Influence of Different Y Chromosomes on Secondary Nondisjunction in D. Melanogaster (open access)

Influence of Different Y Chromosomes on Secondary Nondisjunction in D. Melanogaster

Females heterozygous for a wildtype X chromosome from a Samarkand stock and an chromosome of the composition [formula] were tested for the frequency of X-chromosomal non-disjunction and segregation of the X's when Y chromosomes of different types were present in the females. The Y chromosomes used were 1) a normal unmarked Y, 2) [formula], 3) [formula] and 4) [formula] (a chromosome which arose in one of our experiments and has not yet been analyzed). Since this was only a preliminary test no attempt was made to isogenize the stocks. Larger scale experiments are planned in which these and other Y's will be used and the genetic background will be strictly controlled.
Date: January 18, 1962
Creator: Hildreth, P.
System: The UNT Digital Library
The Tides: A Dynamic Explanation Based Upon Fundamental Physical Concepts (open access)

The Tides: A Dynamic Explanation Based Upon Fundamental Physical Concepts

A model is proposed to directly relate observed tidal action with orbital movements of the moon and the earth. The basic model consists of a unit mass acting as a free point on the rotating earth's surface and being carried into a field gradient. The field is such as to cause the free point to "fall" along the surface, gain a velocity with respect to the earth's surface, and thus produce a tidal interaction at coastal barriers. Gyroscopic and resonant oscillatory current effects are not treated.
Date: January 1962
Creator: Pratt, Ira P., Jr.
System: The UNT Digital Library
Nine-Channel Polychromator For Observation Of Time-Dependent Spectral Line Profiles (open access)

Nine-Channel Polychromator For Observation Of Time-Dependent Spectral Line Profiles

The instrument (polychromator) described observes time-dependent spectral-line profiles by simultaneous measurement at nine different wavelengths of light intensity as a function of time. A cylindrical lens magnifies the dispersion of a Jarrell-Ash Model S2000 Ebert Monochromator and forms an image on a light-pipe solder. Light pipes transfer light from various sections of the image--i.e., different wavelengths--to photomultiplier tubes, and the responses are displayed on oscilloscopes. The instrument has been used to look at total wavelength spans of 15 A and 20 A.
Date: January 22, 1962
Creator: Spillman, George R. & Cooper, William S., III
System: The UNT Digital Library