A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes which alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene.The steroid core structure is typically composed of seventeen carbon atoms, bonded in four "fused" rings: three six-member cyclohexane rings (rings A, B and C in the first illustration) and one five-member cyclopentane ring (the D ring). Steroids vary by the functional groups attached to this four-ring core and by the oxidation state of the rings. Sterols are forms of steroids with a hydroxy group at position three and a skeleton derived from cholestane.: 1785f Steroids can also be more radically modified, such as by changes to the ring structure, for example, cutting one of the rings. Cutting Ring B produces secosteroids one of which is vitamin D3.
Examples include the lipid cholesterol, the sex hormones estradiol and testosterone,: 10–19 and the anti-inflammatory drug dexamethasone.Affect may refer to:
Affect (education)
Affect (linguistics), attitude or emotion that a speaker brings to an utterance
Affect (philosophy)
Affect (psychology), the experience of feeling or emotion
Affect display, signs of emotion, such as facial expression, vocalization, and posture
Affect theory
Affective science, the scientific study of emotion
Affective computing, an area of research in computer science aiming to understand the emotional state of users
Reduced affect display, a.k.a. emotional blunting or affective flattening, a reduction in emotional reactivity
Pseudobulbar affect, a.k.a. labile affect, the unstable display of emotion
Affect (rhetoric), the responsive, emotional feeling that precedes cognition
Affected accent; see Accent (sociolinguistics)
Affect (company), a defunct Japanese video game developerAn economy (from Ancient Greek οἰκονομία (oikonomía) 'management of a household, administration'; from οἶκος (oîkos) 'household', and νέμω (némō) 'distribute, allocate') is an area of the production, distribution and trade, as well as consumption of goods and services by different agents. In general, it is defined 'as a social domain that emphasize the practices, discourses, and material expressions associated with the production, use, and management of resources'. A given economy is a set of processes that involves its culture, values, education, technological evolution, history, social organization, political structure and legal systems, as well as its geography, natural resource endowment, and ecology, as main factors. These factors give context, content, and set the conditions and parameters in which an economy functions. In other words, the economic domain is a social domain of interrelated human practices and transactions that does not stand alone.
Economic agents can be individuals, businesses, organizations, or governments. Economic transactions occur when two groups or parties agree to the value or price of the transacted good or service, commonly expressed in a certain currency. However, monetary transactions only account for a small part of the economic domain.
Economic activity is spurred by production which uses natural resources, labor and capital. It has changed over time due to technology, innovation (new products, services, processes, expanding markets, diversification of markets, niche markets, increases revenue functions) such as, that which produces intellectual property and changes in industrial relations (most notably child labor being replaced in some parts of the world with universal access to education).
A market-based economy is one where goods and services are produced and exchanged according to demand and supply between participants (economic agents) by barter or a medium of exchange with a credit or debit value accepted within the network, such as a unit of currency. A command-based economy is one where political agents directly control what is produced and how it is sold and distributed. A green economy is low-carbon, resource efficient and socially inclusive. In a green economy, growth in income and employment is driven by public and private investments that reduce carbon emissions and pollution, enhance energy and resource efficiency, and prevent the loss of biodiversity and ecosystem services. A gig economy is one in which short-term jobs are assigned or chosen via online platforms. New economy is a term that referred to the whole emerging ecosystem where new standards and practices were introduced, usually as a result of technological innovations. The global economy refers to humanity's economic system or systems overall.