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1.
As pollination biology undergoes unprecedented growth as a discipline, confusion in the use of terms has become increasingly common. The need for a flexible yet unambiguous terminology has become urgent. As an example we discuss how the term “pollination efficiency” is used differently by 18 studies, and “pollinator effectiveness” by seven others. Here we present flowcharts of two general models of pollination systems (biotic and abiotic) that trace all the events from pollen production to development of seed or fruit, and we develop a lexicon for the quantities of pollen, processes of transfers (to a vector, to a stigma), and ratios of quantities that are of interest in studies of pollination and mating systems. An appendix includes a glossary of the definitions we suggest.  相似文献   

2.
Vital Landscape Attributes: Missing Tools for Restoration Ecology   总被引:9,自引:0,他引:9  
Twenty-three “vital ecosystem attributes” (VEAs) were previously proposed to aid in quantitative evaluation of whole ecosystem structure, composition, and functional complexity over time. We here introduce a series of 16 quantifiable attributes for use at a higher spatial scale and ecological organizational level, the landscape. “Vital landscape attributes” (VLAs) should be useful in evaluating the results of ecological restoration or rehabilitation undertaken with a landscape perspective, provided that clear definitions and boundaries are agreed upon for the different spatial and ecological entities involved. Like VEAs, VLAs should be sensitive to changes wrought by human as well as to nonhuman factors leading to ruptures in flow processes or vegetation “switches.” They should be applicable over a wide range of landscape types and therefore aid in conducting rigorous interlandscape comparisons. We present three groups of VLAs: (1) landscape structure and biotic composition, (2) functional interactions among ecosystems within the landscape, and (3) degree, type, and causes of landscape fragmentation and degradation. Ecotones between ecosystems are touched upon by several different VLAs. Because conflicting terminology abounds in this area, we append a glossary defining the problematic terms used.  相似文献   

3.
The most recent edition of the International Code of Botanical Nomenclature (Vienna Code) has superseded all previous editions. One of the notable changes in the Vienna Code is that it contains a glossary of nomenclatural terms defined and used in the Code. It has been made clear that the glossary of these terms is an integral part of the Code. This paper presents a Chinese translation of the definitions of the nomenclatural terms in the Code.  相似文献   

4.
Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; “community,” “assemblage,” “guild,” and “ensemble”. We revisit Fauth et al.'s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre‐1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups.  相似文献   

5.
In recent years, discourses around “personalized,” “stratified,” and “precision” medicine have proliferated. These concepts broadly refer to the translational potential carried by new data-intensive biomedical research modes. Each describes expectations about the future of medicine and healthcare that data-intensive innovation promises to bring forth. The definitions and uses of the concepts are, however, plural, contested and characterized by diverse ideas about the kinds of futures that are desired and desirable. In this paper, we unpack key disputes around the “personalized,” “stratified,” and “precision” terms, and map the epistemic, political and economic contexts that structure them as well as the different roles attributed to patients and citizens in competing future imaginaries. We show the ethical and value baggage embedded within the promises that are manufactured through terminological choices and argue that the context and future-oriented nature of these choices helps to understanding how data-intensive biomedical innovations are made socially meaningful.  相似文献   

6.
Here we present, for the first time, a glossary of biometeorological terms. The glossary aims to address the need for a reliable source of biometeorological definitions, thereby facilitating communication and mutual understanding in this rapidly expanding field. A total of 171 terms are defined, with reference to 234 citations. It is anticipated that the glossary will be revisited in coming years, updating terms and adding new terms, as appropriate. The glossary is intended to provide a useful resource to the biometeorology community, and to this end, readers are encouraged to contact the lead author to suggest additional terms for inclusion in later versions of the glossary as a result of new and emerging developments in the field.  相似文献   

7.
It is increasingly common to quantify and describe behavioral variation in domestic and wild animals in terms of “personality”. Correlating behavioral traits are referred to as personality “dimensions” or “factors” and different dimensions have been reported in different species. “Boldness” is a well-described personality dimension in several species, although some issues remain unclear. Previous models of boldness include both novelty and risk taking, but recent studies indicate that these types of behaviors may reflect separate personality dimensions. In this study, we developed a behavioral test battery for domestic rabbits, and recorded behaviors of 61 individuals in four different situations (novel object, novel arena, social, and predator interactions). We used domestic rabbits as a model because behavioral variation in rabbits has rarely been quantified in terms of personality dimensions, although rabbit behavior is described. We also wanted to investigate behavioral variation in a Swedish rabbit breed of conservation concern — the Gotland rabbit. Factor analysis of the behavioral test measures suggested three personality dimensions: “exploration”, “boldness”, and “anxiety”. Novel object scores clustered in the exploration and boldness factors, whereas scores associated with predator interactions were explained by “anxiety”, indicating that novel object and anti-predator behavior reflect different personality dimensions in rabbits.  相似文献   

8.
Leadership is commonly invoked when accounting for the coordination of group movements in animals, yet it remains loosely defined. In parallel, there is increased evidence of the sharing of group decisions by animals on the move. How leadership integrates within this recent framework on collective decision-making is unclear. Here, we question the occurrence of leadership in horses, a species in which this concept is of prevalent use. The relevance of the three main definitions of leadership – departing first, walking in front travel position, and eliciting the joining of mates – was tested on the collective movements of two semi-free ranging groups of Przewalski horses (Equus ferus przewalskii). We did not find any leader capable of driving most group movements or recruiting mates more quickly than others. Several group members often displayed pre-departure behaviours at the same time, and the simultaneous departure of several individuals was common. We conclude that the decision-making process was shared by several group members a group movement (i.e., partially shared consensus) and that the leadership concept did not help to depict individual departure and leading behaviour across movements in both study groups. Rather, the different proxies of leadership produced conflicting information about individual contributions to group coordination. This study discusses the implications of these findings for the field of coordination and decision-making research.  相似文献   

9.
10.
中国北方农牧交错带土地利用/覆盖变化研究综述   总被引:4,自引:0,他引:4  
土地利用/覆盖变化(LUCC)是人类活动行为与自然生态系统相互作用最为直接的表现形式.近年来由于人类活动的日益加剧使区域生态环境发生了剧烈变化,中国北方农牧交错带作为人类活动的强烈影响区和生态环境敏感区,是土地利用/覆盖变化研究的“热点区域”.本综述基于众多学者对于北方农牧交错带LUCC的研究成果,梳理了关于北方农牧交错带范围界定的进展,总结了当前有关本地区LUCC的研究手段、研究内容以及环境效应与应对措施等方面的最新进展,最后指出了本地区LUCC研究中存在的综合性模拟研究较少、生态环境效应不足等问题,并提出了未来研究中应多手段、多学科、多尺度研究的发展方向.  相似文献   

11.
Biological diversification often includes burst of lineage splitting. Such “radiation” has been known to act as evolutionary arenas with the potential to generate unique phylogenetic clusters and further novel groups. Although these radiations when accompanied by ecological diversification, so-called “adaptive radiation” have persisted as a central premise in evolutionary biology, the ecological and genetic mechanism of such rapid diversification has remained unclear. There are several critical definitions for the pattern of adaptive radiation, and those provide delimitation of adaptive and non-adaptive radiation. That being said, only a few studies have provided any clear demarcations in our understanding of the adaptive and non-adaptive causes of radiation from the mechanism of speciation. Here, we review the current consensus for the causes of adaptive radiation, especially along with the recent theoretical synthesis of “ecological speciation.” Further, we suggest the signature of adaptive and non-adaptive radiation in the earliest stages of diversification from the viewpoint of speciation. These criteria from the speciation view are useful to find the cases with the signatures of adaptive/non-adaptive radiation.  相似文献   

12.
Abstract

The ubiquitous type-3 copper enzyme polyphenol oxidase (PPO) has found itself the subject of profound inhibitor research due to its role in fruit and vegetable browning and mammalian pigmentation. The enzyme itself has also been applied in the fields of bioremediation, biocatalysis and biosensing. However, the nature of PPO substrate specificity has remained elusive despite years of study. Numerous theories have been proposed to account for the difference in tyrosinase and catechol oxidase activity. The “blocker residue” theory suggests that bulky residues near the active site cover CuA, preventing monophenol coordination. The “second shell” theory suggests that residues distant (~8?Å) from the active site, guide and position substrates within the active site based on their properties e.g., hydrophobic, electrostatic. It is also hypothesized that binding specificity is related to oxidation mechanisms of the catalytic cycle, conferred by coordination of a conserved water molecule by other conserved residues. In this review, we highlight recent developments in the structural and mechanistic studies of PPOs and consolidate key concepts in our understanding toward the substrate specificity of PPOs.  相似文献   

13.
14.
Experimental studies have demonstrated that onset, termination, and resumption of oviposition, same as corresponding changes in germarium size, are closely correlated with the dynamics of fat reserves. Even short-term (10 days long) termination of oviposition caused by the absence of aphid preys with the availability of carbohydrate food is accompanied by significant increase in absolute (weight) and relative (the percentage of total dry weight) fat content. This confirms the correctness of considering the studied phenomenon as a “real” reproductive diapause but not as a “short-term interruption of oviposition.” In combination with earlier published data, the results of the study once again suggest that division of insect adaptations to environmental changes into “short-term” and “long-term” adaptations based, correspondingly, on “neural” and “neurohormonal” mechanisms is rather conventional. In reality, a gradient or a spectrum of reactions is observed.  相似文献   

15.
Background and objectiveSince ancient times, honey has been used due to its nutritional and therapeutic value. The role of honey has been acknowledged in the scientific literature however, its use has been controversially discussed and has not been well accepted in modern medicine especially for diabetic patients. This study aimed to investigate the role of honey in diabetic patients.MethodsIn this study, we identified 107 research articles from data based search engines including “PubMed”, “ISI-Web of Science”, “Embase” and “Google Scholar”. The research papers were selected by using the primary key-terms including “Honey”, “Honey bee” and “Diabetes Mellitus”. The research documents in which “Honey” and “Diabetes Mellitus” were debated are included. After screening, we reviewed 66 papers and finally we selected 35 studies which met the inclusion criteria and the remaining documents were excluded.ResultsThis study investigated the preclinical, clinical, human and animal model studies on honey and diabetes mellitus and found that honey decreases the fasting serum glucose, increases the sting C-peptide and 2-h postprandial C-peptide. Although, there is a dearth of data and literature also contrary discussed the use of honey in diabetic patients.ConclusionHoney decreases the fasting serum glucose, increases fasting C-peptide and 2-h postprandial C-peptide. Honey had low glycemic index and peak incremental index in diabetic patients. The use of honey in diabetic patients still has obstacles and challenges and needs more large sample sized, multi-center clinical controlled studies to reach better conclusions.  相似文献   

16.
Living organisms have evolved a complex network of mechanisms to face the unforeseen nutritional and environmental circumstances imposed on their natural habitats, commonly termed “stress”. To learn more about these mechanisms, several challenges are usually applied in the laboratory, namely nutrient starvation, heat shock, dehydration, oxidative exposures, etc. Yeasts are chosen as convenient models for studying stress phenomena because of their simple cellular organization and the amenability to genetic analysis. A vast scientific literature has recently appeared on the defensive cellular responses to stress. However, this plethora of studies covers quite different experimental conditions, making any conclusions open to dispute. In fact, the term “yeast stress” is rather confusing, since the same treatment may be very stressful or irrelevant, depending on the yeast. Customary expressions such as “gentle stress” (non-lethal) or “severe stress” (potentially lethal) should be precisely clarified. In turn, although prototypic yeasts share a common repertoire of signalling responsive pathways to stress, these are adapted to the specific ecological niche and biological activity of each particular species. What does “stress” really mean? Before we go any deeper, we have to define this uncertain meaning along with a proper explanation concerning the terms and conditions used in research on yeast stress.  相似文献   

17.
Three additional phyletic group types, “periphyletic,” “epiphyletic”, and “anaphyletic” (in addition to Hennigian mono‐, para‐, and polyphyletic) are defined in terms of trees and phylogenetic networks (trees with directed reticulate edges) via a generalization of the algorithmic definitions of Farris. These designations concern groups defined as monophyletic on trees, but with additional gains or losses of members from network edges. These distinctions should be useful in discussion of systems with non‐vertical inheritance such as recombination between viruses, horizontal exchange between bacteria, hybridization in plants and animals, as well as human linguistic evolution. Examples are illustrated with Indo‐European language groups.  相似文献   

18.
In the past decades, a persistent progression of diabetic vascular complications despite reversal of hyperglycemia has been observed in both experimental and clinical studies. This durable effect of prior hyperglycemia on the initiation and progression of diabetic vasculopathies was defined as “metabolic memory”. Subsequently, enhanced glycation of cellular proteins and lipids, sustained oxidative stress, and prolonged inflammation were demonstrated to mediate this phenomenon. Recently, emerging evidence strongly suggests that epigenetic modifications may account for the molecular and phenotypic changes associated with hyperglycemic memory. In this review, we presented an overview on the discovery of metabolic memory, the recent progress in its molecular mechanisms, and the future implications related to its fundamental research and clinical application.  相似文献   

19.
The distribution of charged groups in proteins   总被引:6,自引:0,他引:6  
D J Barlow  J M Thornton 《Biopolymers》1986,25(9):1717-1733
The distributions of charged groups in 32 proteins of known three-dimensional structure have been analyzed to determine how regularly the groups are spread over the molecule's surfaces, and to identify and to study those proteins where charge asymmetry would seem important for their function. The distributions have been analyzed in terms of charge “polarity,” surface “charge density,” and electric dipole moments. More detailed studies of the distributions for individual proteins are made using map projections specifically developed for this purpose. In the light of the results obtained we discuss the role of charged groups in relation to protein function.  相似文献   

20.
中国植物激素研究: 过去、现在和未来   总被引:2,自引:0,他引:2  
许智宏  李家洋 《植物学报》2006,23(5):433-442
为了迎接2006年10月在北京召开的“植物激素与绿色革命”香山会议, 使其更具影响力, 本刊组织了一期“植物激素专辑”。本文作为此专辑的序言, 对我国在该领域研究作了概述和评论, 以帮助读者全面地了解我国在该领域的研究历史、现状和未来发展趋势。本文回顾了中国植物激素研究在二十世纪八十年代之前的工作发展历程中的重要成果, 主要集中在生理学研究方面的成果。随着植物分子遗传学技术与原理的不断成熟以及我国经济的飞速发展, 特别是研究队伍的迅速成长, 我国科学家近年来在植物激素代谢调控、转运及激素信号转导等领域取得了重要进展, 特别是激素受体基因分离鉴定、激素控制株型以及激素间的相互作用等方面取得的突破性进展。基于国际植物激素总体研究前沿和我国优势领域, 我们展望提出了我国在植物激素研究领域的未来发展方向与趋势。  相似文献   

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