The comparative performance of gas-focused and electron-lens-focused oscillographs at very high frequencies

We have shown that, by suitable idiotypic manipulation, BALB/c mice can express the major cross-reactive idiotype (CRI) of A/J mice in response to azophenylarsonate (Ars). In order to know if the CRIA idiotype is present in the potential repertoire of BALB/c before any intentional selection, we used polyclonal activation in vitro and limiting dilution analysis. The readout was done with two monoclonal anti-CRIA antibodies that recognize distinct idiotopes on a CRIA+ A/J germline-encoded monoclonal antibody. We studied the frequency of CRIA+ lipopolysaccharide (LPS)-reactive cells in the spleens of nonimmune and immune A/J mice and in the spleens of naive and manipulated (i.e., producing CRIA+ antibodies) BALB/c mice. A/J and BALB/c naive individuals presented very high frequencies of Ars-specific B cells while the frequency of CRIA+ B cells was only a minor subset (0.5%) of the total Ars-specific subset in the two strains. When A/J mice were immunized with Ars-keyhole limpet hemocyanin, a clear preferential expansion of the CRIA+ minor subset of A/J mice was observed (100x). No such enhancement was observed in BALB/c mice similarly treated. Manipulated BALB/c mice presented a higher frequency of CRIA+ anti-Ars B cells than naive or antigen-immunized BALB/c individuals.

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Sounding the ionosphere by incoherent scatter at very high frequencies

Journal of the Institution of Electrical Engineers ◽

10.1049/jiee-3.1963.0325 ◽

1963 ◽

Vol 9 (106) ◽

pp. 432-436

Author(s):

E.D.R. Shearman

Keyword(s):

High Frequencies ◽

Incoherent Scatter ◽

Very High Frequencies ◽

Very High

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The Determination of Dielectric Properties at Very High Frequencies

Proceedings of the IRE ◽

10.1109/jrproc.1934.226763 ◽

1934 ◽

Vol 22 (8) ◽

pp. 1009-1020 ◽

Cited By ~ 2

Author(s):

J.G. Chaffee

Keyword(s):

Dielectric Properties ◽

High Frequencies ◽

Very High Frequencies ◽

Very High

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A Genetically Marked I Element in Drosophila melanogaster Can Be Mobilized When ORF2 Is Provided in trans

Genetics ◽

10.1093/genetics/148.1.267 ◽

1998 ◽

Vol 148 (1) ◽

pp. 267-275

Author(s):

Isabelle Busseau ◽

Sophie Malinsky ◽

Maria Balakireva ◽

Marie-Christine Chaboissier ◽

Danielle Teninges ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Heat Shock ◽

Reverse Transcriptase ◽

Germ Line ◽

Ltr Retrotransposons ◽

Low Frequencies ◽

High Frequencies ◽

In Trans ◽

Very High Frequencies ◽

Very High

Abstract I factors in Drosophila melanogaster are non-LTR retrotransposons similar to mammalian LINEs. They transpose at very high frequencies in the germ line of SF females resulting from crosses between reactive females, devoid of active I factors, and inducer males, containing active I factors. The vermilion marked IviP2 element was designed to allow easy phenotypical screening for retrotransposition events. It is deleted in ORF2 and therefore cannot produce reverse transcriptase. IviP2 can be mobilized at very low frequencies by actively transposing I factors in the germ line of SF females. This paper shows that IviP2 can be mobilized more efficiently in the germ line of strongly reactive females in the absence of active I factors, when it is trans-complemented by the product of ORF2 synthesized from the hsp70 heat-shock promoter. This represents a promising step toward the use of marked I elements to study retrotransposition and as tools for mutagenesis.

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