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Notes: A picosecond pulse (〈1.8 ps) at 8570 A(ring) is successfully generated by a gain switching method in an optically pumped GaAs/AlGaAs multiquantum well laser with a cavity length of 155 μm. This is the narrowest pulse width so far achieved in semiconductor lasers without the external cavity. We believe that this short pulse generation results from the enhanced differential gain due to the two-dimensional properties of the carriers in the quantum wells.

Notes: We study experimentally and theoretically the influence of interface roughness on the mobility of two-dimensional electrons in modulation-doped AlAs/GaAs quantum wells. It is shown that interface roughness scattering is the dominant scattering mechanism in thin quantum wells with a well thickness Lw〈60 A(ring), where electron mobilities are proportional to L6w, reaching 2×103 cm2/V s at Lw∼55 A(ring). From detailed comparison between theory and experiment, it is determined that the "GaAs-on-AlAs'' interface grown by molecular beam epitaxy has a roughness with the height of 3–5 A(ring) and a lateral size of 50–70 A(ring).

Notes: Summary The incidence of endotoxemia was studied in 17 patients who underwent ultrasonic lithotripsy (USL), and compared with the incidence in 11 patients who underwent transurethral resection (TUR) and in 8 patients who underwent other operations. Fourteen of 17 patients (82%) who underwent ultrasonic lithotripsy had endotoxemia. The incidence of endotoxemia after USL was significantly higher than that after TUR (9%) or after other operations (12.5%). Only 2 of the 17 patients (12%) who underwent USL had bacteremia. The organisms isolated were P. mirabilis and S. sanguis, respectively. Six of the 14 patients with endotoxemia after USL suffered high fever. These data suggest that endotoxemia is a factor which causes high fever after USL.

Notes: Summary We have recorded from 661 single neurons in the foveal and parafoveal region of area 17 of the awake trained macaque monkey. The functional properties of 538 cells were investigated in detail, with flashed and moving stimuli of varying form and colour. Irrespective of their functional properties such determined, each neuron was also tested with a 2×2° square of various luminance and colour. This was done in order to get an idea how such a simple stimulus is represented by the activities of neurons in area 17. Most of the neurons showed response preference for certain aspects of visual stimuli. We have distinguished the following functional groups: 1. Sustained spectrally selective neurons (21%). These cells respond with tonic discharges to light of their optimal wavelength, and their spectral selectivity corresponded to that of opponent parvocellular cells of the lateral geniculate body. 44% of these cells were excited selectively by long, 23% by middle and 33% by short wavelength light. When slowly moving the 2×2° square of their preferred wavelength across the receptive field, discharge rate remained elevated, as long as the stimulus covered the RF and with little contour enhancement. The majority of the sustained spectrally sensitive cells responded equally well or better to large than to small (1.0°) stimuli, 17.5% were less activated and few of them completely suppressed by larger stimuli. Such cells were poorly orientation sensitive. Only three cells with weak double opponency could be identified (2.7% of this group). 2. Broadband contour (18%) and 3. Panchromatic contour cells (41%). Most neurons of these two groups were strongly activated by spots (1°) centered on their RF. They showed a short phasic response to contrast borders and most of them responded to luminance contrasts, including contrast reversal and colour contrasts equated for luminance. The broadband contour cells showed a slight wavelength preference with only weak or without any opponent suppression, the panchromatic contour neurons did not show any wavelength selectivity. Most showed orientation or direction sensitivity, but very sharp orientation selectivity was less common in spectrally biassed than in panchromatic contour cells (see Fig. 11). They responded tonically to gratings of optimal orientation and therefore may play a role also for cortical representation of textures. 22% of a restricted sample of panchromatic contour cells (or 9% of all cells) were hypercomplex. 4. Light inhibited cells. 7% of all cells were inhibited by small and large light stimuli of any wavelength centered on their receptive field, and were tonically activated by darkspots or contrasts, comparable to the light inhibited cells of the parvocellular lateral geniculate layers. 5. Neurons without consistant visual responses (11%). These neurons could not be driven by any of our visual stimuli. They were usually found in the upper cortical layers. 61 cells were tested for monocular vs. binocular input. 96% were excited from both eyes with various degrees of ocular dominance, but more binocular cells were contralaterally than ipsilaterally dominated (43 and 22%, respectively). Binocular cells showed qualitatively the same functional properties from both eyes, including spectral selectivity if there was any. Binocular summation varied between cells and was in the average 0.7, probably due to interocular inhibition. Some columnar grouping of cells with similar response properties as defined above was found in vertical penetrations, but “mixed” penetrations were common. Spectrally selective cells with the same spectral preference or light inhibited cells often were found close to each other and in the same penetration, but also often mixed with other cells excited by parvocellular input. This spatial organization is consistant with a columnar segregation of cells excited predominantly by one type of parvocellular afferents on the one hand, and contour cells with a mixed excitatory and a strong inhibitory input, on the other hand, but also indicates a considerable mixing and overlap of functional inputs into any axis perpendicular to the cortical surface. The functional organization of area 17 is compared with that of the lateral geniculate body and the prelunate visual area (V4) as investigated with the same methods and by the same laboratory.

Notes: A new thermal conduction model is proposed for a polymer system filled with a mixture of several types of particles. Predicted values by the new model are compared with experimental data. The model is derived by extending a model that was previously proposed for a two-phase system. The following equation is derived from the new model: log λ = V · (X2 · C2 · log λ2 + X3 · C3 · log λ3 + (1 - V) log (C1 · λ1. When the thermal conductivities of polymer and particles (λ1, λ2, λ3, …) and a mixing ratio of particles (X2, X3, …) are known, thermal conductivity of the filled polymer (λ) with several types of particles can be estimated from the equation, with any volume content of particles (V). Furthermore, from each polymer-filler composite (two-phase system) data, the thermal conductivity of a composite filled with different filler particles can be estimated.