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1. Music
a. not sharp or flat
b. denoting a note that is neither sharp nor flat
c. (of a key or scale) containing no sharps or flats
2. Music of or relating to a trumpet, horn, etc., without valves or keys, on which only notes of the harmonic series of the keynote can be obtained
3. Cards
a. (of a card) not a joker or wild card
b. (of a canasta or sequence) containing no wild cards
c. (of a bid in bridge) describing genuine values; not conventional
4. based on the principles and findings of human reason and what is to be learned of God from nature rather than on revelation
5. Music
a. an accidental cancelling a previous sharp or flat.
b. a note affected by this accidental
6. Pontoon the combination of an ace with a ten or court card when dealt to a player as his or her first two cards

tropical year

tropical yearclick for a larger image
The period between two successive vernal equinoxes, the time the earth takes to complete one orbit around the sun relative to the first point of Aries. Its length was 365 days 5 h 48 min and 45.19 s in 2000, and it is changing by 0.00000006162 x y days (y in Julian years from 2000), or about 5 milliseconds/year. The tropical year differs from the solar year by 1 part in 26,000, since this is the period of the earth's precession about its rotational axis combined with the precession of the perihelion of the earth's orbit. Also called an astronomical, equinoctial, natural, or solar year. It contains one complete cycle of seasons.


An integrated 4GL from Software AG, Germany. The menu-driven version is SUPER/NATURAL.

Natural 2 is a major upgrade to Natural 1.

Version 2.1.7 in the MVS environment (June 1995, also available for Unix).

Natural works with DB2 and various other databases, but Natural and Adabas normally go together. There are many products available in the "Natural" family, including SuperNatural, Natural for Windows, Entire Connection (enables up/downloading and interaction with Excel) and Esperant.


An earlier fourth-generation language from Software AG, Reston, VA, that ran on a variety of computers from micro to mainframe. See fourth-generation language.
References in periodicals archive ?
Except for their definition, while dealing with natural experiments, the "as-if" part can be easily omitted: natural experiments are so favorable because they are seemingly as randomized as usual experiments.
The idea of natural experiments seems problematic mostly because treatment randomization is extremely difficult to claim in observational studies.
The set of samples satisfying the expected exchangeability condition is larger than the set of those satisfying the treatment randomization condition, which increases the possibility of justification of natural experiments.
Qualitative conclusions are a common shortcoming of the use of natural experiment, as Diamond clearly knows.
However, there is no natural experiment by which we can test his idea unless we can find for comparison a number of accessible earth-like planets with biospheres.
First, the theory largely relates to compensated elasticities, whereas the natural experiments provide information primarily on the uncompensated effects.
Of course, natural experiments with these data suffer from all the standard problems mentioned above.
In addition, the natural experiments are not on the same types of taxpayers in each tax change.
13) I also have looked at natural experiments increasing the education infrastructure, for example a large-scale expansion of higher education in the West Bank and Gaza Strip.
My most recent research on school resources, joint with Lavy, (7) exploits a natural experiment arising from the fact that the Israeli State lottery, which uses lottery profits to sponsor various social programs, funded a large-scale computerization effort in many elementary and middle schools.
In my first study of school resources, also joint with Lavy, (9) we use Maimonides' rule capping class size at 40 to construct a natural experiment to estimate the effects of class size on the scholastic achievement of Israeli pupils.
Based on data from a natural experiment, he showed that immigration does not have a negative effect on the labor market of the receiving country.

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