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31.
Some photosynthetic attributes of leaves and stems were seasonally followed in the small-leaved, summer-deciduous, green-stemmed
Mediterranean shrub Calicotome villosa. Both leaves and stems displayed similar photon energy-saturated photosystem 2 (PS2) efficiencies with a minimum during winter.
A second minimum in stems during the leafless summer period could be ascribed to sustained photoinhibition. Yet, stems were
slightly inferior in photon capture, resulting partly from lower chlorophyll (Chl) contents and partly from higher reflectance
due to pubescence. As a result, photon energy-saturated linear electron transport rates were slightly higher in leaves. However,
when the total leaf and stem areas were taken into account, this superiority was abolished during autumn and winter and more
than overturned during spring. Given that during summer the stems were the only photosynthetic organs, the yearly photosynthetic
contribution of stems was much higher. Chl contents in stems displayed a transient and considerable summer drop, accompanied
by an increase in the carotenoid to Chl ratio, indicating a photo-protective adaptation to summer drought through a decrease
of photo-selective capacity, typical for leaves of many Mediterranean plants. 相似文献
32.
To evaluate breastfed infants' responses to scented objects, we videotaped
the facial and bodily reactions of sixty-three infants as they explored, in
succession, three toys that were identical in appearance but different in
their characteristic odor. Two of the toys were scented with odorants
previously shown to be transmitted to human milk, one with ethanol and the
other with vanilla, whereas the third toy was unscented. Each videotape was
subjected to frame-by-frame analysis to measure a variety of behaviors that
are considered either to be exploratory in nature in that they lead to
perceptual information about the object or to reflect the infants' hedonic
reaction. Analyses of these behaviors revealed that the infants looked more
and vocalized less in the presence of the vanilla-scented toy and spent
less time manipulating the ethanol-scented toy when compared with the
unscented toy. Moreover, differential exposure to the odors of ethanol and
vanilla, as indicated by differential consumption of alcohol by a parent or
use of vanilla-scented product by the mother, was related to differential
responses to these odors. These findings suggest that human infants are
able to detect and retain information about the chemical features of their
environment.
相似文献
33.
Uttam M. Pal Anil Vishnu GK Manoj Varma Jayant S. Vaidya Hardik J. Pandya 《Journal of biophotonics》2021,14(8):e202100041
The histopathological diagnosis of cancer is the current gold standard to differentiate normal from cancerous tissues. We propose a portable platform prototype to characterize the tissue's thermal and optical properties, and their inter-dependencies to potentially aid the pathologist in making an informed decision. The measurements were performed on 10 samples from five subjects, where the cancerous and adjacent normal were extracted from the same patient. It was observed that thermal conductivity (k) and reduced-scattering-coefficient (μ's) for both the cancerous and normal tissues reduced with the rise in tissue temperature. Comparing cancerous and adjacent normal tissue, the difference in k and μ's (at 940 nm) were statistically significant (p = 7.94e-3), while combining k and μ's achieved the highest statistical significance (6.74e-4). These preliminary results promise and support testing on a large number of samples for rapidly differentiating cancerous from adjacent normal tissues. 相似文献
34.