General Recognition

Radiocarbon dating (43) has probably gained the widest general recognition (see Radioisotopes). Developed in the late 1940s, it depends on the formation of the radioactive isotope and its decay, with a half-life of 5730 yr. After forms in the upper stratosphere through nuclear reactions of... 

Figure 8.15 Sequence-specific protein-DNA interactions provide a general recognition signal for operator regions in 434 bacteriophage, (a) In this complex between 434 repressor fragment and a synthetic DNA there are two glutamine residues (28 and 29) at the beginning of the recognition helix in the helix-turn-helix motif that provide such interactions with the first three base pairs of the operator region.

General conditions for general recognition as safe, effective, and not misbranded Over-the-counter drug products intended for oral ingestion that contain alcohol... 

General recognition of safety. The US FDA has defined GRAS to mean that there is a reasonable certainty in the views of competent scientists that the substance is not harmful under the intended conditions of use. 

There is general recognition that large additional quantities of CO2 emitted into our atmosphere contribute to the green house climate effect. 

A reasonable certainty in the minds of competent scientists that the substance is not harmful under the intended conditions of use. It is impossible in the present state of scientific knowledge to establish with complete certainty the absolute harmlessness of the use of any substance therefore, safety may be determined by scientific procedures or by general recognition of safety. In determining safety, the following factors shall be considered ... 

Qualified experts must conclude that there is a general recognition of safety for the substance. 

There is general recognition that selectivity for the addition of hydrogen to one compound rather than another in a mixture, or to a particular double bond in a compound which has multiple unsaturation, depends upon the catalyst and the conditions. The illustrated structure-reactivity correlations afford an estimate of the degree of selectivity which may be achieved when adsorption is adequately reversible. The later is aided by a weakening of the attraction between the double bond and the metal center of the catalyst. There are circumstances when the opposite selectivities are desired and kinetic control of adsorption may be required. This aspect of selectivity is not addressed here. 

Competition studies from Szwarc s group provided excellent quantitative insights into the relative affinities of methyl and trifluoromethyl radicals for a host of alkenes [86-88], and from this work came the first general recognition that substituted alkyl radicals could exhibit polar characteristics ranging from nucleophilic to electrophilic. On the basis of such early work, methyl and trifluoromethyl were taken to be the prototypical nucleophilic and electrophilic radicals, respectively, characterizations which it turns out are somewhat exaggerated in both cases. 

Though the Milankovitch conception has recently obtained further (but not general) recognition, its individual aspects have been subject to critical analysis. There are two reasons for this. 

There is no general recognition of MCS in the medical establishment, because of a lack of consensus about whether or not it is a distinct medical condition. The confusion is caused by a lack of a conclusive medical-scientific explanation for MCS, although several possible causes and mechanisms have been proposed. See entry 27-... 

This reaction, reported in 1960, has been shown not only to be one of the most useful photochemical processes for selective functionalization of an unactivated carbon atom in organic synthesis, but has also led to general recognition of the utility of photochemical and radical reactions in organic synthesis. 

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