Populations

Populations
  • 文章类型: Journal Article
    了解招聘,将个人添加到种群或渔业中的过程,对于了解人口动态和促进可持续渔业管理至关重要。在人群中观察到招募动态的重要变化,其中一些种群表现出渐近生产力,而另一些种群表现出过度补偿(即,补偿性密度依赖性招聘)。我们理解招募模式中这种种群间差异的能力受到对潜在机制理解不足的限制,例如密度依赖性之间的复杂相互作用,招募,和环境。此外,大多数关于招募的研究都是使用观察性设计进行的,该设计具有长时间序列,很少以实验控制的方式在人群中复制。没有适当的复制,人群之间的推断是脆弱的,潜在的环境趋势难以量化。为了解决这些问题,我们进行了一项田间试验,操纵了三个野生种群中幼鱼鳟鱼Salvelinusfontinalis的放养密度,以表明这些相邻种群-由于环境条件而表现出不同的密度依赖性模式-在招募动态上也具有重要差异。针对四种股票招募模型进行测试(密度无关,线性,Beverton-Holt,和Ricker),种群在渐近生产力上表现出~两倍的变化,按照贝弗顿-霍尔特模型没有超额补偿。虽然环境变量(例如,温度,pH值,深度,底物)与招募中的人口差异相关,它们并没有提高个体人群的预测能力.将我们的招募模式与经典的鲑鱼案例研究进行比较,发现尽管曲线的形状和参数存在差异(即,Rickervs.Beverton-Holt),出现了约5条YOY鱼/m2的最大放养密度。较高的密度导致招聘的边际增加(Beverton-Holt)或由于过度补偿而减少招聘(Ricker)。
    Understanding recruitment, the process by which individuals are added to a population or to a fishery, is critical for understanding population dynamics and facilitating sustainable fisheries management. Important variation in recruitment dynamics is observed among populations, wherein some populations exhibit asymptotic productivity and others exhibit overcompensation (i.e., compensatory density-dependence in recruitment). Our ability to understand this interpopulation variability in recruitment patterns is limited by a poor understanding of the underlying mechanisms, such as the complex interactions between density dependence, recruitment, and environment. Furthermore, most studies on recruitment are conducted using an observational design with long time series that are seldom replicated across populations in an experimentally controlled fashion. Without proper replication, extrapolations between populations are tenuous, and the underlying environmental trends are challenging to quantify. To address these issues, we conducted a field experiment manipulating stocking densities of juvenile brook trout Salvelinus fontinalis in three wild populations to show that these neighboring populations-which exhibit divergent patterns of density dependence due to environmental conditions-also have important differences in recruitment dynamics. Testing against four stock-recruitment models (density independent, linear, Beverton-Holt, and Ricker), populations exhibited ~twofold variation in asymptotic productivity, with no overcompensation following a Beverton-Holt model. Although environmental variables (e.g., temperature, pH, depth, substrate) correlated with population differences in recruitment, they did not improve the predictive power in individual populations. Comparing our patterns of recruitment with classic salmonid case studies revealed that despite differences in the shape and parameters of the curves (i.e., Ricker vs. Beverton-Holt), a maximum stocking density of about five YOY fish/m2 emerged. Higher densities resulted in very marginal increases in recruitment (Beverton-Holt) or reduced recruitment due to overcompensation (Ricker).
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  • 文章类型: Journal Article
    这项工作提出了COVID-19在新西兰演变过程中的数学模型。该模型使用微分方程系统,该微分方程系统源于对某些概率度量的自然假设,以及该度量在不断发展的单纯形家族上的演变。作者试图创建模型,一方面,是简单和容易遵循。and,另一方面,正确反映了观察到的流行过程。实际目的是对重要参数进行合理的估计,例如感染率随时间的变化,从而量化政府措施的有效性。估计的另一个参数是检测时间和恢复时间的概率分布。
    The work proposes a mathematical model of the process of COVID-19 epidemic as it evolved in New Zealand. The model uses a system of differential equations which emanate from natural assumptions on some probability measure and evolution of this measure on evolving family of simplexes. The authors tried to create the model which, at one hand, is simple and easy to follow. and, at the other hand, reflects the observed epidemic process correctly. The practical aim was to come to justifiable estimations of important parameters like the rate of infection as function of time, thus quantifying effectiveness of the Government measures. Another parameters estimated were the probability distribution of detection times and recovery times.
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  • 文章类型: Journal Article
    该手稿提出了一个概念模型-性健康和综合愉悦(SHIP)模型-用于性健康问题的临床评估和干预。该模型是由一组专门治疗性问题的夫妻/婚姻家庭疗法和心理学家开发的。该模型由五个哲学基础(系统框架,交叉性,生物心理社会模型,寿命方法,和经验主义)和五个核心治疗成分(性素养,性适应和恢复力,关系亲密,以快乐为导向的积极的性行为,和多学科护理)。我们定义每个基础和组件,并将SHIP模型与其他现有的性健康模型进行比较和对比。最后,我们展示了SHIP模型是如何在一所大学的性健康诊所中,为一对顺性/异性恋夫妇提供个体和夫妻治疗的,并就该模型的其他临床应用提出了建议.
    This manuscript presents a conceptual model-the Sexual Health and Integrative Pleasure (SHIP) Model-for the clinical assessment and intervention of sexual health concerns. The model was developed by a group of couple/marital family therapy and psychologists who specialize in the treatment of sexual problems. The model consists of five philosophical foundations (systems framework, intersectionality, biopsychosocial model, lifespan approach, and empiricism) and five core therapeutic components (sexual literacy, sexual adaptation and resilience, relational intimacy, pleasure-oriented positive sexuality, and multidisciplinary care). We define each foundation and component, and compare and contrast the SHIP model with other existing sexual health models. Finally, we demonstrate how the SHIP model was used to provide individual and couple therapy with a cis/heterosexual couple in a university-based sexual health clinic and make recommendations for additional clinical applications of the model.
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  • 文章类型: Journal Article
    查塔姆群岛拥有新西兰一些最珍贵的黑脚鲍鱼(Haliotisiris)床。这种管理良好的渔业包括对渔获量和规模限制的限制,选择性捕鱼方法,和贝类管理。然而,最近生物量和生长参数的下降促使组学研究表征鲍鱼的生物学反应,可能有助于动物管理策略。
    这项研究的目的是表征缓慢和快速生长的代谢产物谱,少年鲍鱼和成年鲍鱼,与支持能量代谢的代谢物有关。
    气相色谱-质谱代谢物分析,应用氯甲酸甲酯烷基化,对从达勒姆角和瓦雷考里遗址收集的幼年和成年鲍鱼样本进行了研究,查塔姆群岛,新西兰。
    从血淋巴和肌肉样本获得的结果表明,来自快速生长地区的鲍鱼,Wharekauri,通过碳水化合物来源促进代谢功能,为脂肪酸和氨基酸合成提供能量。相反,较高的氨基酸水平主要用于促进该人群的增长。幼年鲍鱼的代谢有利于合成代谢,代谢产物从糖酵解和三羧酸循环中转移,用于生产核苷酸,氨基酸和脂肪酸。
    这项研究为鲍鱼种群提供了独特的生理见解,支持使用代谢组学作为研究与生长相关的代谢过程的工具。这项工作为未来的工作奠定了基础,旨在开发用于生长和健康监测的生物标志物,以支持不断增长和更可持续的鲍鱼渔业。
    BACKGROUND: The Chatham Islands has some of the most prized black-footed abalone (Haliotis iris) beds in New Zealand. This well-managed fishery includes restrictions on catch and size limits, selective fishing methods, and shellfish management. However, recent declines in biomass and growth parameters have prompted omics research to characterise the biological responses of abalone, potentially contributing towards animal management strategies.
    OBJECTIVE: The aim of this study was to characterise the metabolite profiles of slow and fast growing, juvenile and adult abalone, relating to metabolites supporting energy metabolism.
    METHODS: A gas chromatography-mass spectrometry metabolite profiling, applying methyl chloroformate alkylation, was performed on juvenile and adult abalone samples collected from Point Durham and Wharekauri sites, Chatham Islands, New Zealand.
    RESULTS: The results obtained from haemolymph and muscle samples indicated that abalone from the fast-growing area, Wharekauri, fuelled metabolic functions via carbohydrate sources, providing energy for fatty acid and amino acid synthesis. Conversely, higher amino acid levels were largely utilised to promote growth in this population. The metabolism of juvenile abalone favoured anabolism, where metabolites were diverted from glycolysis and the tricarboxylic acid cycle, and used for the production of nucleotides, amino acids and fatty acids.
    CONCLUSIONS: This research provides unique physiological insights towards abalone populations supporting the use of metabolomics as a tool to investigate metabolic processes related to growth. This work sets the stage for future work aimed at developing biomarkers for growth and health monitoring to support a growing and more sustainably abalone fishery.
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  • 文章类型: Journal Article
    The genus Scedosporium currently comprises six species, Scedosporium apiospermum, Scedosporium boydii, Pseudallescheria angusta, Scedosporium minutisporum, Scedosporium dehoogii, and Scedosporium aurantiacum, most of which can be distinguished with the primary fungal DNA barcode, the ITS1/2 region of the rDNA gene cluster. In the present study, four additional genetic loci were explored from a phylogenetic point of view enabling a barcoding approach based on K2P pairwise distances to resolve the taxa Scedosporium. We included partial γ-actin (ACT), β-tubulin (BT2), elongation factor 1α (TEF1), and the small ribosomal protein 60S L10 (L1) (RP60S). Phylogenetic inference of each marker individually showed that four out of six species within Scedosporium can be distinguished unambiguously, while strains of S. apiospermum, S. boydii, and P. angusta showed occasional recombination, and accordingly, no genealogical concordance between markers was obtainable. We defined S. apiospermum, S. boydii, and P. angusta as the \'S. apiospermum species complex\' since observed differences were not consistent between lineages, and no clinical differences are known between entities within the complex. While BT2 revealed the best performance among the genetic loci tested at the lineage level, barcoding of the ITS region is sufficient for distinction of all entities in Scedosporium at the species or \'complex\' level.
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  • 文章类型: Journal Article
    养分利用的模拟模型忽略了猪系统成分的变化会影响一组猪的性能的预测均值和方差。这项研究的目的是开发一种方法来研究饲料组成的变化将如何(a)影响养分利用模型的输出和(b)与单个猪的性状引起的变化相互作用。我们使用P摄入和利用模型来解决这些特征。随机性的引入引起了一些方法论上的挑战-例如,在对与饲料混合效率相关的变化进行建模时,如何在饲料成分和猪中产生变化,并说明成分之间的相关性。引入饲料成分和猪表型的变化导致平均消化的适度降低,预测猪种群的保留和排泄P及其相关CV的增加。预计在所考虑的饲养期间,种群中猪的百分比较低,以满足其需求。通过与无变化情况的比较。饲料成分组成的变化比混合效率的变化对性能变化的贡献更大。当考虑到饲料成分和猪性状的变化时,对猪生产性能变异性有主要影响的是前者而不是后者。开发的框架强调了随机变异性对养分利用模型预测的影响。这些后果将对诸如喂养等管理策略的决策产生重大影响。
    Simulation models of nutrient utilisation ignore that variation in pig system components can influence the predicted mean and variance of the performance of a group of pigs. The objective of this study was to develop a methodology to investigate how variation in feed composition would (a) affect the outputs of a nutrient utilisation model and (b) interact with variation that arises from the traits of individual pigs. We used a P intake and utilisation model to address these characteristics. Introduction of stochasticity gave rise to a number of methodological challenges--for example, how to generate variation in both feed composition and pigs and account for correlations between ingredients when modelling variation associated with feed mixing efficiency. Introducing variation in feed composition and pig phenotype resulted in moderate decreases in mean digested, retained and excreted P predicted for a population of pigs and an increase in their associated CV. A lower percentage of pigs in the population were predicted to meet their requirements during the feeding period considered, by comparison with the no-variation scenario. Variation in feed ingredient composition contributed more to performance variation than variation due to mixing efficiency. When variations in both feed composition and pig traits were considered, it was the former rather than the latter that had the dominant influence on variability in pig performance. The developed framework emphasises the consequences of random variability on the predictions of nutrient utilisation models. Such consequences will have a significant impact on decisions about management strategies such as feeding that are subject to variation.
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  • 文章类型: Journal Article
    The number of fishery products with a quite detailed description of the origin is increasing. This trend is driven by the interest of consumers and the fight against illegal unregulated and unreported fisheries. Unfortunately, there is a lack of methods to prove this information experimentally besides the document-based traceability assessments. For marine fish population genetics is a promising strategy, but research is concentrated only on a few species. Saithe is a commercially important fish species, despite the fact that genetic knowledge is scarce regarding the specification of populations. For a comparative study cost- and time-effective strategies were tested: We found RAPD-PCR to be a useful method for low-budget research or prestudies. Adoption of microsatellites from closely related species turned out to be possible with limited success quota. Our results suggest a clustered structure of populations within the Northeast Atlantic, probably overlapping in the northern North Sea.
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  • 文章类型: Journal Article
    In order to provide reliable information about responsiveness of biomarkers during environmental monitoring, there is a need to improve the understanding of inter-population differences. The present study focused on eight populations of zebra mussels and aimed to describe how variable are biomarkers in different sampling locations. Biomarkers were investigated and summarised through the Integrated Biomarker Response (IBR index). Inter-site differences in IBR index were analysed through comparisons with morphological data, proteomic profiles and genetic background of the studied populations. We found that the IBR index was a good tool to inform about the status of sites. It revealed higher stress in more polluted sites than in cleaner ones. It was neither correlated to proteomic profiles nor to genetic background, suggesting a stronger influence of environment than genes. Meanwhile, morphological traits were related to both environment and genetic background influence. Together these results attest the benefit of using biological tools to better illustrate the status of a population and highlight the need of consider inter-population difference in their baselines.
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