9,738 research outputs found

    Party politics in Belize

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    The aim of this paper will be to describe and evaluate the party system of Belize within its historical context as an agency of political development. Toward this end it shall be necessary to outline the governmental structure, to classify the party system within the framework of a morphology of party systems, and to explore the history, ideology and present status of the respective parties. These various considerations will be preparatory to an analysis of the question of whether Belizean political parties are in the procress of constructing a modern political system

    The Relation of the Membrane Potential and Resistance of Nitella to Ion Fluxes

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    The results of this study indicate membrane resistance of Nitella cannot be related to passive fluxes of ions as classical interpretation suggests. When a hyperpolarizing current of about 0. 6 µ amp cm-2 was passed through the membrane, with 42K present in the external solution, it was found that 50% of the current was carried by K+. The increase in K+ influx was 40 times the value predicted by the Goldman passive model for the observed changes in potential. The large transference number for K+ is not in agreement with Kitasato\u27s conclusion that 95% of the cationic influx is due to H+. Membrane potential measurements and tracer studies of the major ions necessitate proposal of an active electrogenic cation efflux. Previous work suggests this is H+ extrusion. The depolarizing effects of increased external [H+] and DNP are explained as decreases in the rate of electrogenic H+ extrusion. Evidence against passive H+ fluxes is presented. Tracer studies also indicate a component of K+ transport which in most cases acts differently from a simple passive mechanism for K+ uptake. The depressing effects of increased external [H+] and DNP on the rate of active H+ extrusion and active K+ influx suggest the H+ pump can act partially as a H+/H+ or H+/K+ exchange pump. The simplest way of accounting for the large K+ transference number would be that the K+ current travels through the electrogenic mechanism

    Foreword to Symposium on School Finance Litigation: Emerging Trends or New Dead Ends?

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    Equality of educational opportunity is an elusive goal. Advocates for underprivileged students have pursued it relentlessly in the courts since the landmark decision fifty years ago in Brown v. Board of Education. Yet children across the United States still attend schools that are both separate and unequal. The United States contains approximately 15,000 school districts. This fragmentation, along with the Supreme Court\u27s decision in Milliken v. Bradley to prohibit mandatory busing across district lines, allows patterns of residential segregation to produce segregated schools. In 2000-01, seventy-two percent of African-American and seventy-six percent of Latino students attended predominantly minority schools. Thirty-seven percent of African- American and Latino students attended schools that were 90-100% minority. One-sixth of African-American and one-ninth of Latino students attended schools that were 99-100% minority

    Optical characterization of LDEF contaminant film

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    Dark brown molecular film deposits were found at numerous locations on the Long Duration Exposure Facility (LDEF) and have been documented in great detail by several investigators. The exact deposition mechanism for these deposits is as yet unknown, although direct and scattered atomic oxygen, and solar radiation interacting with materials outgassing products have all been implicated in the formation process. Specimens of the brown molecular film were taken from below the flange of the experimental tray located at position D10 on the LDEF. The tray was one of two, comprising the same experiment, the other being located on the wake facing side of the LDEF satellite at position B4. Having access to both trays, we were able to directly compare the effect that orientation with respect to the atomic oxygen flux vector had on the formation of the brown molecular film deposits. The film is thickest on surfaces facing toward the exterior, i.e. the tray corner, as can be seen by comparing the lee and wake aspects of the rivets. The patterns appear to be aligned not with the velocity vector but with the corner of the tray suggesting that flux to the surface is due to scattered atomic oxygen rather than direct ram impingement. The role of scattered flux is further supported by more faint plume patterns on the sides of the tray. The angle of these plumes is strongly aligned with the ram direction but the outline of the deposit implies that incident atoms are scattered by collisions with the edges of the opening resulting in a directed, but diffuse, flux of atomic oxygen to the surface. Spectral reflectance measurements in the 2 to 10 micron (4000 to 1000 wavenumbers) spectral range are presented for the film in the 'as deposited' condition and for the free standing film. The material was analyzed by FTIR (Fourier Transform Infrared) microspectroscopy using gold as the reference standard. The 'as deposited' specimen was on an aluminum rivet taken from beneath the tray flange while the free film was obtained by chipping some of the material from the rivet. The transmission spectrum over the 2 to 10 micron range for the free film is presented. This spectrum appears to be essentially the same as that presented by Crutcher et.al. for films formed at vent sites which faced into the ram direction and suggested to originate from urethanes and silicones used on the LDEF. Banks et. al. state that silicones, when exposed to atomic oxygen, release polymeric scission fragments which deposit on surfaces and form a glassy, dark contaminant layer upon further atomic oxygen exposure and solar irradiation
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