962 resultados para Anatomy of plants
Resumo:
In the late 19th Century, the choanae (or internal nares) of the Plesiosauria were identified as a pair of palatal openings located rostral to the external nares, implying a rostrally directed respiratory duct and air path inside the rostrum. Despite obvious functional shortcomings, this idea was firmly established in the scientific literature by the first decade of the 20th Century. The functional consequences of this morphology were only re-examined by the end of the 20th Century, leading to the conclusion that the choanae were not involved in respiration but instead in underwater olfaction, the animals supposedly breathing with the mouth agape. Re-evaluation of the palatal and internal cranial anatomy of the Plesiosauria reveals that the traditional identification of the choanae as a pair of fenestrae situated rostral to the external nares appears erroneous. These openings more likely represent the bony apertures of ducts that lead to internal salt glands situated inside the maxillary rostrum. The 'real' functional choanae (or caudal interpterygoid vacuities), are situated at the caudal end of the bony palate between the sub-temporal fossae, as was suggested in the mid-19th Century. The existence of a functional secondary palate in the Plesiosauria is therefore strongly supported, and the anatomical, physiological, and evolutionary implications of such a structure are discussed.
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Numerical modelling is a valuable tool for simulating the fundamental processes that take place during a heating. The models presented in this paper have enabled a quantitative assessment of the effects of initial pile temperature, pile size and mass and coal particle size on the development of a heating. All of these parameters have a certain criticality in the coal self-heating process.
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We report two functional magnetic resonance imaging (fMRI) experiments which reveal a cortical network activated when perceiving coloured grids, and experiencing the McCollough effect (ME). Our results show that perception of red-black and green-black grids activate the right fusiform gyrus (area V4) plus the left and right lingual gyri, right striate cortex (V1) and left insula. The ME activated the left anterior fusiform gyrus as well as the ventrolateral prefrontal cortex, and in common with colour perception, the left insula. These data confirm the critical role of the fusiform gyrus in actual and illusory colour perception as well as revealing localized frontal cortical activation associated with the ME, which would suggest that a 'top-down' mechanism is implicated in this illusion.
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Most ethnopharmacological studies overlook food plants, yet many edible plants, also have medicinal value. I documented plants that are used as both food and medicine by the Totonac of Zapotitlan de Mendez, Mexico and recorded the presence of selected secondary compounds, and physical characteristics in these plants. Photoactivity, antimicrobial, and antifungal assays also were performed. The presence of these properties were compared among food/medicine plants, food, medicinal, and randomly selected plants. I predicted that a higher percentage of medicinal plants would contain the secondary compounds, physical characteristics, and bioactivity compared to the other groups. Phenolics and cyanogenic glycosides in the medicinal group were significantly greater than in the food/medicine group. The food plants did not differ greatly from the medicinal plants. This research indicates that including food plants in ethnomedical studies could provide a more complete knowledge of peoples therapeutic resources and practices. ^
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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v. 17, n. 2, p. 285-295, abr./jun. 2016.