排序方式: 共有195条查询结果,搜索用时 15 毫秒
191.
Somayeh Naghiloo Zahra Esmaillou Gholamreza Gohari Mohammad Reza Dadpour 《Plant Systematics and Evolution》2014,300(2):329-345
The genus Mentha is a taxonomically complex genus, characterized by large morphological variations. Only a few, frequently overlapping, characters are of value in taxonomy. Comparative floral developmental studies provide an opportunity for better understanding the systematic relationships among different species. The inflorescence and floral ontogeny of three Mentha L. species (M. piperita L., M. pulegium L. and M. suaveolens Ehrh.) were investigated using epi-illumination light microscopy. All three species studied have thyrses with the same developmental pathway. The lack of higher order bracts and the monochasial branching of the higher order inflorescence apices were found as special features of inflorescence ontogeny. Sepals appear unidirectionally from the adaxial side in all except for M. pulegium which shows a modified unidirectional sequence. Variable sequences of petal and stamen appearance from unidirectional to reversed unidirectional sequence are present in all. Significant ontogenetic features include (1) appearance of the corolla as a rim before petal lobes become visible and (2) instability in petal aestivation. Morphological features including densely hairy calyx, five-lobed corolla tube, smaller adaxial stamens and hairy ovary with included style distinguish M. pulegium from the other species. On the basis of our results floral ontogenetic features could be considered important characters for delimiting or diagnosing different sections in the genus Mentha. Variable sequences of petal lobe appearance and instability in petal aestivation were found as unusual developmental characters. 相似文献
192.
Somayeh F. Rastegar Nasser L. Hadipour Mohammad Bigdeli Tabar Hamed Soleymanabadi 《Journal of molecular modeling》2013,19(9):3733-3740
The ability of pristine graphene (PG) and Al-doped graphene (AlG) to detect toxic acrolein (C3H4O) was investigated by using density functional calculations. It was found that C3H4O molecule can be adsorbed on the PG and AlG with adsorption energies about ?50.43 and – v30.92 kcal mol?1 corresponding to the most stable configurations, respectively. Despite the fact that interaction of C3H4O has no obvious effects on the of electronic properties of PG, the interaction between C3H4O and AlG can induce significant changes in the HOMO/LUMO energy gap of the sheet, altering its electrical conductivity which is beneficial to sensor designing. Thus, the AlG may be sensitive in the presence of C3H4O molecule and might be used in its sensor devices. Also, applying an external electric filed in an appropriate orientation (almost stronger than 0.01 a.u.) can energetically facilitate the adsorption of C3H4O molecule on the AlG. 相似文献
193.
Pashaei Somayeh Yarani Reza Mohammadi Pantea Emami Aleagha Mohammad Sajad 《Amino acids》2022,54(6):841-858
Amino Acids - Recently, we reviewed the important role of carbohydrates and lipids metabolism in different clinical aspects of multiple sclerosis (MS) disease. In the current paper, we aimed to... 相似文献
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Somayeh Dodge Gil Bohrer Keith Bildstein Sarah C. Davidson Rolf Weinzierl Marc J. Bechard David Barber Roland Kays David Brandes Jiawei Han Martin Wikelski 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1643)
Variation is key to the adaptability of species and their ability to survive changes to the Earth''s climate and habitats. Plasticity in movement strategies allows a species to better track spatial dynamics of habitat quality. We describe the mechanisms that shape the movement of a long-distance migrant bird (turkey vulture, Cathartes aura) across two continents using satellite tracking coupled with remote-sensing science. Using nearly 10 years of data from 24 satellite-tracked vultures in four distinct populations, we describe an enormous amount of variation in their movement patterns. We related vulture movement to environmental conditions and found important correlations explaining how far they need to move to find food (indexed by the Normalized Difference Vegetation Index) and how fast they can move based on the prevalence of thermals and temperature. We conclude that the extensive variability in the movement ecology of turkey vultures, facilitated by their energetically efficient thermal soaring, suggests that this species is likely to do well across periods of modest climate change. The large scale and sample sizes needed for such analysis in a widespread migrant emphasizes the need for integrated and collaborative efforts to obtain tracking data and for policies, tools and open datasets to encourage such collaborations and data sharing. 相似文献