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The C-12+C-12 fusion reaction is one of the most important for nuclear astrophysics since it determines the carbon ignition in stellar environments. Two experiments which make use of the gamma-particle coincidence technique to measure the C-12+C-12 S-factors at deep sub barrier energies are discussed. Results are presented showing a decrease of the S-factor below E-c.m. = 3 MeV.

background: There is an acute need to uncover biomarkers that reflect the molecular pathologies, underpinning prostate cancer progression and poor patient outcome. We have previously demonstrated that in prostate cancer cell lines PDE4D7 is downregulated in advanced cases of the disease. To investigate further the prognostic power of PDE4D7 expression during prostate cancer progression and assess how downregulation of this PDE isoform may affect disease outcome, we have examined PDE4D7 expression in physiologically relevant primary human samples.\ud methods: About 1405 patient samples across 8 publically available qPCR, Affymetrix Exon 1.0 ST arrays and RNA sequencing data sets were screened for PDE4D7 expression. The TMPRSS2-ERG gene rearrangement status of patient samples was determined by transformation of the exon array and RNA seq expression data to robust z-scores followed by the application of a threshold >3 to define a positive TMPRSS2-ERG gene fusion event in a tumour sample.\ud results: We demonstrate that PDE4D7 expression positively correlates with primary tumour development. We also show a positive association with the highly prostate cancer-specific gene rearrangement between TMPRSS2 and the ETS transcription factor family member ERG. In addition, we find that in primary TMPRSS2-ERG-positive tumours PDE4D7 expression is significantly positively correlated with low-grade disease and a reduced likelihood of progression after primary treatment. Conversely, PDE4D7 transcript levels become significantly decreased in castration resistant prostate cancer (CRPC).\ud conclusions: We further characterise and add physiological relevance to PDE4D7 as a novel marker that is associated with the development and progression of prostate tumours. We propose that the assessment of PDE4D7 levels may provide a novel, independent predictor of post-surgical disease progression.

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In this article we discuss two aspects related to the 12C + 12C fusion reaction at low energies for carbon burning in supermassive stars. First we present plausible arguments for the notion that the observed resonance structures at the lowest measured energies arise from the relatively large spacing and narrow width of 24Mg compound levels at the corresponding excitation energy region. We thus point out that the Incoming Wave Boundary Condition is inappropriate for calculating the fusion cross section under these situations. Secondly, we report on a particle-γ coincidence technique that has been used for the first time to measure the fusion cross section in the system 12C + 12C at low beam energies. Based on these results, it should be possible to measure this important fusion cross section down to the 10 pb level within a reasonable length of time.

We report on a study of the structure of the unbound nucleus He-7 utilizing the proton-removal reaction H-2(Li-8,He-3)He-7. Combining the present results with those of our prior measurements of the neutron-adding reaction H-2(He-6,p)He-7, a consistent picture emerges for the low-lying excitations in He-7. Specifically, the negative-parity sequence of resonances, in order of excitation energies, is consistent with 3/2(-),1/2(-), and 5/2(-). The stable-beam reactions H-2(Li-7,t)Li-6 and H-2(Li-7,He-3)He-6 were also measured. The results are compared with the predictions of nuclear structure models, including those of ab initio quantum Monte Carlo calculations.

The Ni-62(n,gamma)Ni-63(t(1/2) = 100 +/- 2 yr) reaction plays an important role in the control of the flow path of the slow neutron-capture (s) nucleosynthesis process. We have measured for the first time the total cross section of this reaction for a quasi-Maxwellian (kT = 25 keV) neutron flux. The measurement was performed by fast-neutron activation, combined with accelerator mass spectrometry to detect directly the Ni-63 product nuclei. The experimental value of 28.4 +/- 2.8 mb, fairly consistent with a recent calculation, affects the calculated net yield of Ni-62 itself and the whole distribution of nuclei with 62 < A < 90 produced by the weak s process in massive stars. Phys Rev Lett

Nuclear Physics A

The medium spin, near yrast states of the fpg shell nuclei 58Ni, 61Cu, and 61Zn have been studied following the fusion evaporation of a 24Mg beam and a 40Ca target. Discrete transitions were unambiguously identified using the AYEBALL gamma-ray array in conjunction with the Argonne fragment mass analyzer and a split anode ionization chamber. The decay schemes of 5828Ni, 6129Cu, and 6130Zn have been extended with the results of gamma-gamma coincidences and directional correlation from oriented state measurements used to determine the level excitation energies, spins, and parities of a number of near yrast states. The decay schemes deduced are compared with previous work and interpreted in terms of shell model calculations, with a restricted basis of the f5/2, p3/2, p1/2 orbitals outside a 5628Ni core, and either the g9/2 orbital with a closed core, or f7/2 excitations from the core.