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/nat·u·ral/ (nach´ah-r'l) neither artificial nor pathologic.

family planning, natural

methods of preventing conception without the use of artificial contraceptive means. Also called fertility awareness methods. See also contraception.


Substance abuse A substance causing euphoria and analgesia at the desired abuse levels and physical dependence and CNS depression, stupor, coma and death in excess. See Opiates.
Narcotic types
Natural Products extracted from the poppy plant, yielding morphine and heroin, or the coca plant, yielding cocaine and crack
Semi-synthetic Products with opiate activity, eg meperidine and methadone or synthetics, see MPTP; under the umbrella term of narcotic, alkaloids, eg LSD, mescaline, barbiturates, alcohol, marijuana, cocaine, hallucinogens and stimulants, eg antidepressants.
Completely synthetic Products created by synthesis alone, eg fentanyl  


occurs in nature, without the intervention of humans.

natural experiments
occur by chance when all variables for a population are constant except one, which is different for one large part of the population compared with the other, e.g. when half of a flock comes from one climate and the other half is a local resident in another climate.
natural focus
the ecology that is best suited to a biological system, e.g. an individual insect-borne disease; the area in which the disease naturally flourishes best; an ecological niche.
natural history
history of a process or organism as it occurs in nature, e.g. course of a disease from infection to resolution.
natural killer (NK) cell
see natural killer cell.
natural selection
selection occurring in nature, without any human intervention, direct or indirect.
natural ventilation
ventilation without the use of artificially induced energy and the machines which it drives; the forces used are wind and the exchange of heat from within the barn and the external air, controlled by ventilation devices in the walls and the ceiling.

Patient discussion about natural

Q. What is the best natural cure for migraines? Every day I hear something else... would love it if you can share your experience...I'm sick of chemicals:)

A. stay off any products that have a any kind of a caffine content, including chocolate. try this for 3wks, ypu should notice a difference

Q. Is there a recommended natural cure for graves disease? I've been suffering from graves for a year now and really feel tired of it. I'm thinking of trying some natural medications cause the regular ones are dissapointing so far. Any experience with that??

A. I am not familiar with any natural supplements you can take for graves disease, furthermore, it is an illness where you should be on close monitoring of an endocrinologist, and have them tell you which medications you are allowed to take and what could make the situation worse. If regular treatment doesn't seem to help you much you should go for another check up to see how your thyroid is doing.

Q. Is there a natural cure for hpv?

More discussions about natural
References in periodicals archive ?
In the literature the common view is a trade-off between internal and external validities, and natural experiments lie in the middle of the scale (16).
I leave the last word to Acemoglu and co-workers in Chapter 7 of Natural Experiments of History.
There were 7 randomized controlled trials, controlled clinical trials, or natural experiments with a treatment/no treatment comparison.
The standard approach to identifying the elasticity has been to use natural experiments generated by changes in the progressivity of the income tax.
Despite the strong relationships revealed by the observational studies and natural experiments, results from nonmanipulative studies were equivocal.
They are generated by well-designed analyses, but even the best natural experiment does not have the power of a controlled laboratory experiment, so we (and the authors) must apply some prior judgment.
Recently, however, two studies, each utilizing data on a treatment and control group of temporarily impaired workers, have employed natural experiments to examine the impact on the duration of work absence of an increase in benefits.
Component A: To support a 5-year multi-center research network of innovative, non-health system-based, natural experiments approaches to alter the diabetogenic characteristics of US communities.
Just as medicine increasingly has relied on clinical trials rather than observational studies to understand the effects of drugs, diet, and behavior on human health, economists have increasingly published the results of natural experiments in which people are exposed to pollutants in a manner that is plausibly random and health effects are observed.
The evaluation explores the impact of FDK as compared to half-day kindergarten (HDK) by utilizing data from natural experiments occurring in districts across the state.
The Sun makes fantastic natural experiments that allow us to test our ideas about its effects on the climate," lead author of a report newly published in Geophysical Research Letters Prof.
It begins with a description of the differences between formal experiments and natural experiments.

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