The hypothalamus is a small part of the brain that contains a number of nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus is located below the thalamus and is part of the limbic system. It forms the ventral part of the diencephalon. All vertebrate brains contain a hypothalamus. In humans, it is about the size of an almond.
The Lampyridae are a family of elateroid beetles with more than 2,000 described species, many of which are light-emitting. They are soft-bodied beetles commonly called fireflies, lightning bugs, or glowworms for their conspicuous production of light, mainly during twilight, to attract mates. Light production in the Lampyridae is thought to have originated as a warning signal that the larvae were distasteful. This ability to create light was then co-opted as a mating signal and, in a further development, adult female fireflies of the genus Photuris mimic the flash pattern of the Photinus beetle in order to trap their males as prey.
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in the body. Progesterone has a variety of important functions in the body. It is also a crucial metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid.
A steroid is an organic compound with four fused rings arranged in a specific molecular configuration.
Grave of the Fireflies is a 1988 Japanese animated war drama film written and directed by Isao Takahata, and produced by Studio Ghibli. It is based on the 1967 semi-autobiographical short story Grave of the Fireflies by Akiyuki Nosaka.
Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio; in others, it is autogenic, produced by the animals themselves.
Progestogens, also sometimes written progestins, progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy, although they are also present at other phases of the estrous and menstrual cycles.
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry functions to protect a species from predators, making it an anti-predator adaptation. Mimicry evolves if a receiver perceives the similarity between a mimic and a model and as a result changes its behaviour in a way that provides a selective advantage to the mimic. The resemblances that evolve in mimicry can be visual, acoustic, chemical, tactile, or electric, or combinations of these sensory modalities. Mimicry may be to the advantage of both organisms that share a resemblance, in which case it is a form of mutualism; or mimicry can be to the detriment of one, making it parasitic or competitive. The evolutionary convergence between groups is driven by the selective action of a signal-receiver or dupe. Birds, for example, use sight to identify palatable insects and butterflies, whilst avoiding the noxious ones. Over time, palatable insects may evolve to resemble noxious ones, making them mimics and the noxious ones models. In the case of mutualism, sometimes both groups are referred to as "co-mimics". It is often thought that models must be more abundant than mimics, but this is not so. Mimicry may involve numerous species; many harmless species such as hoverflies are Batesian mimics of strongly defended species such as wasps, while many such well-defended species form Müllerian mimicry rings, all resembling each other. Mimicry between prey species and their predators often involves three or more species.
Saponins, also selectively referred to as triterpene glycosides, are bitter-tasting usually toxic plant-derived organic chemicals that have a foamy quality when agitated in water. They are widely distributed but found particularly in soapwort, a flowering plant, the soapbark tree, common corn-cockle, baby’s breath and soybeans. They are used in soaps, medicines, fire extinguishers, as dietary supplements, for synthesis of steroids, and in carbonated beverages. Saponins are both water and fat soluble, which gives them their useful soap properties. Some examples of these chemicals are glycyrrhizin and quillaia, a bark extract used in beverages.
Batrachotoxin (BTX) is an extremely potent cardiotoxic and neurotoxic steroidal alkaloid found in certain species of beetles, birds, and frogs. The name is from the Greek word βάτραχος, bátrachos, 'frog'. Structurally-related chemical compounds are often referred to collectively as batrachotoxins. In certain frogs, this alkaloid is present mostly on the skin. Such frogs are among those used for poisoning darts. Batrachotoxin binds to and irreversibly opens the sodium channels of nerve cells and prevents them from closing, resulting in paralysis and death. No antidote is known.
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP+ or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NADPH as a reducing agent ('hydrogen source'). NADPH is the reduced form, whereas NADP+ is the oxidized form. NADP+ is used by all forms of cellular life.
The Sherman Firefly was a medium tank used by the United Kingdom and some armoured formations of other Allies in the Second World War. It was based on the US M4 Sherman but was fitted with the more powerful British 76.2 mm (3.00 in) calibre 17-pounder anti-tank gun as its main weapon. Conceived as a stopgap until future British tank designs came into service, the Sherman Firefly became the most common vehicle mounting the 17-pounder in the war.
Aggressive mimicry is a form of mimicry in which predators, parasites, or parasitoids share similar signals, using a harmless model, allowing them to avoid being correctly identified by their prey or host. Zoologists have repeatedly compared this strategy to a wolf in sheep's clothing. In its broadest sense, aggressive mimicry could include various types of exploitation, as when an orchid exploits a male insect by mimicking a sexually receptive female, but will here be restricted to forms of exploitation involving feeding. For example, indigenous Australians who dress up as and imitate kangaroos when hunting would not be considered aggressive mimics, nor would a human angler, though they are undoubtedly practising self-decoration camouflage. Treated separately is molecular mimicry, which shares some similarity; for instance a virus may mimic the molecular properties of its host, allowing it access to its cells. An alternative term, Peckhamian mimicry, has been suggested, but it is seldom used.
Space Launch Complex 2 (SLC-2) is an active rocket launch site at Vandenberg Space Force Base, in California, USA. It consists of two launch pads. The East pad was used for Delta, Thor-Agena and Thorad launches between 1966 and 1972 and has been demolished. The West pad was used for Delta, Thor-Agena and Delta II launches from 1966 until 2018, when the Delta II performed its last flight.
Photinus pyralis, better known by the common name, the common eastern firefly, and colloquially called a "lightning bug", is a species of flying beetle. An organ on this species abdomen is responsible for its light production. It is the most common species of firefly in North America, and is typically found east of the Rocky Mountains. Photinus fireflies are often confused with fireflies of the similar-sounding genus, Photuris, which are also found in North America.
The African spotted creeper is a small passerine bird, which is a member of the subfamily Salpornithinae of the treecreeper family Certhiidae. It is found in sub-Saharan Africa in open deciduous forest and mango groves. It does not migrate other than local movements.
Photuris versicolor, is a species complex of firefly common throughout the Eastern United States. Fireflies famously use flash-based visual signalling to find mates at a distance and each species of firefly has a unique flash pattern sequence that males and females of the same species use to identify one another. Researchers have documented the ability of female P. versicolor to hunt males of other firefly species by mimicking the flash responses of female fireflies of other species. Photuris versicolor appear to target males, such as Photinus pyralis, specifically for the lucibufagin steroids that their prey produce.
Nipponoluciola cruciata, known as "genji-botaru" (ゲンジボタル) in Japanese, is a species of firefly found in Japan. Its habitat is small ditches and streams, and its larvae are aquatic. It was formerly known as Luciola cruciata but was revised taxonomically in 2022.
Ethynerone, also known as 17α-(2-chloroethynyl)estra-4,9-dien-17β-ol-3-one, is a steroidal progestin of the 19-nortestosterone group that was first reported in 1961 but was never marketed. Under the developmental code name MK-665, it was studied in combination with mestranol as an oral contraceptive. Development of the drug was discontinued due to concerns surrounding toxicity findings in dogs. It is a chloroethynylated derivative of norethisterone.
Vinyltestosterone is a synthetic anabolic–androgenic steroid (AAS) that was never marketed. However, two 19-nortestosterone derivatives of vinyltestosterone, norvinisterone (17α-vinyl-19-nortestosterone) and norgesterone, have been marketed. They are used as progestins for female hormonal contraception, rather than as AAS.
