A selectivity theory is proposed to help explain how one gender of a species might tend to evolve with greater variability than the other gender. Briefly, the theory says that if one sex is relatively selective, then more variable subpopulations of the opposite sex will tend to prevail over those with lesser variability; and conversely, if one sex is relatively non-selective, then less variable subpopulations of the opposite sex will tend to prevail over those with greater variability. This theory makes no assumptions about differences in means between the sexes, nor does it presume that one sex is selective and the other non-selective. Two mathematical models are presented: a statistical analysis using normally distributed fitness values, and a deterministic analysis using a standard system of coupled ordinary differential equations with exponentially distributed fitness levels. The theory is applied to the classical greater male variability hypothesis.
Some Americans cling desperately to the myth that we are living in a post-racial society, that the election of the first Black president spelled the doom of racism. In fact, racist thought is alive and well in America--more sophisticated and more insidious than ever. And as award-winning historian Ibram X. Kendi argues in Stamped from the Beginning, if we have any hope of grappling with this stark reality, we must first understand how racist ideas were developed, disseminated, and enshrined in American society.
In this deeply researched and fast-moving narrative, Kendi chronicles the entire story of anti-Black racist ideas and their staggering power over the course of American history. Stamped from the Beginning uses the life stories of five major American intellectuals to offer a window into the contentious debates between assimilationists and segregationists and between racists and antiracists. From Puritan minister Cotton Mather to Thomas Jefferson, from fiery abolitionist William Lloyd Garrison to brilliant scholar W.E.B. Du Bois to legendary anti-prison activist Angela Davis, Kendi shows how and why some of our leading proslavery and pro-civil rights thinkers have challenged or helped cement racist ideas in America.
Contrary to popular conceptions, racist ideas did not arise from ignorance or hatred. Instead, they were devised and honed by some of the most brilliant minds of each era. These intellectuals used their brilliance to justify and rationalize deeply entrenched discriminatory policies and the nation's racial disparities in everything from wealth to health. And while racist ideas are easily produced and easily consumed, they can also be discredited. In shedding much-needed light on the murky history of racist ideas, Stamped from the Beginning offers us the tools we need to expose them--and in the process, gives us reason to hope.
I provide a (very) brief introduction to game theory. I have developed these notes to provide quick access to some of the basics of game theory; mainly as an aid for students in courses in which I assumed familiarity with game theory but did not require it as a prerequisite.
This is a collection of introductory, expository notes on applied category theory, inspired by the 2018 Applied Category Theory Workshop, and in these notes we take a leisurely stroll through two themes (functorial semantics and compositionality), two constructions (monoidal categories and decorated cospans) and two examples (chemical reaction networks and natural language processing) within the field. [PDF]
Friends! I am so happy to share that my little booklet “What is Applied Category Theory?” is now available on the arXiv. It’s a collection of introductory, expository notes inspired by the ACT workshop that took place earlier this year. Enjoy! https://t.co/EPYP19z14x pic.twitter.com/O4uVhj401s
— Tai-Danae Bradley (@math3ma) September 18, 2018
See also Notes on Applied Category Theory
This bridge tool matches you with your friends in the decentralized Mastodon network
Une instance mastodon personnelle ouverte pour explorations d'interface-utilisateur admin avant d'envisager des usages de famille.
This Mastodon instance hosted by masto.host was installed on September 12, 2018. During installation, it will be accessible on request to all french indieweb members and all users who have joined the #indieweb channel at jamstatic. The working language will be French. The setting is in progress.
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WPCampus 2018 was held July 12-14, 2018, at Washington University in St. Louis, Missouri. Educators, staff, and those in higher-education gathered to learn how WordPress can be and is used in highe…
Definitions of words that you come in contact with when you use WordPress.
A Micropub browser extension. Contribute to keithjgrant/omnibear development by creating an account on GitHub.
WordCamp for Publishers 2018 Videos Now Available on WordPress.tv
Listen to free MIDI songs, download the best MIDI files, and share the best MIDIs on the web.
Original source of Erdős–Rényi model.
In the mathematical field of graph theory, the Erdős–Rényi model is either of two closely related models for generating random graphs. They are named after mathematicians Paul Erdős and Alfréd Rényi, who first introduced one of the models in 1959, while Edgar Gilbert introduced the other model contemporaneously and independently of Erdős and Rényi. In the model of Erdős and Rényi, all graphs on a fixed vertex set with a fixed number of edges are equally likely; in the model introduced by Gilbert, each edge has a fixed probability of being present or absent, independently of the other edges. These models can be used in the probabilistic method to prove the existence of graphs satisfying various properties, or to provide a rigorous definition of what it means for a property to hold for almost all graphs.
Networks of coupled dynamical systems have been used to model biological oscillators1–4, Josephson junction arrays5,6, excitable media7, neural networks8–10, spatial games11, genetic control networks12 and many other self-organizing systems. Ordinarily, the connection topology is assumed to be either completely regular or completely random. But many biological, technological and social networks lie somewhere between these two extremes. Here we explore simple models of networks that can be tuned through this middle ground: regular networks ‘rewired’ to introduce increasing amounts of disorder. We find that these systems can be highly clustered, like regular lattices, yet have small characteristic path lengths, like random graphs. We call them ‘small-world’ networks, by analogy with the small-world phenomenon13,14 (popularly known as six degrees of separation15). The neural network of the worm Caenorhabditis elegans, the power grid of the western United States, and the collaboration graph of film actors are shown to be small-world networks. Models of dynamical systems with small-world coupling display enhanced signal-propagation speed, computational power, and synchronizability. In particular, infectious diseases spread more easily in small-world networks than in regular lattices.