The Distribution of X-Ray Induced Crossovers from Curly Inversion Heterozygotes of Drosophila melanogaster Females

That crossing may occur in oogonial cells was suggested by the results of experiments by Whittinghill [1] in which crossing over was induced by x-rays in the X-chromosomes of Drosophila females homozygous for the c3G asynaptic factor. It had previously been demonstrated that induced crossovers recovered from Drosophila males were of spermatogonial origin [2,3]. Cooper's observations [4] of chiasmata in gonial cells of both sexes of Drosophila may provide cytological foundations for the hypothesis of gonial origin of some crossovers, particularly those which are x-ray induced. Somatic crossing over, the basis for the occurranece of twin spots in the hypodermis of Drosophilamales and females [5], closely parallels gonial crossing over in the formation of daughter cells which have become homozygous distally. The possible consequences of oogonial crossing over upon linking data, as recently discussed by Whittinghill [6], illustrate the need for further investigation of this phenomena. This paper reports the results of x-ray induced crossing over in Curly inversion heterozygotes of Drosophila melanogaster females, and these results are interpreted in relation to normal, or random, meiotic events as opposed to oogonial events of recombination

Collection and analysis of radar rainfall and satellite data for the Darwin TRMM experiment

The following subject areas are covered: video cloud camera (purpose, design, operation, data); special observing periods (SOP-2, SOP 2.5 - an extension of SOP-2); Garand algorithm; and warm rain

A simulator investigation of the use of digital data link for pilot/ATC communications in a single pilot operation

Studies have shown that radio communications between pilots and air traffic control contribute to high pilot workload and are subject to various errors. These errors result from congestion on the voice radio channel, and missed and misunderstood messages. The use of digital data link has been proposed as a means of reducing this workload and error rate. A critical factor, however, in determining the potential benefit of data link will be the interface between future data link systems and the operator of those systems, both in the air and on the ground. The purpose of this effort was to evaluate the pilot interface with various levels of data link capability, in simulated general aviation, single-pilot instrument flight rule operations. Results show that the data link reduced demands on pilots' short-term memory, reduced the number of communication transmissions, and permitted the pilots to more easily allocate time to critical cockpit tasks while receiving air traffic control messages. The pilots who participated unanimously indicated a preference for data link communications over voice-only communications. There were, however, situations in which the pilot preferred the use of voice communications, and the ability for pilots to delay processing the data link messages, during high workload events, caused delays in the acknowledgement of messages to air traffic control

Gamma-ray emission associated with Cluster-scale AGN Outbursts

Recent observations have revealed the existence of enormously energetic ~10^61 erg AGN outbursts in three relatively distant galaxy clusters. These outbursts have produced bubbles in the intra-cluster medium, apparently supported by pressure from relativistic particles and/or magnetic fields. Here we argue that if > GeV particles are responsible then these particles are very likely protons and nuclei, rather than electrons, and that the gamma-ray emission from these objects, arising from the interactions of these hadrons in the intra-cluster medium, may be marginally detectable with instruments such as GLAST and HESS.Comment: 8 pages, 4 figures, accepted by MNRA

A Decision Support System for Joint Force Air Component Commander (JFACC) Combat Planning

This system allows assessment of the Master Air Attack Plan (MAAP) during construction and at completion. The system functions around a relational database management system providing a decision support tool for the Guidance, Apportionment, & Targeting (GAT) cell of Central Command\u27s JFACC Combat Plans. A Microsoft Access application is programmed to provide PC-based, real time evaluation of air campaign goals and constraints. The decision support system was validated in February 1997 by the CENTAF combat plans staff at Blue Flag 97-1. The software and user\u27s manual are maintained at HQ ACC/XP-Studies and Analysis Squadron

Citizens\u27 understandings of the Vocational Agriculture Department in the Church Hill High School

The purpose of this study was to find out what citizens know about the vocational agriculture department in the Church Hill High School. The specific areas included are the administrative policies, teacher, finance, course of study, facilities, Future Farmers of America, and out of School classes