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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 80 (1990), S. 465-469 
    ISSN: 1432-2242
    Keywords: Microspore-derived population ; Fatty acids ; Inheritance ; Brassica napus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The inheritance of major fatty acids in seed triglycerides was studied in three homozygous microspore-derived populations of spring rapeseed (Brassica napus L.). Crosses were made among parents with contrasting amounts of erucic, oleic, linoleic and linolenic acids. Microspores from F1 plants were cultured, and haploid plants were colchicine-doubled to provide homozygous populations reflecting F1 gametic arrays for fatty acid genotypes. Segregation ratios of the gametic arrays for specific fatty acid contents were compared to hypothetical models by the Chi-square test. Segregation pattern confirmed that erucic acid levels were controlled by two major loci, each having two alleles with additive effects. Oleic acid segregation indicated control of accumulation by at least two segregating genetic systems, one acting on chain elongation and the other involving desaturation. Accumulations of erucic acid and oleic acid were influenced by the same two loci, which control the chain elongation steps leading from oleic acid to erucic acid. Oleic acid was further influenced by at least two additional segregating loci involved in control of desaturation of oleic acid to form linoleic acid. Segregating alleles at loci involved in desaturation had a much smaller influence on oleic acid content than alleles segregating at loci controlling, the elongation of oleic acid to erucic acid. In a population free of erucic acid, the segregation pattern of linoleic acid levels fit a model involving segregating alleles at two loci. In contrast, segregation for linolenic acid content fits a three-locus additive model. In this study, microspore culture technology provided a rapid method of defining F1 gametic segregation for inheritance analyses.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-5060
    Keywords: Brassica napus ; oilseed rape ; doubled haploids ; fatty acids ; microspore-derived population ; single seed descent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Microspore embryogenesis technology allows plant breeders to efficiently generate homozygous micros-pore-derived breeding populations of oilseed rape (Brassica napus L.) without traditional generations of inbreeding. This study was conducted to compare the frequency distribution of microspore-derived population and single seed descent populations with respect to fatty acids of seed oil. Both microspore-derived populations and single seed descent populations were produced from each of three crosses made between selected parents containing contrasting amount of erucic, oleic, linoleic and linolenic acids. The fatty acid content of F3 plants derived lines (F5 seed) developed by single seed descent was compared to that of microspore-derived populations. The means, ranges and distribution pattern of seed fatty acid contents were similar in both populations for each fatty acid studied, although a few heterozygous lines were observed in the single seed descent populations. The results indicated that microspore-derived population form random, homozygous F1 plant derived gametic arrays for all fatty acids evaluated. Selection for altered fatty acid composition in microspore-derived and single seed descent homozygous populations should be equally efficient, in the absence of linkage of traits investigated.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-5060
    Keywords: Brassica napus ; rapeseed fatty acid accumulation ; microspore-derived embryo ; zygotic seed ; triacylglyceride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Microspore culture of rapeseed (Brassica napus L.) has provided a powerful tool not only for breeding but also in developmental studies. In this study, microspore-derived embryos (MDE) of B. napus were evaluated as a model in seed for studying accumulations of triacylglyceride (TAG) fatty acids in both a low and high erucic acid rapeseed line; and accumulations of TAG and free fatty acids (FFA) in a high erucic acid rapessed line. The accumulation patterns confirmed that MDE had a similar TAG fatty acid profile to seed during the embryo development within each genotype. The oil accumulation in MDE after 36 days in culture (DIC) approached levels similar to those in zygotic seed 25 days after flowering (DAF). Significant differences were detected in contents of both total free fatty acids and specific free fatty acids between MDE and seed. During the developmental period, total free fatty acids changed from 16% to 2.1% in MDE, but from 10.5% to 0.1% in seed. MDE had much higher percentage of free linolenic and erucic acids than seed, particularly during the late developmental stages. The current study indicated that MDE can be used as a model to study TAG and TAG fatty acids in seed but caution must be taken to study free fatty acid metabolism.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 31 (1992), S. 141-149 
    ISSN: 1573-5044
    Keywords: Brassica napus ; cryopreservation ; in vitro embryo ; microspore ; rapeseed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microspore cryopreservation is a potentially powerful method for long-term storage of germplasm for in vitro embryo production in plant species. In this study, several factors influencing embryo production following the ultra-low temperature (−196 °C in liquid nitrogen) storage of isolated microspores of rapeseed (Brassica napus L.) were investigated. Microspores were prepared in cryogenic vials and subjected to various cooling treatments before immersion in liquid nitrogen for varying periods. Efficiency of microspore cryopreservation was reflected by in vitro embryo production from frozen microspores. Of all the cooling treatments, microspores treated with a cooling rate of 0.25% °C/min and a cooling terminal temperature of −35 °C before immersion in liquid nitrogen produced the highest embryo yields (18% and 40% of unfrozen controls in two genotypes, respectively). Fast thawing in a 35 °C water bath was necessary to recover a high number of embryos from microspore samples being frozen at a higher cooling rate, while thawing speed did not affect samples after freezing at a slower cooling rate. The storage density of cryopreserved microspores affected embryo production. Storage at the normal culture density (8×104 microspores/ml) was less efficient for embryo production than at high densities (4×106 microspores/ml and 1.6×107 microspores/ml), although no significant difference was found between the high densities. Evaluation of plant lines derived from frozen microspores indicated no variation in isozyme pattern and no enhanced cold tolerance of these lines. Isolated microspores of B. napus could be stored for extended period for in vitro embryo production.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 27 (1989), S. 538-542 
    ISSN: 1741-0444
    Keywords: Electrogastrography ; Gastric activity ; Phase shift
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Electrogastric signals have been successfully measured both intraluminally and cutaneously. although it has been claimed by several researchers that the propagation direction of the electrogastric activities cannot be observed from cutaneous recordings, it is the aim of the paper to show that it is feasible. The reason why the propagation direction has never been observed from cutaneous recordings is that the reported methods for the abdominal measurements are not adequate. In the paper it is pointed out that the stomach should be localised before the measurement and the electrodes should be attached along the longitudinal axis of the stomach.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 29 (1991), S. 339-350 
    ISSN: 1741-0444
    Keywords: Bio-potential ; Electrogastrography ; Gastric motility ; Myoelectrical activity ; Signal analysis ; Slow wave ; Stomach
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Electrogastrography (EGG), the cutaneous recording of the myoelectrical activity of the stomach using surface electrodes, is attractive due to its non-invasiveness and its correlation with gastric motility. Since the first measurement of the EGG, a great deal of research effort has been expended on investigating its relationship with specific activities of the stomach in question. In this review, we discuss how to measure the EGG, what information is available in the EGG, how to extract useful information from the EGG and the prospective applications of the EGG. After a brief historic evolution of the EGG, we first discuss the measurement of the EGG, the importance of localisation of the stomach and the characteristics of the EGG. The most commonly used EGG data-analysis methods, both power spectral analysis and waveform analysis, are then outlined. Some of prospective applications of the EGG in clinical diagnosis and medical research are described, mainly concerning the correlation between EGG amplitude and gastric motility and that between EGG rhythmic variations and motility disorders. Specifically, we present studies on pre- and postprandial EGGs, observation of the propagation direction of the gastric slow wave and gastric electrical dysrhythmias and their correlation with gastric motility.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 28 (1990), S. 531-536 
    ISSN: 1741-0444
    Keywords: Autoregressive moving average modelling ; Electrogastrography ; Gastric motility ; Gastric slow wave ; Spectral analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The recording of the human, gastric myoelectrical activity, by means of cutaneous electrodes is called electrogastrography (EGG). It provides a noninvasive method of studying electrogastric behaviour. The normal frequency of the gastric signal is about 0·05 Hz. However, sudden changes of its frequency have been observed and are generally considered to be related to gastric motility disorders. Thus, spectral analysis, especially online spectral analysis, can serve as a valuable tool for practical purposes. The paper presents a new method of the adaptive spectral analysis of cutaneous electrogastric signals using autoregressive moving average (ARMA) modelling. It is based on an adaptive ARMA filter and provides both time and frequency information of the signal. Its performance is investigated in comparison with the conventional FFT-based periodogram method. Its properties in tracking time-varying instantaneous frequencies are shown. Its applications to the running spectral analysis of cutaneous electrogastric signals are presented. The proposed adaptive ARMA spectral analysis method is easy to implement and is efficient in computations. The results presented in the paper show that this new method provides a better performance and is very useful for the online monitoring of cutaneous electrogastric signals.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Annals of biomedical engineering 26 (1998), S. 859-869 
    ISSN: 1573-9686
    Keywords: Spectral analysis ; Matching pursuit ; Stomach ; Gastric motility ; Electrogastrography ; Evolutionary programming ; Signal analysis ; Electrogastrogram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The electrogastrogram (EGG) is a surface measurement of gastric myoelectrical activity. The normal frequency of gastric myoelectrical activity in humans is 3 cycles/min. Abnormal frequencies in gastric myoelectrical activity have been found to be associated with functional disorders of the stomach. The aim of this article was, therefore, to develop new time-frequency analysis methods for the detection of gastric dysrhythmia from the EGG. A concept of overcomplete signal representation was used. Two algorithms were proposed for the optimization of the overcomplete signal representation. One was a fast algorithm of matching pursuit and the other was based on an evolutionary program. Computer simulations were performed to compare the performance of the proposed methods in comparison with existing time-frequency analysis methods. It was found that the proposed algorithms provide higher frequency resolution than the short time Fourier transform and Wigner-Ville distribution methods. The practical application of the developed methods to the EGG is also presented. It was concluded that these methods are well suited for the time-frequency analysis of the EGG and may also be applicable to the time-frequency analysis of other biomedical signals. © 1998 Biomedical Engineering Society. PAC98: 8780+s, 0705Kf
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Annals of biomedical engineering 27 (1999), S. 88-95 
    ISSN: 1573-9686
    Keywords: Electrogastrography ; Gastric motility ; Stomach ; Filter banks ; Neural networks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Dysrhythmia in gastric myoelectrical activity has been frequently observed in patients with gastric motor disorders and gastrointestinal symptoms. The assessment of the regularity of gastric myoelectrical activity is of great clinical significance. The aim of this study was to develop an automated assessment method for the regularity of gastric myoelectrical activity from the surface electrogastrogram (EGG). The method proposed in this paper was based on the filter bank and neural network. First, the EGG signal was divided into frequency subbands using filter bank analysis. Second, a parameter called the subband energy ratio (SER) was computed for each subband signal. A multilayer perceptron neural network was then used to automatically classify the EGG signal into four categories: bradygastria, normal, tachygastria, and arrhythmia, using the SER as the input. The EGG recording was made using the standard method of electrogastrography by placing electrodes on the abdominal surface. The study was performed in 40 patients with various gastric motor disorders, ten healthy adults, and ten healthy children. The neural network was trained and tested using the EGG data obtained from the patients. The regularity of gastric myoelectrical activity was assessed based on the classification of the minute-by-minute EGG segments. Using the running spectral analysis method as a gold standard, the proposed automated method had an accuracy of 100% for the training set and 97% for the test set. It was concluded that the proposed method provides an accurate and automatic assessment of the regularity of gastric myoelectrical activity from the EGG. © 1999 Biomedical Engineering Society. PAC99: 8780-y, 8717-d, 0705Mh, 0270Hm
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 31 (1993), S. 60-67 
    ISSN: 1741-0444
    Keywords: Electrogastrogram ; Electrogastrography ; Gastric motility ; Intestinal motility ; Myoelectrical activity ; Spectral analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
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