How Sustainable is Organic Agriculture?

Dan Anderson - UIUC Dept. of Natural Resources and Environmental Sciences. For some time now, organic food has been one of the fastest growing segments of the food industry, growing at a rate of about 20% annually for the last 10 years. Those who purchase organic food do so for a variety of reasons - flavor, health, environmental and social. Critics claim that organic food is for an elite, high-income customer base, willing to spend more for food they falsely believe is better. Furthermore, critics claim that organic farming is not productive enough to meet the growing food challenges of a 6 billion plus world population. They also contend there is no evidence that organic food is healthier than food produced by conventional, chemical-intensive methods. Recent research provides evidence that organic food is healthier and that organic farming is often as productive as conventional farming. This presentation will explore how sustainable organic and natural farming methods are for farmer, consumers and the environment

How Algorithmic Confounding in Recommendation Systems Increases Homogeneity and Decreases Utility

Recommendation systems are ubiquitous and impact many domains; they have the potential to influence product consumption, individuals' perceptions of the world, and life-altering decisions. These systems are often evaluated or trained with data from users already exposed to algorithmic recommendations; this creates a pernicious feedback loop. Using simulations, we demonstrate how using data confounded in this way homogenizes user behavior without increasing utility

Nonlinear Bessel beams

The effect of the Kerr nonlinearity on linear non-diffractive Bessel beams is investigated analytically and numerically using the nonlinear Schr\"odinger equation. The nonlinearity is shown to primarily affect the central parts of the Bessel beam, giving rise to radial compression or decompression depending on whether the nonlinearity is focusing or defocusing, respectively. The dynamical properties of Gaussian-truncated Bessel beams are also analysed in the presence of a Kerr nonlinearity. It is found that although a condition for width balance in the root-mean-square sense exists, the beam profile becomes strongly deformed during propagation and may exhibit the phenomena of global and partial collapse.Comment: 15 pages, 7 figure

Buk bilong Pikinini Literacy Program Evaluation 2018: Evaluation Report

Buk bilong Pikinini (BbP) provides access to early childhood education and care (ECEC) programs with a specific focus on English language literacy for children from vulnerable communities in Papua New Guinea. This is highly relevant, given the fact that there is likely an over-representation of illiteracy in disadvantaged households and few opportunities for children within those households to be ready for a school system with English as the language of instruction. Established in 2007, BbP has been in operation for more than 10 years and has opened 17 library sites in that time. This evaluation provides evidence about the likely effectiveness of the programs relative to best practice and in the early childhood and school policy and program delivery context of PNG. The major methods used were literature review and critical review of BbP documentation, and stakeholder consultations, semi-structured interviews and observations of classrooms

Epidemic Variability in Hierarchical Geographical Networks with Human Activity Patterns

Recently, some studies have revealed that non-Poissonian statistics of human behaviors stem from the hierarchical geographical network structure. On this view, we focus on epidemic spreading in the hierarchical geographical networks, and study how two distinct contact patterns (i. e., homogeneous time delay (HOTD) and heterogeneous time delay (HETD) associated with geographical distance) influence the spreading speed and the variability of outbreaks. We find that, compared with HOTD and null model, correlations between time delay and network hierarchy in HETD remarkably slow down epidemic spreading, and result in a upward cascading multi-modal phenomenon. Proportionately, the variability of outbreaks in HETD has the lower value, but several comparable peaks for a long time, which makes the long-term prediction of epidemic spreading hard. When a seed (i. e., the initial infected node) is from the high layers of networks, epidemic spreading is remarkably promoted. Interestingly, distinct trends of variabilities in two contact patterns emerge: high-layer seeds in HOTD result in the lower variabilities, the case of HETD is opposite. More importantly, the variabilities of high-layer seeds in HETD are much greater than that in HOTD, which implies the unpredictability of epidemic spreading in hierarchical geographical networks

The Relation of Thermal Fluctuation and Information-Entropy for One-Dimensional Rindler Oscillator

Within the framework of thermo-field-dynamics (TFD), the information-entropies associated with the measurements of position and momentum for one-dimensional Rindler oscillator are derived, and the connection between its information-entropy and thermal fluctuation is obtained. A conclusion is drawn that the thermal fluctuation leads to the loss of information.Comment: 14 pages, 1 figur

Integrability and Conservation Laws for the Nonlinear Evolution Equations of Partially Coherent Waves in Noninstantaneous Kerr Media

It is shown that the evolution equations describing partially coherent wave propagation in noninstantaneous Kerr media are integrable and have an infinite number of invariants. A recursion relation for generating these invariants is presented, and it is demonstrated how to express them in the coherent density, self-consistent multimode, mutual coherence, and Wigner formalisms