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101.
Observational and manipulative studies have revealed that alien plant invasions are an outcome of interplay between a myriad
of biotic and abiotic factors operating at various spatio-temporal stages and scales. Despite the salient role of ubiquitous
arbuscular mycorrhizal (AM) fungi in plant interactions, studies exploring the role of such symbionts in invasiveness of alien
species and invasibility of communities are limited, in part because of difficult-culturablilty of AM fungi on artificial
media and apparent complexities in manipulations of AM-plant interactions in field and laboratory experiments. Moreover, analysis
of the AM-plant invasion studies conducted so far have yielded contradictory results with some indicating facilitation of
invasion by AM fungi and others its inhibition. Other studies have indicated that arbuscular mycorrhizal symbiosis has no
effect on invasiveness of alien plants. While arbuscular mycorrhizas may facilitate invasiveness of some alien plants, such
plants may also potentially impact mycorrhizal community structure and functions in the invaded habitats in different ways.
The present review addresses these paradoxically conflicting observations in the context of mutualism-commensalism-parasitism
gradient that characterizes the relationship between AM fungi and their alien vs. native hosts and also discusses the influence
of alien invasive plants on mycorrhizal community structure of invaded ecosystems. Through critical analysis of costs and
benefits for invasive plants that associate with AM fungi in their introduced range, invasion-induced shifts in AM mutualism
are evaluated in the context of their impact on native biodiversity. Underlining limitations of methodologies and experimental
designs usually employed to understand AM-mediated plant invasiveness, we proposes herein some alternative frameworks and
experimental approaches to overcome these limitations. 相似文献
102.
Rajakumar P Mohammed Abdul Rasheed A Iman Rabia A Chamundeeswari D 《Bioorganic & medicinal chemistry letters》2006,16(23):6019-6023
Macrocyclic di- and tetra-amides with thia- and oxylinkages were synthesized and screened for in vitro anti-inflammatory activity. Cyclophane diamide 15 showed a dose-dependent activity, while the other cyclophane amides 16-20 exhibited mild activity. 相似文献
103.
Anthelmintic resistance: the state of play revisited 总被引:1,自引:0,他引:1
Helminthosis is one of the major constraints in the successful wool and mutton industry throughout the world. Anthelmintic Resistance (AR) is said to have been established when previously effective drug ceases to kill exposed parasitic population at the therapeutically recommended dosages. Anthelmintic resistance is almost cosmopolitan in distribution and it has been reported in almost all species of domestic animals and even in some parasites of human beings. Some of the most important species of parasites of small ruminants in which AR has been reported include: Haemonchus spp., Trichostrongylus spp. Teladorsagia spp., Cooperia spp. Nematodirus spp., and Oesophagostomum spp. All the major groups of anthelmintics have been reported for development of variable degrees of resistance in different species of gastrointestinal nematodes. This paper describes the global scenario of prevalence and methods used for detection of AR in small ruminants. Different mechanisms and contributory factors for the development of AR are discussed. Various options and alternate strategies for the control and/or delay in the onset of AR are suggested in the light of available information. 相似文献
104.
Andrea Parisi Samuel P. C. Brand Joe Hilton Rabia Aziza Matt J. Keeling D. James Nokes 《PLoS computational biology》2021,17(7)
We explore the spatial and temporal spread of the novel SARS-CoV-2 virus under containment measures in three European countries based on fits to data of the early outbreak. Using data from Spain and Italy, we estimate an age dependent infection fatality ratio for SARS-CoV-2, as well as risks of hospitalization and intensive care admission. We use them in a model that simulates the dynamics of the virus using an age structured, spatially detailed agent based approach, that explicitly incorporates governmental interventions and changes in mobility and contact patterns occurred during the COVID-19 outbreak in each country. Our simulations reproduce several of the features of its spatio-temporal spread in the three countries studied. They show that containment measures combined with high density are responsible for the containment of cases within densely populated areas, and that spread to less densely populated areas occurred during the late stages of the first wave. The capability to reproduce observed features of the spatio-temporal dynamics of SARS-CoV-2 makes this model a potential candidate for forecasting the dynamics of SARS-CoV-2 in other settings, and we recommend its application in low and lower-middle income countries which remain understudied. 相似文献
105.
106.
Belibi F Zafar I Ravichandran K Segvic AB Jani A Ljubanovic DG Edelstein CL 《American journal of physiology. Renal physiology》2011,300(5):F1235-F1243
Cyst expansion in polycystic kidney disease (PKD) results in localized hypoxia in the kidney that may activate hypoxia-inducible factor-1α (HIF-1α). HIF-1α and autophagy, a form of programmed cell repair, are induced by hypoxia. The purposes were to determine HIF-1α expression and autophagy in rat and mouse models of PKD. HIF-1α was detected by electrochemiluminescence. Autophagy was visualized by electron microscopy (EM). LC3 and beclin-1, markers of autophagy, were detected by immunoblotting. Eight-week-old male heterozygous (Cy/+) and 4-wk-old homozygous (Cy/Cy) Han:SPRD rats, 4-wk-old cpk mice, and 112-day-old Pkd2WS25/- mice with a mutation in the Pkd2 gene were studied. HIF-1α was significantly increased in massive Cy/Cy and cpk kidneys and not smaller Cy/+ and Pkd2WS25/- kidneys. On EM, features of autophagy were seen in wild-type (+/+), Cy/+, and cpk kidneys: autophagosomes, mitophagy, and autolysosomes. Specifically, autophagosomes were found on EM in the tubular cells lining the cysts in cpk mice. The increase in LC3-II, a marker of autophagosome production and beclin, a regulator of autophagy, in Cy/Cy and cpk kidneys, followed the same pattern of increase as HIF-1α. To determine the role of HIF-1α in cyst formation and/or growth, Cy/+ rats, Cy/Cy rats, and cpk mice were treated with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). 2ME2 had no significant effect on kidney volume or cyst volume density. In summary, HIF-1α is highly expressed in the late stages of PKD and is associated with an increase in LC3-II and beclin-1. The first demonstration of autophagosomes in PKD kidneys is reported. Inhibition of HIF-1α did not have a therapeutic effect. 相似文献
107.
Vogt S Portig I Irqsusi M Ruppert V Weber P Ramzan R 《Journal of bioenergetics and biomembranes》2011,43(4):425-435
Induction of heat shock proteins (hsp) has been shown to protect cells from ischemia by providing transient tolerance against
myocardial injury and improving postischemic functional recovery. Attenuation of ATP depletion and earlier restoration of
ATP content on reperfusion are thought to play a role in this scenario. Hsp induction is accompanied by altered enzyme activity
of the respiratory chain, the major generator of ATP under physiological conditions. This report addresses the question whether
processing and final assembly of the active holoenzyme cytochrome c oxidase (CcO, complex IV), member of the respiratory chain,
is compromised under hypoxic conditions unless protected by stress proteins. Special focus is laid on function of the enzyme’s
subunits and importance of cellular energy availability and maintenance. 相似文献
108.
A molecular dynamics simulation study of mononuclear iron 15S-lipoxygenase (15S-LOX) from rabbit reticulocytes was performed
to investigate its structure and dynamics; newly developed AMBER force field parameters were employed for the first coordination
sphere of the catalytic iron (II). The results obtained from this study demonstrate that the structural features of the catalytic
iron coordination site are in good agreement with available data obtained from experiments. The motional flexibility of the
N-terminal β-barrel domain is greater than the C-terminal catalytic domain; flexibility was assessed in terms of B-factors and secondary structure calculations. The significant features obtained for the relative motional flexibility of
these two domains of 15S-LOX in solution as well as the isolated C-terminal domain were analyzed in terms of radius of gyration
and maximum diameter, which correlated well with the structural flexibility of 15-lipoxygenase-1 in solution as probed by
small-angle X-ray scattering. The motional flexibility indicates interdomain motion between the N-terminal β-barrel and the
C-terminal catalytic domain; this was further verified by the evaluation of central bending in the solvated LOX molecule,
which identified an unstructured stretch of amino acids as the interdomain linker. The average bending angle confirmed significant
central bending between these two domains, which was linked to the high degree of motional freedom of the N-terminal β-barrel
domain in aqueous solutions. This can be considered to have biological relevance for membrane binding as well as for regulating
the catalytic domain. 相似文献
109.
Comparative genomics is enhanced by data mining the rapidly expanding DNA sequence databases. Because of the immense amount of data, computational tools and methods are needed to augment traditional manual visualizations and manipulations of these data. GeneOrder2.0, a Java-based interactive software programme, organizes genome sequence data into tabular and graphical visualizations of the extent of colinearity of genes between any two chromosome genomes of < or =250 kilobases. Both GenBank and proprietary data can be analyzed with this tool. 相似文献
110.
Anjum Zafar Fan Wu Kristine Hardy Jasmine Li Wen Juan Tu Robert McCuaig Janelle Harris Kum Kum Khanna Joanne Attema Philip A. Gregory Gregory J. Goodall Kirsti Harrington Jane E. Dahlstrom Tara Boulding Rebecca Madden Abel Tan Peter J. Milburn Sudha Rao 《Molecular and cellular biology》2014,34(16):2961-2980