competitor

竞争对手
  • 文章类型: Journal Article
    父母的照顾行为已发展成为提高生殖成功率的生活史策略,特别是在面临挑战环境的生物体中。然而,产妇护理的变化,例如,为了应对社会环境和相关的竞争生态后果而采取的护蛋行为,仍然很大程度上未知。这项研究通过检查掠食性螨中母性护理行为的可塑性及其对后代生存以及种内和种间竞争的影响,解决了当前知识的差距。我们的结果表明,生殖雌性经常表现出保护卵子的行为,当存在种间竞争者时,加强产妇护理工作。在没有产妇护理的情况下,卵块更容易被捕食。保护雌性增加了卵的存活率,并对同种和异种竞争者的存活产生了不利影响,检测到更高的死亡率。我们的发现强调了产妇护理行为的生态意义,并建议不建议将C.eruditus和Neoseiuluscucueris(Oudemans)一起释放用于存储产品中的病虫害管理。
    Parental care behavior has evolved as a life history strategy to improve reproductive success, particularly in organisms facing challenging environments. However, the variation in maternal care, such as egg-guarding behavior in response to the social environment and the associated ecological consequence of competition, remains largely unknown. This study addresses a gap in current knowledge by examining the plasticity of maternal care behavior in the predatory mite C. eruditus and its impact on offspring survival and intra- and interspecific competition. Our results demonstrated that the reproductive females frequently exhibit egg-guarding behaviors, with enhanced maternal care efforts when the interspecific competitor is present. Egg masses are significantly more vulnerable to predation in the absence of maternal care. Guarding females increased egg survival rates and adversely influenced the survival of both con- and heterospecific competitors, with higher mortality rates being detected. Our findings highlight the ecological significance of maternal care behaviors and suggest that releasing C. eruditus and Neoseiulus cucumeris (Oudemans) together is not recommended for pest management in storage products.
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  • 文章类型: Journal Article
    吸附剂吸附有机化合物的知识对于评估有机化合物的环境命运并将其从环境中去除至关重要。线性吸附,作为传统非线性吸附的补充,先前提出用于多溶质系统中碳纳米管(CNT)介孔表面上有机化合物的线性吸附。然而,CNTs不是验证线性吸附机理的理想吸附剂,因为它们的类分区相组分,如移动石墨烯层,可以通过线性分区机制负责线性吸附,从而论证了线性吸附理论。在这项研究中,因此,介孔活性炭(MAC),被广泛接受为无分配相分量的模型,选择作为吸附剂来研究典型有机化合物在双溶质体系中的吸附,以验证线性吸附现象是否存在。硝基苯在MAC上的等温线从非线性变为线性,4-硝基苯酚达到1400mg/L,线性等温线斜率随着4-硝基苯酚浓度的增加而下降更多,直到4000mg/L。它符合吸附的特性(即,竞争),但不是分区(即,非竞争),证实了线性吸附的存在。等温线线性归因于通过置换和多层吸附减少了吸附相互作用。此外,非极性化合物在MAC上的线性吸附可能发生与非极性或极性竞争者,而对于极性化合物,线性吸附可以发生只有极性竞争者。观察到的线性吸附和有机化合物在无分配相组分的MAC上的竞争证实了线性吸附的存在,这为有机化合物的吸附理论提供了新的见解。研究结果为提高有机污染环境风险评价的准确性和提高环境有机污染治理效率提供了较好的吸附理论基础。
    Knowledge of organic compounds adsorption by adsorbents is essential for evaluating the environmental fates of organic compounds and removing them from the environment. Linear adsorption, as a supplement to the traditionally nonlinear adsorption, was previously proposed for the linear sorption of organic compounds on the mesoporous surface of carbon nanotubes (CNTs) in multi-solute system. However, CNTs are not the ideal adsorbent to verify the linear adsorption mechanism, because of their partition-like phase components such as mobile graphene layers that could be responsible for the linear sorption through linear partition mechanism instead, and thus the linear adsorption theory was argued. In this study, therefore, mesoporous activated carbon (MAC), widely accepted as the model free of partition phase components, was selected as an adsorbent to investigate the adsorption of typical organic compounds in the bi-solute system for verifying whether the linear adsorption phenomenon existed or not. The isotherm of nitrobenzene on MAC was changed from nonlinear to linear with 4-nitrophenol up to 1400 mg/L, and the linear isotherm slope decreased more as 4-nitrophenol concentration increased until 4000 mg/L. It agreed with the characteristics of adsorption (i.e., competition) but not partition (i.e., noncompetition), confirming the existence of linear adsorption. The isotherm linearity was attributed to the reduction of adsorption interactions by displacement and multilayer adsorption. Moreover, linear adsorption of apolar compounds on MAC could occur with apolar or polar competitors, while for polar compounds, linear adsorption could occur with only polar competitors. The observed linear sorption and the competition of organic compounds in the bi-solute system on MAC free of partition phase components verified that the linear adsorption existed, which gives a new insight into the adsorption theory for organic compounds. The results could provide better fundamental theory of adsorption for improving the accuracy of environmental risk assessment of organic pollution and enhancing the efficiency of organic pollution control in the environment.
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  • 文章类型: Journal Article
    背景:女性健美运动员通过控制饮食来建立理想的体格,补充,锻炼到极端水平。在准备参加比赛的女性健美运动员中,蛋白质摄入量过多和饮食补充剂的使用无处不在,即,赛季中的竞争对手,然而,这两种饮食行为的动力相对未知。计划行为理论(TPB)已用于解释饮食行为。该研究的目的是研究TPB如何解释季节性竞争对手的蛋白质摄入量和膳食补充剂的使用。
    方法:使用横截面设计,开发了一份在线问卷,已验证,并服用以收集膳食补充剂的使用,TPB变量,以及112个赛季中竞争对手的其他措施。使用多次24小时饮食回顾评估蛋白质摄入量。使用多元回归分析确定TPB与蛋白质摄入量和膳食补充剂使用之间的关联,同时调整混杂因素。
    结果:对于蛋白质摄入量:态度,主观规范,感知的行为控制解释了8%的意图变化;主观规范独立预测意图。行为信念预测态度;主观规范由培训师/教练预测,锻炼伙伴,和社交媒体影响者。对于膳食补充剂的使用:意向解释了膳食补充剂使用差异的5%;态度,主观规范,感知到的行为控制共同解释了意图差异的38%。对膳食补充剂使用的态度是由五个因素预测的(不是浪费钱,帮助改善体质,维持能量水平,提供足够的卡路里,帮助恢复)。主观规范的主要决定因素是竞争对手,社交媒体影响者,教练/教练。感知行为控制由三个因素预测(购买的难易程度,可负担的购买,可供购买)。
    结论:TPB可预测女性健美运动员在季节中的膳食补充剂使用情况,但使用TPB可预测蛋白质摄入量的证据很少。卫生专业人员应使用策略制定有效的干预措施,使健康教育信息与季节竞争对手的结果信念保持一致,并与他人合作,以影响更安全有效的膳食补充剂使用。
    Women bodybuilders build their ideal physique by manipulating their diet, supplement, and exercise regimens to extreme levels. Excess protein intake and dietary supplement use is ubiquitous in women bodybuilders preparing for a competition, i.e., in-season competitors, however the impetus for these two dietary behaviors are relatively unknown. The Theory of Planned Behavior (TPB) has been used to explain dietary behaviors. The purpose of the study was to examine how the TPB can explain protein intake and dietary supplement use in in-season competitors.
    Using a cross-sectional design, an online questionnaire was developed, validated, and administered to collect dietary supplement use, TPB variables, and other measures from 112 in-season competitors. Protein intake was assessed using multiple 24-h dietary recalls. Associations between TPB and protein intake and dietary supplement use were determined with multiple regression analysis while adjusting for confounders.
    For protein intake: attitude, subjective norm, and perceived behavioral control explained 8% of the variance in intention; subjective norm independently predicted intention. Behavioral beliefs predicted attitude; subjective norm was predicted by trainer/coach, workout partners, and social media influencers. For dietary supplement use: intention explained 5% of the variance in dietary supplement use; attitude, subjective norm, and perceived behavioral control together explained 38% of the variance in intention. Attitudes towards dietary supplements use were predicted by five factors (not a waste of money, help improve physique, sustain energy levels, provide enough calories, help with recovery). Primary determinants of subjective norm were fellow competitors, social media influencers, and trainer/coach. Perceived behavioral control was predicted by three factors (ease of purchase, affordability to purchase, availability to purchase).
    TPB predicted dietary supplement use in women bodybuilders during in-season but there was little evidence for the prediction of protein intake using the TPB. Health professionals should develop effective interventions using strategies that align health education messages with in-season competitors\' outcome beliefs and collaborate with their referent others to influence safer and effective dietary supplement use.
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  • 文章类型: Journal Article
    草种(禾本科)分布在全球,适应广泛的气候,表达多样化的功能策略。我们利用竞争对手探索了草种的功能策略,应力公差,ruderal(CSR)系统,并询问物种策略如何与其功能性状相关,气候分布和自然范围之外的自然化倾向。我们使用了一组全局的草种性状数据,根据基于叶片性状的CSR系统对功能策略进行分类。与寿命(年度或常年)相关的策略差异,光合类型(C3或C4),或归化(原生或引入)进行了调查。此外,分析了与CSR分类中未包括的性状的相关性,并拟合了一个模型来预测一个物种的平均年平均温度和年降水量,作为CSR得分的函数。C4物种的竞争力值高于C3物种,多年生植物的胁迫耐受性值高于一年生植物,引进的物种比本地物种具有更明显的竞争-规则策略。企业社会责任分类之间的关系,基于叶子的特征,和其他功能性状进行了分析。竞争力与身高呈正相关,虽然规则与特定的根长相关,表明叶和根经济学背后的地上和地下性状都有助于实现企业社会责任战略。Further,气候与CSR分类之间的关系表明,具有竞争策略的物种在温暖的气候和高降水中更为常见,而具有胁迫耐受性策略的物种在寒冷气候和低降水中更为常见。这里提出的研究结果表明,基于叶片性状的功能策略的CSR分类与对构成寿命基础的草种适应的期望相匹配,光合类型,归化和气候。
    Grass species (family Poaceae) are globally distributed, adapted to a wide range of climates and express a diversity of functional strategies. We explored the functional strategies of grass species using the competitor, stress tolerator, ruderal (CSR) system and asked how a species\' strategy relates to its functional traits, climatic distribution and propensity to become naturalized outside its native range. We used a global set of trait data for grass species to classify functional strategies according to the CSR system based on leaf traits. Differences in strategies in relation to lifespan (annual or perennial), photosynthetic type (C3 or C4), or naturalisation (native or introduced) were investigated. In addition, correlations with traits not included in the CSR classification were analyzed, and a model was fitted to predict a species\' average mean annual temperature and annual precipitation across its range as a function of CSR scores. Values for competitiveness were higher in C4 species than in C3 species, values for stress tolerance were higher in perennials than in annuals, and introduced species had more pronounced competitive-ruderal strategies than native species. Relationships between the CSR classification, based on leaf traits, and other functional traits were analyzed. Competitiveness was positively correlated with height, while ruderality was correlated with specific root length, indicating that both above- and belowground traits underlying leaf and root economics contribute to realized CSR strategies. Further, relationships between climate and CSR classification showed that species with competitive strategies were more common in warm climates and at high precipitation, whereas species with stress tolerance strategies were more common in cold climates and at low precipitation. The findings presented here demonstrate that CSR classification of functional strategies based on leaf traits matches expectations for the adaptations of grass species that underlie lifespan, photosynthetic type, naturalization and climate.
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  • 文章类型: Journal Article
    为了应对来自食草动物和竞争对手的挑战,植物使用限制健康的资源来产生(自动)有毒的防御。茉莉酸(JA)信号,由MYC2转录因子(TF)介导,被认为可以重新配置新陈代谢,以最大程度地减少这些正式的防御成本,并优化复杂环境中的适应性。为了研究这种代谢重新配置的上下文依赖性,我们通过RNAi在烟草中对NaMYC2a/b进行了沉默,并在田间对植物进行了表型分析,并与竞争对手和移动食草动物进行了越来越现实的温室设置。NaMYC2a/b有正常的植物激素反应,以及在食草动物减少的环境中更高的生长和适应性,但是由于特殊代谢物的积累减少,在田间高食草动物负荷环境中遭到破坏。在与竞争对手和移动食草动物的合作中,在单基因型设置中,irMYC2a/b植物的适应度低于EV,但在混合基因型设置中的适应度增加。代谢的相关性分析,抗性和生长特征揭示了大多数初级和专门代谢部门的预期防御/生长关联。值得注意的例外是一些HGL-DTG和酚酰胺,它们在单基因型和混合基因型设置之间有所不同,与代谢物功能三分法模糊的预期一致。MYC2TF介导初级和专门代谢部门的重新配置,以使植物在复杂环境中优化其适应性。
    In response to challenges from herbivores and competitors, plants use fitness-limiting resources to produce (auto)toxic defenses. Jasmonate signaling, mediated by MYC2 transcription factors (TF), is thought to reconfigure metabolism to minimize these formal costs of defense and optimize fitness in complex environments. To study the context-dependence of this metabolic reconfiguration, we cosilenced NaMYC2a/b by RNAi in Nicotiana attenuata and phenotyped plants in the field and increasingly realistic glasshouse setups with competitors and mobile herbivores. NaMYC2a/b had normal phytohormonal responses, and higher growth and fitness in herbivore-reduced environments, but were devastated in high herbivore-load environments in the field due to diminished accumulations of specialized metabolites. In setups with competitors and mobile herbivores, irMYC2a/b plants had lower fitness than empty vector (EV) in single-genotype setups but increased fitness in mixed-genotype setups. Correlational analyses of metabolic, resistance, and growth traits revealed the expected defense/growth associations for most sectors of primary and specialized metabolism. Notable exceptions were some HGL-DTGs and phenolamides that differed between single-genotype and mixed-genotype setups, consistent with expectations of a blurred functional trichotomy of metabolites. MYC2 TFs mediate the reconfiguration of primary and specialized metabolic sectors to allow plants to optimize their fitness in complex environments.
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  • 文章类型: Journal Article
    Airbnb, which launched its business in 2009, has experienced explosive growth by creating value through the sharing economy business model. The Airbnb business model helps property owners exploit underutilized assets. However, along with its rapid growth, controversies have arisen among many stakeholders, especially the traditional hotel industry, communities, and policymakers. This study reviews academic articles to pinpoint the factors involved in the relationships among Airbnb and its multiple stakeholders. The aim is to identify the benefits, drawbacks, and issues surrounding Airbnb. The analysis is based on the perspectives of six Airbnb stakeholders: guests, hosts, employees, communities, competitors, and policymakers. A variety of scholarly journals indexed in the Scopus database were reviewed, with 282 included in the final analysis. The analysis will be useful for academics, practitioners, and policymakers alike, as it summarizes the Airbnb relevant actors, identifies key factors that influence stakeholder behavior, and assesses the power and level of influence of each stakeholder. Ultimately, the study points to potential directions for future research on Airbnb.
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  • 文章类型: Journal Article
    Most signaling cascades ultimately lead to changes in gene expression by modulating the activity of transcription factors (TFs). The electrophoretic mobility shift assay (EMSA) is a simple but powerful in vitro method for investigation of specific protein-DNA interactions. It makes use of the fact that protein-DNA complexes have a lower electrophoretic mobility in gels than free DNA has. The application of labeled probes in combination with unlabeled competitors allows investigation of DNA-binding specificity and identification of binding motifs with single base-pair resolution. Here we describe the application of EMSAs for the study of interactions of the brassinosteroid-regulated TFs, BRASSINAZOLE-RESISTANT1, (BZR1), BRI1-ETHYL METHANESULFONATE-SUPPRESSOR1 (BES1)/BZR2, and CESTA with putative binding sites. The classical approach using radiolabeled probes, as well as the more recent application of fluorescent probes, is described and the advantages and disadvantages of both methods are discussed.
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  • 文章类型: Journal Article
    Biological invasions are a key component of global change, and understanding the drivers of global invasion patterns will aid in assessing and mitigating the impact of invasive species. While invasive species are most often studied in the context of one or two trophic levels, in reality species invade communities comprised of complex food webs. The complexity and integrity of the native food web may be a more important determinant of invasion success than the strength of interactions between a small subset of species within a larger food web. Previous efforts to understand the relationship between food web properties and species invasions have been primarily theoretical and have yielded mixed results. Here, we present a synthesis of empirical information on food web connectance and species invasion success gathered from different sources (estimates of food web connectance from the primary literature and estimates of invasion success from the Global Invasive Species Database as well as the primary literature). Our results suggest that higher-connectance food webs tend to host fewer invaders and exert stronger biotic resistance compared to low-connectance webs. We argue that while these correlations cannot be used to infer a causal link between food web connectance and habitat invasibility, the promising findings beg for further empirical research that deliberately tests for relationships between food web connectance and invasion.
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  • 文章类型: Journal Article
    BACKGROUND: Competitive binding assays can be used to decipher not only the binding kinetics of studied ligands but also the binding site preference. Such assays are an essential step in the characterization of radioligands. However, the currently used competition assays require high concentrations of usually expensive ligands and still provide only binding site preference. By employing the time-resolved competition assay presented in this paper, binding characteristics including binding site preference can be obtained using less ligand.
    METHODS: To demonstrate the appropriateness of the time-resolved competition assay, we developed an assay in which the ligand binding was interrupted with a competitor. Experiments were performed on human carcinoma cell lines expressing epidermal growth factor receptor (EGFR). The targeting of the receptor was performed with radio-iodinated epidermal growth factor (EGF). The employed competitors involved either natural ligand transforming growth factor alpha (TGF-α) or anti-EGFR antibodies cetuximab and panitumumab targeting the same EGFR domain.
    RESULTS: Radio-iodinated EGF bound to EGFR was displaced with either low concentrations of cetuximab or high concentrations of panitumumab. In the case of TGF-α, we observed no competitive displacement of bound EGF at either high or low concentrations. When comparing the time-resolved competition assay with a manual competition assay, the resulting data of measured inhibition constants were in agreement.
    CONCLUSIONS: The results summarised in this study confirm the appropriateness of the time-resolved competition assay for assessing ligand binding properties. The assay has the potential to complement or replace conventional competition assays for determining binding site preference in the future.
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    文章类型: Journal Article
    The infection behavior of Steinernema carpocapsae infective juveniles (IJ) was investigated in the presence and absence of S. glaseri. Mixed inoculation of S. carpocapsae with S. glaseri IJ significantly raised the nictation rates of S. carpocapsae IJ. Significantly more S. carpocapsae IJ migrated to the host insect in the mixed inoculation with S. glaseri IJ on agar plates. More S. carpocapsae IJ penetrated into the host insect placed 2 cm below the surface in the mixed inoculation with S. glaseri IJ. More S. glaseri than S. carpocapsae IJ penetrated into hosts placed 7 cm deep. Irrespective of host location, the male ratio of S. carpocapsae IJ established in the host body was always higher in the mixed inoculation with S. glaseri IJ.
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