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🔗 Economics 🔗 Books

Basic Economics is a non-fiction book by American economist Thomas Sowell published by Basic Books in 2000. The original subtitle was A Citizen's Guide to the Economy, but from the third edition in 2007 on it was subtitled A Common Sense Guide to the Economy.

Basic Economics is focused on how societies create prosperity or poverty for their peoples by the way they organize their economies.

🔗 Psychology 🔗 Neuroscience 🔗 Physiology

The effects of stress on memory include interference with a person's capacity to encode memory and the ability to retrieve information. Stimuli, like stress, improved memory when it was related to learning the subject. During times of stress, the body reacts by secreting stress hormones into the bloodstream. Stress can cause acute and chronic changes in certain brain areas which can cause long-term damage. Over-secretion of stress hormones most frequently impairs long-term delayed recall memory, but can enhance short-term, immediate recall memory. This enhancement is particularly relative in emotional memory. In particular, the hippocampus, prefrontal cortex and the amygdala are affected. One class of stress hormone responsible for negatively affecting long-term, delayed recall memory is the glucocorticoids (GCs), the most notable of which is cortisol. Glucocorticoids facilitate and impair the actions of stress in the brain memory process. Cortisol is a known biomarker for stress. Under normal circumstances, the hippocampus regulates the production of cortisol through negative feedback because it has many receptors that are sensitive to these stress hormones. However, an excess of cortisol can impair the ability of the hippocampus to both encode and recall memories. These stress hormones are also hindering the hippocampus from receiving enough energy by diverting glucose levels to surrounding muscles.

Stress affects many memory functions and cognitive functioning of the brain. There are different levels of stress and the high levels can be intrinsic or extrinsic. Intrinsic stress level is triggered by a cognitive challenge whereas extrinsic can be triggered by a condition not related to a cognitive task. Intrinsic stress can be acutely and chronically experienced by a person. The varying effects of stress on performance or stress hormones are often compared to or known as "inverted-u" which induce areas in learning, memory and plasticity. Chronic stress can affect the brain structure and cognition.

Studies considered the effects of both intrinsic and extrinsic stress on memory functions, using for both of them Pavlovian conditioning and spatial learning. In regard to intrinsic memory functions, the study evaluated how stress affected memory functions that was triggered by a learning challenge. In regard to extrinsic stress, the study focused on stress that was not related to cognitive task but was elicited by other situations. The results determined that intrinsic stress was facilitated by memory consolidation process and extrinsic stress was determined to be heterogeneous in regard to memory consolidation. Researchers found that high stress conditions were a good representative of the effect that extrinsic stress can cause on memory functioning. It was also proven that extrinsic stress does affect spatial learning whereas acute extrinsic stress does not.

🔗 Russia 🔗 Norway 🔗 Holidays 🔗 Sweden 🔗 Ethnic groups 🔗 Finland 🔗 Norse history and culture

The Sámi National Day is an ethnic national day for the Sámi (Saami) people that falls on February 6, the date when the first Sámi congress was held in 1917 in Trondheim, Norway. The congress was the first time that Norwegian and Swedish Sámi came together across national borders to work on finding solutions to common problems.

In 1992 at the 15th Sámi Conference in Helsinki, Finland, a resolution was passed that Sámi National Day should be celebrated on February 6 to commemorate the first Sámi congress in 1917, that Sami National Day is for all Sámi, regardless of where they live, and on that day the Sámi flag should be flown and the Sámi anthem sung in the local Sámi language. The first time Sami National Day was celebrated was in 1993, when the International Year of Indigenous People was proclaimed open in Jokkmokk, Sweden by the United Nations.

Since then, celebrating the day has become increasingly popular. In Norway, it is compulsory for municipal administrative buildings to fly the Norwegian flag, and optionally also the Sami flag, on February 6. Particularly notable is the celebration in Norway's capital Oslo, where the bells in the highest tower of Oslo City Hall play the Sami national anthem as the flags are raised. Some larger places have taken to arranging festivities in the week around the Sami National Day. The National Day has been included in the almanacs published by the University of Helsinki since 2004. The Norwegian, Swedish, and Finnish authorities recommend general flagging on the day.

By coincidence, February 6 was also the date representatives of the Sámi of the Kola Peninsula gathered annually to meet with Russian bureaucrats to debate and decide on issues of relevance to them. This assembly, called the Kola Sobbar, has been dubbed the "first Sámi Parliament" by the researcher Johan Albert Kalstad. However, the founding of the Kola Sobbar did not influence the choice of the date for Sámi People's Day, as the assembly existed only during the late 1800s and was largely forgotten until the early 2000s.

🔗 Mathematics

Hilbert's twenty-fourth problem is a mathematical problem that was not published as part of the list of 23 problems known as Hilbert's problems but was included in David Hilbert's original notes. The problem asks for a criterion of simplicity in mathematical proofs and the development of a proof theory with the power to prove that a given proof is the simplest possible.

The 24th problem was rediscovered by German historian Rüdiger Thiele in 2000, noting that Hilbert did not include the 24th problem in the lecture presenting Hilbert's problems or any published texts. Hilbert's friends and fellow mathematicians Adolf Hurwitz and Hermann Minkowski were closely involved in the project but did not have any knowledge of this problem.

This is the full text from Hilbert's notes given in Rüdiger Thiele's paper. The section was translated by Rüdiger Thiele.

The 24th problem in my Paris lecture was to be: Criteria of simplicity, or proof of the greatest simplicity of certain proofs. Develop a theory of the method of proof in mathematics in general. Under a given set of conditions there can be but one simplest proof. Quite generally, if there are two proofs for a theorem, you must keep going until you have derived each from the other, or until it becomes quite evident what variant conditions (and aids) have been used in the two proofs. Given two routes, it is not right to take either of these two or to look for a third; it is necessary to investigate the area lying between the two routes. Attempts at judging the simplicity of a proof are in my examination of syzygies and syzygies [Hilbert misspelled the word syzygies] between syzygies (see Hilbert 42, lectures XXXII–XXXIX). The use or the knowledge of a syzygy simplifies in an essential way a proof that a certain identity is true. Because any process of addition [is] an application of the commutative law of addition etc. [and because] this always corresponds to geometric theorems or logical conclusions, one can count these [processes], and, for instance, in proving certain theorems of elementary geometry (the Pythagoras theorem, [theorems] on remarkable points of triangles), one can very well decide which of the proofs is the simplest. [Author's note: Part of the last sentence is not only barely legible in Hilbert's notebook but also grammatically incorrect. Corrections and insertions that Hilbert made in this entry show that he wrote down the problem in haste.]

🔗 Geography

The First Law of Geography, according to Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." This first law is the foundation of the fundamental concepts of spatial dependence and spatial autocorrelation and is utilized specifically for the inverse distance weighting method for spatial interpolation and to support the regionalized variable theory for kriging. It is a modern formulation of David Hume's principle of contiguity.

Tobler first presented his seminal idea during a meeting of the International Geographical Union's Commission on Qualitative Methods held in 1969 and later published by him in 1970. Though simple in its presentation, this idea is profound. Without it, "the full range of conditions anywhere on the Earth's surface could in principle be found packed within any small area. There would be no regions of approximately homogeneous conditions to be described by giving attributes to area objects. Topographic surfaces would vary chaotically, with slopes that were everywhere infinite, and the contours of such surfaces would be infinitely dense and contorted. Spatial analysis, and indeed life itself, would be impossible."

Less well known is his second law, which complements the first: "The phenomenon external to an area of interest affects what goes on inside".

🔗 Environment 🔗 Economics 🔗 Law 🔗 Anthropology 🔗 Sociology 🔗 Game theory

The tragedy of the anticommons is a type of coordination breakdown, in which a commons does not emerge, even when general access to resources or infrastructure would be a social good. It is a mirror-image of the older concept of tragedy of the commons, in which numerous rights holders' combined use exceeds the capacity of a resource and depletes or destroys it. The "tragedy of the anticommons" covers a range of coordination failures, including patent thickets and submarine patents. Overcoming these breakdowns can be difficult, but there are assorted means, including eminent domain, laches, patent pools, or other licensing organizations.

The term originally appeared in Michael Heller's 1998 article of the same name and is the thesis of his 2008 book. The model was formalized by James M. Buchanan and Yong Yoon. In a 1998 Science article, Heller and Rebecca S. Eisenberg, while not disputing the role of patents in general in motivating invention and disclosure, argue that biomedical research was one of several key areas where competing patent rights could actually prevent useful and affordable products from reaching the marketplace.

🔗 Computing 🔗 Systems 🔗 Engineering 🔗 Systems/Systems engineering

The purpose of a system is what it does (POSIWID) is a systems thinking heuristic coined by Stafford Beer, who observed that there is "no point in claiming that the purpose of a system is to do what it constantly fails to do." The term is widely used by systems theorists, and is generally invoked to counter the notion that the purpose of a system can be read from the intentions of those who design, operate, or promote it. When a system's side effects or unintended consequences reveal that its behavior is poorly understood, then the POSIWID perspective can balance political understandings of system behavior with a more straightforwardly descriptive view.

🔗 Computing

Logic Theorist is a computer program written in 1956 by Allen Newell, Herbert A. Simon and Cliff Shaw. It was the first program deliberately engineered to perform automated reasoning and is called "the first artificial intelligence program". It would eventually prove 38 of the first 52 theorems in Whitehead and Russell's Principia Mathematica, and find new and more elegant proofs for some.

🔗 London 🔗 Philately 🔗 Trains 🔗 Trains/UK Railways 🔗 London Transport

The London Pneumatic Despatch Company (also known as the London Pneumatic Dispatch Company) was formed on 30 June 1859, to design, build and operate an underground railway system for the carrying of mail, parcels and light freight between locations in London. The system was used between 1863 and 1874.

🔗 Economics 🔗 Lists

This is a list of some of the major unsolved problems, puzzles, or questions in economics. Some of these are theoretical in origin and some of them concern the inability of orthodox economic theory to explain an empirical observation.