Hybrid and Perennial Tetraploid Ryegrasses Are at least as Productive and Persistent as Perennial Diploids in Dryland Conditions in Northern Tasmania

Perennial ryegrass Lolium perenne is the preferred grass for fertile conditions and high rainfall areas or those with irrigation. Persistence of ryegrass can become a problem in drier and warmer areas (Fraser 1994). Even in high rainfall areas of south eastern Australia receiving between 550 and 750 mm of annual rainfall, loss of perennial ryegrass within a few years from sowing is a common problem (Waller and Sale 2001). This work aimed to examine the ability of a range of lines and cultivars of ryegrass to produce and persist under dryland conditions and rotational grazing by sheep in northern Tasmania, Australia

A Common-Path Heterodyne Interferometer for Surface Profiling in Microelectronic Fabrication

We describe the design of a common-path heterodyne laser interferometer for the surface profiling of micron-sized photopatterned features during the microelectronic fabrication process. The common-path design of the interferometer’s reference and measurement arms effectively removes any path length difference in the measurement which can be attributed to the movement of the target surface. It is shown that repeated surface profiling during the ion milling process allows the difference in etch rates between the photoresist layer and the exposed portions of the underlying substrate layer to be monitored online. A prototype apparatus has been assembled and results demonstrating the usefulness of the device are reported. The surface profiles of both a photopatterned nickel–iron trench and an unmasked aluminum trench are measured and compared to those obtained using a stylus-based scanning profiler and an atomic force microscope

Individual Genetic Susceptibility

Risk estimates derived from epidemiological studies of exposed populations, as well as the maximum permissible doses allowed for occupational exposure and exposure of the public to ionizing radiation are all based on the assumption that the human population is uniform in its radiosensitivity, except for a small number of individuals, such as ATM homozygotes who are easily identified by their clinical symptoms. The hypothesis upon which this proposal is based is that the human population is not homogeneous in radiosensitiviry, but that radiosensitive sub-groups exist which are not easy to identify. These individuals would suffer an increased incidence of detrimental radiation effects, and distort the shape of the dose response relationship. The radiosensitivity of these groups depend on the expression levels of specific proteins. The plan was to investigate the effect of 3 relatively rare, high penetrate genes available in mice, namely Atm, mRad9 & Brca1. The purpose of radiation protection is to prevent! deterministic effects of clinical significance and limit stochastic effects to acceptable levels. We plan, therefore to compare with wild type animals the radiosensitivity of mice heterozygous for each of the genes mentioned above, as well as double heterozygotes for pairs of genes, using two biological endpoints: a) Ocular cataracts as an important and relevant deterministic effect, and b) Oncogenic transformation in cultured embryo fibroblasts, as a surrogate for carcinogenesis, the most relevant stochastic effect

Policy Point—Counterpoint: Do African American Athletes Have an Obligation to Fight Against Racial Injustice?

This policy point-counterpoint, authored by history Ph.D. candidates BJ Marach and J. Marcos Reynolds, frames black-athletic activism as a longstanding historical debate reaching back to the late 1800s. Both argue for the efficacy of such activism and ground their analysis in the “Revolt of the Black Athlete” of the late 1960s. From here they diverge. Marach contends that black athletes are under no obligation to protest racial injustice, while Reynolds concludes that their platform and position within the black community requires that they act

Mutual Information for Explainable Deep Learning of Multiscale Systems

Timely completion of design cycles for complex systems ranging from consumer electronics to hypersonic vehicles relies on rapid simulation-based prototyping. The latter typically involves high-dimensional spaces of possibly correlated control variables (CVs) and quantities of interest (QoIs) with non-Gaussian and possibly multimodal distributions. We develop a model-agnostic, moment-independent global sensitivity analysis (GSA) that relies on differential mutual information to rank the effects of CVs on QoIs. The data requirements of this information-theoretic approach to GSA are met by replacing computationally intensive components of the physics-based model with a deep neural network surrogate. Subsequently, the GSA is used to explain the network predictions, and the surrogate is deployed to close design loops. Viewed as an uncertainty quantification method for interrogating the surrogate, this framework is compatible with a wide variety of black-box models. We demonstrate that the surrogate-driven mutual information GSA provides useful and distinguishable rankings on two applications of interest in energy storage. Consequently, our information-theoretic GSA provides an "outer loop" for accelerated product design by identifying the most and least sensitive input directions and performing subsequent optimization over appropriately reduced parameter subspaces.Comment: 27 pages, 8 figures. Added additional example