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1.
Sampa Kundu Taposhi Hazra Tapan Chakraborty Subir Bera Mahasin Ali Khan 《Plant Diversity》2023,(5):569-589
Equisetum(Equisetaceae) has long been a focus of attention for botanists and palaeontologists because,given its extensive and well-documented fossil record,it is considered the oldest extant vascular plant and a key element in understanding vascular plant evolution.However,to date,no authentic fossil evidence of Equisetum has been found from the Indian Cenozoic.Here,we describe a new fossil species,namely,E.siwalikum sp.nov.,recovered from the middle Siwalik(Late Miocene) sediments of Himachal P... 相似文献
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Hai-Su Hu Jiu-Yang Mao Xue Wang Yu-Ze Liang Bei Jiang De-Quan Zhang 《Plant Diversity》2023,(5):523-534
Roscoea is an alpine or subalpine genus from the pan-tropical family Zingiberaceae,which consists of two disjunct groups in geography,namely the "Chinese" clade and the "Himalayan" clade.Despite extensive research on the genus,Roscoea species remain poorly defined and relationships between these species are not well resolved.In this study,we used plastid genomes of nine species and one variety to resolve phylogenetic relationships within the "Chinese" clade of Roscoea and as DNA super barcodes f... 相似文献
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Mahasin Ali Khan Sumana Mahato Robert A.Spicer Teresa E.V.Spicer Ashif Ali Taposhi Hazra Subir Bera 《Plant Diversity》2023,(3):243-264
The Eastern Himalayas are renowned for their high plant diversity.To understand how this modern botanical richness formed,it is critical to investigate past plant biodiversity preserved as fossils throughout the eastern Himalayan Siwalik succession(middle Miocene-early Pleistocene).Here,we present a summary of plant diversity records that document Neogene floristic and climate changes.We do this by compiling published records of megafossil plant remains,because these offer better spatial and tem... 相似文献
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Morris SC 《BioEssays : news and reviews in molecular, cellular and developmental biology》2000,22(12):1053-1056
In recent years, two schools of thought have emerged with regard to the Cambrian "explosion". One argues that it was very quick, with phyla tumbling into existence in a virtual geological instant. The other view has a more relaxed temporal perspective. It looks to slow aeons of cryptic metazoan history, which led to a final breakthrough in the Cambrian, not in evolution but of fossilization potential. Yet both views have serious difficulties. Now, in a recent issue of Biological Reviews, Graham Budd and S?ren Jensen(1) argue for a third way. In an intriguing blend of functional morphology, the fossil record and cladistic thinking, they suggest that the assembly of metazoan bodyplans took place in a surprisingly straightforward manner. 相似文献
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Xufang Chen Yazhou Zhang Lishen Qian Renyu Zhou Hang Sun Jianguo Chen 《Plant Diversity》2024,(2):247-255
When benefiting other beneficiaries, cushion plants may reciprocally receive feedback effects. The feedback effects on different sex morphs, however, remains unclear. In this study, taking the gynodioecious Arenaria polytrichiodes as a model species, we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio, and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios. The total benef... 相似文献
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The effect of the establishment of Entodinium caudatum on the population of Eudiplodinium maggii was examined in the rumen of three sheep fed a hay/ground barley diet. The cell concentration of E. maggii were 15.9-38.5 and 11.7-12.4 x 10(3) cells per g of the rumen contents in the absence and presence of E. caudatum, respectively. Microscopic analysis showed that starch was the only material engulfed by eudiplodinia irrespective of the time after feeding and the presence or absence of E. caudatum. Up to 82-93% of individuals contained starch grains when E. maggii was the only ciliate species in the rumen; the proportion was 70-77% after entodinia had been established. The largest quantity of starch engulfed by E. maggii ciliates was 12.4-19.0 and 6.7-7.6 mg per 100 mg protozoal dry mass in the absence and presence of entodinia, respectively. No visible engulfment of hay was observed in vivo in spite of the fact that hay particles up to 42 microns in length were dominating in rumen fluid. Ingestion of fresh particles of hay separated from the rumen digesta was found when they were added in the proportion of 1 g per 40 mL suspension of ciliates. No preferential intake of starch was observed when E. maggii ciliates were incubated in vitro with a mixture of hay and barley starch. It is suggested that competition for starch between the two ciliate species was responsible for the drop in the numbers of E. maggii. This could result from a too low concentration of small particles of hay in the rumen fluid. 相似文献
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Hong Qian 《Plant Diversity》2023,(2):169-176
Human activities have caused the exchange of species among different parts of the world.When introduced species become naturalized and invasive,they may cause great negative impacts on the environment and human societies,and pose significant threats to biodiversity and ecosystem structure.Knowledge on phylogenetic relatedness between native and non-native species and among non-native species at different stages of species invasion may help for better understanding the drivers of species invasion... 相似文献
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Hui-Jun Guo Jin-Ling Huang Yun-Heng Ji Rong Li Chun-Lin Long Qin-Er Yang Yong-Ping Yang Ting-Shuang Yi 《Plant Diversity》2023,(3):239-240
<正>Professor Heng Li (李恒,March 9,1929-January 12,2023) was a legendary plant taxonomist and phytogeographer at the Kunming Institute of Botany,Chinese Academy of Sciences (Fig.1).She made important contributions to our understanding of China’s flora,including the biodiversity and biogeography of Dulong Valley and the Gaoligong Mountains,as well as the vegetation of plateau lakes and wetlands in Southwest China. 相似文献
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John Boakes John P. Peach Stuart M. McGill Author vitae 《Journal of electromyography and kinesiology》1998,8(6):423-427
Many low-back patients undergo electromyography (EMG)-based evaluations of muscle performance but present to the clinic after being prescribed muscle relaxants. The question that needed to be addressed was, do centrally acting muscle relaxants (methocarbamol; Robaxin®) affect the EMG spectral indices of muscle fatigue that are often used to assess muscle performance. Participants performed an isometric spine extension protocol involving a 30 s fatigue exertion trial, then 1 min rest, and finally a 10 s long repeat exertion trial, at a 60% maximum voluntary contraction (MVC) level of exertion. Seven men were tested on two separate days (approximately 3–7 days apart), one day while medicated (six doses) with Robaxin and on another while not medicated. Specifically, the following parameters were studied in the bilateral multifidus (L5), lower erector spinae (L3) and upper erector spinae (T9): the slope of median power frequencies (MPFs) over the duration of the trial and the initial y-intercept of the MPF. The results generally suggest that methocarbamol (Robaxin) does not have any significant affect on the EMG median power frequency of the extensors during a fatiguing contraction followed by a repeat exertion, at least in normal people (one exception was observed—one side of multifidus at L5). However, given that this appears to be the first study of its kind, and that a relatively small number of subjects were used in this study, further investigation is needed to make a definitive conclusion about the effects of this drug on the several features of the electromyogram, over a broad spectrum of the clinical population performing a wider variety of tasks. 相似文献
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Karla J.P.Silva-Souza Maíra G.Pivato Vinícius C.Silva Ricardo F.Haidar Alexandre F.Souza 《Plant Diversity》2023,(4):369-384
Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America.We also evaluated the contribution of three sets of determinants of the occurrence-and abundance-based subregions.We compiled data on tree species composition from 894local assembl... 相似文献
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A forest’s productivity can be optimized by the application of rules derived from monopolized circles. A monopolized circle
is defined as a circle whose center is a tree and whose radius is half of the distance between the tree itself and its nearest
neighbor. Three characteristics of monopolized circle are proved. (1) Monopolized circles do not overlay each other, the nearest
relationship being tangent. (2) “Full uniform pattern” means that the grid of trees (a×b=N) covers the whole plot, so that the distance between each tree in a row is the same as the row spacing. The total monopolized
circle area with a full uniform pattern is independent on the number of trees and
times the plot area. (3) If a tree is removed, the area of some trees’ monopolized circle will increase without decreasing
the monopolized circles of the other trees. According to the above three characteristics, “uniform index” is defined as the
total area of monopolized circles in a plot divided by the total area of the monopolized circles, arranged in a uniform pattern
in the same shaped plot. According to the definition of monopolized circle, the distribution of uniform index
for a random pattern and
the variance of L is
. It is evident that E(L) is independent on N and the plot area; hence, L is a relative index. L can be used to compare the uniformity among plots with different areas and the numbers of trees. In a random pattern, where
L is equivalent to the tree density of the plot in which the number of trees is 1 and the area is π, the influence of tree number and plot area to L is eliminated. When n→∞, D(L)→0 and
it indicates that the greater the number of tree is in the plots, the smaller the difference between the uniform indices
will be. There are three types of patterns for describing tree distribution (aggregated, random, and uniform patterns). Since
the distribution of L in the random pattern is accurately derived, L can be used to test the pattern types. The research on Moarshan showed that the whole plot has an aggregated pattern; the
first, third, and sixth parts have an aggregated pattern; and the second, fourth, and fifth parts have a random pattern. None
of the uniform indices is more than 0.318 (1/∏), which indicates that uniform patterns are rare in natural forests. The rules
of uniform index can be applied to forest thinning. If you want to increase the value of uniform index, you must increase
the total area of monopolized circles, which can be done by removing select trees. “Increasing area trees” are the removed
trees and can increase the value of the uniform index. A tree is an increasing area tree if the distance between the tree
and its second nearest neighbor is
times longer than that between the tree itself and its first nearest neighbor, which is called the
rule. It was very interesting to find that when six plots were randomly separated from the original plot, the proportion
of increasing area trees in each plot was always about 0.5 without exception. In random pattern, the expected proportion of
increasing area trees is about 0.35–0.44, which is different from the sampling value of 0.5. The reason is very difficult
to explain, and further study is needed. Two criteria can be used to identify which trees should be removed to increase the
uniform index during forest thinning. Those trees should be (1) trees whose monopolized circle areas are on the small side
and (2) increasing area trees, which are found via the
rule.
Translated from Acta Ecologica Sinica, 2005, 25(1) (in Chinese) 相似文献
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Bailong Zhao 《Plant Diversity》2024,(2):280-282
<正>The International Fossil Plant Names Index (IFPNI, 2014-onwards)not only serves as an online gateway to the fossil plant name registry for the global scientific community, but also serves as a comprehensive and dynamic archive of fossil plants (Doweld, 2016, 2022).Since its establishment in 2014, the IFPNI has accumulated more than 80,000 entries of fossil plant names, along with information on over 10,000 documents and over 6000 paleobotanists, all supported by exhaustive data, demonst... 相似文献
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Carbone A 《The International journal of biological markers》2001,16(1):1-4
The technologies used in histopathology are changing as a consequence of the current revolutionary progress in several areas of biology. It is likely that general cancer management will improve because of the impact of molecular techniques and immunohistochemistry on tumor diagnosis and classification and on the determination of prognosis and response to therapy. Moreover, as therapies are starting to be modelled after the distinctive molecular characteristics of a specific tumor, the availability of molecular tests to all patients will become a matter of great importance. 相似文献
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Pueyo A Figueiras AM Benito C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):513-517
The menadione reductase (MNR), the nicotinamide adenine dinucleotide dehydrogenase (NDH) and diaphorase (DIA) isozymes were
studied in the allohexaploid Triticum aestivum cv ”Chinese Spring” and in five diploid Triticeae species. The Mnr1, Ndh3 and Dia1 loci were located on the chromosome arms 3AL, 3BL and 3DL of T. aestivum, respectively. These loci were also located on the 3H chromosome of Hordeum vulgare cv ”Betzes”, the 3L chromosome of Aegilops longissima and the 6RL chromosome arm of Secale cereale cv ”Imperial”. The chromosomal location results together with the segregation studies support a tetrameric behaviour of the
MNR1, NDH3 and DIA1 isozymes. The Ndh1 and Dia3 loci were located on homoeologous group 4 showing a monomeric behaviour. The chromosomal locations and linkage data of the
Mnr, Ndh and Dia loci suggest that Mnr1=Ndh3=Dia1; Ndh1=Dia3 and Ndh2=Dia2.
Received: 3 June 2001 / Accepted: 11 July 2001 相似文献
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The effect of phenols on the hydrolysis of substituted phenyl β-d-gluco- and β-d-xylo-pyranosides by β-d-glucosidase from Stachybotrys atra has been investigated. Depending on the glycon part of the substrate and on the phenol substituent, the hydrolysis is either inhibited or activated. With aryl β-d-xylopyranosides, transfer of the xylosyl residue to the phenol, with the formation of new phenyl β-d-xylopyranosides, is observed. With aryl β-d-glucopyranosides, such transfer does not occur when phenols are used as acceptors, but it does occur with anilines. A two-step mechanism, in which the first step is partially reversible, is proposed to explain these observations. A qualitative analysis of the various factors determining the overall effect of the phenol is given. 相似文献
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Xu Chen Haining Lu Zhengru Ren Yuqiu Zhang Ruoxuan Liu Yunhai Zhang Xingguo Han 《Plant Diversity》2024,(2):256-264
Tall clonal grasses commonly display competitive advantages with nitrogen(N) enrichment. However, it is currently unknown whether the height is derived from the vegetative or reproductive module.Moreover, it is unclear whether the height of the vegetative or reproductive system regulates the probability of extinction and colonization, and determines species diversity. In this study, the impacts on clonal grasses were studied in a field experiment employing two frequencies(twice a year vs. monthl... 相似文献
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《Plant Diversity》2023,(2):238-242
<正>Introduction Types of paper Contributions falling into the following categories will be considered for publication:original articles,review articles,short letters,modelling/theory and methods articles,rapid reports and special thematic issues.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list. 相似文献