The Last of Us is a 2013 action-adventure game developed by Naughty Dog and published by Sony Computer Entertainment. Players control Joel, a smuggler tasked with escorting a teenage girl, Ellie, across a post-apocalyptic United States. The Last of Us is played from a third-person perspective. Players use firearms and improvised weapons and can use stealth to defend against hostile humans and cannibalistic creatures infected by a mutated fungus in the genus Cordyceps. In the online multiplayer mode, up to eight players engage in cooperative and competitive gameplay. Development of The Last of Us began in 2009, soon after the release of Naughty Dog's previous game, Uncharted 2: Among Thieves. For the first time in the company's history, Naughty Dog split into two teams; while one team developed Uncharted 3: Drake's Deception, the other half developed The Last of Us. The relationship between Joel and Ellie became the focus, with all other elements developed around it. Actors Troy Baker and Ashley Johnson portrayed...

Sir Hans Adolf Krebs, FRS (, German: [hans ˈʔaːdɔlf ˈkʁeːps] (listen); 25 August 1900 – 22 November 1981) was a German-born British biologist, physician and biochemist. He was a pioneer scientist in the study of cellular respiration, a biochemical process in living cells that extracts energy from food and oxygen and makes it available to drive the processes of life. He is best known for his discoveries of two important sequences of chemical reactions that take place in the cells of humans and many other organisms, namely the citric acid cycle and the urea cycle. The former, often eponymously known as the "Krebs cycle", is the key sequence of metabolic reactions that provides energy in the cells of humans and other oxygen-respiring organisms; and its discovery earned Krebs a Nobel Prize in Physiology or Medicine in 1953. With Hans Kornberg, he also discovered the glyoxylate cycle, which is a slight variation of the citric acid cycle found in plants, bacteria, protists...

A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products (ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host. Different types of organisms have different essential nutrients. Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts, to...

The Oxus treasure (Persian: گنجینه آمودریا) is a collection of about 180 surviving pieces of metalwork in gold and silver, most relatively small, and around 200 coins, from the Achaemenid Persian period which were found by the Oxus river about 1877–1880. The exact place and date of the find remain unclear, but is often proposed as being near Kobadiyan. It is likely that many other pieces from the hoard were melted down for bullion; early reports suggest there were originally some 1500 coins, and mention types of metalwork that are not among the surviving pieces. The metalwork is believed to date from the sixth to fourth centuries BC, but the coins show a greater range, with some of those believed to belong to the treasure coming from around 200 BC. The most likely origin for the treasure is that it belonged to a temple, where votive offerings were deposited over a long period. How it came to be deposited is unknown.As a group, the treasure is the most important survival of what was once an enormous production of Achaemenid work in precious metal. It displays a very wide range of quality of execution, with the many gold votive plaques mostly crudely executed, some perhaps...

In planetary astronomy, a centaur is a small Solar System body with either a perihelion or a semi-major axis between those of the outer planets (between Jupiter and Neptune). Centaurs generally have unstable orbits because they cross or have crossed the orbits of one or more of the giant planets; almost all their orbits have dynamic lifetimes of only a few million years, but there is one known centaur, 514107 Kaʻepaokaʻawela, which may be in a stable (though retrograde) orbit. Centaurs typically exhibit the characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. Observational bias toward large objects makes determination of the total centaur population difficult. Estimates for the number of centaurs in the Solar System more than 1 km in diameter range from as low as 44,000 to more than 10,000,000.The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory and the one used here, was 944 Hidalgo in 1920. However, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest confirmed centaur is 10199 Chariklo, which at...

In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from one neuron to another. Neurons are specialized to pass signals to individual target cells, and synapses are the means by which they do so. At a synapse, the plasma membrane of the signal-passing neuron (the presynaptic neuron) comes into close apposition with the membrane of the target (postsynaptic) cell. Both the presynaptic and postsynaptic sites contain extensive arrays of molecular machinery that link the two membranes together and carry out the signaling process. In many synapses, the presynaptic part is located on an axon and the postsynaptic part is located on a dendrite or soma. Astrocytes also exchange information with the synaptic neurons, responding to synaptic activity and, in turn, regulating neurotransmission. Synapses (at least chemical synapses) are stabilized in position by synaptic adhesion molecules (SAMs) projecting from both the pre- and post-synaptic neuron and sticking together where they...

Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to PPh3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists as relatively air stable, colorless crystals at room temperature. It dissolves in non-polar organic solvents such as benzene and diethyl ether. Preparation and structure Triphenylphosphine can be prepared in the laboratory by treatment of phosphorus trichloride with phenylmagnesium bromide or phenyllithium. The industrial synthesis involves the reaction between phosphorus trichloride, chlorobenzene, and sodium: PCl3 + 3 PhCl + 6 Na → PPh3 + 6 NaClTriphenylphosphine crystallizes in triclinic and monoclinic modification. In both cases, the molecule adopts a pyramidal structure with propeller-like arrangement of the three phenyl groups. ...

Social stratification refers to a society's categorization of its people into groups based on socioeconomic factors like wealth, income, race, education, ethnicity, gender, occupation, social status, or derived power (social and political). As such, stratification is the relative social position of persons within a social group, category, geographic region, or social unit.In modern Western societies, social stratification is typically defined in terms of three social classes: the upper class, the middle class, and the lower class; in turn, each class can be subdivided into the upper-stratum, the middle-stratum, and the lower stratum. Moreover, a social stratum can be formed upon the bases of kinship, clan, tribe, or caste, or all four. The categorization of people by social stratum occurs most clearly in complex state-based, polycentric, or feudal societies, the latter being based upon socio-economic relations among classes of nobility and classes of peasants. Whether social stratification first appeared in hunter-gatherer, tribal, and band societies or whether it began with agriculture and large-scale means of social exchange remains a matter of debate in the...

Infographics (a clipped compound of "information" and "graphics") are graphic visual representations of information, data, or knowledge intended to present information quickly and clearly. They can improve cognition by utilizing graphics to enhance the human visual system's ability to see patterns and trends. Similar pursuits are information visualization, data visualization, statistical graphics, information design, or information architecture. Infographics have evolved in recent years to be for mass communication, and thus are designed with fewer assumptions about the readers' knowledge base than other types of visualizations. Isotypes are an early example of infographics conveying information quickly and easily to the masses. Overview Infographics have been around for many years and recently the increase of the number of easy-to-use, free tools have made the creation of infographics available to a large segment of the population. Social media sites such as Facebook and Twitter have also allowed for individual infographics to be spread among many people around the world. Infographics are widely used in the age of short attention...