A measure of the variation shown by a set of observations, defined by the sum of the squares of deviations from the mean, divided by the number of degrees of freedom in the set of observations.
n. see standard deviation.
DC.
Synonym: N. grandiflora DC.
Family: Valerianaceae.
Habitat: Alpine Himalayas, Kumaon, Sikkim and Bhutan.
English: Spikenard, Musk-root.
Ayurvedic: Maansi, Jataamaansi, Bhuutajataa, Tapaswini, Sulo- mashaa, Jatilaa, Naladaa.
Unani: Sumbul-e-Hindi, Sambul-ut- Teeb, Naardeen-e-Hindi, Baalchhar.
Siddha/Tamil: Sadamanchil.
Action: Used as a substitute for Valerian. Tranquilizer, sedative, hypotensive. Used for the treatment of epilepsy, hysteria, convulsive affections, palpitation of heart and in intestinal colic. A decoction of powdered roots is prescribed as a home remedy for high blood pressure. It is used in dysmenorrhoea for pain relief and smooth menstrual flow. It is used in hair oil for arresting hair loss and greying of hair.
The Ayurvedic Pharmacopoeia of India recommends dry rhizomes in obstinate skin diseases, erysipelas, disturbed mental state and insomnia.The rhizome is rich in sesquiter- penoids. The crude drug gave an oil (yield 2.5% v/w), which contains d- nardostachone, valeranone and jata- mansone as the major ketonic sesqui- terpenes. The oil potentiated phenobarbital narcosis in rats, reduced brain serotonin content and decreased the conditioned avoidance performance in cats.Jatamansone was shown to exert tranquilizing effect in mice and monkeys. In rabbits, jatamansone was found to impair biosynthesis of serotonin in the brain leading to a reduction in brain level of 5-hydroxytrypta- mine. The degradation of serotonin was unaffected. The mode of action of jatamansone was thus in variance with that of reserpine which has direct action on the cell to liberate serotonin.On the other hand, the alcoholic extract of the roots of Indian Nard caused an overall increase in the levels of central monamines, 5-hydroxy indole acetic acid and the inhibitory amino acids, gamma-aminobutyric acid, norepinephrine, dopamine and serotonin in rat brain.In a clinical trial on hyperkinetic children, jatamansone showed significant reduction in hyperactivity and improvement in restlessness and aggressiveness, almost at par with D- amphetamine.The volatile oil was found to be less active than quinidine in several tests. It did not counteract digitalis induced ventricular arrhythmias.Jatamansone semicarbazone, a sesquiterpene ketone, was found to possess antiestrogenic activity.N. jatamansi is also used in place of Muraa (Selinum tenuifolium Wall. ex DC.)
Dosage: Root—2-3 g powder; 5-10 g for infusion; 50-100 ml infusion. (API, Vol. I; CCRAS.)... nardostachys jatamansi
1 The quality of being sharply defined or stated. One measure of precision is the number of distinguishable alternatives from which a measurement was selected, sometimes indicated by the number of significant digits in the measurement. Another measure of precision is the standard error of measurement, the standard deviation of a series of replicate determinations of the same quantity. Precision does not imply accuracy. 2 In statistics, precision is defined as the inverse of the variance of a measurement or estimate.... precision
a framework designed to improve communication between health-care professionals and patients with dementia. It consists of four stages – validation, emotion, reassurance, and activity – which enable staff to acknowledge their patients’ perception of a situation, even where this is at variance with reality.... vera
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