John W. Watts

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Galactic cosmic rays consist of protons, electrons and ions, most of which are believed to be accelerated to relativistic speeds in supernova remnants. All components of the cosmic rays show an intensity that decreases as a power law with increasing energy (for example as E(-2.7)). Electrons in particular lose energy rapidly through synchrotron and inverse(More)
Protoplast fusion studies between various auxotrophic mutants of Nicotiana plumbaginifolia were performed to optimize conditions for PEG-mediated fusion and to identify factors influencing the plant protoplast fusion process. Numerous parameters in the isolation, culture, and fusion of protoplasts were tested, and established fusion protocols were compared.(More)
In order to optimise expression of a foreign protein in transgenic plants we investigated the potential benefits of including a viral untranslated leader sequence within a plant transformation vector. A variety of 5 leaders, including the tobacco mosaic virus (TMV) leader sequence and 31 nucleotides of the cauliflower mosaic virus (CaMV) 35S RNA leader,(More)
The results of ATIC-2 baloon experiment (2002–2003) for energy spectra of protons, He, C, O, Ne, Mg, Si, Fe, some groups of nuclei, and all-particle spectrum in primary cosmic rays are presented in energy region 50 GeV–200 TeV. The conclusion is that the spectra of protons and helium nuclei are essentially different (the spectrum of protons is steeper) and(More)
The Japanese American Cooperative Emulsion Experiments (JACEE) have recently carried out a series of Antarctic circumpolar long duration balloon flights (JACEE-10 ∼ JACEE-13) for the study of high energy elemental composition and energy spectra of cosmic ray particles. The total exposure factor of these experiments is 664 m2hr, which corresponds to about(More)
Tobacco mesophyll protoplasts have been examined by electron microscopy during isolation procedures and after 24 hours culture in a medium known to support cell wall regeneration. During isolation the plasmalemma shows little structural differentiation apart from the formation of small vacuoles in the cytoplasm. After 24 hours of culture, several types of(More)
The use of antibiotics to control infections in cultures of protoplasts of leaf mesophyll cells has been examined. The antifungal agents nystatin and amphotericin B were non-toxic to protoplasts at concentrations that controlled fungal growth (25 units and 2.5 μg/ml respectively). Of the antibacterial agents examined, only carbenicillin and, to a lesser(More)
Mixtures of protoplasts of two auxotrophic mutants of Physcomitrella patens, one requiring thiamine (aneurine), the other p-aminobenzoic acid, have been subjected to electrofusion. The protoplasts were aligned in an alternating electric field (500 KHz, 20 V RMS/cm) and induced to fuse by a brief DC pulse (800 V/cm, time constant lms). After culture, first(More)