We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60$\to$–70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.

The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

Drawing on a landscape analysis of existing data-sharing initiatives, in-depth interviews with expert stakeholders, and public deliberations with community advisory panels across the U.S., we describe features of the evolving medical information commons (MIC). We identify participant-centricity and trustworthiness as the most important features of an MIC and discuss the implications for those seeking to create a sustainable, useful, and widely available collection of linked resources for research and other purposes.

SNP in the vitamin D receptor (VDR) gene is associated with risk of lower respiratory infections. The influence of genetic variation in the vitamin D pathway resulting in susceptibility to upper respiratory infections (URI) has not been investigated. We evaluated the influence of thirty-three SNP in eleven vitamin D pathway genes (DBP, DHCR7, RXRA, CYP2R1, CYP27B1, CYP24A1, CYP3A4, CYP27A1, LRP2, CUBN and VDR) resulting in URI risk in 725 adults in London, UK, using an additive model with adjustment for potential confounders and correction for multiple comparisons. Significant associations in this cohort were investigated in a validation cohort of 737 children in Manchester, UK. In all, three SNP in VDR (rs4334089, rs11568820 and rs7970314) and one SNP in CYP3A4 (rs2740574) were associated with risk of URI in the discovery cohort after adjusting for potential confounders and correcting for multiple comparisons (adjusted incidence rate ratio per additional minor allele ≥1·15, Pfor trend ≤0·030). This association was replicated for rs4334089 in the validation cohort (Pfor trend=0·048) but not for rs11568820, rs7970314 or rs2740574. Carriage of the minor allele of the rs4334089 SNP in VDR was associated with increased susceptibility to URI in children and adult cohorts in the United Kingdom.

Objectives: Relatively few studies have investigated relationships between performance on clinical memory measures and indexes of underlying neuropathology related to Alzheimer’s disease (AD). This study investigated predictive relationships between Free and Cued Selective Reminding Test (FCSRT) cue efficiency (CE) and free-recall (FR) measures and brain amyloid levels, hippocampal volume (HV), and regional cortical thickness. Methods: Thirty-one older controls without memory complaints and 60 patients presenting memory complaints underwent the FCSRT, amyloid imaging using [F18]-flutemetamol positron emission tomography, and surface-based morphometry (SBM) using brain magnetic resonance imaging. Three groups were considered: patients with high (Aβ+P) and low (Aβ− P) amyloid load and controls with low amyloid load (Aβ− C). Results: Aβ+P showed lower CE than both Aβ− groups, but the Aβ− groups did not differ significantly. In contrast, FR discriminated all groups. SBM analyses revealed that CE indexes were correlated with the cortical thickness of a wider set of left-lateralized temporal and parietal regions than FR. Regression analyses demonstrated that amyloid load and left HV independently predicted FCSRT scores. Moreover, CE indexes were predicted by the cortical thickness of some regions involved in early AD, such as the entorhinal cortex. Conclusions: Compared to FR measures, CE indexes appear to be more specific for differentiating persons on the basis of amyloid load. Both CE and FR performance were predicted independently by brain amyloid load and reduced left HV. However, CE performance was also predicted by the cortical thickness of regions known to be atrophic early in AD. (JINS, 2016, 22, 991–1004)

A mixed integer linear programming model was developed to simulate the decision environment faced by an entry-level vegetable producer contemplating production for the whole-sale market. The model included activities which permitted consideration of 13 vegetable crops within a spring, summer, and fall rotational system. Rotations were permitted within given bounds established by marketing, rotational, and price risk constraints. Rotations were generally stable with respect to markets and relative to crop mixes as target income and acceptable negative deviation levels were varied. Spring and fall broccoli and turnip greens and late spring-summer yellow and zucchini squash were dominant crops in the triple crop rotations in the Atlanta and Cincinnati markets.

The public health burden of alcohol is unevenly distributed across the life course, with levels of use, abuse, and dependence increasing across adolescence and peaking in early adulthood. Here, we leverage this temporal patterning to search for common genetic variants predicting developmental trajectories of alcohol consumption. Comparable psychiatric evaluations measuring alcohol consumption were collected in three longitudinal community samples (N = 2,126, obs = 12,166). Consumption-repeated measurements spanning adolescence and early adulthood were analyzed using linear mixed models, estimating individual consumption trajectories, which were then tested for association with Illumina 660W-Quad genotype data (866,099 SNPs after imputation and QC). Association results were combined across samples using standard meta-analysis methods. Four meta-analysis associations satisfied our pre-determined genome-wide significance criterion (FDR < 0.1) and six others met our ‘suggestive’ criterion (FDR <0.2). Genome-wide significant associations were highly biological plausible, including associations within GABA transporter 1, SLC6A1 (solute carrier family 6, member 1), and exonic hits in LOC100129340 (mitofusin-1-like). Pathway analyses elaborated single marker results, indicating significant enriched associations to intuitive biological mechanisms, including neurotransmission, xenobiotic pharmacodynamics, and nuclear hormone receptors (NHR). These findings underscore the value of combining longitudinal behavioral data and genome-wide genotype information in order to study developmental patterns and improve statistical power in genomic studies.

Agricultural economics occupies an unique position in most agriculture programs because it and rural sociology are the only social sciences among a broad array of plant, animal, and technical disciplines. As economic and technological changes have added to the complexity, of U.S. agriculture, the relative importance of agricultural economics has increased. The demand for individuals possessing knowledge of the technical aspects of agriculture and the ability to evaluate the social and economic ramifications of alternatives is increasing.