The field additivity of the M-cone pathway was measured with psychometric functions at 10 times absolute threshold on monochromatic fields and their mixtures. Observers detected a 500 nm test on 530 or 610 nm fields, and a 530 nm test on 481 or 622 nm fields. For both sets of wavelengths, field additivity held with the 1 deg test, 10 deg field condition which defines II-4 and with the 3.6 min a...

This paper presents an analysis of the 19.5 GHz clear-air signal level measurement variations over a line of sight link set up between two campuses of University of KwaZulu-Natal in Durban, South Africa. The measurement over the link spans a period of eleven months. An analytical expression for fade depth exceedance is proposed for KwaZulu-Natal, in South Africa. The link outage probability is ...

The newest dimension of the Digital Divide is access to broadband (high-speed) Internet service. Using comprehensive U.S. data covering all forms of access technology (chiefly DSL and cable modem), I look for evidence of unequal broadband availability in areas with high concentrations of poor, minority, or rural households. There is little evidence of unequal availability based on income or on ...

Extensive density functional theory calculations of the O1s binding energies, adsorption energies, and the experimentally measured in situ X-ray photoelectron spectra of oxygen on silver are reported in an effort to clarify which species are present during ethylene epoxidation. We find that the O1s binding energy of an oxygen adatom increases near linearly with its adsorption energy due to the ...

The involvement of defined regions of Escherichia coli 16S rRNA in the fidelity of decoding has been examined by analyzing the effects of rRNA mutations on misreading errors at the ribosomal A and P sites. Mutations in the 1400-1500 region, the 530 loop and in the 1050/1200 region (helix 34) all caused readthrough of stop codons and frameshifting during elongation and stimulated initiation from...

In this study of the electroretinograms of dragonflies (adults and nymphs) the objectives were to determine the number of classes of photoreceptors present in the visual system and to allocate these to particular morphological regions. There are probably five classes of photoreceptors present with peak sensitivities near 550, 530, 518, 420, and < 380 mmicro. The dorsal ocelli contain two classe...

We examined whether signals from rods and S cones can combine to produce a threshold response. Test flashes of specific wavelengths superposed on a long wavelength adapting field were used to isolate threshold responses from the two receptor systems, simultaneously and at the same retinal location. Dark adaptation experiments and spectral sensitivity determinations indicated that, in the adapta...

BACKGROUND Electrochemical approach to the assessment of acid-base states should provide a better mechanistic explanation of the metabolic component than methods that consider only pH and carbon dioxide. HYPOTHESIS/OBJECTIVES Simplified strong ion equation (SSIE), using published dog-specific values, would predict the measured serum pH of diseased dogs. ANIMALS Ten dogs, hospitalized for va...