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Project

1-Wire Weather Station

The weather station in this project is quite basic, measuring only temperature, pressure, and humidity, but it may be easily expanded to measure other weather components, such as wind speed and rainfall. The design is based on using a series of…

Project

3x3x3 LED Cube

LEDs (light-emitting diodes) are rectifying semiconductor devices that convert electrical energy into electromagnetic radiation. You can use these devices to create a 3-dimensional light display. LED cubes require some care and good soldering skills…

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Chatbot, an Artificially Intelligent Microcontroller

The term "Chatbot" is used for a computer or computer program that is made to emulate some form of human intelligence through conversation. In this project, you will learn how easy it is to make a specific microcontroller—an Arduino™ Uno—seem as…

Project

Heart-Rate Monitor

This project uses a sensitive light-detecting resistor to detect small changes in the light beaming through your finger as your blood pumps through tiny arteries in the finger. This device is not the same as the heart-rate monitors typically used in…

Project

Text-Controlled RGB LED

A red, green, and blue (RGB) light-emitting diode (LED) is a useful electronic component that can produce visible light in a variety of colors. This is done by varying the intensity of the light output of the three different color LED elements (red,…

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from article Language theory

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Derivation tree of the sentence THE GIRL SEES THE BOY.

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from article Language theory

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Hierarchy of abstract machines and languages.

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from article Data warehouse

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Architecture of a data warehouse. (R. Strohm et al. Oracle® Database Concepts 11g Release (1.11) B28318-01, Oracle, July 2007)

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from article Swim bladder

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Young trout (Salmo trutta), showing the swim bladder. The trout is one of the primitive teleosts which have the swim bladder connected to the gut.

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from article Swim bladder

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Diagram showing the blood supply to the gas gland. Blood traveling away from the gland is stippled. There are far more capillaries in the rete than are shown in this diagram.

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from article Electromagnetic pulse (EMP)

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The explosion from the Climax test shot of Operation Upshot-Knothole, conducted in June 1953 at the Nevada Test Site. (Credit: National Nuclear Security Administration/Nevada Site Office/DOE)

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from article Electromagnetic pulse (EMP)

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Total gamma source strength versus time for nominal 1-megaton surface burst. Both horizontal and vertical scales are logarithmic.

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from article Electromagnetic pulse (EMP)

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Schematic representation of the EMP in a high-altitude burst. The extent of the source region varies with the altitude and the yield of the explosion.

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from article Clypeasteroida

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Major features of a clypeasteroid sand dollar, Leodia sexiesperforata (a species typical of the Caribbean), from the family Mellitidae. Aboral view is on the left; oral view is on the right.

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from article Batrachoidiformes

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Atlantic midshipman (Porichthys plectrodon, order Batrachoidiformes). (Photo courtesy of the SEFSC Pascagoula Laboratory, Collection of Brandi Noble, Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and…

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from article Vacuole

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Vacuoles are important membrane-bound intracellular compartments. (Left) Protozoan vacuoles serve a variety of functions. For example, contractile vacuoles are involved in osmoregulation, controlling the excretion of water from the cell. The food…

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from article Vacuole

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A large lipid vacuole surrounded by a mantle of multinucleated giant cells. This type of vacuole occurs in exogenous lipid (lipoid) pneumonia, which is caused by inhalation or aspiration of a fatty substance. (Credit: Yale Rosen)

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from article Mycoplasmas

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Mycoplasmas. (a) Mycoplasma hominis, phase contrast micrograph (courtesy of W. Bredt). (b) Spiroplasma citri, electron micrograph of negatively stained specimen (courtesy of R. M. Cole). (c) Mycoplasma colony on solid nutrient medium. (d) Ureaplasma…

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from article Fibrinogen

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Fibrinogen models. (a) Computer image of the symmetrical molecule. (b) Model for end-to-end aggregation. (c) Half-staggered molecular overlap between side-to-side aggregated filaments in a clot network. (Parts a and b from C. Cohen et al., The…

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from article Fibrinogen

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Physiological pathway for the clotting of fibrinogen in normal plasma. Clotting time is measured by forming the (fibrin)n network; this, however, is not the end product. Unless this clot undergoes ligation by γ-glutamyl-ε-lysine cross-links,…

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from article Fibrinogen

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Formation of γ-glutamyl-ε-lysine peptide bridges between fibrin molecules is the last enzyme-catalyzed reaction in blood clotting.

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from article Plant hormone

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Plant hormones, such as gibberellins, are chemical messengers synthesized within plants, where they help to regulate a variety of physiological processes, including growth, differentiation, and development. The stunted plant on the left lacks…

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from article Plant hormone

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Five of the most important plant hormones: auxin (indoleacetic acid; IAA), gibberellin (gibberellic acid; GA3), cytokinin (zeatin), abscisic acid, and ethylene. (Copyright © McGraw-Hill Education)

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from article Plant hormone

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A simplified view of the interaction of three branching hormones. (Left) Auxin promotes production of strigolactones (SL), while limiting that of cytokinins (CK) at bud nodes. This blocks bud outgrowth in intact plants. (Right) After decapitation,…

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from article Plant hormone

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The plant hormone ethylene initiates a signal transduction cascade that activates the transcription of a suite of genes needed for fully developed, ripe fruits and vegetables. The top illustration shows a normal path of ethylene synthesis leading to…

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from article Plant hormone

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Auxin transport within a plant takes place in a cell-to-cell fashion, mainly in the vascular cambium and the procambial strands, but probably also in epidermal cells. Transport to the root probably involves the phloem. The transport mechanism…

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from article Endocrinology

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The main endocrine glands in a human male. (Copyright © McGraw Hill)

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from article Paracrinoidea

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Reconstructions of two paracrinoids showing different proposed living positions. (a) Amygdalocystites from the Late Ordovician of Ontario, Canada, held up some distance in the water column by a curved attached stem (after T. E. Guensburg, J.…

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from article Sporozoa

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Fine structure of a coccidian merozoite (Eimeria miyairii from the rat). (a) Longitudinal section. Cross sections at levels of (b) nucleus, (c) Golgi complex, (d) large dense granules, (e) cytostome, (f) paired organelle, and (g) conoid. (After…

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from article Sporozoa

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Mature (sporulated) oocyst of a coccidium (Eimeria). (After N.D.Levine, Protozoan Parasites of Domestic Animals and of Man, Burgess, 1961)

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from article Sporozoa

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Life cycle of the chicken coccidium Eimeria tenella. The numbered steps are explained in the text. (After N.D.Levine, Protozoan Parasites of Domestic Animals and of Man, Burgess, 1961)

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from article Video streaming

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Video streaming on the latency requirements scale.

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from article DNA microarray

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An example of microarray data presentation is shown. In this experiment, five to seven different samples of a series of tissues are organized by column. Each column is one tissue. Tissue names are indicated across the top. The level of expression of…

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from article Nitrogen fixation

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A mechanism for the functioning of the two components of nitrogenase. The box signifies that a complex of Fe and Mo-Fe proteins forms the active enzyme.

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from article Temperature adaptation in animals

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Body temperature (°C) versus ambient temperature (°C) for (left) endotherm and (right) ectotherm animals. Temperature adaptation is one of the key characteristics necessary to ensure that an animal can live and exist in its environment over a…

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from article Temperature adaptation in animals

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A collared lizard basking on a dried lava rock. The body temperature of this ectotherm is determined by sources of heat external to the body. (Credit: David Parsons/iStockphoto/Getty Images)

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from article Temperature adaptation in animals

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The Arctic wolf is an endotherm with a thick pelage that reduces the cost of thermoregulation in cold environments. (Credit: Cultura Creative/Alamy Stock Photo)

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from article Hippo pathway (developmental biology)

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Illustration depicting Hippo pathway components in (a) Drosophila and (b) mammals, with arrows and blunt lines indicating activation and inhibition, respectively. Expression of the pro-proliferative genes occurs when the Hippo pathway is “OFF.”…

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from article Synbranchiformes

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Synbranchus madeirae, a swamp eel belonging to the family Synbranchidae. [Photo from T. P. Carvalho et al., Fishes from the upper Yuruá river, Amazon basin, Peru, Check List, 5(3):673–691, 2009]

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from article Synbranchiformes

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Macrognathus siamensis, commonly called the spotfin spiny eel, belonging to the family Mastacembelidae. (Photo courtesy of the U.S. Geological Survey)

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from article Teleostei

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An Atlantic blue marlin (Makaira nigricans) jumping out of the ocean. This popular sport fish is one of the members of the Teleostei. (Photo by Ken Neill, National Marine Fisheries Service, National Oceanic and Atmospheric Administration)

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from article Teleostei

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Phylogeny of the Teleostei.

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from article Spinal cord

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Spinal cord and brain (ventral aspect). Nerve roots and chief autonomic ganglia are shown. (Credit: Based on an original illustration by H. V. Neal and H. W. Rand)

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from article Spinal cord

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Human spinal cord sectioned to show the white matter and gray matter. (Credit: Based on an original illustration by G. M. Wyburn)

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from article Oligosaccharide

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Blood group antigens. Five antigens are formed from a single glycolipid or glycoprotein precursor by adding various monosaccharide residues to different places in the oligosaccharide chain (where R can be protein or lipid). The monosaccharide…

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from article Gyrator

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Two-port microwave network. (a) Scattering matrix representation. (b) Currents and voltages.

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