Defying birth defects through diet?

The risk of certain birth defects can be modified by maternal diet. A high-fat maternal mouse diet has recently been reported to substantially increase the penetrance of birth defects known to be associated with a deficiency of transcription factor Cited2 as well as induce cleft palate. These effects were associated with a more than twofold reduction in embryonic expression of Pitx2c. This investigation suggests the need to further explore this provocative gene-diet interaction in human studies

Folic Acid Food Fortification—Its History, Effect, Concerns, and Future Directions

Periconceptional intake of folic acid is known to reduce a woman’s risk of having an infant affected by a neural tube birth defect (NTD). National programs to mandate fortification of food with folic acid have reduced the prevalence of NTDs worldwide. Uncertainty surrounding possible unintended consequences has led to concerns about higher folic acid intake and food fortification programs. This uncertainty emphasizes the need to continually monitor fortification programs for accurate measures of their effect and the ability to address concerns as they arise. This review highlights the history, effect, concerns, and future directions of folic acid food fortification programs

Flash-Heating of Circumstellar Clouds by Gamma Ray Bursts

The blast-wave model for gamma-ray bursts (GRBs) has been called into question by observations of spectra from GRBs that are harder than can be produced through optically thin synchrotron emission. If GRBs originate from the collapse of massive stars, then circumstellar clouds near burst sources will be illuminated by intense gamma radiation, and the electrons in these clouds will be rapidly scattered to energies as large as several hundred keV. Low-energy photons that subsequently pass through the hot plasma will be scattered to higher energies, hardening the intrisic spectrum. This effect resolves the "line-of-death" objection to the synchrotron shock model. Illuminated clouds near GRBs will form relativistic plasmas containing large numbers of electron-positron pairs that can be detected within ~ 1-2 days of the explosion before expanding and dissipating. Localized regions of pair annihilation radiation in the Galaxy would reveal past GRB explosions.Comment: 9 pages, 1 figure, submitted to ApJ Letter

Enhanced low-energy γ\gamma-decay strength of 70^{70}Ni and its robustness within the shell model

Neutron-capture reactions on very neutron-rich nuclei are essential for heavy-element nucleosynthesis through the rapid neutron-capture process, now shown to take place in neutron-star merger events. For these exotic nuclei, radiative neutron capture is extremely sensitive to their $\gamma$-emission probability at very low $\gamma$ energies. In this work, we present measurements of the $\gamma$-decay strength of $^{70}$Ni over the wide range $1.3 \leq E_{\gamma} \leq 8$ MeV. A significant enhancement is found in the $\gamma$-decay strength for transitions with $E_\gamma < 3$ MeV. At present, this is the most neutron-rich nucleus displaying this feature, proving that this phenomenon is not restricted to stable nuclei. We have performed $E1$-strength calculations within the quasiparticle time-blocking approximation, which describe our data above $E_\gamma \simeq 5$ MeV very well. Moreover, large-scale shell-model calculations indicate an $M1$ nature of the low-energy $\gamma$ strength. This turns out to be remarkably robust with respect to the choice of interaction, truncation and model space, and we predict its presence in the whole isotopic chain, in particular the neutron-rich $^{72,74,76}\mathrm{Ni}$.Comment: 9 pages, 9 figure

Emerging collectivity from the nuclear structure of Xe 132: Inelastic neutron scattering studies and shell-model calculations

Inelastic neutron scattering was used to study the low-lying nuclear structure of 132Xe. A comprehensive level scheme is presented, as well as new level lifetimes, multipole mixing ratios, branching ratios, and transition probabilities. Comparisons of these data as well as previously measured E2 strengths and g factors are made with new shell-model calculations for 132, 134, 136 Xe to explore the emergence of collectivity in the Xe isotopes with N<82 near the closed shell.This material is based upon work supported by the US National Science Foundation under Grant No. PHY-1606890. This research was also sponsored in part by the Australian Research Council under Grant No. DP17010167

Inelastic Neutron Scattering Studies of \u3csup\u3e76\u3c/sup\u3eGe and \u3csup\u3e76\u3c/sup\u3eSe: Relevance to Elevance to Neutrinoless Double-β Decay

Inelastic neutron scattering measurements were performed at the University of Kentucky Accelerator Laboratory on enriched 76Ge and 76Se scattering samples. From measurements at incident neutron energies from 2.0 to 4.0 MeV, many new levels were identified and characterized in each nucleus; level lifetimes, transition probabilities, multipole mixing ratios, and other properties were determined. In addition, γ-ray cross sections for the 76Ge(n,n′γ) reaction were measured at neutron energies up to 5.0 MeV, with the goal of determining the cross sections of γ rays in 2040-keV region, which corresponds to the region of interest in the neutrinoless double β decay of 76Ge. Gamma rays from the three strongest branches from the 3952-keV level were observed, but the previously reported 2041-keV γ ray was not. Population cross sections across the range of incident neutron energies were determined for the 3952-keV level, resulting in a cross section of ~0.1 mb for the 2041-keV branch using the previously determined branching ratios. Beyond this, the data from these experiments indicate that previously unreported γ rays from levels in 76Ge can be found in the 2039-keV region

Are Land-use Changes Reflected in Diets of Mourning Doves (Zenaida macroura) in Eastern South Dakota

Food habits of the mourning dove (Zenaida macroura) have been extensively studied in the southern United States (McClure 1943, Korschgen 1958, Carpenter 1971) and consist primarily of vegetable matter throughout their range (Beckwith 1959). Diet studies in several states have indicated agricultural crops, specifically corn and wheat, were the most readily consumed plant seeds (Korshgen 1958, Carpenter 1971). Similarities observed in diets of doves were dependent on the agricultural crops available within the area. For example, in Missouri, some seasonal variability was documented suggesting doves forage based on food availability as much as by food preference (Korschgen 1958). However, in the agriculturally dominated landscape of east central South Dakota (SD), the two most important food items for doves were green (Setaria viridis) and yellow foxtail (S. glauca; Van’t Hul and Jenks 1992)

NOTES: ARE LAND-USE CHANGES REFLECTED IN DIETS OF MOURNING DOVES (ZENAIDA MACROURA) IN EASTERN SOUTH DAKOTA

Food habits of the mourning dove (Zenaida macroura) have been extensively studied in the southern United States (McClure 1943, Korschgen 1958, Carpenter 1971) and consist primarily of vegetable matter throughout their range (Beckwith 1959). Diet studies in several states have indicated agricultural crops, specifically corn and wheat, were the most readily consumed plant seeds (Korshgen 1958, Carpenter 1971). Similarities observed in diets of doves were dependent on the agricultural crops available within the area. For example, in Missouri, some seasonal variability was documented suggesting doves forage based on food availability as much as by food preference (Korschgen 1958). However, in the agriculturally- dominated landscape of east central South Dakota (SD), the two most important food items for doves were green (Setaria viridis) and yellow foxtail (S. glauca; Van’t Hul and Jenks 1992). Large-scale land use changes have occurred in eastern South Dakota in the past few decades and several factors have contributed to increased grassland to cropland conversion (Wright and Wimberly 2013). Conversion of grasslands to agricultural crops has increased as demand for biofuels and commodity prices increased (Secchi and Babcock 2007, Searchinger et al. 2008, Fargione et al. 2009, Wright and Wimberly 2013). In east central South Dakota, corn and soybean plantings have increased from 2,400,000 ha in 1991 to 4,400,000 ha in 2013 (United States Department of Agriculture 2014). These significant land-use changes that have occurred in the intervening 20 years may influence mourning dove feeding habits. We compared mourning dove diet composition in Minnehaha County, South Dakota, USA, to those published 20 years earlier from a study conducted approximately 60 km north (Van’t Hul and Jenks 1992)

Nuclear Structure of \u3csup\u3e76\u3c/sup\u3eGe from Inelastic Neutron Scattering Measurements and Shell Model Calculations

The low-lying, low-spin levels of 76Ge were studied with the (n,n′γ) reaction. Gamma-ray excitation function measurements were performed at incident neutron energies from 1.6 to 3.7 MeV, and γ-ray angular distributions were measured at neutron energies of 3.0 and 3.5 MeV. From these measurements, level spins, level lifetimes, γ-ray intensities, and multipole mixing ratios were determined. No evidence for a number of previously placed levels was found. Below 3.3 MeV, many new levels were identified, and the level scheme was re-evaluated. The B(E2) values support low-lying band structure. The 2+ mixed-symmetry state has been identified for the first time. A comparison of the level characteristics with large-scale shell model calculations yielded excellent agreement

“No-Spin” States and Low-Lying Structures in \u3csup\u3e130\u3c/sup\u3eXe and \u3csup\u3e136\u3c/sup\u3eXe

Inelastic neutron scattering on solid 130XeF2 and 136XeF2 targets was utilized to populate excited levels in 130Xe and 136Xe. When calculating nuclear matrix elements vital to the understanding of double-beta decay, it is important to have a clear understanding of the low-lying level structure of both the parent and daughter nucleus. Of particular relevance to double-beta decay searches are the assignments of 0+ states. We show here that in the case of 130Xe there are several discrepancies in the adopted level structure. We found that one previous 0+ candidate level (1590 keV) can be ruled out and assigned two additional candidates (2223 and 2242 keV). In 136Xe we question the previous assignment of a 0+ level at 2582 keV. Excitation function and angular distribution measurements were utilized to make spin and parity assignments of levels and place new transitions