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Subject: Music

This US group was formed in Los Angeles, California, in 1978 by Steve Allen (guitar, vocals) and Ron Flynt (bass, vocals), two expatriate musicians from Tulsa, Oklahoma. Drummer Mike Gallo ...

peptide

peptide   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
99 words
Illustration(s):
1

...bonds are formed by the reaction between adjacent carboxyl (–COOH) and amino (–NH 2 ) groups with the elimination of water (see illustration). Dipeptides contain two amino acids, tripeptides three, and so on. Polypeptides contain more than 20 and usually 100–300. Naturally occurring oligopeptides (of less than 20 amino acids) include the tripeptide glutathione and the pituitary hormones antidiuretic hormone and oxytocin, which are octapeptides. Peptides also result from protein breakdown, e.g. during digestion. Formation of a peptide bond ...

ecdysones

ecdysones   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
133 words
Illustration(s):
1

... steroid hormones produced by the prothoracic gland ( q.v .) of insects, required for molting and puparium formation; also called molting hormones . The structural formulas for alpha and beta ecdysone are illustrated. Beta ecdysone is sometimes called 20-hydroxy-ecdysone (20 HE). The precursor of alpha ecdysone is dietary cholesterol ( q.v .). The alpha ecdysone synthesized by the prothoracic gland is converted in peripheral tissues, such as the fat body, to beta ecdysone, which is the active molting hormone. The conversion involves the...

Cuckoo Roller

Cuckoo Roller   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
475 words
Illustration(s):
3

...Distribution Madagascar, Comoro Islands. Habitat Forests, scrub. Size Length 38–50cm (15–20in). Plumage In males, iridescent, green-purple back, wings, and tail, pale gray head, white underparts; in females, mottled red-brown and greenish back, mottled brown head, red-brown tail, underparts creamy heavily spotted with black. Bill slaty, eyes black; male with red legs, female brown. Voice Loud, plaintive whistle, “qui-yu” repeated. Nest Unlined tree hole 4–6m (13–20ft) above forest floor. Eggs 2 cream-buff, rounded ovals. Diet Chameleons, locusts, (hairy)...

flagellum

flagellum plural   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
146 words
Illustration(s):
1

... ( plural flagella ) 1. in prokaryotes, a whip-like motility appendage present on the surface of Flavin adenine dinucleotide some species. Bacterial flagellae range in length from 2 to 20 nanometers. Bacteria having a single flagellum are called monotrichous; those with a tuft of flagella at one pole are called lophotrichous; and those with flagella covering the entire surface are called peritrichous . Antigens associated with flagella are called H antigens . Compare with pilus . 2. in eukaryotes, flagellum refers to a threadlike...

gramicidin S

gramicidin S   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
141 words
Illustration(s):
1

...to isomerize l - to d -phenylalanine and to transfer it to the proline attached to E 1 . The two identical polypeptides are then joined head to tail to form a decapeptide. This rare type of polypeptide synthesis is very uneconomical and cannot generate molecules greater than 20 amino acids...

16S rRNA

16S rRNA   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
144 words
Illustration(s):
1

...rRNA the RNA molecule found in the small ribosomal subunits of prokaryotes. This RNA is often abbreviated SSU rRNA (small subunit rRNA). The secondary structure of the 16S rRNA of E. coli is shown. This 30S subunit also contains 20 specific proteins. The folding pattern results from hydrogen bonding of C to G and A to U molecules. The nucleotides are numbered starting with 1 at the 5′ end and ending with 1542 at the 3′ end. Comparison of the nucleotide sequence of 16S rRNAs from widely diverse species has allowed the construction of...

Microarray Technology

Microarray Technology   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
392 words
Illustration(s):
1

...Chemical microarrays Contain chemical compounds. Used, for example, to select potential drugs with particular chemical binding properties. Preparation of DNA microarrays There are two basic types of DNA microarrays. In situ oligonucleotide arrays (DNA chips) DNA oligonucleotides (20–25 nucleotides) are assembled in situ on a quartz wafer or glass slide, using a photolithography process similar to that used to make microprocessor chips. A single chip may contain up to a million specified oligonucleotides at regularly spaced sites called addresses, or...

Australasian Treecreepers

Australasian Treecreepers   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
554 words
Illustration(s):
2

...Forest, woodland, and tall shrubland. Size Length 14–19cm (5.5–7.5in); weight 20–40g (0.7–1.4oz). Plumage Upperparts brown to black, underparts buff to rufous with black and white striping or spotting; broad, pale wing-bar. Voice Loud piping notes, trills, chatters; harsh grates, rattles. Nest Cup in hole of tree, hollow branch, or stump. Eggs 1–4, white to pink with varying amount of red-brown to purple-brown markings. Incubation period 14–24 days; nestling period 20–27 days. Diet Insects (primarily ants, some beetles), spiders, nectar, rarely seeds...

amino acid

amino acid   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
221 words
Illustration(s):
1

...polar; the nature of the R group determines the properties of any particular amino acid. Through the formation of peptide bonds, amino acids join together to form short chains ( peptides ) or much longer chains ( polypeptides ). Proteins are composed of various proportions of about 20 commonly occurring amino acids ( see table ). The sequence of these amino acids in the protein polypeptides determines the shape, properties, and hence biological role of the protein. Some amino acids that never occur in proteins are nevertheless important, e.g. ornithine and...

popcorn

popcorn   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
133 words
Illustration(s):
1

... Zea mays ( q.v. ) to be cultivated was a popcorn that evolved in Mexico at different altitudes and culturing conditions, and it underwent introgressive hybridization ( q.v .) with teosinte ( q.v. ). A popcorn such as the Tom Thumb (short plants with small ears) has a genome size 20% smaller than a sweet corn such as Black Mexican. See kernel . Quantitative inheritance in maize . Distribution of ear lengths in parents, F 1 , and F 2 generations of a cross between Tom Thumb popcorn and Black Mexican sweet...

Chevrotains

Chevrotains   Reference library

The Encyclopedia of Mammals (3 ed.)

Reference type:
Subject Reference
Current Version:
2007
Subject:
Science and technology, Life Sciences
Length:
1,163 words
Illustration(s):
2

...rain forest, particularly rocky; nocturnal head–body length 50–58cm (20–23in); shoulder height 25–30cm (10–12in); tail length 3cm (1.2in); weight about 3kg (6.6lb). Coat: reddish brown, with lighter spots and stripes; more or less similar to Water chevrotain. Breeding: gestation probably 5 months. Lesser mouse deer Tragulus javanicus Lesser mouse deer or Lesser Malay chevrotain SE Asia. Tropical rain forest and mangroves; nocturnal. head–body length 44–48cm (17–19in); shoulder height 20cm (8in); tail length 6.5–8cm (2.5–3.2in); weight 1.7–2.6kg....

Mountain Beaver

Mountain Beaver   Reference library

The Encyclopedia of Mammals (3 ed.)

Reference type:
Subject Reference
Current Version:
2007
Subject:
Science and technology, Life Sciences
Length:
1,275 words
Illustration(s):
3

...chamber, although some may occur 2m (6.6ft) or more below ground. Tunnels are generally 15–20cm (6–8in) in diameter and occur at various levels; those closest to the surface are used for travel; deep ones lead to the nest and food caches. Burrow openings occur every 4–6m (13–20ft) or more, depending on vegetative cover and number of animals occupying a particular area. Densities vary from 1 or 2 mountain beavers per hectare (2.5 acres) in poor habitat to 20 or more per hectare in good habitat. Up to 75 per hectare have been kill‐trapped in reforested...

Siamese twins

Siamese twins   Reference library

The Oxford Companion to the Body

Reference type:
Subject Reference
Current Version:
2003
Subject:
Science and technology, Life Sciences
Length:
633 words
Illustration(s):
1

...organs. Throughout recorded history there are many references to surviving conjoined twins. One of the earliest reports concern Mary and Eliza Chalkhurst , born at Biddenden, Kent, England in the year 1100 . They died in 1134 within six hours of each other. They bequeathed 20 acres of land to the church wardens from which a yearly income was used to provide, for the poor, cakes with the imprint of their effigies ‘in their habit as they lived’ together with bread and cheese. For many years this ceremony took place on Easter Monday at their birthplace. As...

Rockjumpers and Rockfowl

Rockjumpers and Rockfowl   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
673 words
Illustration(s):
3

...4 species in 2 genera Rockjumpers Genus Chaetops 2 species: Damara rockjumper ( Chaetops pycnopygius ), rockjumper ( Chaetops frenatus ), with two races, the Cape rockjumper ( C. f. frenatus ) and the Orange-breasted rockjumper ( C. f. aurantius ). Thornveld and fynbos. Length 20–27cm (8–11in); weight 24–30g (0.8–1oz). Plumage : streaked brownish above and dark rufous below; rufous rump, white-tipped dark tail, white eyebrows and malar stripe. Sexes slightly dissimilar. Voice : melodious warble or tuneless varied song. Various alarm, anxiety, and...

Trumpeters

Trumpeters   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
574 words
Illustration(s):
3

...The birds usually walk, but have the ability to run fast; they can easily outpace dogs. They are gregarious, and can sometimes be seen moving in flocks of 100 or more over the forest floor. They are poor fliers, but at dusk their noisy groups flutter rather laboriously some 6–9m (20–30ft) up to roost in forest trees. The three species are all mainly confined to the Amazon and Orinoco basins, with each one having a discrete range that is generally separated from that of other trumpeter species by a large river. The bulk of their diet is made up of ripe, fallen...

Butcherbirds and their Allies

Butcherbirds and their Allies   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
698 words
Illustration(s):
3

...fiercely territorial; a small proportion of the birds are even known to attack humans during the breeding season. Mating systems vary widely. Across much of Australia, the magpies live in simple pairs. In some southern populations, however, territorial groups can contain as many as 20 birds, and up to five females can build nests and lay eggs within a territory. Genetic studies have revealed that, despite the territorial nature of the species, many females mate with males from outside their own group. Nevertheless, both the males and other members of the group...

Dwarf and Mouse Lemurs

Dwarf and Mouse Lemurs   Reference library

The Encyclopedia of Mammals (3 ed.)

Reference type:
Subject Reference
Current Version:
2007
Subject:
Science and technology, Life Sciences
Length:
2,829 words
Illustration(s):
2

...vegetation; nocturnal. head–body length 10–20cm (4–8in); tail length 10–20cm (4–8in); weight 30–70g (1–2.5oz). Coat: fur on back gray to gray brown; white to cream below; large membranous ears. Breeding: gestation 60 days; litter size 2–3. Longevity: to 15 years in captivity. Conservation status: Lower Risk, affected by habitat destruction. Eastern rufous mouse lemur Microcebus rufus E Madagascar, in forest fringes and secondary vegetation; nocturnal. head–body length 10–20cm (4–8in); tail length 10–20cm (4–8in); weight 30–70g (1–2.5oz). Coat: fur on...

Cuckoo-shrikes

Cuckoo-shrikes   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
1,464 words
Illustration(s):
3

...with moss and lichen. The nests of some Australian cicadabirds are occasionally grouped together. Eggs 2–5; white or pale green, blotched with brown, purple, or gray. Incubation, where known, 14 days (small Lalage triller species) to 20–23 days ( Coracina and Campephaga cuckoo-shrikes); nestling period 12 and 20–25 days respectively for the same two groups. Diet Mainly arthropods, especially caterpillars; some species take fruit, others a few lizards and frogs. Conservation status The Réunion cuckoo-shrike ( Coracina newtoni ) is Endangered, and 3...

Emu

Emu   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
1,411 words
Illustration(s):
2

...keep moving at bodyweights as low as 20kg (44lb). Second, emus are only forced to stay in one place when the male is sitting on eggs. At other times they can move without limitation, admittedly at a slow pace when with small chicks. Since the male does not eat, drink, or defecate during incubation, he is independent of the local food supply for this period. The Male–Young Bond Breeding Biology Emus pair in December and January, each couple defending a territory of about 30sq km (12sq mi). The female lays her clutch of 9–20 eggs in April, May, and June. Once the...

electron microscope

electron microscope   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
306 words
Illustration(s):
1

...together with any secondary electrons emitted, are collected. This current is used to modulate a separate electron beam in a TV monitor, which scans the screen at the same frequency, consequently building up a picture of the specimen. The resolution is limited to about 10–20 nm. See also field-emission microscope ; field-ionization microscope ; immunoelectron microscopy . Principle of transmission electron microscope http://micro.magnet.fsu.edu/primer/java/electronmicroscopy/magnify1/index.html Tutorial featuring virtual scanning electron...

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