2019 The Author(s) Electric quadrupole matrix elements, Mp, for the Jπ=2+→0+, ΔT=0, T=1 transitions across the A=46 isobaric multiplet 46Cr-46V-46Ti have been measured at GSI with the FRS-LYCCA-AGATA setup. This allows direct insight into the isospin purity of the states of interest by testing the linearity of Mp with respect to Tz. Pairs of nuclei in the T=1 triplet were studied using identical reaction mechanisms in order to control systematic errors. The Mp values were obtained with two different methodologies: (i) a relativistic Coulomb excitation experiment was performed for 46Cr and 46Ti; (ii) a “stretched target” technique was adopted here, for the first time, for lifetime measurements in 46V and 46Ti. A constant value of Mp across the triplet has been observed. Shell-model calculations performed within the fp shell fail to reproduce this unexpected trend, pointing towards the need of a wider valence space. This result is confirmed by the good agreement with experimental data achieved with an interaction which allows excitations from the underlying sd shell. A test of the linearity rule for all published data on complete T=1 isospin triplets is presented
Spin-gap isomer in
No full textEvidence has been obtained for the existence of the long predicted 16+ spin-gap isomer in 96Cd. The decay of the isomer was identified and studied following the use of an 850 MeV/u beam of 124Xe impinging on a Be target and the fragment recoil separator at the GSI Laboratory. Gamma decays from the fragments were detected using the RISING gamma ray array, in its stopped beam configuration, plus a silicon active stopper. The data obtained have been compared with shell model predictions, which indicate that the isoscalar neutron-proton interaction plays a key role in the formation of the isomer
Low-lying electric dipole -continuum for the unstable Fe nuclei: Strength evolution with neutron number
No full textThe γ -ray emission from the nuclei Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E 1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ -ray spectra the summed E 1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E 1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1 states (three-phonon states) inducing a strong fragmentation of the E 1 nuclear response below the neutron binding energy
Study of isomeric states in Pb-198,Pb-200,Pb-202,Pb-206 and Hg-206 populated in fragmentation reactions
No full textIsomeric states in isotopes in the vicinity of doubly-magic 208Pb were populated following reactions of a relativistic 208Pb primary beam impinging on a 9Be fragmentation target. Secondary beams of 198,200,202,206Pb and 206Hg were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed γ rays were detected with the Advanced Gamma Tracking Array (AGATA). Decay schemes were re-evaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei 206Pb/206Hg was found to differ from the population of multi neutron-hole isomeric states in 198,200,202Pb
