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from article Information processing (psychology)

The four major lobes of the cerebral cortex, that is, the frontal, parietal, temporal, and occipital lobes, are responsible for different aspects of information processing. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

Horizontal associative memory with a serious associative interference problem (who plays tennis—John, Peter, or both?) and no encoding of where each proposition begins and ends. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

Vertical associative memory where concepts are grouped into phrases and propositions by associating each concept to a higher-order node that represents the entire group. (Copyright © McGraw-Hill Education)

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from article Octopoda

An octopod swimming in the ocean. (Credit: Getty Images/iStockphoto)

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from article Octopoda

Hapalochlaena maculosa, the Southern or lesser blue-ringed octopus, has vivid, small blue rings on its body and arms, highlighted with black outlines. Location: Mrs. Watson's Bay, Lizard Island, Great Barrier Reef, Australia. (Credit: Clyde F. E.…

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from article Octopoda

Hapalochlaena fasciata, the blue-lined octopus, has vivid blue lines on its body and rings on its arms, highlighted with black outlines. Location: Long Reef, New South Wales, Australia. (Credit: Clyde F. E. Roper)

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from article Octopoda

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from article Polyplacophora

Chiton on a rock surface. (Photo courtesy of the NOAA Okeanos Explorer Program, National Oceanic and Atmospheric Administration)

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from article Polyplacophora

Polyplacophoran mollusk (chiton): (a) dorsal view; (b) ventral view.

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from article Eclipse

The August 21, 2017 total solar eclipse, as seen from Hopkinsville, Kentucky, USA at 2:25 p.m. EDT. (Credit: NASA)

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from article Eclipse

Circumstances of solar and lunar eclipses (not to scale).

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from article Eclipse

Diamond-ring effect at the beginning of totality during the solar eclipse of July 11, 2010, observed from Easter Island in the middle of the Pacific Ocean. (Credit: Jay M. Pasachoff/Science Faction, Muzhou Lu, and Craig Malamut, Williams College…

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from article Eclipse

Total solar eclipse of July 11, 2010, observed from Easter Island in the Pacific Ocean. (a) Image composited from several exposures using radial filters in order to show a wide dynamic range of intensity of the corona and to bring out the structures…

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from article Eclipse

Solar eclipse of April 8, 2005, observed during totality from a ship in the mid-Pacific Ocean, west of the Galápagos Islands. (Credit: Jay M. Pasachoff and Dava Sobel/Science Faction)

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from article Eclipse

Paths of all total solar eclipses from 2001 through 2025. The point of greatest eclipse is indicated by an asterisk on each eclipse path. (Credit: Eclipse map by Michael Zeiler, www.eclipse-maps.com. Eclipse paths by Xavier Jubier, xjubier.free.fr.)

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from article Eclipse

Cross section through the Earth's shadow cone (umbra) at the Moon's distance, showing the motion of the Moon at three types of lunar eclipses: penumbral eclipse, partial umbral eclipse, and total umbral eclipse.

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from article Eclipse

Stages of the total lunar eclipse of December 21, 2010. (Credit: Glenn Schneider)

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from article Eclipse

Total lunar eclipse of December 9, 1992, which was so dark that it rendered the Moon nearly invisible during totality. (Credit: F. Espenak)

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from article Aconchulinida

Aconchulinida. (a) Penardia cometa. (b) Penardia mutabilis.

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from article Surveillance radar

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from article Siphonaptera

Head of Spilopsyllus cuniculi (rabbit flea), with extended mouthparts.

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from article Planet

An artist’s impression of a mere sampling of the planetary diversity expected to exist in nature. [Credit: C. Pulliam & D. Aguilar (CfA)]

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from article Planet

Plan of the solar system's major and dwarf planets. (a) Solar system out to Neptune. (b) Dwarf planets in the outer solar system (Credit: Emily L. Schaller)

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from article Planet

Orbital elements, which determine the position of a planet in its orbit and the orientation of the orbit in space. Symbols explained in text.

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from article Planet

The interiors of the 8 planets and the dwarf planet Pluto. Mercury, Venus, Earth, and Mars are characterized by dense, metallic cores and lower-density mantles and crusts. Jupiter and Saturn have compositions that mimic the Sun's, though…

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from article Planet

Complex lunar crater Bullialdus, 60 km (37 mi) in diameter, shows terraced sides, a central peak, and a flat bottom. It may be compared to the small (less than 8 km or 5 mi) crater in the foreground, which is simple and bowl-shaped. (Credit: NASA)

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from article Planet

Ultraviolet images from the Hubble Space Telescope, which reveal auroral emission surrounding the north magnetic pole of Jupiter. [Credit: NASA, ESA, and J. Nichols (University of Leicester)]

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from article Island biogeography

Equilibrium number of species (Sequilibrium) is determined by the intersection of the immigration ( I ) and extinction ( E ) rate curves. P is the maximum number of species in the source pool.

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from article Wilkinson Microwave Anisotropy Probe

Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft. (Courtesy of NASA/WMAP Science Team)

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from article Wilkinson Microwave Anisotropy Probe

WMAP sky-scan strategy. (a) Location of the satellite relative to the Earth and Sun (not to scale), and the orientation of the satellite and of the lines of sight to the spots on the sky focused by the primary reflectors, which continually changed…

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from article Wilkinson Microwave Anisotropy Probe

WMAP full-sky CMB anisotropy map. The microwaves captured in this picture from WMAP are from when the universe was 378,000 years old, over 13 × 109 years ago. It is a “baby picture” of the universe, equivalent to taking a picture of an 80-year-old…

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from article Digenea

Diagrams of various adult types of digenean trematodes. (After R. M. Cable, An Illustrated Laboratory Manual of Parasitology, Burgess, Minneapolis, 1940)

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from article Digenea

Digenean trematode life cycle. (After R. M. Cable, An Illustrated Laboratory Manual of Parasitology, Burgess, Minneapolis, 1940)

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from article Learning

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from article Learning

Brain activity can be recorded in various ways, from single-cell activity (top tracing) to the familiar electrical patterns ("brain waves") of an electroencephalogram (bottom tracing). (Credit: Based on an original drawing by C. Cotman and J.…

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from article Biofilm

Biofilms are highly structured communities of microorganisms that are surface-associated or attached to one another, and are enclosed within a self-produced protective extracellular matrix. Biofilm formation and actions involve a number of stages:…

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from article Ctenothrissiformes

A Cretaceous ctenothrissiform fossil, Ctenothrissa sp. (order Ctenothrissiformes), on a limestone matrix found in Lebanon. Size: 90 mm (3.5 in.). (Photo courtesy of The Virtual Fossil Museum)

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from article Acari

Parasitiformes body plan. Lateral view of a predatory adult female Mesostigmata showing major body regions and important structures. Scale bar = 0.1 mm (0.004 in.). (Scanning electron micrograph by D. E. Walter)

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from article Acari

Acariformes body plan. (a) Adult female Oribatida (Sarcoptiformes) in lateral view showing major body regions and important structures. (b) Hexapod larva (Trombidiformes): dorsal view of a chigger, a parasite of vertebrates. (c) Octopod deutonymph…

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from article Ecosystem

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from article Ecosystem

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from article Ecosystem

Food chains are limited by energy transfer. In this illustration, energy is transferred from the Sun to a plant (producer) to a primary consumer and to a secondary consumer. Energy is used by the producer and consumer organisms and is lost to the…

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from article Ecosystem

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from article Ecosystem

General model of the carbon cycle in ecosystems: (A) carbon dioxide (CO2) from the air; (B) carbon from decomposition; (C) carbon from fossil fuels; (D) natural events (for example, forest fires and volcanoes) release CO2 into the air. (Copyright ©…

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from article Biodiversity

Global biodiversity hotspots. There are more than 30 biodiversity hotspots located around the world. These areas have experienced severe habitat losses (at least 70%) as the result of human activities, hampering the work of conservationists in their…

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from article Biodiversity

A regional analysis of 25 oceanic regions shows that 92% of all known biodiversity falls into a dozen groups, of which crustaceans (for example, crabs, shrimps, and lobsters), mollusks (for example, snails, bivalves, squids, and octopus), and fish…

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from article Biodiversity

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from article Haplosporida

Spore of Urosporidium fuliginosum.

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from article Haplosporida

Stages in the development of Icthyosporidium giganteum.

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from article Hyperbolic geometry

Examples of simple hyperbolic knots and links. (a) Figure-8 knot. (b) Whitehead link.

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from article Urodela

A typical member of the order Urodela: the longtail salamander (Eurycea longicauda). (Credit: Ryan Hagerty/U.S. Fish and Wildlife Service)

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from article Urodela

Southern dwarf siren (Pseudobranchus axanthus), which has undergone limb degeneration and retains only tiny forelimbs. (Credit: U.S. Geological Survey)

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from article Urodela

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from article Urodela

California tiger salamander (Ambystoma californiense). (Credit: John Cleckler/U.S. Fish and Wildlife Service)

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from article Urodela

The two-toed amphiuma salamander (Amphiuma means). (Credit: Southeast Ecological Center, U.S. Geological Survey)

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from article Urodela

The northern red salamander (Pseudotriton ruber ruber) is a member of the family Plethodontidae. (Credit: Alicia Lafever/U.S. National Park Service)

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from article Thirst and sodium appetite

Regulation of cellular water. ADH = antidiuretic hormone.

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from article Thirst and sodium appetite

Hypovolemic thirst and sodium appetite are caused by altered sensory information from an underfilled circulation, reinforced by increases in circulating angiotensin II and mineralocorticoids. Angiotensin peptides generated from components of a…

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from article Chamois

Alpine chamois (Rupicapra rupicapra). (Photograph courtesy of Brent Huffman/Ultimate Ungulate Images)

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from article Environmental management

Environmental management seeks to provide solutions to the practical problems that humans encounter or create, including the production of garbage and waste. (Credit: Walter Zerla/Getty Images)

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from article Environmental management

Without proper environmental management, economic and industrial development often lead to environmental pollution, especially in urban environments. (Credit: Simon Alvinge/123RF)

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from article Chicxulub impact crater

Bouguer gravity anomaly map over the Chicxulub impact crater. The coastline is designated by a thin white line, cenotes (natural pits) and sinkholes are designated by black dots, and the city of Mérida and the town of Chicxulub Puerto are designated…

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from article Chicxulub impact crater

Seismic line imaging of what lies beneath the seafloor, showing the Chicxulub impact crater. The crater includes many faults that can be grouped into an exterior ring fault, a series of outer ring faults, and a series of inner ring faults. Within…

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from article Amniota

Basic types of vertebrate eggs.

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from article Amniota

Embryo developing in amniote eggs.

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from article Mecoptera

Male scorpion fly (Panorpa), order Mecoptera.

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from article Marine ecology

Marine ecology investigates the basic structural and functional relationships within and among living populations and their physical–chemical environments in marine ecosystems. In this photograph, a cold water reef in California is host to a…

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from article Marine ecology

The snaking waterways of a mangrove estuary in northwestern Madagascar. (Credit: Michael Fay/Getty Images/National Geographic RF)

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from article Marine ecology

Estuary salt marshes in the Grand Bay National Estuarine Research Reserve, Mississippi. (Credit: P. R. Hoar/National Oceanic and Atmospheric Administration)

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from article Marine ecology

Coral bleaching in the lagoon of Huahine Island, French Polynesia. Coral bleaching is the response of corals to environmental stress in which they eject the single-cell algae that live within the transparent coral tissue, making the white coral…

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from article Ursa Minor

Modern boundaries of the constellation Ursa Minor, the Little Bear. The celestial equator is 0° of declination, which corresponds to celestial latitude. Right ascension corresponds to celestial longitude, with each hour of right ascension…

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from article Venus

Venus compared to Earth in size. Note that the image of Venus at left does not include the planet's thick, opaque atmosphere. The image was obtained by the Magellan spacecraft that orbited Venus from 1990 to 1994. Magellan used cloud-penetrating…

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from article Venus

Venus viewed in visible light by the Galileo spacecraft during a 1990 gravity assist flyby on the probe's ultimate journey to Jupiter. (Credit: NASA)

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from article Venus

Global Venus clouds, as viewed in the ultraviolet from Venus Express. These features can be used to track winds and atmospheric motion at the cloud tops. Convection clouds can be seen near the equator (top of image), whereas streaky brighter clouds…

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from article Venus

Inhomogeneities in the total thickness of the clouds between 48 and 70 km (30 and 43 mi) show up in the near-infrared. These clouds, seen only at night, are backlit from the hot atmosphere below it (similar to a Chinese lantern), where bright…

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from article Venus

Perspective view of the southern boundary of Laksmi Planum, a plateau 2.5–4.0 km (1.5–2.5 mi) high. (Credit: NASA/JPL)

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from article Venus

Magellan image of the central and northern parts of the highland region Ovda Regio (north at top). Ridges running approximately east-west (horizontally) have been interpreted as resulting from crustal shortening (compression). Ridges are cut by…

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from article Venus

Perspective view of a portion of the Western Eistla Regio, with a rift valley in the foreground and the volcanoes Gula Mons (right) and Sif Mons (left) on the horizon. (Credit: NASA/JPL)

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from article Venus

Sapas Mons, one of several large volcanic edifices that compose the broad equatorial rise known as Alta Regio. (Credit: NASA/JPL)

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from article Venus

Computer-simulated perspective view, based on data from Magellan spacecraft, showing three impact craters in the northwestern portion of Lavinia Planitia with diameters ranging from 37 to 63 km (23 to 39 mi). (Credit: NASA/JPL)

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from article Swamp, marsh, and bog

Young cypress trees growing out of a swamp located in the Florida Everglades. (Credit: Getty Images)

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from article Plant vulnerability to climate change

Subarctic tundra and vegetation of the Denali National Park and Preserve in Alaska. As a result of climate change and the resultant poleward and upward shift of plant ranges, plants and their ecosystems may become particularly vulnerable. (Credit:…

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from article Plant vulnerability to climate change

Blue grama (Bouteloua gracilis) growing in Montana. As a result of warming temperatures, this type of grass could face decreased productivity, allowing forbs to increase and making the ecosystem less tolerant of drought and grazing. (Credit: Matt…

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from article Plant vulnerability to climate change

Modeled distribution of suitable climate space in Europe for stiff sedge (Carex bigelowii), which is an Arctic-Alpine plant: (a) during the period 1961–1990 (green color = suitable climate space during the 1961–1990 period); (b) climate model…

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from article Plant vulnerability to climate change

The endangered western prairie fringed orchid (Platanthera praeclara) is declining across much of its range in North America. (Credit: U.S. Fish and Wildlife Service)

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from article Saccopharyngiformes

Pelican or gulper eel (Eurypharynx pelecanoides), a member of the order Saccopharyngiformes. [Photo by Alexei Orlov, Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), Moscow, Russia]

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from article Ecological modeling

EverSnail ecological model (left) graphical interface and (right) snail kite holding an apple snail in its talons. The snail kite is an endangered species in the Florida Everglades, United States, and feeds on, almost exclusively, the apple snail.…

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from article Astronomy

A photograph of the Milky Way in the night sky over the European Southern Observatory's 3.6-metre telescope, at right, at the La Silla Observatory in northern Chile. [Credit: ESO/B. Tafreshi (twanight.org)]

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from article Astronomy

An artist’s impression of the exoplanet GJ 504, a world several times the size of Jupiter and anticipated to have a magenta color, still glowing from its initial formation. (Credit: NASA's Goddard Space Flight Center/S. Wiessinger)

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from article Astronomy

The Hubble Space Telescope in orbit above Earth. (Credit: NASA)

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from article Automatic landing system

Schematic of radar-beam system for aircraft-carrier and shore applications.

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from article Speech

Human head and thorax. (Courtesy of G. E. Peterson)

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from article Speech

Action of the glottis during speech. (a) Six successive positions of the vocal folds in one vibration cycle at 120 Hz. (b) Relation between pitch and vocal fold tension. (Courtesy of D. W. Farnsworth)

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from article Speech

Sound spectrograms of the utterance “speech production.” (a) Energy patterns: A, pulse; B, periodic; C, aperiodic; and D, silence. (b) The dotted lines represent the pitch pattern of the utterance.

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from article Speech

Computer-generated three-dimensional spectral display of the spoken syllable “yah.”

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from article Speech

Speech flakes of vowels in the words (a) “far,” (b) “food,” and (c) “fee.” (Courtesy of Charles Wooters)

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from article Speech

Regions of the brain involved in speech. (a) Left hemisphere, usually more involved in speech functions than the right hemisphere. (b) A model for the neural processes involved in speaking a heard word. Arrows indicate the path of the relayed signal…

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from article Orbital motion