Gamma-ray spectroscopy at TRIUMF-ISAC: The new frontier of radioactive ion beam research

High-resolution gamma-ray spectroscopy is essential to fully exploit the unique scientific opportunities at the next generation radioactive ion beam facilities such as the TRTUMF Isotope Separator and Accelerator (TSAC). At IS AC the 871 spectrometer and its associated auxiliary detectors is optimize for p-decay studies while TIGRESS an array of segmented clover HPGe detectors has been designed for studies with accelerated beams. This paper gives a brief overview of these facilities and also presents recent examples of the diverse experimental program carried out at the STI spectrometer. © 2009 American Institute of Physics

Assessment of epidermal growth factor receptor (EGFR) expression in primary colorectal carcinomas and their related metastases on tissue sections and tissue microarray

Metastatic colorectal carcinomas (CRC) resistant to chemotherapy may benefit from targeting monoclonal therapy cetuximab when they express the epidermal growth factor receptor (EGFR). Because of its clinical implications, we studied EGFR expression by immunohistochemistry on tissue sections of primary CRC (n=32) and their related metastases (n=53). A tissue microarray (TMA) was generated from the same paraffin blocks to determine whether this technique could be used for EGFR screening in CRC. On tissue sections, 84% of the primary CRC and 94% of the metastases were EGFR-positive. When matched, they showed a concordant EGFR-positive status in 78% of the cases. Moreover, staining intensity and extent of EGFR-positive cells in the primary CRC correlated with those observed in the synchronous metastases. On TMA, 65% of the primary CRC, 66% of the metastases, and 43% of the matched primary CRC metastases were EGFR-positive. There was no concordant EGFR status between the primary and the metastatic sites. A strong discrepancy of EGFR status was noted between TMA and tissue sections. In conclusion, EGFR expression measured in tissue sections from primary CRC and their related metastases was found to be similar and frequent, but it was significantly underestimated by the TMA technique

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

The TRIUMF Nuclear Structure Program and TIGRESS

The Isotope Separator and Accelerator (ISAC) facility located at the TRIUMF laboratory in Vancouver, Canada, is one of the world's most advanced ISOL-type radioactive ion beam facilities. An extensive {gamma}-ray spectroscopy program at ISAC is centered around two major research facilities: (1) the 8{pi} {gamma}-ray spectrometer for {beta}-delayed {gamma}-ray spectroscopy experiments with the low-energy beams from ISAC-I, and (2) the next-generation TRIUMF-ISAC Gamma-Ray Escape Suppressed Spectrometer (TIGRESS) for in-beam experiments with the accelerated radioactive ion beams. An overview of these facilities and recent results from the diverse program of nuclear structure and fundamental interaction studies they support is presented

STRATEGIC PLANNING AND ENTERPRISE ZONES

State policy makers are concerned about costs of past policies whose benefits are often difficult to determine. Some have recommended a strategic approach to state economic policy making in order to eliminate ad hoc incentives. Lessons derived from the literature on state enterprise zones are used to assess the 1993 Federal Empowerment Zone and Enterprise Community initiative. States can expand policy alternatives by fostering the growth of a marketplace of economic development ideas at the local level. Strategic plans should focus on development of competing, bottom-up solutions, rather than packages of specific incentives. Copyright 2000 by The Policy Studies Organization.