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Graham H. Pyke 《植物科学评论》2017,36(3):179-189
The literature on fire-stimulated flowering is reviewed in terms of post-fire flowering patterns, proximal ultimate factors that affect flowering of plants post-fire, as well as application of evolutionary theory and development of evolutionary models in relation to fire-stimulated flowering. Consideration is given to the concepts involved, available empirical information, and areas that warrant further research. Understanding the factors responsible for fire-stimulated flowering is limited. Studies suggest factors involved, but confounding of variables prevents their separation. Experiments evaluate different factors, but there have been few such studies and little consideration regarding soil attributes, synergistic effects of multiple factors, and large-scale factors such as herbivory, florivory, seed dispersal, and pollination. Understanding the adaptive nature, and hence evolution, of fire-stimulated flowering is poor. Prevalence of particular fire-related responses has been related to geographical and other patterns, with deduction of adaptive nature of plant responses to fire and factors driving evolution of these responses. However, confounding of factors hinders this approach and can lead to disagreement between researchers. A better approach would be to hypothesize that evolution has resulted in plant responses to fire that are Evolutionarily Stable Strategies and to develop consequent mathematical models for such evolution, leading to predictions and tests. However, this approach requires quantitative assessment of responses to fire-related factors and influences of such responses on plant fitness, and so far few such assessments exist. This poor state of knowledge regarding plants with fire-stimulated flowering means that we cannot easily replace or enhance fire for managing species with fire-stimulated flowering, as sometimes necessary, and it also restricts their commercial cultivation. Experimental evaluation of plant responses to fire and development of evolutionary models is required. Our knowledge of the factors that trigger post-fire flowering by re-sprouting plant species remains poor, and so we cannot incorporate relationships between them and plant fitness into mathematical models of plant evolution. 相似文献
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California''s Department of Health Services, recognizing the serious community health problem presented by uncontrolled hypertension, developed community-based programs of early detection and referral, follow-up and education. Special consideration was given to underserved populations at high risk. A statewide probability household survey was conducted and showed an improvement in control status during the past decade for definite and critical hypertension, but not for mild hypertension. With diminishing public resources, future efforts must be cost effective, focus on care for persons known to have hypertension and encourage maximum coordination between private and public agencies. 相似文献
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《Cell cycle (Georgetown, Tex.)》2013,12(20):3137-3142
MicroRNAs regulate gene networks and therefore are inherently complex. MicroRNAs themselves function in networks of other microRNAs, some of which are co-expressed from the same locus. To better understand the interplay among microRNAs that underlies their functions, we examined the potential of combinatorial effects of endogenously and exogenously co-expressed microRNAs. In this review, we first distill the similarities and differences between three microRNA families that function in cell division, miR-16, miR-34a and miR-106b, with emphasis on their exquisite phenotypic diversity. Given that the microRNAs affect cell cycle progression via distinct targets, we tested for phenotypic synergism among them. Furthermore, we investigate target regulation by individual and pooled microRNAs to gain insight into interactions among microRNAs co-expressed from the same chromosomal locus. The ability of microRNAs to modulate multiple genes within a molecular pathway engenders a novel way of thinking about targeting pathways: instead of a one-inhibitor-one-target model, multiple components in a pathway can be modulated by a microRNA resulting in a potent yet reversible inhibition of the pathway. To fully realize this potential, we need to understand how microRNAs function singly and in concert with each other. 相似文献
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Pauline Burger Hortense Plainfoss Xavier Brochet Farid Chemat Xavier Fernandez 《化学与生物多样性》2019,16(10)
For centuries, perfumes consisted in a combination of natural ingredients, mainly of plant origin. From the 19th century on, the advent of organic synthesis enabled the deployment of multiple synthetic olfactory notes, enriching significantly the perfumers’ portfolio. Chemistry is ever since the foundation of modern perfumery. However, sustainable‐minded consumers, massively rejecting synthetics for safety and ecological issues, engaged a global return to nature in numerous sectors, and the fragrance industry is not outdone. Sustainable extraction of natural products, making use of innovative technologies, process intensification and agro‐based solvents, constitutes the answer to develop eco‐conceived fragrant ingredients covering every olfactory family without endangering biodiversity any further. The objective of this review is to draw a clear picture of where those technological advances are today and to assess the ones that may be effectively transposed at the industrial scale tomorrow. 相似文献
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Singh Anamika Duche Rachael Terumbur Wandhare Arundhati Ganesh Sian Jaspreet Kaur Singh Brij Pal Sihag Manvesh Kumar Singh Kumar Siddharth Sangwan Vikas Talan Shreya Panwar Harsh 《Probiotics and antimicrobial proteins》2023,15(1):44-62
Probiotics and Antimicrobial Proteins - The growing consumer awareness towards healthy and safe food has reformed food processing strategies. Nowadays, food processors are aiming at natural,... 相似文献
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The authors review the epidemiology, clinical manifestations, diagnosis, and treatment of fungal thyroiditis cases previously
reported in the medical literature. Aspergillus was by far the most common cause of fungal thyroiditis. Immunocompromised patients, such as those with leukemia, lymphoma,
autoimmune diseases, and organ-transplant patients on pharmacological immunosuppression were particularly at risk. Fungal
thyroiditis was diagnosed at autopsy as part of disseminated infection in a substantial number of patients without clinical
manifestations and laboratory evidence of thyroid dysfunction. Local signs and symptoms of infection were indistinguishable
from other infectious thyroiditis and included fever, anterior cervical pain, thyroid enlargement sometimes associated with
dysphagia and dysphonia, and clinical and laboratory features of transient hyperthyroidism due to the release of thyroid hormone
from follicular cell damage, followed by residual hypothyroidism. Antemortem diagnosis of fungal thyroiditis was made by direct
microscopy and culture of a fine-needle aspirate, or/and biopsy in most cases. Since most patients with fungal thyroiditis
had disseminated fungal infection with delay in diagnosis and treatment, the overall mortality was high. 相似文献
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Susan Parman 《American anthropologist》2000,102(3):660-661
Cyborgs. Cyberspace?: An Ethnographer Looks to the Future. David Hakken. New York: Routledge, 1999. 264 pp. 相似文献
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Macit Ilkit 《Mycopathologia》2010,170(3):143-154
Tinea capitis favosa, a chronic inflammatory dermatophyte infection of the scalp, affects over 90% of patients with anthropophilic
Trichophyton schoenleinii. T. violaceum, T. verrucosum, zoophilic T. mentagrophytes (referred to as ‘var. quinckeanum’), Microsporum canis, and geophilic M. gypseum have also been recovered from favic lesions. Favus is typically a childhood disease, yet adult cases are not uncommon. Interestingly,
favus is less contagious than other dermatophytoses, although intrafamilial infections are reported and have been widely discussed
in the literature. Clinical presentation of T. schoenleinii infections is variable: this fungus can be isolated from tinea capitis lesions that appear as gray patches, but symptom-free
colonization of the scalp also occurs. Although in the past T. schoenleinii was the dominant fungus recovered from dermatophytic scalp lesions, worldwide the incidence has decreased except in China,
Nigeria, and Iran. Favus of the glabrous skin and nails are reported less frequently than favus of the scalp. This review
discusses the clinical features of favus, as well as the etiological agents, global epidemiology, laboratory diagnosis, and
a short history of medical mycology. 相似文献
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On and Around Microtubules: An Overview 总被引:1,自引:0,他引:1
Richard H. Wade 《Molecular biotechnology》2009,43(2):177-191
Microtubules are hollow tubes some 25 nm in diameter participating in the eukaryotic cytoskeleton. They are built from αβ-tubulin heterodimers that associate to form protofilaments running lengthwise along the microtubule wall with the β-tubulin subunit facing the microtubule plus end conferring a structural polarity. The α- and β-tubulins are highly conserved. A third member of the tubulin family, γ-tubulin, plays a role in microtubule nucleation and assembly. Other members of the tubulin family appear to be involved in microtubule nucleation. Microtubule assembly is accompanied by hydrolysis of GTP associated with β-tubulin so that microtubules consist principally of ‘GDP-tubulin’ stabilized at the plus end by a short ‘cap’. An important property of microtubules is dynamic instability characterized by growth randomly interrupted by pauses and shrinkage. Many proteins interact with microtubules within the cell and are involved in essential functions such as microtubule growth, stabilization, destabilization, and interactions with chromosomes during cell division. The motor proteins kinesin and dynein use microtubules as pathways for transport and are also involved in cell division. Crystallography and electron microscopy are providing a structural basis for understanding the interactions of microtubules with antimitotic drugs, with motor proteins and with plus end tracking proteins. 相似文献
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城市林业概述与发展趋势 总被引:5,自引:0,他引:5
随着社会经济的快速发展和城市化进程的加快,城市环境问题日益成为社会各界关注的焦点,城市林业在城市建设与发展中的地位和作用越来越受到重视。从自然属性与社会属性,地域范围与层次的角度介绍了城市林业的基本概念和内涵,并比较了城市林业与传统林业、现代园林在属性、经营管理和功能方面的差别。借助已有的研究数据和成果,阐述了城市林业在城市发展中的作用,提出了现代城市林业面临的机遇和挑战以及未来发展趋势。 相似文献
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Masking, as is well known, enables an organism to act immediately and in an appropriate way to changes of the environment, integrating with internally produced rhythmicity. It now appears that masking can be used to cover a far wider range of problems than was originally intended. To separate masking effects from the effects due to an internal oscillator, several techniques have been used. Such protocols, however, like the constant routine protocol, often replace one form of masking by another. The situation becomes even more complex when one realizes that the output of an internal oscillator modifies the input. The question might be asked whether it is possible to study the properties of the internal oscillator in vivo at all. This article attempts to produce a framework for future discussions. 相似文献
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Masking, as is well known, enables an organism to act immediately and in an appropriate way to changes of the environment, integrating with internally produced rhythmicity. It now appears that masking can be used to cover a far wider range of problems than was originally intended. To separate masking effects from the effects due to an internal oscillator, several techniques have been used. Such protocols, however, like the constant routine protocol, often replace one form of masking by another. The situation becomes even more complex when one realizes that the output of an internal oscillator modifies the input. The question might be asked whether it is possible to study the properties of the internal oscillator in vivo at all. This article attempts to produce a framework for future discussions. 相似文献
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Cellular restriction of HIV-1 replication has traditionally been thought of as protein mediated: APOBEC3G hypermutates HIV-1 genomic RNA, but is counteracted by Vif; Tetherin inhibits the release of budding virions but is counteracted by Vpu. In recent years, new evidence suggesting that miRNAs and other components of the miRNA pathway act as HIV-1 restriction factors has come to light, along with the identification of strategies that HIV-1 employs to surmount these host obstacles. In this article, we summarize and discuss the literature to date regarding the complex relationship between HIV-1 and miRNA-mediated inhibition. 相似文献
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SYNOPSIS.The cardiac lethal mutation was discovered in a strainof axolotls (Ambysloma mexkanum) imported from Mexico. Embryoshomozygous recessive for the c gene develop in a normal fashionuntil the heartbeat stage of development. At this time, heartaction is observed in unaffected siblings, but in cardiac lethalembryos heart action is not apparent. Affected animals hatchand swim, but do not feed. Within a few days, ascites developsand the animals die within a short time afterward. The c geneis inherited as a simple recessive. The direct effect of gene c is unknown. Data has been presentedwhich suggests that gene c alters the anterior endoderm whichmay be a specific heart inductor in this species. Alternatively,the failure of heart action may result from an ionic imbalancein the immediate heart environment. This paper reviews the relevantexperiments and presents new data supporting each of these suggestionsfor the mechanism of action of the cardiac lethal gene. 相似文献
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The importance and essential functions of glial cells in the nervous system are now beginning to be understood and appreciated.
Glial cell lines have been instrumental in the elucidation of many of these properties. In this Overview, the origin and
properties of most of the existing cell lines for the major glial types: oligodendroglia, astroglia, microglia and Schwann
cells, are documented. Particular emphasis is given to the culture conditions for each cell line and the degree to which the
line can differentiate in vitro and in vivo. The major molecular markers for each glial cell lines are indicated. Finally,
methods by which the glial cell lines have been developed are noted and the future directions of glial cell line research
are discussed. 相似文献