Sampling

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  • 文章类型: Letter
    暂无摘要。
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  • 文章类型: Journal Article
    车厢内的材料含有提高性能的半挥发性有机化合物(SVOCs)。由于这些SVOCs未与材料化学结合,它们可以以缓慢的速度从材料中散发到周围,导致人类暴露。这项研究旨在通过研究车厢空气(气相和空气中的颗粒)和灰尘中18种潜在的内分泌干扰化学物质,来增加对车厢中SVOCs丰度的理解。我们还研究了这些化学物质的含量如何随车厢内的温度以及通风设置而变化,与人类接触有关。在气体和颗粒相中的温度和SVOC浓度之间观察到正相关,80°C时的平均气相水平比25°C时的平均水平高18-16,000倍,而所研究物质的平均颗粒相水平高出4.6-40,000倍。这项研究还表明,在实际驾驶条件下,几种SVOCs的水平低于检测限,即,通风激活。为了限制人类在汽车舱内接触SVOCs,建议在进入前给温暖的汽车通风,并在驾驶过程中打开通风,因为温度和通风对SVOC水平都有显著影响。
    Materials in car cabins contain performance-enhancing semi-volatile organic compounds (SVOCs). As these SVOCs are not chemically bound to the materials, they can emit from the materials at slow rates to the surrounding, causing human exposure. This study aimed at increasing the understanding on abundance of SVOCs in car cabins by studying 18 potential endocrine disrupting chemicals in car cabin air (gas phase and airborne particles) and dust. We also studied how levels of these chemicals varied by temperature inside the car cabin along with ventilation settings, relevant to human exposure. A positive correlation was observed between temperature and SVOC concentration in both the gas and the particle phase, where average gas phase levels at 80 °C were a factor of 18-16,000 higher than average levels at 25 °C, while average particle phase levels were a factor of 4.6-40,000 higher for the studied substances. This study also showed that levels were below the limit of detection for several SVOCs during realistic driving conditions, i.e., with the ventilation activated. To limit human exposure to SVOCs in car cabins, it is recommended to ventilate a warm car before entering and have the ventilation on during driving, as both temperature and ventilation have a significant impact on SVOC levels.
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  • 文章类型: Journal Article
    在过去的三十年中,药物消耗的增加以及对水生环境的各自后果一直是许多研究的重点。在这一领域的各个方面进行了调查,考虑不同的制药集团,并采用广泛的研究方法。从不同研究领域的角度设计和回答了各种问题,导致个人发现和结论的大量混合。总的来说,研究结果提供了全面的概述。各种各样的方法和策略,然而,在比较和组合来自异构项目的信息时,需要密切关注。这篇评论严格审查了各种采样技术以及分析方法在有关废水处理厂(WWTP)中药物活性化合物(PhAC)和造影剂(CA)行为的研究中的应用。关于采样和分析的结合,讨论了其对特定科学问题的适用性。不同的研究重点需要不同的方法,回答不同的问题。概述了处理污水处理厂中PhAC和CA的命运和退化的研究,讨论他们的战略方法和发现。这篇综述包括抗癌药物的调查,抗生素,镇痛药和抗炎药,抗糖尿病药,β受体阻滞剂,荷尔蒙避孕药,降脂药,抗抑郁药以及X射线和磁共振成像的造影剂。
    Increasing consumption of pharmaceuticals and the respective consequences for the aquatic environment have been the focus of many studies over the last thirty years. Various aspects in this field were investigated, considering diverse pharmaceutical groups and employing a wide range of research methodologies. Various questions from the perspectives of different research areas were devised and answered, resulting in a large mix of individual findings and conclusions. Collectively, the results of the studies offer a comprehensive overview. The large variety of methods and strategies, however, demands close attention when comparing and combining information from heterogeneous projects. This review critically examines the application of diverse sampling techniques as well as analytical methods in investigations concerning the behavior of pharmaceutically active compounds (PhACs) and contrast agents (CAs) in wastewater treatment plants (WWTPs). The combination of sampling and analysis is discussed with regard to its suitability for specific scientific problems. Different research focuses need different methods and answer different questions. An overview of studies dealing with the fate and degradation of PhACs and CAs in WWTPs is presented, discussing their strategic approaches and findings. This review includes surveys of anticancer drugs, antibiotics, analgesics and anti-inflammatory drugs, antidiabetics, beta blockers, hormonal contraceptives, lipid lowering agents, antidepressants as well as contrast agents for X-ray and magnetic resonance imaging.
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  • 文章类型: Journal Article
    背景:人群病毒载量(VL),艾滋病毒传播潜力的最全面的衡量标准,由于缺乏对所有艾滋病毒感染者的完整抽样,因此无法直接测量。
    目标:给定HIV诊所的电子健康记录(EHR),这个群体的一个有偏见的样本,可能被用来试图推算这一措施。
    方法:我们模拟了一个由10,000名个体组成的群体,并根据几何平均值为4449拷贝/mL的监测数据进行了VL校准。我们从(A)源种群中采样了3个假设的EHR,(B)那些被诊断的人,和(C)那些被保留在照管中的人。我们的分析使用抽样权重,然后进行贝叶斯调整,从每个EHR估算出人口VL。然后使用来自特拉华州HIV诊所的EHR数据来测试这些方法。
    结果:加权后,估计值以相应更宽的95%间隔向人群值的方向移动,如下:诊所A:4364(95%间隔1963-11,132)拷贝/mL;诊所B:4420(95%间隔1913-10,199)拷贝/mL;诊所C:242(95%间隔113-563)拷贝/mL.贝叶斯调整的加权进一步改进了估计。
    结论:这些发现表明,方法学调整对于从单个诊所的EHR估计群体VL是无效的,而没有资源密集型的信息先验的阐明。
    BACKGROUND: Population viral load (VL), the most comprehensive measure of the HIV transmission potential, cannot be directly measured due to lack of complete sampling of all people with HIV.
    OBJECTIVE: A given HIV clinic\'s electronic health record (EHR), a biased sample of this population, may be used to attempt to impute this measure.
    METHODS: We simulated a population of 10,000 individuals with VL calibrated to surveillance data with a geometric mean of 4449 copies/mL. We sampled 3 hypothetical EHRs from (A) the source population, (B) those diagnosed, and (C) those retained in care. Our analysis imputed population VL from each EHR using sampling weights followed by Bayesian adjustment. These methods were then tested using EHR data from an HIV clinic in Delaware.
    RESULTS: Following weighting, the estimates moved in the direction of the population value with correspondingly wider 95% intervals as follows: clinic A: 4364 (95% interval 1963-11,132) copies/mL; clinic B: 4420 (95% interval 1913-10,199) copies/mL; and clinic C: 242 (95% interval 113-563) copies/mL. Bayesian-adjusted weighting further improved the estimate.
    CONCLUSIONS: These findings suggest that methodological adjustments are ineffective for estimating population VL from a single clinic\'s EHR without the resource-intensive elucidation of an informative prior.
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  • 文章类型: Journal Article
    美国大多数田地玉米都接受了新烟碱类种子处理,用于早季管理,土壤害虫。据报道,在印第安纳州,Maladeraformosae(Brenske)的灌木丛(鞘翅目:Scarabaeidae)以幼小的田间玉米为食,并以低比率和高比率的clothianidin种子处理为食,密歇根州,俄亥俄州。有趣的是,这些侵扰仅限于该地区的沙质土壤。这项研究的目的是(1)评估玉米中的grub种群是否仅限于沙质土壤,(2)评估土壤类型是否会影响Formosae的存活,(3)确定土壤类型是否影响植物对噻虫胺的吸收,可能解释了按土壤类型观察到的台湾M.在单个玉米田中,我们观察到的沙子(>80%的沙子含量)比壤土(<80%的沙子含量)多10倍。Grub对成虫的存活不受土壤类型的影响。然后,我们比较了在沙土或壤土中生长的玉米幼苗的根和芽中的噻虫胺种子处理浓度。在两种土壤类型中生长的玉米的根和芽中发现了相似量的活性成分。2周内,两种土壤类型中的噻虫胺浓度在根和芽中均显着下降,与无杀虫剂控制没有差异。这些发现表明,相对于壤土,除杀虫剂暴露外,其他因素导致沙子中的台湾M.幼虫的丰度更高,即使在同一个领域。
    Most field corn in the United States receives a neonicotinoid seed treatment for the management of early-season, soil-dwelling insect pests. Grubs of Maladera formosae (Brenske) (Coleoptera: Scarabaeidae) have been reported feeding on young field corn with both low and high rates of clothianidin seed treatments in Indiana, Michigan, and Ohio. Anecdotally, these infestations are restricted to sandy soils in the region. The purpose of this study was to (1) evaluate whether grub populations in corn are restricted to sandy soils, (2) assess whether soil type influences M. formosae survival, and (3) determine whether soil type affects clothianidin uptake by the plant, possibly explaining the observed differences in M. formosae abundance by soil type. We observed nearly 10-times more grubs in sand (>80% sand content) than loam (<80% sand content) soil within a single corn field. Grub survival to adult was not influenced by soil type. We then compared the concentrations of clothianidin seed treatment in the roots and shoots of corn seedlings grown in either sand or loam soil over time. Similar amounts of the active ingredient were found in the roots and shoots of corn grown in both soil types. Within 2 week, the clothianidin concentrations in both soil types had significantly declined in roots and shoots and were no different from the no-insecticide control. These findings suggest that factors other than insecticide exposure contribute to the higher abundance of M. formosae larvae in sand relative to loam soils, even within the same field.
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  • 文章类型: Journal Article
    近年来见证了基于流的强大生成模型的发展,扩散,或者自回归神经网络,在从广泛领域的应用实例中生成数据方面取得了显著成功。对这些方法的性能和局限性的理解进行了理论分析,然而,具有挑战性。在本文中,我们通过分析这些方法对具有已知概率分布的一类问题的采样效率,并将其与蒙特卡洛马尔可夫链和Langevin动力学等更传统方法的采样性能进行比较,朝着这个方向迈出了一步。我们专注于一类在与自旋眼镜有关的无序系统的统计物理学中广泛研究的概率分布,统计推断,和约束满意度问题。我们利用了这样一个事实,即通过基于流量的采样,基于扩散的,或自回归网络方法可以等效地映射到修改的概率度量的贝叶斯最佳去噪的分析。我们的发现表明,由于沿算法的去噪路径存在一阶相变,这些方法在采样时遇到了困难。我们的结论是双向的:我们确定了这些方法无法有效采样的参数区域,而使用标准的蒙特卡洛或Langevin方法是可能的。我们还确定了发生相反情况的区域:标准方法效率低下,而讨论的生成方法效果很好。
    Recent years witnessed the development of powerful generative models based on flows, diffusion, or autoregressive neural networks, achieving remarkable success in generating data from examples with applications in a broad range of areas. A theoretical analysis of the performance and understanding of the limitations of these methods remain, however, challenging. In this paper, we undertake a step in this direction by analyzing the efficiency of sampling by these methods on a class of problems with a known probability distribution and comparing it with the sampling performance of more traditional methods such as the Monte Carlo Markov chain and Langevin dynamics. We focus on a class of probability distribution widely studied in the statistical physics of disordered systems that relate to spin glasses, statistical inference, and constraint satisfaction problems. We leverage the fact that sampling via flow-based, diffusion-based, or autoregressive networks methods can be equivalently mapped to the analysis of a Bayes optimal denoising of a modified probability measure. Our findings demonstrate that these methods encounter difficulties in sampling stemming from the presence of a first-order phase transition along the algorithm\'s denoising path. Our conclusions go both ways: We identify regions of parameters where these methods are unable to sample efficiently, while that is possible using standard Monte Carlo or Langevin approaches. We also identify regions where the opposite happens: standard approaches are inefficient while the discussed generative methods work well.
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  • 文章类型: Journal Article
    对病毒的职业暴露进行评估对于在早期阶段确定病毒储库和传播源以及有助于防止在员工之间和普通人群之间传播至关重要。测量工人的暴露量有助于评估保护和缓解措施的有效性。本范围审查的目的是概述在不同的职业和室内环境中进行空气传播病毒暴露评估的可用方法和已经实施的方法。从不同研究中获得的结果可能有助于制定未来的标准和指南,以确保在职业环境中进行可靠的风险表征,这对于实施有效的控制措施至关重要。该搜索旨在在选定的数据库中选择2010年1月1日至2023年6月30日之间的研究。50篇关于病毒暴露评估的论文符合资格标准,并被选择用于数据提取。总的来说,这项研究发现了有关病毒评估的知识差距,并指出了进一步研究的需求。发现了几个差异(运输温度,洗脱步骤,...),以及缺乏与暴露条件相关的重要数据(上下文信息)的公布。有了可用的信息,不可能在采用不同方法的研究之间比较结果,即使使用相同的方法,由于在检索的上下文信息和/或数据解释方面缺乏共识,因此报告了基于专家判断的不同结论/建议。应考虑到评估的不同目标,开展有关现场靶向采样方法和实验室中有关要采用的测定方法的未来研究。
    Assessment of occupational exposure to viruses is crucial to identify virus reservoirs and sources of dissemination at an early stage and to help prevent spread between employees and to the general population. Measuring workers\' exposure can facilitate assessment of the effectiveness of protective and mitigation measures in place. The aim of this scoping review is to give an overview of available methods and those already implemented for airborne virus\' exposure assessment in different occupational and indoor environments. The results retrieved from the different studies may contribute to the setting of future standards and guidelines to ensure a reliable risk characterization in the occupational environments crucial for the implementation of effective control measures. The search aimed at selecting studies between January 1st 2010 and June 30th 2023 in the selected databases. Fifty papers on virus exposure assessment fitted the eligibility criteria and were selected for data extraction. Overall, this study identified gaps in knowledge regarding virus assessment and pinpointed the needs for further research. Several discrepancies were found (transport temperatures, elution steps, …), as well as a lack of publication of important data related to the exposure conditions (contextual information). With the available information, it is impossible to compare results between studies employing different methods, and even if the same methods are used, different conclusions/recommendations based on the expert judgment have been reported due to the lack of consensus in the contextual information retrieved and/or data interpretation. Future research on the field targeting sampling methods and in the laboratory regarding the assays to employ should be developed bearing in mind the different goals of the assessment.
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  • 文章类型: Journal Article
    背景:教育神经科学研究,研究学习的神经生物学机制,历史上纳入了主要来自白色的样本,中产阶级,和/或郊区人口。然而,在不关注代表性的研究中进行抽样可能会导致有偏见的解释和结果,这些结果不太容易推广到预期的目标人群。先前的研究揭示了群体内和跨群体的神经认知结果的差异,进一步表明,这种做法可能会掩盖具有实际意义的重大影响。
    历史边缘化社区的消极态度,源于历史虐待,有偏见的研究结果,以及研究团队之间隐含或明确的态度,会阻碍多元化参与。研究过程的质量,包括语言要求,研究地点,时间需求会产生额外的障碍。
    方法:灵活的数据收集方法,社区扩张,透明的报告可以建立信任并增强抽样多样性。长期解决方案包括优先考虑与边缘化社区相关的研究问题,增加劳动力多样性,以及样本人口统计数据的详细报告。这种共同努力对于强大的教育神经科学研究至关重要,以最大程度地扩大学习者的积极影响。
    BACKGROUND: Educational neuroscience research, which investigates the neurobiological mechanisms of learning, has historically incorporated samples drawn mostly from white, middle-class, and/or suburban populations. However, sampling in research without attending to representation can lead to biased interpretations and results that are less generalizable to an intended target population. Prior research revealing differences in neurocognitive outcomes both within- and across-groups further suggests that such practices may obscure significant effects with practical implications.
    UNASSIGNED: Negative attitudes among historically marginalized communities, stemming from historical mistreatment, biased research outcomes, and implicit or explicit attitudes among research teams, can hinder diverse participation. Qualities of the research process including language requirements, study locations, and time demands create additional barriers.
    METHODS: Flexible data collection approaches, community engaugement, and transparent reporting could build trust and enhance sampling diversity. Longer-term solutions include prioritizing research questions relevant to marginalized communities, increasing workforce diversity, and detailed reporting of sample demographics. Such concerted efforts are essential for robust educational neuroscience research to maximize positive impacts broadly across learners.
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  • 文章类型: Journal Article
    体视学,肺形态测量的黄金标准,关键取决于组织的采样进行分析。随机抽样方法保证器官的每个部分都有平等的机会被包括在分析中,因此,他们保证整体的代表性样本。然而,当感兴趣的生物或病理结构罕见和/或不均匀地分布在整个肺时,随机抽样方法可能效率低下,甚至导致无意义的数据。在这种情况下,有针对性的抽样方法可能是有用的,这有助于将分析项目与适当的参考空间联系起来。目标立体学极大地受益于宏观和微观水平的多分辨率成像技术以及数字分割工具的日益增加的可用性。因此,本文概述了两个基本的抽样场景:1.在第一种情况下,随后使用计算机断层扫描和显微镜对气道/动脉树进行分段,并对树的特定分支进行立体测量.2.第二种情况涉及病理性病变的异质分布。这种类型的分析可以分为两个阶段:评估肺内的目标病变(LOI)和评估LOI内的子区室。一起来看,有针对性的体视学在体视学理论有一个彻底的基础,不仅能够显着提高分析的效率,而且产生新类型的信息,将失去与经典的随机抽样方法。
    Stereology, the gold standard of lung morphometry, critically depends on sampling of tissue for analysis. Random sampling approaches guarantee each part of the organ an equal chance of being included in the analysis, hence they guarantee a representative sample of the whole. However, when biological or pathological structures of interest are rare and/or heterogeneously distributed over the whole lung, the random sampling approach can be inefficient or even result in meaningless data. In such cases, a targeted sampling approach can be useful which helps to relate the analytical items to an appropriate reference space. Targeted stereology greatly benefits from the increasing availability of multi-resolution imaging techniques at macroscopic and microscopic level as well as digital tools of segmentation. As such, the present article outlines two basic sampling scenarios: 1. In the first scenario, computed tomography and microscopy are subsequently used to segment the airway/arterial tree and perform stereological measurements on specific branches of the tree. 2. The second scenario deals with heterogeneous distribution of pathological lesions. This type of analysis can be divided into two stages: assessment of lesions of interest (LOI) within the lung and assessment of subcompartments within LOI. Taken together, targeted stereology has a thorough foundation in stereological theory and is not only able to significantly increase the efficiency of the analysis but also to yield new types of information that would be lost with the classical random sampling approach.
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  • 文章类型: Journal Article
    面对广泛的水危机,要满足世界对水的迫切需求,需要做的两件主要事情是收集水和循环利用。要做到这一点,本研究更加关注各种环境领域中使用的水管理策略。为了有效地分配水,拯救它,满足各种用途的水质要求,必须在牢记人口密度指数的同时应用智能水管理机制。本次审查揭示了水和废水回收的最新趋势,利用几种人工智能(AI)和机器学习(ML)技术进行分发,雨水收集,和灌溉模型的控制。为这些目的收集的数据是独特的,形式不同。可以使用AI开发有效的水管理系统,深度学习(DL)和物联网(IoT)结构。这项研究调查了几种使用人工智能的水管理方法,具有案例研究和样本统计评估的DL和物联网,为水管理提供有效的框架。
    The two main things needed to fulfill the world\'s impending need for water in the face of the widespread water crisis are collecting water and recycling. To do this, the present study has placed a greater focus on water management strategies used in a variety of contexts areas. To distribute water effectively, save it, and satisfy water quality requirements for a variety of uses, it is imperative to apply intelligent water management mechanisms while keeping in mind the population density index. The present review unveiled the latest trends in water and wastewater recycling, utilizing several Artificial Intelligence (AI) and machine learning (ML) techniques for distribution, rainfall collection, and control of irrigation models. The data collected for these purposes are unique and comes in different forms. An efficient water management system could be developed with the use of AI, Deep Learning (DL), and the Internet of Things (IoT) structure. This study has investigated several water management methodologies using AI, DL and IoT with case studies and sample statistical assessment, to provide an efficient framework for water management.
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