Proximal Instability

George Kaplan has shown that US states with greater inequality have higher rates of violence, more disability, more people without health insurance, less investment in education and literacy, and poorer educational outcomes, all of which he calls structural characteristics. Moreover, the socioenvironmental characters of population areas are importantly related to the mortality rates, independent of the characters of individuals. In addition, personal and socioeconomic risk factors cluster together in areas of low income and high mortality. In a thorough local study of Alameda County, California, Kaplan examined parts of the pathways linking social class and mortality. His basic claim is that health inequality is correlated to social instability, which is in turn correlated to the lack of investment in structural characteristics, such as education, proximity of healthful food outlets, pharmacies, accessibility of transportation, etc. 

The conclusions from this rather elementary survey of the symmetry constraint problem all point in the same general direction. The imposition of symmetry constraints (other than the Pauli principle) on a variationally-based model is either unnecessary or harmful. Far from being necessary to ensure the physical reality of the wave function, these constraints often lead to absurd results or numerical instabilities in the implementation. The spin eigenfunction constraint is only realistic when the electrons are in close proximity and in such cases comes out of the UHF calculation automatically. The imposition of molecular spatial symmetry on the AO basis is not necessary if that basis has been chosen carefully — i.e. is near optimum. Further, any breakdowns in the spatial symmetry of the AO basis are a useful indication that the basis has been chosen badly or is redundant. 

Compounds which contain both oxidising and reducing functions in close proximity on a molecular basis tend towards explosive instability, and usually with low energy of activation. Relevant types are salts of reducing bases with oxidising acids, and metal oxosalts with coordinated nitrogenous reducants. 

The origin of ihe instability of N-acylpyridiniunn salts and iheir quinolilniutn counterparts is the proximity of the positive charge on nitrogen to the positive end ol the dipole of the carbonyl group. 

Recently, a nonspecific enzyme capable of degrading the precursor was extracted from Navel orange albedo (63). Nicol and Chandler (63) used a proximate assay for the degrading enzyme that is, the substrate was not identified except as a limonin precursor. The crude extracts from albedo contained degradation activity that was concentrated by 40 to 60% saturation with (NH J SO. Instability of the enzyme prevented further purification. 

Occlusions find their way into the crystal structure when the supersaturation in close proximity to the crystal surface is high enough to lead to an unstable surface. Such instability leads to the creation of dendrites, which then join to trap mother liquor in pools of liquid within the crystal. Occlusions are often visible and can be avoided through careful control of the supersaturation in the crystallizer. 

Atoms are first stripped of their electrons at very high temperatures this creates a plasma (ionized gas) of positive ions. Then the positive ions must be brought into close enough proximity, so that the strong attractive force between nucleons can overwhelm the Coulomb repulsion between them. Magnetic fields can confine hot plasmas of ions, provided that collective instabilities of these plasmas can be controlled. For a successful nuclear fusion reactor, three requirements must be met (1) The density of the plasma must exceed some critical value p. (2) The plasma confinement time must exceed some critical value t. (3) The temperature of the plasma must exceed some critical value 9... 

The marked instability of aspirin is due to two structural features one, that it is an aromatic ester and, for reasons previously discussed, it is, therefore, more labile than an aliphatic ester and two, the ortho relationship of the acetoxy group to the carboxylate. Owing to this proximity, aspirin is subject to intramolecular catalysis of the ester hydrolysis. The pATa of aspirin is 3.6, and, therefore, it exists predominately... 

All of these causes may be expected in practical Hall cells. The vertical magnetic field is caused by horizontal currents around the cell (adjacent potline, ring bus, etc.) and by position dependent horizontal current in the aluminum and collector bars the field varies with proximity to these currents. The current flow is predominantly vertical across the electrolyte between anode and metal, because of the high resistivity of the electrolyte, but develops significant horizontal components on entering the much more conductive metal. In practice, all of these mechanisms can be related to instabilities... 

Thibodeau SN, Bren G, Schaid D. Microsatelhte instability in cancer of the proximal colon. Science 1993 260 816-9. 

Some visual stress grading rules limit the growth rate and exclude all pith. There are two separate issues. The exclusion of with-pith material is understandable as corewood in its vicinity has a number of undesirable characteristics, including low density, low stiffness, and dimensional instability. However, a restriction on growth rate is less satisfactory unless it is coupled with a criterion that addresses ring curvature to ensure that such sorting only excludes material in proximity to the pith. 

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