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πŸ”— The Cuckoo's Egg

πŸ”— Espionage πŸ”— Books πŸ”— Computer Security πŸ”— Computer Security/Computing

The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage is a 1989 book written by Clifford Stoll. It is his first-person account of the hunt for a computer hacker who broke into a computer at the Lawrence Berkeley National Laboratory (LBNL).

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πŸ”— Heslington Brain

πŸ”— Anthropology πŸ”— Archaeology πŸ”— Yorkshire

The Heslington Brain is a 2,600-year-old human brain found inside a skull buried in a pit in Heslington, Yorkshire, in England, by York Archaeological Trust in 2008. It is the oldest preserved brain ever found in Eurasia, and is believed to be the best-preserved ancient brain in the world. The skull was discovered during an archaeological dig commissioned by the University of York on the site of its new campus on the outskirts of the city of York. The area was found to have been the site of well-developed permanent habitation between 2,000–3,000 years before the present day.

A number of possibly ritualistic objects were found to have been deposited in several pits, including the skull, which had belonged to a man probably in his 30s. He had been hanged before being decapitated with a knife and his skull appears to have been buried immediately. The rest of the body was missing. Although it is not known why he was killed, it is possible that it may have been a human sacrifice or ritual murder.

The brain was found while the skull was being cleaned. It had survived despite the rest of the tissue on the skull having disappeared long ago. After being extracted at York Hospital, the brain was subjected to a range of medical and forensic examinations by York Archaeological Trust which found that it was remarkably intact, though it had shrunk to only about 20% of its original size. It showed few signs of decay, though most of its original material had been replaced by an as yet unidentified organic compound, due to chemical changes during burial.

According to the archaeologists and scientists who have examined it, the brain has a "resilient, tofu-like texture". It is not clear why the Heslington brain survived, although the presence of a wet, anoxic environment underground seems to have been an essential factor, and research is still ongoing to shed light on how the local soil conditions may have contributed to its preservation.

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πŸ”— Peer-to-Peer Insurance

πŸ”— Finance & Investment

Peer-to-peer insurance is a reciprocity insurance contract through the Collaborative consumption concept.

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πŸ”— ItΓ΄ Calculus

πŸ”— Mathematics πŸ”— Statistics

ItΓ΄ calculus, named after Kiyosi ItΓ΄, extends the methods of calculus to stochastic processes such as Brownian motion (see Wiener process). It has important applications in mathematical finance and stochastic differential equations.

The central concept is the ItΓ΄ stochastic integral, a stochastic generalization of the Riemann–Stieltjes integral in analysis. The integrands and the integrators are now stochastic processes:

Y t = ∫ 0 t H s d X s , {\displaystyle Y_{t}=\int _{0}^{t}H_{s}\,dX_{s},}

where H is a locally square-integrable process adapted to the filtration generated by X (Revuz & Yor 1999, Chapter IV), which is a Brownian motion or, more generally, a semimartingale. The result of the integration is then another stochastic process. Concretely, the integral from 0 to any particular t is a random variable, defined as a limit of a certain sequence of random variables. The paths of Brownian motion fail to satisfy the requirements to be able to apply the standard techniques of calculus. So with the integrand a stochastic process, the ItΓ΄ stochastic integral amounts to an integral with respect to a function which is not differentiable at any point and has infinite variation over every time interval. The main insight is that the integral can be defined as long as the integrand H is adapted, which loosely speaking means that its value at time t can only depend on information available up until this time. Roughly speaking, one chooses a sequence of partitions of the interval from 0 to t and constructs Riemann sums. Every time we are computing a Riemann sum, we are using a particular instantiation of the integrator. It is crucial which point in each of the small intervals is used to compute the value of the function. The limit then is taken in probability as the mesh of the partition is going to zero. Numerous technical details have to be taken care of to show that this limit exists and is independent of the particular sequence of partitions. Typically, the left end of the interval is used.

Important results of ItΓ΄ calculus include the integration by parts formula and ItΓ΄'s lemma, which is a change of variables formula. These differ from the formulas of standard calculus, due to quadratic variation terms.

In mathematical finance, the described evaluation strategy of the integral is conceptualized as that we are first deciding what to do, then observing the change in the prices. The integrand is how much stock we hold, the integrator represents the movement of the prices, and the integral is how much money we have in total including what our stock is worth, at any given moment. The prices of stocks and other traded financial assets can be modeled by stochastic processes such as Brownian motion or, more often, geometric Brownian motion (see Black–Scholes). Then, the ItΓ΄ stochastic integral represents the payoff of a continuous-time trading strategy consisting of holding an amount Ht of the stock at time t. In this situation, the condition that H is adapted corresponds to the necessary restriction that the trading strategy can only make use of the available information at any time. This prevents the possibility of unlimited gains through clairvoyance: buying the stock just before each uptick in the market and selling before each downtick. Similarly, the condition that H is adapted implies that the stochastic integral will not diverge when calculated as a limit of Riemann sums (Revuz & Yor 1999, Chapter IV).

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πŸ”— Hy

πŸ”— Computing πŸ”— Computer science πŸ”— Computing/Software

Hy (alternately, Hylang) is a programming language, a dialect of the language Lisp designed to interact with the language Python by translating expressions into Python's abstract syntax tree (AST). Hy was introduced at Python Conference (PyCon) 2013 by Paul Tagliamonte.

Similar to Kawa's and Clojure's mapping of s-expressions onto the Java virtual machine (JVM), Hy is meant to operate as a transparent Lisp front end to Python's abstract syntax. Lisp allows operating on code as data (metaprogramming). Thus, Hy can be used to write domain-specific languages. Hy also allows Python libraries, including the standard library, to be imported and accessed alongside Hy code with a compiling step converting the data structure of both into Python's AST.

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  • "Hy" | 2019-08-04 | 850 Upvotes 141 Comments
  • "Hy" | 2016-11-07 | 70 Upvotes 5 Comments

πŸ”— Inverted totalitarianism

πŸ”— United States πŸ”— Politics

The political philosopher Sheldon Wolin coined the term inverted totalitarianism in 2003 to describe what he saw as the emerging form of government of the United States. Wolin analysed the United States as increasingly turning into a managed democracy (similar to an illiberal democracy). He uses the term "inverted totalitarianism" to draw attention to the totalitarian aspects of the American political system while emphasizing its differences from proper totalitarianism, such as Nazi and Stalinist regimes.

The book Days of Destruction, Days of Revolt (2012) by Chris Hedges and Joe Sacco portrays inverted totalitarianism as a system where corporations have corrupted and subverted democracy and where economics bests politics. Every natural resource and living being is commodified and exploited by large corporations to the point of collapse as excess consumerism and sensationalism lull and manipulate the citizenry into surrendering their liberties and their participation in government.

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πŸ”— Someone should add a column to this Wikipedia page about Y-Combinator StartUps: Status

πŸ”— California πŸ”— Companies πŸ”— Technology πŸ”— Private Equity πŸ”— California/San Francisco Bay Area

YΒ Combinator is an American seed accelerator launched in March 2005 and has been used to launch over 2,000 companies including Stripe, Airbnb, Cruise Automation, DoorDash, Coinbase, Instacart, and Dropbox. The combined valuation of the top YC companies was over $155Β billion as of October, 2019.

πŸ”— Ronald Read – Philanthropist, investor, janitor, and gas station attendant

πŸ”— United States πŸ”— Biography πŸ”— Military history πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— United States/Military history - U.S. military history πŸ”— Military history/Military biography πŸ”— Biography/military biography πŸ”— Military history/World War II πŸ”— United States/Vermont

Ronald James Read (October 23, 1921 – June 2, 2014) was an American philanthropist, investor, janitor, and gas station attendant. Read grew up in Dummerston, Vermont, in an impoverished farming household. He walked or hitchhiked 4Β mi (6.4Β km) daily to his high school and was the first high school graduate in his family. He enlisted in the United States Army during World War II, serving in Italy as a military policeman. Upon an honorable discharge from the military in 1945, Read returned to Brattleboro, Vermont, where he worked as a gas station attendant and mechanic for about 25 years. Read retired for one year and then took a part-time janitor job at J. C. Penney where he worked for 17 years until 1997.

Read died in 2014. He received media coverage in numerous newspapers and magazines after bequeathing US$1.2 million to Brooks Memorial Library and $4.8 million to Brattleboro Memorial Hospital. Read amassed a fortune of almost $8 million by investing in dividend-producing stocks, avoiding the stocks of companies he did not understand such as technology companies, living frugally, and being a buy and hold investor in a diversified portfolio of stocks with a heavy concentration in blue chip companies.

πŸ”— Skid Row

πŸ”— California πŸ”— California/Los Angeles area

Skid Row is a neighborhood in Downtown Los Angeles. The area is also known as Central City East.

As of a 2019 count, the population of the district was 4,757. Skid Row contains one of the largest stable populations (about 2,783) of homeless people in the United States and has been known for its condensed homeless population since the 1930s. Its long history of police raids, targeted city initiatives, and homelessness advocacy make it one of the most notable districts in Los Angeles.

Covering fifty city blocks (2.71 sq mi) immediately east of downtown Los Angeles, Skid Row is bordered by Third Street to the north, Seventh Street to the south, Alameda Street to the east, and Main Street to the west.

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