23 research outputs found
Neutron and proton spectra from the decay of hypernuclei
We have determined the spectra of neutrons and protons following the decay of
hypernuclei through the one- and two-nucleon induced mechanisms. The
momentum distributions of the primary nucleons are calculated and a Monte Carlo
simulation is used to account for final state interactions. From the spectra we
calculate the number of neutrons () and protons () per
decay and show how the measurement of these quantities, particularly , can
lead to a determination of , the ratio of neutron to
proton induced decay. We also show that the consideration of the
two-nucleon induced channel has a repercussion in the results, widening the
band of allowed values of with respect to what is
obtained neglecting this channel.Comment: 30 pages, 12 Postscript figures, uuencoded file, ReVTeX, epsf.st
Life design and career counseling: contributions to social justice
The chapter begins with the presentation of LDC framework. In the second section, considerations are given on LDC possibilities for enhancing decent work and social justice. From this perspective of social exclusion, designated social integrationist, participation in paid work is viewed as the key to social inclusion (Watts, 2001). At the end of this section the relevance of contextual factors in career development of disadvantaged populations is referred to highlight the importance of these interventions not be exclusively focused on inter- and intrapersonal career development factors, but also take into consideration social action at the institutional, community, public policy and international/global levels (Cook, 2017). In the next section, the process of balancing the focus on the self-determination of the individual with a focus on a transformation of contextual factors that reinforce the disadvantaged position (Blustein, et al., 2005; Prilleltensky, 1997) is illustrated by presenting an intervention in which LDC was integrated into supported employment approach. Our proposal focuses exclusively on collaborative activities at the individual, institutional and communal level, with these being the tiers which the counselor can more easily influence as part of their more routine interaction with disadvantaged populations in general. The chapter concludes with an overview of the subject and a reference on LDC limitations for the intervention with disadvantaged populations in general
Targeted analysis of cell-free circulating tumor DNA is suitable for early relapse and actionable target detection in patients with neuroblastoma
PURPOSE: Treating refractory or relapsed neuroblastoma remains challenging. Monitoring body fluids for tumor-derived molecular information indicating minimal residual disease supports more frequent diagnostic surveillance and may have the power to detect resistant subclones before they give rise to relapses. If actionable targets are identified from liquid biopsies, targeted treatment options can be considered earlier. EXPERIMENTAL DESIGN: Droplet digital PCR assays assessing MYCN and ALK copy numbers and allelic frequencies of ALK p.F1174L and ALK p.R1275Q mutations were applied to longitudinally collected liquid biopsies and matched tumor tissue samples from 31 patients with high-risk neuroblastoma. Total cell-free DNA (cfDNA) levels and marker detection were compared with data from routine clinical diagnostics. RESULTS: Total cfDNA concentrations in blood plasma from patients with high-risk neuroblastoma were higher than in healthy controls and consistently correlated with neuron-specific enolase levels and lactate dehydrogenase activity but not with 123I-meta-iodobenzylguanidine scores at relapse diagnosis. Targeted cfDNA diagnostics proved superior for early relapse detection to all current diagnostics in two patients. Marker analysis in cfDNA indicated intratumor heterogeneity for cell clones harboring MYCN amplifications and druggable ALK alterations that were not detectable in matched tumor tissue samples in 17 patients from our cohort. Proof-of-concept is provided for molecular target detection in cerebrospinal fluid from patients with isolated CNS relapses. CONCLUSIONS: Tumor-specific alterations can be identified and monitored during disease course in liquid biopsies from pediatric patients with high-risk neuroblastoma. This approach to cfDNA surveillance warrants further prospective validation and exploitation for diagnostic purposes and to guide therapeutic decisions
Two and three nucleon induced photon absorption
We have investigated the mechanisms leading to two and three body photon absorption in nuclei. At photon energies around the pion production threshold we obtain a fraction of three body absorption of less than 10% of the total, contradicting previous theoretical claims that it dominates the absorption process. The strength of the three body channel grows smoothly with the photon energy reaching a maximum of about 60% of the total direct absorption at energies of the photon around 400 MeV