PubMed · 11855199
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
Kathy Sitzman. 2002. Tips for shiftworkers.. https://pubmed.ncbi.nlm.nih.gov/11855199/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The aim of this study was to develop a noninvasive method to observe polyunsaturated fatty acids (PUFAs) behavior in the human body using Fourier transform infrared spectroscopy. For the noninvasive measurement of human oral mucosa, we have used infrared spectroscopy with a suitable attachment for an in vivo attenuated total reflectance system. The fatty acid contents in the tissues were determined by gas-chromatography mass-spectrometry after methylation. The alkene C-H stretching vibrations of unsaturated fatty acids in dietary oils showed infrared absorption bands with various peak positions and intensities at around 3010 cm(-1) depending on the extent of unsaturation and their species. The diurnal fluctuation of the alkene peak position of oral mucosa suggested that the contents of PUFAs were increased gradually in the early afternoon, and these data were supported by the direct determination of fatty acid species in oral mucosa where the relative increase of arachidonic and docosahexaenoic acids was observed in the early afternoon. This diurnal change of alkene peak position resembled the pattern of a "lipid factor" change calculated with the factor analysis applied to the overall infrared spectrum. We could monitor the diurnal fluctuations of PUFA contents of human oral mucosa noninvasively using a reagent-free infrared analysis system. The measurement of alkene and methylene infrared bands may provide a useful tool for detecting changes in PUFA balance in the human body.
Quantitative genetics of adaptive traits is made difficult by the genotypexenvironment interaction. A classical assumption is that QTLs identified in both stressed and control conditions correspond to constitutive traits whereas those identified only in stressed treatments are stress-specific and correspond to adaptive traits. This hypothesis was tested by comparing, in the same set of experiments, two ways of analysing the genetic variability of the responses of maize leaf growth to water deficit. One QTL detection was based on raw phenotypic traits (length and width of leaf 6) of 100 recombinant inbred lines (RILs) in four experiments with either well-watered or stressing conditions in the field or in the greenhouse. Another detection followed a method proposed recently which consists of analysing intrinsic responses of the same RILs to environmental conditions, determined jointly over several experiments. QTLs of three responses were considered: (i) leaf elongation rate per unit thermal time in the absence of stress, (ii) its response to evaporative demand in well-watered plants, and (iii) its response to soil water status in the absence of evaporative demand. The QTL of leaf length differed between experiments, but colocalized in seven cases out of 13 with QTLs of the intrinsic leaf elongation rate, even in experiments with stressing conditions. No colocalization was found between QTLs of leaf length under water deficit and QTLs of responses to air or soil water status. By contrast, QTLs of leaf width colocalized in all experiments, regardless of environmental conditions. The classical method of identifying the QTL of constitutive versus adaptive traits therefore did not apply to the experiments presented here. It is suggested that identification of the QTL of parameters of response curves provides a promising alternative for dealing with the genetic variability of adaptive traits.
Explore the source record for details and available documents.