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Exciton interaction in a double-stranded helical polymer, such as a homogeneous polynucleotide, leads to a splitting of each excited electronic energy level of the monomer into two exciton bands of energy levels. Consideration of the selection rules derived from zeroth-order functions show that for double-stranded polynucleotides r + ?r* transitions are allowed to, at most, one exciton level of each band, both polarized perpendicularly to the helix axis: whereas, n -?r* transitions are allowed only to one level of the upper band, that being polarized parallel t o the helix axis. Examination of the spectral properties of the four constituents of deoxyribonucleic acid (DNA) reveals that although exciton bands probably exist in regions of spectral overlap, there should be isolated energy levels lying below the main exciton bands. These levels may act as localized energy traps during excitation propagation through the helix. In order to treat the problem of hypochromism, it is necessary to use first-order functions. An equation (similar t o one derived by Tinoco) is developed which takes into account the effect of exciton interaction and dispersion-force interaction on the oscillator strength of the helix. Application of this equatiox to a helical, double-stranded polyadenylic acid having the configuration of DNA indicates that perturbation resulting from dispersion-force interaction among the bases can account for the observed hypochromism.

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This article offers derrida's deconstruction as a philosophy and practical strategy that challenges the assumed, factual nature of "disability" as a construct explaining human differences. The appeal of deconstruction lies in the contradictory philosophy currently articulated by the inclusion movement, a philosophy that simultaneously supports the disability construct as objective reality while calling for students "with disabilities" to be placed in educational settings designed for students considered nondisabled. This article proposes deconstruction as one coherent philosophical orientation for inclusion, an approach that critiques the political and moral hierarchy of ability and disability. A deconstructionist critique of disability is explained and demonstrated. Practical suggestions for the utilization of deconstruction by special educators are outlined.

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