A systematic review of grandparents’ influence on grandchildren’s cancer risk factors

Many lifestyle patterns are established when children are young. Research has focused on the potential role of parents as a risk factor for non communicable disease in children, but there is limited investigation of the role of other caregivers, such as grandparents. The aim of this review was to identify and synthesise evidence for any influence grandparents’ care practices may have on their grandchildren’s long term cancer risk factors. A systematic review was carried out with searches across four databases (MEDLINE, Embase, Web of Science, PsycINFO) as well as searches of reference lists and citing articles, and Google Scholar. Search terms were based on six areas of risk that family care could potentially influence–weight, diet, physical activity, tobacco, alcohol and sun exposure. All study designs were included, as were studies that provided an indication of the interaction of grandparents with their grandchildren. Studies were excluded if grandparents were primary caregivers and if children had serious health conditions. Study quality was assessed using National Institute for Health and Care Excellence checklists. Grandparent impact was categorised as beneficial, adverse, mixed or as having no impact. Due to study heterogeneity a meta-analysis was not possible. Qualitative studies underwent a thematic synthesis of their results. Results from all included studies indicated that there was a sufficient evidence base for weight, diet, physical activity and tobacco studies to draw conclusions about grandparents’ influence. One study examined alcohol and no studies examined sun exposure. Evidence indicated that, overall, grandparents had an adverse impact on their grandchildren’s cancer risk factors. The theoretical work in the included studies was limited. Theoretically underpinned interventions designed to reduce these risk factors must consider grandparents’ role, as well as parents’, and be evaluated robustly to inform the evidence base further

β and γ bands in N = 88 , 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory : vibrations, shape coexistence, and superdeformation

CITATION: Majola, S. N. T. et al. 2019. β and γ bands in N=88, 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory: Vibrations, shape coexistence, and superdeformation. Physical Review C, 100(4). doi:10.1103/PhysRevC.100.044324.The original publication is available at https://journals.aps.org/prc/A comprehensive systematic study is made for the collective β and γ bands in even-even isotopes with neutron numbers N = 88 to 92 and proton numbers Z = 62 (Sm) to 70 (Yb). Data, including excitation energies, B(E0) and B(E2) values, and branching ratios from previously published experiments are collated with new data presented for the first time in this study. The experimental data are compared to calculations using a five-dimensional collective Hamiltonian (5DCH) based on the covariant density functional theory (CDFT). A realistic potential in the quadrupole shape parameters V (β,γ ) is determined from potential energy surfaces (PES) calculated using the CDFT. The parameters of the 5DCH are fixed and contained within the CDFT. Overall, a satisfactory agreement is found between the data and the calculations. In line with the energy staggering S(I) of the levels in the 2γ + bands, the potential energy surfaces of the CDFT calculations indicate γ -soft shapes in the N = 88 nuclides, which become γ rigid for N = 90 and N = 92. The nature of the 02 + bands changes with atomic number. In the isotopes of Sm to Dy, they can be understood as β vibrations, but in the Er and Yb isotopes the 02 + bands have wave functions with large components in a triaxial superdeformed minimum. In the vicinity of 152Sm, the present calculations predict a soft potential in the β direction but do not find two coexisting minima. This is reminiscent of 152Sm exhibiting an X(5) behavior. The model also predicts that the 03 + bands are of two-phonon nature, having an energy twice that of the 02 + band. This is in contradiction with the data and implies that other excitation modes must be invoked to explain their origin.https://journals.aps.org/prc/abstract/10.1103/PhysRevC.100.044324Publisher’s versio

Compound-specific amino acid 15N-stable isotope probing for the quantification of biological nitrogen fixation in soils

Biological nitrogen fixation (BNF) performed by diazotrophs is vital to our understanding of ecosystem functions, as plant nitrogen (N) is commonly a limiting nutrient for primary productivity. However, significant limitations have remained in our knowledge of the controls and rates of this process, due to technical difficulties in directly quantifying nitrogen (N2) fixation rates. To address this, we developed a novel compound-specific 15N-stable isotope probing method involving analysis of acid hydrolysable soil amino acids (AAs) by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) for the quantification of BNF in soils. By analysing 15N-enriched AAs (as N-acetyl, O-isopropyl derivatives), this new approach aimed to provide greater specificity compared to existing methods, and to contribute previously unobtainable quantitative information on the capture and flow of N2 fixed in soils. Laboratory incubations using 15N2 gas were carried out on surface peat over 15 days to obtain quantitative measures of N2 fixation by the microbial community. Longer incubations with the addition of a glucose energy source significantly increased the level of 15N enrichment, i.e. N fixed. The enhanced detection limits of 15N-AAs by GC-C-IRMS, compared to bulk soil δ15N value determinations, was key to assessments of N2 fixation. Valuable insights into the assimilation pathway of the applied 15N2-substrate were revealed; for peat soils, 15N incorporation into glutamate dominated over other AAs