Planetary camera control improves microfiche production

Microfiche is prepared using an automatic control system for a planetary camera. The system provides blank end-of-row exposures and signals card completion so the legend of the next card may by photographed

HOW TO MAKE SCANSION EARN ITS KEEP IN SCHOOLS

Some years ago, when asked for comr. . .!nts on the new core syllabus for Senior Certificate Latin, I suggested that scansion be eliminated. My reasons were twofold: for one thing I felt that the mark allocation simply did not justify the amount of time needed to master the skill. (One is acutely conscious of "cost-effectiveness" these days.) Secondly, in 25 years of lecturing I have never found a first-year student - and I must include myself- who proved, by the ability to read Latin verse as verse, that scansion was anything more than an artificial exercise devised for its own sake. (The utilitarian argument again.) I am not now justifying the retention of a difficult hurdle for pupils to surmount, invoking the witty adage that invention is the mother of necessity. There is a practical reason to recommend scansion: clearly the sound of language was of major importance to the Romans, as readers used to read aloud to themselves, and the recitatio was a common event in the life of litterateurs especially under the early Empire. Since the current format of examination papers shows how far pupils' literary critical originality and frank opinion are encouraged, I now hope to give some practical help to teachers to prepare their charges a puero for an enjoyable and rewarding encounter with scansion

Some Aspects of Position Pseudoallelism

Contrasting interpretations of position pseudoallelism are discussed, and the types of position effect which characterize this phenomenon are illustrated, with special reference to the case of the bithorax series of five pseudoallelic loci in Drosophila melanogaster. Most of the results in this latter case can be simply interpreted on the basis of a chain of gene-controlled reactions in which each intermediate substance is postulated to act in a dual capacity: as substrate for the succeeding reaction and as a determiner of a specific physiological process. The model also gives a consistent picture of the way in which different levels of developmental determination may be controlled by the different genes of the series

Some Aspects of Position Pseudoallelism

Contrasting interpretations of position pseudoallelism are discussed, and the types of position effect which characterize this phenomenon are illustrated, with special reference to the case of the bithorax series of five pseudoallelic loci in Drosophila melanogaster. Most of the results in this latter case can be simply interpreted on the basis of a chain of gene-controlled reactions in which each intermediate substance is postulated to act in a dual capacity: as substrate for the succeeding reaction and as a determiner of a specific physiological process. The model also gives a consistent picture of the way in which different levels of developmental determination may be controlled by the different genes of the series

An affine generalization of evacuation

We establish the existence of an involution on tabloids that is analogous to Schutzenberger's evacuation map on standard Young tableaux. We find that the number of its fixed points is given by evaluating a certain Green's polynomial at $q = -1$, and satisfies a "domino-like" recurrence relation.Comment: 32 pages, 7 figure

Barium release system

A chemical system is described for releasing a good yield of free barium neutral atoms and barium ions in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium. The barium is released in the vapor phase so that it can be ionized by solar radiation and also be excited to emit resonance radiation in the visible range. The ionized luminous cloud of barium becomes a visible indication of magnetic and electrical characteristics in space and allows determination of these properties over relatively large areas at a given time

Sequence analysis of the cis-regulatory regions of the bithorax complex of Drosophila

The bithorax complex (BX-C) of Drosophila, one of two complexes that act as master regulators of the body plan of the fly, has now been entirely sequenced and comprises approximate to 315,000 bp, only 1.4% of which codes for protein. Analysis of this sequence reveals significantly overrepresented DNA motifs of unknown, as well as known, functions in the nonprotein-coding portion of the sequence. The following types of motifs in that portion are analyzed: (i) concatamers of mono-, di-, and trinucleotides; (ii) tightly clustered hexanucleotides (spaced less than or equal to 5 bases apart); (iii) direct and reverse repeats longer than 20 bp; and (iv) a number of motifs known from biochemical studies to play a role in the regulation of the BX-C. The hexanucleotide AGATAC is remarkably overrepresented and is surmised to play a role in chromosome pairing. The positions of sites of highly overrepresented motifs are plotted for those that occur at more than five sites in the sequence, when <0.5 case is expected. Expected values are based on a third-order Markov chain, which is the optimal order for representing the BXCALL sequence

Rocket having barium release system to create ion clouds in the upper atmosphere

A chemical system for releasing a good yield of free barium atoms and barium ions to create ion clouds in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium is presented