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Antagonism
Antagonism may refer to: *The characteristic of an antagonist *Antagonism (chemistry), where the involvement of multiple agents reduces their overall effect *Receptor antagonist or pharmacological antagonist, a substance that binds to the site an agonist would bind to, without causing activation *Antagonism (phytopathology), an effect that suppresses the activity of a plant pathogen *Reflexive antagonism Reciprocal inhibition describes the relaxation of muscles on one side of a joint to accommodate contraction on the other side. In some allied health disciplines, this is known as reflexive antagonism. The central nervous system sends a message to ... of muscles * Intraspecific antagonism, disharmonious or antagonistic interaction between two individuals of the same species See also * Antagonist (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves " '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, |
Intraspecific Antagonism
Intraspecific antagonism means a disharmonious or antagonistic interaction between two individuals of the same species. As such, it could be a sociological term, but was actually coined by Alan Rayner and Norman Todd working at Exeter University in the late 1970s, to characterise a particular kind of zone line formed between wood-rotting fungal mycelia. Intraspecific antagonism is one of the expressions of a phenomenon known as vegetative or somatic incompatibility. Fungal individualism Zone lines form in wood for many reasons, including host reactions against parasitic encroachment, and inter-specific interactions, but the lines observed by Rayner and Todd when transversely-cut sections of brown-rotted birch tree trunk or branch were incubated in plastic bags appeared to be due to a reaction between different individuals of the same species of fungus. This was a startling inference at a time when the prevailing orthodoxy within the mycological community was that of the "u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonism (chemistry)
Chemical antagonists impede the normal function of a system. They function to invert the effects of other molecules. The effects of antagonists can be seen after they have encountered an agonist, and as a result, the effects of the agonist is neutralized. Antagonists such as dopamine antagonist slow down movement in lab rats. Although they hinder the joining of enzymes to substrates, Antagonists can be beneficial. For example, not only do angiotensin receptor blockers, and angiotensin-converting enzyme (ACE) inhibitors work to lower blood pressure, but they also counter the effects of renal disease in diabetic and non-diabetic patients. Chelating agents, such as calcium di sodium defeated, fall into the category of antagonists and operate to minimize the lethal effects of heavy metals such as mercury or lead. In chemistry, antagonism is a phenomenon wherein two or more agents in combination have an overall effect that is less than the sum of their individual effects. The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonism (phytopathology)
In phytopathology, antagonism refers to the action of any organism that suppresses or interferes with the normal growth and activity of a plant pathogen, such as the main parts of bacteria or fungi. These organisms can be used for pest control and are referred to as biological control agents. They may be predators, parasites, parasitoids, or pathogens that attack a harmful insect, weed or plant disease or any other organism in its vicinity. The inhibitory substance is highly specific in its action, affecting only a specific species. Many soil microorganisms are antagonistic. They secrete a potent enzyme which destroys other cells by digesting their cell walls and degrade the cellular material as well as released protoplasmic material serves as a nutrient for the inhibitor organism, for example ''Aspergillus'' has an antagonistic effect on ''Penicillium'' and '' Cladosporium''. ''Trichoderma'' has an effect on actinomycetes. ''Pseudomonas ''Pseudomonas'' is a genus of Gram-nega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflexive Antagonism
Reciprocal inhibition describes the relaxation of muscles on one side of a joint to accommodate contraction on the other side. In some allied health disciplines, this is known as reflexive antagonism. The central nervous system sends a message to the agonist muscle to contract. The tension in the antagonist muscle is activated by impulses from motor neurons, causing it to relax. Mechanics Joints are controlled by two opposing sets of muscles called extensors and flexors, that work in synchrony for smooth movement. When a muscle spindle is stretched, the stretch reflex is activated, and the opposing muscle group must be inhibited to prevent it from working against the contraction of the homonymous muscle. This inhibition is accomplished by the actions of an inhibitor interneuron in the spinal cord. The afferent of the muscle spindle bifurcates in the spinal cord. One branch innervates the alpha motor neuron that causes the homonymous muscle to contract, producing the reflex. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, rival," which is derived from ''anti-'' ("against") and ''agonizesthai'' ("to contend for a prize"). Types Heroes and villains The antagonist is commonly positioned against the protagonist and their world order. While most narratives will often portray the protagonist as a hero and the antagonist as a villain, like Harry Potter and Lord Voldemort in ''Harry Potter'', the antagonist does not always appear as the villain. In some narratives, like Light Yagami and L in ''Death Note'', the protagonist is a villain and the antagonist is an opposing hero. Antagonists are conventionally presented as making moral choices less savory than those of protagonists. This condition is often used by an author to create conflict within a story. This i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
