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Topic Review
Last Glacial Period
The last glacial period occurred from the end of the Eemian interglacial to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from c. 2,588,000 years ago to present. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used to include this early phase. During this last glacial period there were alternating episodes of glacier advance and retreat. Within the last glacial period the Last Glacial Maximum was approximately 22,000 years ago. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make it difficult to compare the details from continent to continent (see picture of ice core data below for differences). Approximately 13,000 years ago, the Late Glacial Maximum began. The end of the Younger Dryas about 11,700 years ago marked the beginning of the Holocene geological epoch, which includes the Holocene glacial retreat. From the point of view of human archaeology, the last glacial period falls in the Paleolithic and early Mesolithic periods. When the glaciation event started, Homo sapiens were confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Homo erectus in Asia. Near the end of the event, Homo sapiens migrated into Eurasia and Australia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the last glacial period in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover. The retreat of the glaciers 15,000 years ago allowed groups of humans from Asia to migrate to the Americas.
  • 10.5K
  • 21 Oct 2022
Topic Review
Ground-Penetrating Radar in Soil Studies
Information on the spatiotemporal variability of soil properties and states within the agricultural landscape is vital to identify management zones supporting precision agriculture (PA). Ground-penetrating radar (GPR) and electromagnetic induction (EMI) techniques have been applied to assess soil properties, states, processes, and their spatiotemporal variability. 
  • 9.9K
  • 14 Jun 2023
Topic Review
The Heritage Foundation
The Heritage Foundation (abbreviated to Heritage) is an American conservative think tank based in Washington, D.C., primarily geared towards public policy. The foundation took a leading role in the conservative movement during the presidency of Ronald Reagan, whose policies were taken from Heritage's policy study Mandate for Leadership. Since then, The Heritage Foundation has continued to have a significant influence in U.S. public policy making, and is considered to be one of the most influential conservative public policy organizations in the United States .
  • 9.8K
  • 07 Nov 2022
Topic Review
School Strike for the Climate
The school strike for the climate (Swedish: Skolstrejk för klimatet), also known variously as Fridays for Future (FFF), Youth for Climate, Climate Strike or Youth Strike for Climate, is an international movement of school students who take time off from class on Fridays to participate in demonstrations to demand action from political leaders to take action to prevent climate change and for the fossil fuel industry to transition to renewable energy. Publicity and widespread organising began after Swedish schoolgirl Greta Thunberg staged a protest in August 2018 outside the Swedish Riksdag (parliament), holding a sign that read "Skolstrejk för klimatet" ("School strike for the climate"). A global strike on 15 March 2019 gathered more than one million strikers. Around 2200 strikes were organised in 125 countries. On 24 May 2019, the second global strike took place, in which 1600 events across 150 countries drew hundreds of thousands of protesters. The events were timed to coincide with the 2019 European Parliament election. The 2019 Global Week for Future was a series of 4500 strikes across over 150 countries, focused around Friday 20 September and Friday 27 September. Likely the largest climate strikes in world history, 20 September strikes gathered roughly 4 million protesters, many of them schoolchildren, including 1.4 million people on strike in Germany. On 27 September, an estimated 2 million people participated in demonstrations worldwide, including over 1 million protesters in Italy and several hundred thousand protesters in Canada.
  • 9.5K
  • 06 Dec 2022
Topic Review
Hardiness Zone
A hardiness zone is a geographic area defined to encompass a certain range of climatic conditions relevant to plant growth and survival. The original and most widely-used system, developed by the United States Department of Agriculture (USDA) as a rough guide for landscaping and gardening, defines 13 zones by annual extreme minimum temperature. It has been adapted by and to other countries (such as Canada) in various forms. Unless otherwise specified, "hardiness zone" or simply "zone" usually refers to the USDA scale. For example, a plant may be described as "hardy to zone 10": this means that the plant can withstand a minimum temperature of −1 °C (30.2 °F) to 3.9 °C (39.0 °F). Other hardiness rating schemes have been developed as well, such as the UK Royal Horticultural Society and US Sunset Western Garden Book systems.
  • 8.6K
  • 04 Nov 2022
Topic Review
Mediterranean Climate
A Mediterranean climate /ˌmɛdɪtəˈreɪniən/ or dry summer climate is characterized by dry summers and mild, wet winters. The climate receives its name from the Mediterranean Basin, where this climate type is most common. Mediterranean climate zones are typically located along the western sides of continents, between roughly 30 and 45 degrees north and south of the equator. The main cause of Mediterranean, or dry summer climate, is the subtropical ridge which extends northwards during the summer and migrates south during the winter due to increasing north-south temperature differences. The resulting vegetation of Mediterranean climates are the garrigue or maquis in the Mediterranean Basin, the chaparral in California, the fynbos in South Africa, the mallee in Australia, and the matorral in Chile. Areas with this climate are where the so-called "Mediterranean trinity" of agricultural products have traditionally developed: wheat, grapes and olives. Most historic cities of the Mediterranean basin lie within Mediterranean climatic zones, including Algiers, Athens, Barcelona, Beirut, İzmir, Jerusalem, Marseille, Naples, Rome, Tunis, Valencia, and Valletta. Major cities with Mediterranean climates outside of the Mediterranean basin include Adelaide, Cape Town, Casablanca, Dushanbe, Lisbon, Los Angeles , Perth, Porto, Sacramento, San Diego, San Francisco , San Jose, CA, Santiago, Tashkent and Victoria.
  • 8.5K
  • 07 Nov 2022
Topic Review
Extreme Weather Events of 535–536
The extreme weather events of 535–536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2,000 years. The event is thought to have been caused by an extensive atmospheric dust veil, possibly resulting from a large volcanic eruption conjectured to be either in Asia, the Americas, Europe, or other locations. Its effects were widespread, causing unseasonable weather, crop failures, and famines worldwide.
  • 8.4K
  • 23 Nov 2022
Topic Review
Urbanization
Urbanization (or urbanisation) refers to the population shift from rural to urban areas, the decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It is predominantly the process by which towns and cities are formed and become larger as more people begin living and working in central areas. Although the two concepts are sometimes used interchangeably, urbanization should be distinguished from urban growth. Whereas urbanization refers to the proportion of the total national population living in areas classified as urban, urban growth strictly refers to the absolute number of people living in those areas. The United Nations has projected that half of the world's population will live in urban areas at the end of 2008. It is predicted that by 2050 about 64% of the developing world and 86% of the developed world will be urbanized. That is equivalent to approximately 3 billion urbanites by 2050, much of which will occur in Africa and Asia. Notably, the United Nations has also recently projected that nearly all global population growth from 2017 to 2030 will be by cities, with about 1.1 billion new urbanites over the next 10 years. Urbanization is relevant to a range of disciplines, including urban planning, geography, sociology, architecture, economics, and public health. The phenomenon has been closely linked to modernization, industrialization, and the sociological process of rationalization. Urbanization can be seen as a specific condition at a set time (e.g. the proportion of total population or area in cities or towns), or as an increase in that condition over time. Therefore, urbanization can be quantified either in terms of the level of urban development relative to the overall population, or as the rate at which the urban proportion of the population is increasing. Urbanization creates enormous social, economic and environmental changes, which provide an opportunity for sustainability with the "potential to use resources more efficiently, to create more sustainable land use and to protect the biodiversity of natural ecosystems." Urbanization is not merely a modern phenomenon, but a rapid and historic transformation of human social roots on a global scale, whereby predominantly rural culture is being rapidly replaced by predominantly urban culture. The first major change in settlement patterns was the accumulation of hunter-gatherers into villages many thousand years ago. Village culture is characterized by common bloodlines, intimate relationships, and communal behavior, whereas urban culture is characterized by distant bloodlines, unfamiliar relations, and competitive behavior. This unprecedented movement of people is forecast to continue and intensify during the next few decades, mushrooming cities to sizes unthinkable only a century ago. As a result, the world urban population growth curve has up till recently followed a quadratic-hyperbolic pattern. Today, in Asia the urban agglomerations of Osaka, Tokyo, Mumbai, Dhaka, Karachi, Jakarta, Shanghai, Chongqing, Guangzhou, Manila, Seoul, and Beijing are each already home to over 20 million people, while Delhi is forecast to approach or exceed 40 million people in the year 2035. Cities such as Tehran, Istanbul, Mexico City, São Paulo, London, Moscow, New York City, Lagos, Los Angeles, and Cairo are, or soon will be, home to over 15 million people each.
  • 7.7K
  • 09 Oct 2022
Topic Review
Critical Factors in Renewable Energy Generation
The factors influencing the development of renewable energy in the electrical power sector can be grouped into four main clusters: (i) economic factors, (ii) legal and policy factors, (iii) social acceptance factors, and (iv) adverse impacts of renewable energy projects on the ecological environment.
  • 7.6K
  • 16 Dec 2021
Topic Review
Impulse Buying Behavior in Fast Fashion Physical Stores
The health crisis caused by COVID-19 has affected consumption and payment patterns worldwide. Consumers have had to change their habits and deal with new sanitation guidelines and have often struggled with lengthy infrastructure closures. These factors significantly influenced both the choice of payment methods and purchase decisions made by consumers. Still, consumption patterns during the pandemic as a new social situation have not yet been thoroughly investigated. 
  • 7.4K
  • 22 Apr 2022
Topic Review
Hockey Stick Controversy
In the hockey stick controversy, the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed. Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries, and the name "hockey stick graph" was coined for figures showing a long-term decline followed by an abrupt rise in temperatures. These graphs were publicised to explain the scientific findings of climatology, and in addition to scientific debate over the reconstructions, they have been the topic of political dispute. The issue is part of the global warming controversy and has been one focus of political responses to reports by the Intergovernmental Panel on Climate Change (IPCC). Arguments over the reconstructions have been taken up by fossil fuel industry–funded lobbying groups attempting to cast doubt on climate science. The use of proxy indicators to get quantitative estimates of the temperature record of past centuries was developed from the 1990s onwards, and found indications that recent warming was exceptional. The Bradley & Jones 1993 reconstruction introduced the "Composite Plus Scaling" (CPS) method used by most later large-scale reconstructions, and its findings were disputed by Patrick Michaels at the United States House Committee on Science. In 1998, Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce Mann, Bradley & Hughes 1998 (MBH98), the first eigenvector-based climate field reconstruction (CFR). This showed global patterns of annual surface temperature, and included a graph of average hemispheric temperatures back to 1400. In Mann, Bradley & Hughes 1999 (MBH99) the methodology was extended back to 1000. The term hockey stick was coined by the climatologist Jerry D. Mahlman, to describe the pattern this showed, envisaging a graph that is relatively flat to 1900 as forming an ice hockey stick's "shaft", followed by a sharp increase corresponding to the "blade". A version of this graph was featured prominently in the 2001 IPCC Third Assessment Report (TAR), along with four other reconstructions supporting the same conclusion. The graph was publicised, and became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th-century warmth was exceptional. Those disputing the graph included Pat Michaels, the George C. Marshall Institute and Fred Singer. A paper by Willie Soon and Sallie Baliunas claiming greater medieval warmth was used by the Bush administration chief of staff Philip Cooney to justify altering the first Environmental Protection Agency Report on the Environment. The paper was quickly dismissed by scientists in the Soon and Baliunas controversy, but on July 28, Republican Jim Inhofe spoke in the Senate citing it to claim "that man-made global warming is the greatest hoax ever perpetrated on the American people". Later in 2003, a paper by Steve McIntyre and Ross McKitrick disputing the data used in MBH98 paper was publicised by the George C. Marshall Institute and the Competitive Enterprise Institute. In 2004, Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph, though this was disputed and he later accepted that the effect was very small. In 2005, McIntyre and McKitrick published criticisms of the principal component analysis methodology as used in MBH98 and MBH99. The analysis therein was subsequently disputed by published papers, including Huybers 2005 and Wahl & Ammann 2007, which pointed to errors in the McIntyre and McKitrick methodology. In June 2005, Rep. Joe Barton launched what Sherwood Boehlert, chairman of the House Science Committee, called a "misguided and illegitimate investigation" into the data, methods and personal information of Mann, Bradley and Hughes. At Boehlert's request, a panel of scientists convened by the National Research Council was set up, which reported in 2006, supporting Mann's findings with some qualifications, including agreeing that there were some statistical failings but these had little effect on the result. Barton and U.S. Rep. Ed Whitfield requested Edward Wegman to set up a team of statisticians to investigate, and they supported McIntyre and McKitrick's view that there were statistical failings, although they did not quantify whether there was any significant effect. They also produced an extensive network analysis which has been discredited by expert opinion and found to have issues of plagiarism. Arguments against the MBH studies were reintroduced as part of the Climatic Research Unit email controversy, but dismissed by eight independent investigations. More than two dozen reconstructions, using various statistical methods and combinations of proxy records, have supported the broad consensus shown in the original 1998 hockey-stick graph, with variations in how flat the pre-20th century "shaft" appears. The 2007 IPCC Fourth Assessment Report cited 14 reconstructions, 10 of which covered 1,000 years or longer, to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years. Over a dozen subsequent reconstructions, including Mann et al. 2008 and PAGES 2k Consortium 2013, have supported these general conclusions.
  • 7.1K
  • 21 Oct 2022
Topic Review
Palm Oil Mill Effluent (POME)
Disposal of palm oil mill effluent (POME), which is highly polluting from the palm oil industry, needs to be handled properly to minimize the harmful impact on the surrounding environment.
  • 7.0K
  • 01 Nov 2021
Topic Review
Visual Appearance of Oil
The visual appearance of oil spills at sea is often used as an indicator of spilled oil properties, state and slick thickness. These appearances and the oil properties that are associated with them are reviewed in this entry. The appearance of oil spills is an estimator of thickness of thin oil slicks, thinner than a rainbow sheen (<3 µm). Rainbow sheens have a strong physical explanation. Thicker oil slicks (e.g., >3 µm) are not correlated with a given oil appearance. At one time, the appearance of surface discharges from ships was thought to be correlated with discharge rate and vessel speed; however, this approach is now known to be incorrect. Oil on the sea can sometimes form water-in-oil emulsions, dependent on the properties of the oil, and these are often reddish in color. These can be detected visually, providing useful information on the state of the oil. Oil-in-water emulsions can be seen as a coffee-colored cloud below the water surface. Other information gleaned from the oil appearance includes coverage and distribution on the surface.
  • 6.5K
  • 27 Jan 2021
Topic Review
Artificial Island Developments
Artificial island development (AID) to tackle rampant urbanization on scarce land puts all marine biodiversity at huge risk and is recognized as a global conservation issue worldwide.
  • 6.3K
  • 16 May 2022
Topic Review
Deforestation and Global Warming
Deforestation is a primary contributor to climate change. Land use changes, especially in the form of deforestation, are the second largest anthropogenic source of atmospheric carbon dioxide emissions, after fossil fuel combustion. Greenhouse gases are emitted during combustion of forest biomass and decomposition of remaining plant material and soil carbon. Global models and national greenhouse gas inventories give similar results for deforestation emissions. Although deforestation and peatland degradation are only about 10% of global carbon dioxide emissions (As of 2019), growing forests are also a carbon sink with additional potential to mitigate the effects of climate change. Some of the effects of climate change, such as more wildfires, may increase deforestation. Deforestation comes in many forms: wildfire, agricultural clearcutting, livestock ranching, and logging for timber, among others. The vast majority of agricultural activity resulting in deforestation is subsidized by government tax revenue. Forests cover 31% of the land area on Earth and annually 75,700 square kilometers (18.7 million acres) of the forest is lost. Mass deforestation continues to threaten tropical forests, their biodiversity and the ecosystem services they provide. The main area of concern of deforestation is in tropical rain forests since they are home to the majority of the planet's biodiversity.
  • 6.0K
  • 29 Nov 2022
Topic Review
Properties and Synthesis of Photocatalysts
The photocatalysts must be characterized by the ability to absorb radiation from a wide spectral range of light, the appropriate position of the semiconductor energy bands in relation to the redox reaction potentials, and the long diffusion path of charge carriers, besides the thermodynamic, electrochemical, and photoelectrochemical stabilities.
  • 5.9K
  • 30 Dec 2022
Topic Review
Colorants in Water and Toxicity
Dyes (colorants) are used in many industrial applications, and have become vital to the industrial production infrastructure. However,  effluents of some dyeing industries contain toxic chemicals, which are detrimental to both the environment and human health. Therefore,  wastewater containing dyes must be properly treated before discharging to surrounding water bodies, and this paper summarises that the most effective current method of effluent treatment for dye industries is adsorption using Biochar.
  • 5.8K
  • 08 Feb 2021
Topic Review
Environmental Awareness and Individual’s Altruism
Environmental awareness is the level of how much people are interested in or care about environmental issues. Environmental awareness can be either local or global one depending on the type of environmental problem. Studies have argued that this awareness tends to be related to an individual’s altruism, which is one’s action that benefits others without expecting some kind of external reward. The connection between environmental awareness and altruism is getting attention from scholars since both concepts are prosocial ones but it is uncertain if people who are highly aware of environmental issues may not be always acting altruistically. However, it is likely that altruistic people are more likely to have high environmental awareness.
  • 5.8K
  • 28 Oct 2020
Topic Review
Plant Growth-Promoting Rhizobacteria
Plant growth-promoting bacteria (PGPR) are soil bacteria living in the rhizosphere which, through the secretion of various regulatory molecules, are involved in promoting plant growth and development. They can be found associated with the roots (rhizosphere), with the leaves (phyllosphere), or within the plant (endosphere). The endophytes (PGPE) are generally the most effective in supporting growth; being inside the plant tissues, they can communicate with the host plant and exert their beneficial effect much more efficiently.
  • 5.7K
  • 28 Feb 2022
Topic Review
Environmental Protection and Sustainable Development in Madagascar
Located on the East coast of Africa, Madagascar is the world’s fourth-biggest island; Madagascar is host to 12,000 species of vascular plants (96% endemic). Over 90% of all its wildlife is found nowhere else on earth, and 5% of all of the earth’s biodiversity is found in Madagascar. A place where environmental degradation problems have created severe erosion and water quality problems. Despite its biological and cultural diversity, Madagascar is among the poorest countries in the world, with approximately 78% of the population living in extreme poverty with an average income of less than USD 2 per day, and more than three-quarters of the population in rural areas engaged in natural resources dependent livelihood activities. 
  • 5.7K
  • 07 Dec 2022
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