Freshwater ecosystemFreshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands. They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and vegetation. There are three basic types of freshwater ecosystems: Lentic (slow moving water, including pools, ponds, and lakes), lotic (faster moving water, for example streams and rivers) and wetlands (areas where the soil is saturated or inundated for at least part of the time).
Global citiesA megalopolis (ˌmɛgəˈlɒpəlɪs) or a supercity, also called a megaregion, is a group of metropolitan areas which are perceived as a continuous urban area through common systems of transport, economy, resources, ecology, and so on. They are integrated enough that coordinating policy is valuable, although the constituent metropolises keep their individual identities. The megalopolis concept has become highly influential as it introduced a new, larger scale thinking about urban patterns and growth.
DemocracyDemocracy (from dēmokratía, dēmos 'people' and kratos 'rule') is a system of government and form of liberalism in which state power is vested in the people, or the general population of a state based on principles of liberty and free will. According to the United Nations, democracy "provides an environment that respects human rights and fundamental freedoms, and in which the freely expressed will of people is exercised." In a direct democracy, the people have the direct authority to deliberate and decide legislation.
Early Middle AgesThe Early Middle Ages (or early medieval period), sometimes controversially referred to as the Dark Ages, is typically regarded by historians as lasting from the late 5th or early 6th century through the 10th century. They marked the start of the Middle Ages of European history, following the decline of the Western Roman Empire, and preceding the High Middle Ages ( 11th to 14th centuries). The alternative term late antiquity, for the early part of the period, emphasizes elements of continuity with the Roman Empire, while Early Middle Ages is used to emphasize developments characteristic of the earlier medieval period.
Regional geographyRegional geography is a major branch of geography. It focuses on the interaction of different cultural and natural geofactors in a specific land or landscape, while its counterpart, systematic geography, concentrates on a specific geofactor at the global level. Attention is paid to unique characteristics of a particular region such as natural elements, human elements, and regionalization which covers the techniques of delineating space into regions.
Middle AgesIn the history of Europe, the Middle Ages or medieval period (also spelled mediæval or mediaeval) lasted approximately from the late 5th to the late 15th centuries, aligning with the post-classical period of global history. It began with the fall of the Western Roman Empire in 476 AD and ended with the fall of Constantinople in 1453 AD before transitioning into the Renaissance and then the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: antiquity, medieval, and modern.
Modern EraThe modern era is the period of human history that succeeds the Middle Ages (which ended around 1500 AD) up to the present. This terminology is a historical periodization that is applied primarily to European and Western history. The modern era can be further divided as follows: The early modern period lasted from c. AD 1500 to 1800 and resulted in wide-ranging intellectual, political and economic change.
Political ideologiesAn ideology is a set of beliefs or philosophies attributed to a person or group of persons, especially those held for reasons that are not purely epistemic, in which "practical elements are as prominent as theoretical ones." Formerly applied primarily to economic, political, or religious theories and policies, in a tradition going back to Karl Marx and Friedrich Engels, more recent use treats the term as mainly condemnatory.
Belief systemsThe world's principal religions and spiritual traditions may be classified into a small number of major groups, though this is not a uniform practice. This theory began in the 18th century with the goal of recognizing the relative levels of civility in different societies, but this practice has since fallen into disrepute in many contemporary cultures. Initially, Christians had a simple dichotomy of world beliefs: Christian civility versus foreign heresy or barbarity.
Architectural stylesAn architectural style is a set of characteristics and features that make a building or structure notable or historically identifiable. It is a sub-class of style in the visual arts generally, and most styles in architecture relate closely to a wider contemporary artistic style. A style may include such elements as form, method of construction, building materials, and regional character. Most architecture can be classified within a chronology of styles which changes over time, reflecting changing fashions, beliefs and religions, or the emergence of new ideas, technology, or materials which make new styles possible.
Classical antiquityClassical antiquity, also known as the classical era, classical period, classical age, or simply antiquity, is the period of cultural history between the 8th century BC and the 8th century AD centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome known as the Greco-Roman world. It is the period in which both Greek and Roman societies flourished and wielded huge influence throughout much of Europe, North Africa, and West Asia.
Theoretical linguisticsTheoretical linguistics is a term in linguistics which, like the related term general linguistics, can be understood in different ways. Both can be taken as a reference to theory of language, or the branch of linguistics which inquires into the nature of language and seeks to answer fundamental questions as to what language is, or what the common ground of all languages is. The goal of theoretical linguistics can also be the construction of a general theoretical framework for the description of language.
LanguageLanguage is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and written forms, and may also be conveyed through sign languages. The vast majority of human languages have developed writing systems that allow for the recording and preservation of the sounds or signs of language. Human language is characterized by its cultural and historical diversity, with significant variations observed between cultures and across time.
UrbanismUrbanism is the study of how inhabitants of urban areas, such as towns and cities, interact with the built environment. It is a direct component of disciplines such as urban planning, a profession focusing on the design and management of urban areas, and urban sociology, an academic field which studies urban life. Many architects, planners, geographers, and sociologists investigate the way people live in densely populated urban areas. There is a wide variety of different theories and approaches to the study of urbanism.
Conservation biologyRedirect2|Biological conservation|ConservationBiology (journal)|and|Biological Conservation (journal)Biological Conservation (journal)|and|Conservation Ecology (journal)Conservation Ecology (journal)|the popular movement|Conservationism Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions.
HistoryHistory (derived ) is the systematic study and documentation of the human past. The period of events before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well as the memory, discovery, collection, organization, presentation, and interpretation of these events. Historians seek knowledge of the past using historical sources such as written documents, oral accounts, art and material artifacts, and ecological markers.
GeographyGeography (from Greek: γεωγραφία, geographia. Combination of Greek words 'Geo' (The Earth) and 'Graphien' (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be.
PoliticsPolitics () is the set of activities that are associated with making decisions in groups, or other forms of power relations among individuals, such as the distribution of resources or status. The branch of social science that studies politics and government is referred to as political science. It may be used positively in the context of a "political solution" which is compromising and nonviolent, or descriptively as "the art or science of government", but also often carries a negative connotation.
ReligionReligion is a range of social-cultural systems, including designated behaviors and practices, morals, beliefs, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that generally relate humanity to supernatural, transcendental, and spiritual elements—although there is no scholarly consensus over what precisely constitutes a religion. Different religions may or may not contain various elements ranging from the divine, sacredness, faith, and a supernatural being or beings.
LinguisticsLinguistics is the scientific study of language. The modern-day scientific study of linguistics takes all aspects of language into account — i.e., the cognitive, the social, the cultural, the psychological, the environmental, the biological, the literary, the grammatical, the paleographical, and the structural. Linguistics is based on a theoretical as well as descriptive study of language, and is also interlinked with the applied fields of language studies and language learning, which entails the study of specific languages.
