526 research outputs found

    Investigating the chromatic contribution to recognition of facial expression

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    A pedestrian may judge the intentions of another person by their facial expression amongst other cues and aiding such evaluation after dark is one aim of road lighting. Previous studies give mixed conclusions as to whether lamp spectrum affects the ability to make such judgements. An experiment was carried out using conditions better resembling those of pedestrian behaviour, using as targets photographs of actors portraying facial expressions corresponding to the six universally recognised emotions. Responses were sought using a forced-choice procedure, under two types of lamp and with colour and grey scale photographs. Neither lamp type nor image colour was suggested to have a significant effect on the frequency with which the emotion conveyed by facial expression was correctly identified

    Laser Spectroscopy of Niobium Fission Fragments: First Use of Optical Pumping in an Ion Beam Cooler Buncher

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    A new method of optical pumping in an ion beam cooler buncher has been developed to selectively enhance ionic metastable state populations. The technique permits the study of elements previously inaccessible to laser spectroscopy and has been applied here to the study of Nb. Model independent mean-square charge radii and nuclear moments have been studied for 90,90m,91,91m,92,93,99,101,103^{90,90 m,91,91 m,92,93,99,101,103}Nb to cover the region of the N=50 shell closure and N≈60 sudden onset of deformation. The increase in mean-square charge radius is observed to be less than that for Y, with a substantial degree of ÎČ softness observed before and after N=60

    Nuclear spins, magnetic moments and quadrupole moments of Cu isotopes from N = 28 to N = 46: probes for core polarization effects

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    Measurements of the ground-state nuclear spins, magnetic and quadrupole moments of the copper isotopes from 61Cu up to 75Cu are reported. The experiments were performed at the ISOLDE facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is however strongly reduced at N=40 due to the parity change between the pfpf and gg orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps.Comment: 13 pagers, 19 figures, accepted by Physical Review

    Isomer shift and magnetic moment of the long-lived 1/2+^{+} isomer in 3079^{79}_{30}Zn49_{49}: signature of shape coexistence near 78^{78}Ni

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    Collinear laser spectroscopy has been performed on the 3079^{79}_{30}Zn49_{49} isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in 79^{79}Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins I=9/2I = 9/2 and I=1/2I = 1/2 are firmly assigned to the ground and isomeric states. The magnetic moment ÎŒ\mu (79^{79}Zn) = −-1.1866(10) ÎŒN\mu_{\rm{N}}, confirms the spin-parity 9/2+9/2^{+} with a Îœg9/2−1\nu g_{9/2}^{-1} shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment ÎŒ\mu (79m^{79m}Zn) = −-1.0180(12) ÎŒN\mu_{\rm{N}} supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the N=50N = 50 shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state: ή⟹rc2⟩79,79m\delta \langle r^{2}_{c}\rangle^{79,79m} = +0.204(6) fm2^{2}, providing first evidence of shape coexistence.Comment: 5 pages, 4 figures, 1 table, Accepeted by Phys. Rev. Lett. (2016

    Halos and related structures

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    The halo structure originated in nuclear physics but is now encountered more widely. It appears in loosely bound, clustered systems where the spatial extension of the system is significantly larger than that of the binding potentials. A review is given on our current understanding of these structures, with an emphasis on how the structures evolve as more cluster components are added, and on the experimental situation concerning halo states in light nuclei.Comment: 27 pages, 3 figures, Contribution to Nobel Symposium 152 "Physics With Radioactive Beams

    Theranostic pretargeted radioimmunotherapy of colorectal cancer xenografts in mice using picomolar affinity 86Y- or 177Lu-DOTA-Bn binding scFv C825/GPA33 IgG bispecific immunoconjugates

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    Purpose: GPA33 is a colorectal cancer (CRC) antigen with unique retention properties after huA33-mediated tumor targeting. We tested a pretargeted radioimmunotherapy (PRIT) approach for CRC using a tetravalent bispecific antibody with dual specificity for GPA33 tumor antigen and DOTA-Bn–(radiolanthanide metal) complex. Methods: PRIT was optimized in vivo by titrating sequential intravenous doses of huA33-C825, the dextran-based clearing agent, and the C825 haptens [superscript 177]Lu-or [superscript 86]Y-DOTA-Bn in mice bearing the SW1222 subcutaneous (s.c.) CRC xenograft model. Results: Using optimized PRIT, therapeutic indices (TIs) for tumor radiation-absorbed dose of 73 (tumor/blood) and 12 (tumor/kidney) were achieved. Estimated absorbed doses (cGy/MBq) to tumor, blood, liver, spleen, and kidney for single-cycle PRIT were 65.8, 0.9 (TI 73), 6.3 (TI 10), 6.6 (TI 10), and 5.3 (TI 12), respectively. Two cycles of PRIT (66.6 or 111 MBq [superscript 177]Lu-DOTA-Bn) were safe and effective, with a complete response of established s.c. tumors (100 – 700 mm³) in nine of nine mice, with two mice alive without recurrence at >140 days. Tumor log kill in this model was estimated to be 2.1 – 3.0 based on time to 500-mm³ tumor recurrence. In addition, PRIT dosimetry/diagnosis was performed by PET imaging of the positron-emitting DOTA hapten [superscript 86]Y-DOTA-Bn. Conclusion: We have developed anti-GPA33 PRIT as a triplestep theranostic strategy for preclinical detection, dosimetry, and safe targeted radiotherapy of established human colorectal mouse xenografts.National Institute of Mental Health (U.S.) (Grant R01-CA-101830
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