blocking

阻塞
  • 文章类型: Journal Article
    经常使用观察性研究来估计暴露或治疗对结果的影响。为了获得对治疗效果的无偏估计,准确测量暴露是至关重要的。一种常见的暴露错误分类是召回偏差,这发生在回顾性队列研究中,当研究对象可能不准确地回忆他们过去的暴露。特别具有挑战性的是,在自我报告的二元曝光的背景下,差异召回偏差,其中偏差可能是方向性的,而不是随机的,其程度根据所经历的结果而变化。本文做出了一些贡献:(1)即使没有验证研究,它也为平均治疗效果建立了界限;(2)它提出了基于不同假设的各种策略的多种估计方法;(3)它提出了一种敏感性分析技术来评估因果结论的稳健性,结合了先前研究的见解。通过探索各种模型错误指定场景的仿真研究,证明了这些方法的有效性。然后将这些方法用于研究儿童期身体虐待对成年后心理健康的影响。
    Observational studies are frequently used to estimate the effect of an exposure or treatment on an outcome. To obtain an unbiased estimate of the treatment effect, it is crucial to measure the exposure accurately. A common type of exposure misclassification is recall bias, which occurs in retrospective cohort studies when study subjects may inaccurately recall their past exposure. Particularly challenging is differential recall bias in the context of self-reported binary exposures, where the bias may be directional rather than random and its extent varies according to the outcomes experienced. This paper makes several contributions: (1) it establishes bounds for the average treatment effect even when a validation study is not available; (2) it proposes multiple estimation methods across various strategies predicated on different assumptions; and (3) it suggests a sensitivity analysis technique to assess the robustness of the causal conclusion, incorporating insights from prior research. The effectiveness of these methods is demonstrated through simulation studies that explore various model misspecification scenarios. These approaches are then applied to investigate the effect of childhood physical abuse on mental health in adulthood.
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  • 文章类型: Journal Article
    在社交媒体网络上,美国人的政治分类很强。这通常归因于具有共同党派关系的人之间的优先领带形成(即同质)。这里,除了同质驾驶的各种网络之外,我们还展示了一个额外的因素:优先预防社会关系。在Twitter上的两个现场实验中,我们创建了看起来像人类的机器人账户,识别为民主党人或共和党人,,然后随机分配用户,以跟踪这些帐户之一。除了优先跟进合作社外,我们发现,在第一个实验中,用户屏蔽反党派账户的可能性是合作账户的12倍,在第二个实验中,相对于中立账户或合作账户,阻止反党派账户的可能性要高出4倍。然后,我们在一项调查实验中复制了这些发现,并发现了阻止的关键动机的证据:希望避免看到被阻止用户发布的任何内容。此外,我们发现民主党人比共和党人更倾向于阻止反派,并且这种不对称可能是由于阻止发布低质量或政治倾斜内容的帐户(而不是基于身份的阻止中的不对称)。我们的结果表明,对反党派的优先阻止是推动社交媒体上政治分类的重要现象。
    There is strong political assortment of Americans on social media networks. This is typically attributed to preferential tie formation (i.e. homophily) among those with shared partisanship. Here, we demonstrate an additional factor beyond homophily driving assorted networks: preferential prevention of social ties. In two field experiments on Twitter, we created human-looking bot accounts that identified as Democrats or Republicans, and then randomly assigned users to be followed by one of these accounts. In addition to preferentially following-back copartisans, we found that users were 12 times more likely to block counter-partisan accounts compared to copartisan accounts in the first experiment, and 4 times more likely to block counter-partisan accounts relative to a neutral account or a copartisan account in the second experiment. We then replicated these findings in a survey experiment and found evidence of a key motivation for blocking: wanting to avoid seeing any content posted by the blocked user. Additionally, we found that Democrats preferentially blocked counter-partisans more than Republicans, and that this asymmetry was likely due to blocking accounts who post low-quality or politically slanted content (rather than an asymmetry in identity-based blocking). Our results demonstrate that preferential blocking of counter-partisans is an important phenomenon driving political assortment on social media.
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  • 文章类型: Journal Article
    在酸性预处理过程中,在预处理的木质纤维素基材表面上形成的木质素沉积物可能会非生产性地吸附昂贵的酶,从而影响纤维素的酶促水解效率。在这篇文章中,花生蛋白(PP),一种生物相容的非催化蛋白质,与脱脂花生粉(DPF)分离作为木质素阻断添加剂以克服这种不利影响。在酶解介质中添加2.5g/LPP,在5FPU/g葡聚糖的低纤维素酶载量下,经苯基磺酸(PSA)预处理的竹底物的葡萄糖产率从38%显著增加至94%,同时实现相似的葡萄糖产率需要17.5FPU/g葡聚糖的纤维素酶载量而不添加PP。在正戊醇预处理的竹子和PSA预处理的桉树基质上也观察到类似的促进作用。PP对酶促水解的促进作用归因于通过疏水和/或氢键相互作用阻断木质素沉积物。这显著降低了纤维素酶在PSA木质素上的非生产性吸附。同时,与没有蛋白质预提取的情况相比,PP提取还有助于将残留的DPF用作生产胶合板的粘合剂。该方案为提高木本和农业生物质的价值提供了可持续和可行的方法。花生蛋白,一种生物相容的非催化蛋白质,可以阻断木质素,提高酶水解效率,从而促进生物炼制的经济性。
    Lignin deposits formed on the surface of pretreated lignocellulosic substrates during acidic pretreatments can non-productively adsorb costly enzymes and thereby influence the enzymatic hydrolysis efficiency of cellulose. In this article, peanut protein (PP), a biocompatible non-catalytic protein, was separated from defatted peanut flour (DPF) as a lignin blocking additive to overcome this adverse effect. With the addition of 2.5 g/L PP in enzymatic hydrolysis medium, the glucose yield of the bamboo substrate pretreated by phenylsulfonic acid (PSA) significantly increased from 38 to 94% at a low cellulase loading of 5 FPU/g glucan while achieving a similar glucose yield required a cellulase loading of 17.5 FPU/g glucan without PP addition. Similar promotion effects were also observed on the n-pentanol-pretreated bamboo and PSA-pretreated eucalyptus substrates. The promoting effect of PP on enzymatic hydrolysis was ascribed to blocking lignin deposits via hydrophobic and/or hydrogen-bonding interactions, which significantly reduced the non-productive adsorption of cellulase onto PSA lignin. Meanwhile, PP extraction also facilitated the utilization of residual DPF as the adhesive for producing plywood as compared to that without protein pre-extraction. This scheme provides a sustainable and viable way to improve the value of woody and agriculture biomass. Peanut protein, a biocompatible non-catalytic protein, can block lignin, improve enzymatic hydrolysis efficiency and thereby facilitate the economics of biorefinery.
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  • 文章类型: Journal Article
    两种Wolbachia菌株,WMel和WAlbB,已被感染为埃及伊蚊,以替代种群,以减少登革热传播。来自各个流行地点的流行病学数据表明,实施此策略后,登革热传播显着减少。在这项研究中,我们调查了Wolbachia菌株wMel和wAlbB对Ae的影响。在共同的遗传背景下的埃及伊蚊适合度。我们发现Ae.感染wMel菌株的埃及伊蚊雌性与感染wAlbB菌株的雌性相比表现出显着差异。具体来说,感染mel的雌性产卵明显减少,摄入较少量的血液,产蛋率降低,与感染wAlbB菌株的蚊子相比,在更晚的年龄表现出Wolbachia密度降低。相反,与未感染Wolbachia的标本相比,wAlbB菌株仅显示出轻度的负面影响。这些对Ae的不同影响。感染wMel或wAlbB后的埃及伊蚊适应性可能对入侵本地Ae的种群替代策略的成功具有重要意义。特有环境中的埃及伊蚊种群。需要进一步的研究来更好地了解这些健身效应差异的潜在机制及其对基于Wolbachia的登革热控制计划的长期疗效的潜在影响。重要的是登革热等虫媒病毒的传播,Zika,基孔肯雅热在全球范围内呈上升趋势。减少虫媒病毒负担的最有希望的策略之一是释放两种Wolbachia感染的埃及伊蚊中的一种:wMel和wAlbB。这种方法是否成功的一个关键方面涉及两种Wolbachia菌株对蚊子生活史特征的适应性成本。例如,我们发现WMel感染了Ae.埃及伊蚊雌性产卵明显减少,摄入较少量的血液,产蛋率降低,与感染wAlbB菌株的蚊子相比,在更晚的年龄表现出Wolbachia密度降低。相反,与未感染Wolbachia的标本相比,wAlbB菌株仅显示出轻度的负面影响。感染wMel或wAlbB后,这些对蚊子适应性的差异影响可能对种群替代策略入侵本地Ae的成功具有重要意义。埃及伊蚊种群。
    Two Wolbachia strains, wMel and wAlbB, have been transinfected into Aedes aegypti mosquitoes for population replacement with the aim of reducing dengue transmission. Epidemiological data from various endemic sites suggest a pronounced decrease in dengue transmission after implementing this strategy. In this study, we investigated the impact of the Wolbachia strains wMel and wAlbB on Ae. aegypti fitness in a common genetic background. We found that Ae. aegypti females infected with the wMel strain exhibited several significant differences compared with those infected with the wAlbB strain. Specifically, wMel-infected females laid significantly fewer eggs, ingested a lower amount of blood, had a reduced egg production rate, and exhibited a decreased Wolbachia density at a later age compared with mosquitoes infected with the wAlbB strain. Conversely, the wAlbB strain showed only mild negative effects when compared with Wolbachia-uninfected specimens. These differential effects on Ae. aegypti fitness following infection with either wMel or wAlbB may have important implications for the success of population replacement strategies in invading native Ae. aegypti populations in endemic settings. Further research is needed to better understand the underlying mechanisms responsible for these differences in fitness effects and their potential impact on the long-term efficacy of Wolbachia-based dengue control programs.IMPORTANCEThe transmission of arboviruses such as dengue, Zika, and chikungunya is on the rise globally. Among the most promising strategies to reduce arbovirus burden is the release of one out of two strains of Wolbachia-infected Aedes aegypti: wMel and wAlbB. One critical aspect of whether this approach will succeed involves the fitness cost of either Wolbachia strains on mosquito life history traits. For instance, we found that wMel-infected Ae. aegypti females laid significantly fewer eggs, ingested a lower amount of blood, had a reduced egg production rate, and exhibited a decreased Wolbachia density at a later age compared with mosquitoes infected with the wAlbB strain. Conversely, the wAlbB strain showed only mild negative effects when compared with Wolbachia-uninfected specimens. These differential effects on mosquito fitness following infection with either wMel or wAlbB may have important implications for the success of population replacement strategies in invading native Ae. aegypti populations.
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    文章类型: Preprint
    人类学习对类似规则的结构和用于培训的示例课程很敏感。在由简洁规则管理的任务中,当相关示例在试验中被阻止时,学习更健壮,但是在没有这样的规则的情况下,交错更有效。迄今为止,没有一个神经模型能同时捕捉到这些看似矛盾的效应。在这里,我们表明,在经过元学习训练的神经网络和大型语言模型(LLM)中,“上下文学习”(ICL)都会自发出现相同的权衡。ICL是通过在激活动力学中实现的内部循环算法来学习“上下文中”新任务的能力-无需权重更改。预先训练的LLM和金属学习变压器的实验表明,ICL在涉及规则结构的任务中表现出人类表现出的阻塞优势,反过来,同时进行的权重学习再现了人类在缺乏这种结构的任务中观察到的交织优势。
    Human learning is sensitive to rule-like structure and the curriculum of examples used for training. In tasks governed by succinct rules, learning is more robust when related examples are blocked across trials, but in the absence of such rules, interleaving is more effective. To date, no neural model has simultaneously captured these seemingly contradictory effects. Here we show that this same tradeoff spontaneously emerges with \"in-context learning\" (ICL) both in neural networks trained with metalearning and in large language models (LLMs). ICL is the ability to learn new tasks \"in context\" - without weight changes - via an inner-loop algorithm implemented in activation dynamics. Experiments with pretrained LLMs and metalearning transformers show that ICL exhibits the blocking advantage demonstrated in humans on a task involving rule-like structure, and conversely, that concurrent in-weight learning reproduces the interleaving advantage observed in humans on tasks lacking such structure.
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  • 文章类型: Journal Article
    将私人事件纳入我们的科学哲学是避免二元论并保持客观的组成部分,而不是对看不见的头脑做出假设。然而,包含在分析中无法观察到的行为和刺激会带来明显的问题。研究隐蔽行为的一种既定方法是检查假定需要口头调解的任务,并观察参与者的表现如何受到影响,当他们被要求在任务中大声说话(通常称为“阻塞”),再次假设这将使你难以或不可能同时秘密地与自己交谈。这项研究调查了声乐阻断对测序任务的影响,或者按照指定的顺序排列东西。在一个实验中,排序的项目是抽象线条图,第二个实验使用不同纹理的织物刺激(或“触觉卡”)。在第二个实验中,参与者学会了机智,然后在蒙住眼睛的同时对触觉刺激进行排序。在两种实验方式中,声音阻塞对假定的秘密排练的影响是不同的。这项初步研究提供了对隐蔽行为的本质的见解,因为它与不同的感官有关,并提出了有关研究隐蔽调解的一般性的问题。
    The inclusion of private events in the philosophy of our science is integral to avoid dualism and remain objective rather than making assumptions about an unseen mind. However, the inclusion of behaviors and stimuli which cannot be observed in an analysis poses obvious issues. One established method of studying covert behavior is to examine tasks that are presumed to require verbal mediation, and observing how a participant\'s performance is affected when they are required to speak out loud during the task (often called \"blocking\"), again presuming this will make it difficult or impossible to simultaneously talk to yourself covertly. This study investigated the effects of vocal blocking on a sequencing task, or lining things up in a specified order. In one experiment, the items sequenced were abstract line drawings, and a second experiment used differently textured fabric stimuli (or \"tactile cards\"). In the second experiment, participants learned to tact and then sequence the tactile stimuli while they were blindfolded. The effect of vocal blocking on putative covert rehearsal was dissimilar across the two modalities of the experiments. This preliminary study provides insight into the nature of covert behavior as it relates to different senses and opens questions about the generality of studies examining covert mediation.
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  • 文章类型: Journal Article
    基于六个详细的语言案例研究,其中重点在形态上被标记,我们提出了一种新颖的焦点标记形式理论,它可以捕捉这些以及熟悉的英语韵律重点标记。特别注意焦点融合的模式,也就是说,当焦点的不同大小和/或位置通过相同的形式不可区分地实现时。我们方法的关键成分是复杂的成分(不仅仅是文字)可能会被直接集中标记,焦点标记的选择受阻挡的支配。
    Based on six detailed case studies of languages in which focus is marked morphosyntactically, we propose a novel formal theory of focus marking, which can capture these as well as the familiar English-type prosodic focus marking. Special attention is paid to the patterns of focus syncretism, that is, when different size and/or location of focus are indistinguishably realized by the same form. The key ingredients to our approach are that complex constituents (not just words) may be directly focally marked, and that the choice of focal marking is governed by blocking.
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  • 文章类型: Journal Article
    基于高渗透率分布式光伏接入交直流配电网的场景,本文分析了柔性互联通道阻塞失效后配电网频率和电压的动态特性。为了增强故障后系统的暂态稳定性,本文综合考虑了光伏机组的主动调节能力,提出了具有灵活互联通道阻塞的单端配电网应急协调控制策略。首先,非故障通道在短时间内过载,然后电气距离等因素的综合影响,系统调频效果的响应时间和调整成本进行定量评估;根据评估结果,光伏和同步单元由“控制而不是跳闸”控制,最后,进行高频跳闸,基于“光伏第一”的原则。频率控制完成后,建立了系统的无功优化模型,并采用改进的禁忌粒子群算法进行求解,从而优化配电网节点的电压。最后,建立了等效仿真模型来验证协调控制策略。
    Based on the scenario of high-penetration distributed photovoltaic connected to an AC/DC distribution network, this paper analyzes the dynamic characteristics of frequency and voltage in a distribution network after the blocking failure of the flexible interconnection channel. In order to enhance the transient stability of the system after the fault, this paper comprehensively considers the active regulation ability of photovoltaic units, and puts forward an emergency coordinated control strategy for a single-ended distribution network with flexible interconnection channel blocking. Firstly, the non-fault channel is overloaded for a short time, then the comprehensive influence of factors such as electrical distance, response time and adjustment cost on the frequency modulation effect of the system is quantitatively evaluated; according to the evaluation results, the photovoltaic and synchronous units are controlled by \"control instead of tripping\", and finally, the high-frequency tripping is carried out, based on the principle of \"photovoltaics first\". After the frequency control is completed, the reactive power optimization model of the system is established, and the improved tabu-particle swarm optimization algorithm is used to solve it, so as to optimize the voltage of the distribution network nodes. Finally, an equivalent simulation model is established to verify the coordinated control strategy.
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  • 文章类型: Journal Article
    本文介绍了基于随机对照试验(RCT)数据进行推断的理由和局限性。我们认为,从患者人群中获得具有代表性的随机样本对于临床试验是不可能的,因为患者是随着时间的推移而连续累积的,因此包括一个方便的样本。仅符合协议输入标准。因此,该试验的样本不太可能代表可确定的患者人群。我们使用因果图来说明临床试验样本中干预措施的随机分配与真正的简单或分层随机抽样之间的差异,在调查中执行。我们认为特定群体的统计数据,例如RCT中治疗组的中位生存时间估计,作为对较大患者群体参数的估计,其意义有限。相比之下,干预措施之间的随机分配有助于对治疗效果进行比较因果推断,如风险比或响应概率之间的差异。比较推断还需要假设可从临床试验的便利样本转移到目标患者群体。我们专注于随机化程序的后果和局限性,以澄清对数据科学和RCT解释至关重要的互补概念对之间的区别。这些包括内部和外部有效性,通用性和可运输性,不确定性和可变性,代表性和包容性,阻塞和分层,相关性和鲁棒性,正向和反向因果推理,治疗意向和方案分析,以及潜在的结果和反事实。
    This article describes rationales and limitations for making inferences based on data from randomized controlled trials (RCTs). We argue that obtaining a representative random sample from a patient population is impossible for a clinical trial because patients are accrued sequentially over time and thus comprise a convenience sample, subject only to protocol entry criteria. Consequently, the trial\'s sample is unlikely to represent a definable patient population. We use causal diagrams to illustrate the difference between random allocation of interventions within a clinical trial sample and true simple or stratified random sampling, as executed in surveys. We argue that group-specific statistics, such as a median survival time estimate for a treatment arm in an RCT, have limited meaning as estimates of larger patient population parameters. In contrast, random allocation between interventions facilitates comparative causal inferences about between-treatment effects, such as hazard ratios or differences between probabilities of response. Comparative inferences also require the assumption of transportability from a clinical trial\'s convenience sample to a targeted patient population. We focus on the consequences and limitations of randomization procedures in order to clarify the distinctions between pairs of complementary concepts of fundamental importance to data science and RCT interpretation. These include internal and external validity, generalizability and transportability, uncertainty and variability, representativeness and inclusiveness, blocking and stratification, relevance and robustness, forward and reverse causal inference, intention to treat and per protocol analyses, and potential outcomes and counterfactuals.
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  • 文章类型: Journal Article
    嗜铬细胞瘤和副神经节瘤(PPGL)是罕见的肿瘤,和这些患者的动态血压监测(ABPM)数据以及阻断对ABPM参数的影响有限。我们的目标是在印度西部我们中心的一组PPGL中描述ABPM参数。
    对有ABPM数据的PPGL患者进行回顾性研究。人口统计细节,分泌状态,并检索了ABPM数据。变异系数(CV)计算为以百分比计的标准偏差/平均值。
    在纳入的39名患者中,演示时的平均年龄为39.3±14.2岁;20名(51.3%)为男性,25(64.1%)高血压,平均肿瘤直径为5.3cm。在18例基线ABPM没有药物治疗的患者中,那些夜间血压下降的人(6/18,33%)有更高的血清间肾上腺素(中位数313.2vs.34.7pg/ml,P=0.028)。尽管办公室血压(BP)正常,8.9%的收缩压血压读数>140mmHg,1.2%为>160mmHg。在29例ABPM阻滞前后的患者中,平均血压(收缩压121.6vs.132.5mmHg,P=0.014;舒张压68.9vs.76.4mmHg,P=0.005)和血压读数高于140mmHg的百分比(中位数9.4%与24.4%,P=0.016)在高血压(n=19)患者术前阻断后显著降低,而CV是相似的。氨氯地平或哌唑嗪阻断的患者的阻断后ABPM特征相似。
    ABPM提供了有关PPGL中BP特性的其他信息。术前阻断可降低BP偏移的幅度,但不影响BP变异性。
    UNASSIGNED: Pheochromocytoma and paraganglioma (PPGL) are rare tumors, and data on ambulatory blood pressure monitoring (ABPM) in these patients and the effect of blocking on ABPM parameters is limited. We aimed to describe ABPM parameters in a cohort of PPGL at our center in western India.
    METHODS: Retrospective study of patients with PPGL whose ABPM data was available. Demographic details, secretory status, and ABPM data were retrieved. Coefficient of variability (CV) was calculated as standard deviation/mean in percentage.
    RESULTS: In the 39 included patients, mean age at presentation was 39.3 ± 14.2 yr; 20 (51.3%) were males, 25 (64.1%) hypertensive, and mean tumor diameter was 5.3 cm. In 18 patients whose baseline ABPM was done without medications, those with nocturnal blood pressure dipping (6/18, 33%) had higher serum metanephrines (median 313.2 vs. 34.7 pg/ml, P = 0.028). Despite normal office blood pressure (BP), 8.9% of systolic BP readings were >140 mmHg, and 1.2% were >160 mmHg. Among 29 patients with both pre and post-block ABPM, mean BP (systolic 121.6 vs. 132.5 mmHg, P = 0.014; diastolic 68.9 vs. 76.4 mmHg, P = 0.005) and percentage of BP readings above 140 mmHg (median 9.4% vs. 24.4%, P = 0.016) were significantly lowered after the preoperative blockade in hypertensive ( n = 19) patients, whereas CV was similar. The post-blockade ABPM characteristics were similar in patients blocked with amlodipine or prazosin.
    CONCLUSIONS: ABPM provides additional information about BP characteristics in PPGL. The preoperative blocking decreases the magnitude of BP excursions but does not affect BP variability.
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