Naphthyridinomycin, a new broad-spectrum antibiotic

A new antibiotic, naphthyridinomycin, was isolated in crystalline form from the culture filtrate of Streptomyces lusitanus AY B-1026. The antibiotic is active against a large number of both gram-positive and gram-negative bacteria, and inactive against Candida albicans, Trichophyton granulosum and Microsporum gypseum. The antibiotic is toxic in mice.

Influence of longitudinal vibrations on the diffraction images of bright incoherent disks

The intensity distribution in the images of uniform bright incoherent disks is obtained in the presence of longitudinal vibrations by using the Fourier Hankel transform method. Results are given in graphical form for disks with various diameter values. It is observed that in certain cases the presence of longitudinal vibrations completely distorts the object. Hence a detailed analysis of image intensity distribution should prove useful to those engaged in interpretation of photographs in aerial reconnaissance work.

Characteristic fringe function for time-average holography of periodic nonsinusoidal vibrations

In this paper the characteristic fringe function of hologram interferometry has been evaluated for the case of periodic, nonsinusoidal vibrations represented by a Jacobian elliptic function. To consider the reconstructed holographic image of an object, use has been made of an equation derived from considerations of the effect of motion on coherence. Graphical representation of the fringe irradiance distribution in the reconstructed image is given. It is shown that, as the motion departs from pure sinusoidal form, the intensity of the fringes increases considerably as compared with that for a pure sinusoidal case.

Diffraction images of truncated sine and square wave periodic objects in the presence of linear image motion

Intensity distribution in the diffraction images of truncated one-dimensional periodic objects formed in the presence of linear image motion by a diffraction-limited optical system has been studied. Incoherent sine and square wave objects have been considered with a various number of cycles and for various degrees of image motion. The graphical presentation of results clearly shows the degradation in the image due to linear motion blur. Image contrast and average irradiance have been tabulated for a number of cases. For certain values of the motion parameter spurious resolution results. It has been found that the number of periods in the target required to approximate a target with infinite number of periods in the presence of linear motion is more than that in the absence of motion. For certain values of linear motion blur, the contrast remains zero irrespective of the number of periods considered.