Production of long-lived activities in fusion materials

Neutron cross sections have been measured near 14 MeV for reactions leading to long-lived radioisotopes in fusion materials. Results are summarized for various reactions leading to /sup 26/Al (720,000 y), /sup 55/Fe (2.73 y), /sup 63/Ni (100 y), /sup 59/Ni (76,000 y), and /sup 94/Nb (20,300 y). New data are presented for the production of /sup 91/Nb (680 y) from /sup 92/Mo, and from /sup 93/Mo (3500 y) and /sup 93m/Nb (13.6 y) for /sup 94/Mo. Our measurements suggest that the half-life of /sup 91/Nb may be shorter (350 y) than previous estimates. Measured cross sections are used to predict the production of these isotopes for various fusion reactor designs. 20 refs., 4 tabs

Analysis of long-lived isotopes by liquid scintillation spectrometry

Neutron production cross sections are reported for reactions leading to long-lived isotopes in fusion reactor materials. Pure elements and separated isotopes were irradiated with 14.6 to 14.8 MeV neutron fluences up to 10 Y n/cmS. Undesired activities were chemically separated and the long-lived activities were measured using both liquid scintillation and x-ray spectrometry. Results are presented for the reactions VWFe(n,2n)VVFe (2.73 y), WUNi(n,2n)WTNi (100 y), WTCu(n,P)WTNi, and WNi(n,2n)VZNi (76,000 y)

Parenting through grief: A cross-sectional study of recently bereaved adults with minor children

Background: Grieving adults raising parentally-bereaved minor children experience persistently elevated symptoms of depression and grief. However, the factors associated with their mental health outcomes are not well understood. Aim: To investigate the psychosocial and demographic characteristics associated with grief distress and depressive symptom severity in bereaved adults with minor children. Design: Cross-sectional, web-based survey. Setting/participants: Eight hundred forty-five bereaved adults raising minor (age <18 years) children who had experienced the death of a co-parent. Primary outcomes were grief distress (Prolonged Grief Disorder-13), depressive symptoms (Patient-Reported Outcomes Measurement Information System-Depression), and widowed parenting self-efficacy (WPSES). Results: Mean grief scores were 33.5; mean depression scores were 58.3. Among the 690 individuals more than 6 months bereaved, 132 (19.3%) met criteria for prolonged grief disorder. In adjusted models, participants reporting higher grief scores were more recently bereaved, identified as mothers, non-Caucasian, had lower education and income, and had not anticipated their co-parent’s death. The statistical modeling results for depression scores were similar to grief scores except that depression was not associated with anticipation of co-parent death. Parents reporting lower WPSES scores had higher grief and depression scores. Retrospective assessments of more intense parenting worries at the time of co-parent death were also associated with higher grief and depression scores. Conclusions: For bereaved adults with minor children, unanticipated co-parent death was linked with higher grief distress but not symptoms of depression. Addressing parenting concerns may represent a common pathway for improving the mental health of parentally-bereaved families

Atlantic Behavioral Response Study: Experimental Design, Analytical Methods, and Preliminary Results

Excerpted from ESOMM - 2018, 6th International Meeting on the Effects of Sound in the Ocean on Marine Mammals The Hague, The Netherlands

The 44Ti(α, p) reaction and its implication on the 44Ti yield in supernovae

Cross sections for the 44Ti(α, p)47V reaction which significantly affects the yield of 44Ti in supernovae were measured in the energy range 5.7MeV ≤ Ec.m. ≤ 9 MeV, using a beam of radioactive 44Ti. The cross sections and the deduced astrophysical reaction rates are larger than the results from theoretical calculations by about a factor of 2. The implications of this increase in the reaction rate for the search of supernovae using space-based gamma detectors are discussed

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Measurement of long-lived isotopes in fusion materials

Neutron cross section measurements are reviewed for the production of long-lived isotopes in fusion reactor materials. Samples were irradiated at 14.5 to 14.8 MeV at the RTNSII facility. Long-lived reaction products were detected using gamma and x-ray spectroscopy, liquid scintillation spectrometry, and accelerator mass spectrometry. Radiochemical separations were performed for many samples prior to analysis. Results are summarized for reactions leading to /sup 26/Al (720,000 y), /sup 53/Mn (3,700,000 y), /sup 55/Fe (2.73 y), /sup 63/Ni (100 y), /sup 59/Ni (76,000 y), /sup 91/Nb (700 y), and /sup 94/Nb (20,300 y). 17 refs., 2 figs., 4 tabs

Analysis of IFR samples at ANL-E

The Analytical Chemistry Laboratory analyzes a variety of samples submitted by the different research groups within IFR. This talk describes the analytical work on samples generated by the Plutonium Electrorefiner, Large Scale Electrorefiner and Waste Treatment Studies. The majority of these samples contain Transuranics and necessitate facilities that safely contain these radioisotopes. Details such as: sample receiving, dissolution techniques, chemical separations, Instrumentation used, reporting of results are discussed. The Importance of Interactions between customer and analytical personnel Is also demonstrated

The production of sup 49 V, sup 93 Mo, sup 93m Nb and other long-lived isotopes in fusion materials with 14 MeV neutrons

Results are presented for measurements of neutron cross sections for the production of {sup 49}V (331 d) from vanadium and for {sup 93}Mo (3500 a) and {sup 93m}Nb (16 a) from natural and {sup 94}Mo-enriched molybdenum targets near 14 MeV. The targets were irradiated at the Rotating Target Neutron Source II to fluences up to 10{sup 18} n/cm{sup 2}. Radiochemical separations were performed to separate the desired nuclides from interferring activities. Activity measurements were then performed using x-ray counting techniques. Results are compared with calculations and the measured cross sections are used to predict the level of these activities in a first-wall fusion reactor material. Previous results are also reviewed for similar measurements of the production of {sup 55}Fe, {sup 63}Ni, {sup 59}Ni, {sup 94}Nb, and {sup 91}Nb. Comparisons with theoretical calculations suggest possible revisions of the halflives of {sup 59}Ni and {sup 91}Nb