Predicting trophic relations in ecological networks: a test of the Allometric Diet Breadth Model

Few of food web theory hypotheses/predictions can be readily tested using empirical data. An exception is represented by simple probabilistic models for food web structure, for which the likelihood has been derived. Here I test the performance of a more complex model for food web structure that is grounded in the allometric scaling of interactions with body size and the theory of optimal foraging (Allometric Diet Breadth Model - ADBM). This deterministic model has been evaluated measuring the fraction of trophic relations correctly predicted. I contrast this value with that produced by simpler models based on body sizes and find that the data does not favor the more complex model: the information on allometric scaling and optimal foraging does not significantly increase the fit to the data. Also, I take a different approach and compute the p-value for the fraction of trophic interactions correctly predicted by ADBM with respect to three probabilistic null models. I find that the ADBM is clearly better at predicting links than random graphs, but other models can do even better. Although optimal foraging and allometric scaling could improve our understanding of food webs, the models need to be ameliorated to find support in the data.Comment: 28 pages, 3 figures, 4 table

Fringe Groups and Their Beliefs in Conspiracies

My topic centers around the series of questions asked in the Chapman University Survey of American Fears on conspiracy theories and the degree to which Americans believe in them. The claims of such theories can range from strange, but ultimately harmless, such as the belief that the United States faked the Apollo 11 Moon Landing in 1969, to accusations with much serious implications such as the belief that the government is hiding information on the Las Vegas and/or Sandy Hook mass shootings. The latter recently made news with the biggest advocate of the “false flag shootings” belief, none other than living-meme, Alex Jones, being banned on nearly every media outlet within 24 hours. Though he had not encouraged such threats, some believers of the conspiracy harassed the parents of Newtown victims, and others. I want to find out what changes in the belief in conspiracy theories has occurred in the last few years, and hopefully create a hypothesis on why a change may have occurred. I will be using the Chapman University Survey of American Fears for my base data, along with books on the psychology behind belief in conspiracy theories. Ultimately, I want to see if there is a relationship between party affiliation/fringe groups and the belief in conspiracy theories. Finding which specific conspiracies certain groups believe will also give us insight into the mindset and ideas of that particular group. Fear of unemployment and fear of running out of money may also have a secondary effect on belief in such theories. My research paper will find and analyzes the data sets to support or not support my hypothesizes

Covid 19 & Qanon: Enter the World of Conspiracies

From Covid-19 to Qanon to a global warming hoax, we live in a world drowning in misinformation spread on the internet. Q-anonymous, a purposed government “leaker” is an alleged high-level government informant, according to Qanon followers, who posted cryptic messages about a satanic government on the now-defunct forum website, 8chan. This project will examine the possible relationship between a belief in various conspiracy theories associated with Qanon and how the Coronavirus affected rates of belief, utilizing the Chapman Survey of American Fears, a national study using a representative sample of U.S. adults. I expect to find that partisanship will play a large role in predicting rates of belief in Qanon. I believe I will find this relationship to be dependent on the nature of the conspiracy theories themselves. Conspiracy theories that stress governmental lies and secret groups of great control likely will likely have gained support in light of the Coronavirus outbreak and subsequent shutdowns. In this project, Questions on partisanship, Qanon and two COVID19 related conspiracy theories will be used to test for the aforementioned ideas. I expect believers in COVID19 related conspiracy theories to have a higher belief in the notion the government is hiding information about Qanon. With this project, I hope to identify the links between conspiracy theory belief, Qanon, and the Covid-19 virus in order to better understand public attitudes on the subject

Barriers to success: A technical review on the limits and possible future roles of small scale gasifiers

Literature and manuals refer to biomass gasification as one of the most efficient processes for power generation, highlighting features, such as residual biomass use, distributed generation and carbon sequestration, that perfectly incorporate gasification into circular economies and sustainable development goals. Despite these features, small scale applications struggle to succeed as a leading solution for sustainable development. The aim of this review is to investigate the existing technological barriers that limit the spreading of biomass gasification from a socio-technical point of view. The review outlines how existing technologies originated from under feed-in-tariff regimes and highlights where the current design goals strongly differ from what will be needed in the near future. Relevant market-ready small-scale gasification systems are analyzed under this lens, leading to an analysis of the reactor and filtration design. To help understand the economical sustainability of these plants, an analysis of the influence of capital expenditures and operating expenditures on the return of investment is included in the discussion. Finally, a literature review on prototypes and pre-market reactors is used as a basis for spotting the characteristics of the system that will likely resolve issues around fuel flexibility, cost efficiency and load variability

Reactivity and stability of large ecosystems

The study of local stability has a long tradition in community ecology. Stability describes whether an ecological system will eventually return to its original steady state after being perturbed. More recently, the study of the transient dynamics of ecological systems has been recognized as crucial, given that continuously disturbed systems might never reach a steady state, and thus the instantaneous response to perturbations could largely determine species persistence. A stable equilibrium can be nonreactive -- all perturbations decay immediately, or reactive -- some perturbations are initially amplified before decaying. Here we derive analytical criteria for the reactivity of large ecological systems in which species interact at random. We find that in large ecological systems both stability and reactivity are governed by the same quantities: number of species, means of the intra- and inter-specific interaction strengths, variance of inter-specific interactions, and the correlation of pairwise interactions. We identify two phase transitions, one from nonreactivity to reactivity and one from stability to instability. As reactivity is an intermediate state between nonreactivity and instability, it could be used to develop an early-warning signal for systems approaching instability