Mixture models

混合物模型
  • 文章类型: Journal Article
    概率回归模型的混合是将协变量信息纳入群体异质性学习的最常见技术之一。尽管具有灵活性,由于协变量之间的多重共线性,可能会出现不可靠的估计。在本文中,我们通过无监督学习方法开发了Liu型收缩方法,以在存在多重共线性的情况下估计模型系数。我们通过期望最大化算法的分类和随机版本来评估我们提出的方法的性能。我们使用数值模拟表明,所提出的方法优于其Ridge和最大似然对应物。最后,我们应用我们的方法分析50岁及以上女性的骨矿物质数据。
    The mixture of probabilistic regression models is one of the most common techniques to incorporate the information of covariates into learning of the population heterogeneity. Despite its flexibility, unreliable estimates can occur due to multicollinearity among covariates. In this paper, we develop Liu-type shrinkage methods through an unsupervised learning approach to estimate the model coefficients in the presence of multicollinearity. We evaluate the performance of our proposed methods via classification and stochastic versions of the expectation-maximization algorithm. We show using numerical simulations that the proposed methods outperform their Ridge and maximum likelihood counterparts. Finally, we apply our methods to analyze the bone mineral data of women aged 50 and older.
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  • 文章类型: Journal Article
    加纳寻求降低新生儿死亡率,在医院设施和社区,仍然是一场噩梦。可持续发展目标3中规定的实现新生儿健康生活和福祉的追求在充满挑战的医院设施和社区中持续存在。尽管如此,朝着这个方向不断努力。这项研究调查了在Bono地区的Sunyani和SunyaniWest市政议会的所有医院设施中阻碍与新生儿死亡率作斗争的因素,加纳。
    该研究利用了由新生儿死亡组成的新生儿死亡率数据,结构设施相关变量,医疗人力资源,医院设施和产后护理的类型。数据是2014年至2019年纵向收集的。使用负二项障碍回归(NBH)模型分析了这些变量,以确定在设施级别造成这种威胁的因素。获得了特定原因的死亡,以确定两个市政议会医疗机构中新生儿死亡的主要原因。
    该研究确定,这些地区新生儿死亡的主要原因是出生窒息(46%),早产(33%),新生儿败血症(11%)和新生儿黄疸(7%)。NBH显示,医院设施中的新生儿死亡率取决于孵化器的数量,监控设备,洗手设施,CPAPb机器,辐射加温器,理疗机,助产士,医院设施中的儿科医生和儿科护士。
    新生儿败血症的早期处理,出生窒息,早产和新生儿感染是减少新生儿死亡的必要条件。政府和卫生部门的所有利益攸关方应向所有医院设施提供消除这种威胁所需的基本设备和医疗人力资源。这将使可持续发展目标三,这需要所有人的健康生活和福祉,一个现实。
    UNASSIGNED: Ghana\'s quest to reduce neonatal mortality, in hospital facilities and communities, continues to be a nightmare. The pursuit of achieving healthy lives and well-being for neonates as enshrined in Sustainable Development Goal three lingered in challenging hospital facilities and communities. Notwithstanding that, there have been increasing efforts in that direction. This study examines the contributing factors that hinder the fight against neonatal mortality in all hospital facilities in the Sunyani and Sunyani West Municipal Assemblies in Bono Region, Ghana.
    UNASSIGNED: The study utilized neonatal mortality data consisting of neonatal deaths, structural facility related variables, medical human resources, types of hospital facilities and natal care. The data was collected longitudinally from 2014 to 2019. These variables were analysed using the negative binomial hurdle regression (NBH) model to determine factors that contribute to this menace at the facility level. Cause-specific deaths were obtained to determine the leading causes of neonatal deaths within health facilities in the two municipal assemblies.
    UNASSIGNED: The study established that the leading causes of neonatal mortality in these districts are birth asphyxia (46%), premature birth (33%), neonatal sepsis (11%) and neonatal jaundice (7%). The NBH showed that neonatal mortality in hospital facilities depend on the number of incubators, monitoring equipment, hand washing facilities, CPAPb machines, radiant warmers, physiotherapy machines, midwives, paediatric doctors and paediatric nurses in the hospital facility.
    UNASSIGNED: Early management of neonatal sepsis, birth asphyxia, premature birth and neonatal infections is required to reduce neonatal deaths. The government and all stakeholders in the health sector should provide all hospital facilities with the essential equipment and the medical human resources necessary to eradicate the menace. This will make the realization of Sustainable Development Goal three, which calls for healthy lives and well-being for all, a reality.
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  • 文章类型: Journal Article
    目的:接触环境化学物质与胎盘形态和功能的改变有关吗?
    结论:邻苯二甲酸盐,一类普遍存在的化学物质,显示与胎盘重量改变有关,胎盘血管阻力(PVR),和胎盘效率。
    背景:只有少数流行病学研究评估了酚和邻苯二甲酸酯对胎盘健康的影响。他们的结果受到与这些化合物的快速排泄有关的暴露测量误差以及对有限数量的斑点尿液样品进行评估暴露的依赖的影响。
    准母子队列,改进非持久性化学品的暴露评估,2014年至2017年招募的参与者。样本量介于355(出生时测量的胎盘参数:胎盘重量和胎盘与胎儿重量比(PFR):胎盘效率的代表)和426(怀孕期间测量的胎盘参数:胎盘厚度和血管阻力)之间。
    方法:酚类(四种对羟基苯甲酸酯,两种双酚,三氯生,和二苯甲酮-3),13邻苯二甲酸酯代谢物,在妊娠第二和第三三个月期间收集的受试者体内重复尿液样本中测量了两种非邻苯二甲酸酯增塑剂代谢物(中位数=21份样本/妊娠月/女性).在怀孕期间测量胎盘厚度和PVR。出生时对胎盘称重并计算PFR。使用调整的线性回归和贝叶斯内核机器回归来评估酚和邻苯二甲酸酯(单独或作为混合物)与胎盘参数之间的关联。还研究了儿童性别的效果改变。
    结果:几种邻苯二甲酸盐代谢产物与胎盘结局呈负相关。邻苯二甲酸单苄基酯(MBzP)浓度,在怀孕的第二和第三个三个月,与出生时胎盘重量的减少有关(β=-20.1g[95%CI:-37.8;-2.5]和β=-17.4g[95%CI:-33.2;-1.6],第二和第三个三个月,分别)和PFR(β=-0.5[95%CI:-1,-0.1]和β=-0.5[95%CI:-0.9,-0.1],对于第二和第三个三个月,分别)。此外,妊娠晚期MBzP与PVR呈负相关(β=-0.9[95%CI:-1.8;0.1])。邻苯二甲酸单正丁酯(MnBP),在两个孕期均与PVR呈负相关(β=-1.3,95%CI:[-2.3,-0.2],和β=-1.2,95%CI:[-2.4,-0.03],对于第二和第三个三个月,分别)。儿童性别分层后,Σ邻苯二甲酸二异壬酯(DiNP)(第二或第三三个月暴露,根据所考虑的结果)与妊娠晚期PVR降低相关,以及男性胎盘重量和PFR下降。未观察到苯酚生物标志物的关联。
    结论:不能排除误报。因此,与多个结局(MnBP和DiNP)相关或现有文献报道的与胎盘结局(MBzP)相关的化学物质应被视为主要结果.
    结论:我们的结果与体外研究一致,表明邻苯二甲酸酯靶向过氧化物酶体增殖物激活受体γ,在涉及关键胎盘发育过程如滋养细胞增殖的核受体家族中,迁移,和入侵。除了出生时的胎盘重量,我们研究了怀孕期间的胎盘参数,这可以更广泛地了解环境化学物质如何在怀孕过程中影响母胎交换。我们的发现有助于越来越多的证据表明邻苯二甲酸酯暴露对胎盘健康的不利影响。
    背景:这项工作得到了法国研究机构-ANR(MEMORI项目ANR-21-CE34-0022)的支持。SEPAGES队列得到了欧洲研究理事会(N°311765-E-DOHaD)的支持,欧洲共同体第七框架计划(FP7/2007-206-N°308333-892HELIX),欧盟地平线2020研究与创新计划(N°874583ATHLETE项目,N°825712OBERON项目),法国研究机构-ANR(PAPER项目ANR-12-PDOC-0029-01,SHALCOH项目ANR-14-CE21-0007,ANR-15-IDEX-02和ANR-15-IDEX5,GUMME项目ANR-18-CE36-005,ETAPE项目ANR-18-CE36-0005-EDeN项目ANR-19-01,法国食品局,环境与职业健康与安全ANSES(CNAP项目EST-2016-121,PENDORE项目EST-2016-121,HyPAxE项目EST-2019/1/039,PENDALIRE项目EST-2022-169),癌症计划(加拿大航空项目),法国癌症研究基金会癌症研究协会,法国慢性病捐赠基金AGIR-APMC(项目PRENAPAR,LCI-FOT,DysCard),法国呼吸健康捐赠基金,法国基金会(CLIMATHES-00081169,SEPAGES5-00099903,ELEMENTUM-00124527)。新泽西州得到了格勒诺布尔阿尔卑斯大学博士奖学金的支持。V.M.由SaraBorrell博士后研究合同(CD22/00176)支持,由CarlosIII(西班牙)和NextGenerationEU基金授予。作者声明没有利益冲突。
    背景:ClinicalTrials.govNCT02852499。
    OBJECTIVE: Is exposure to environmental chemicals associated with modifications of placental morphology and function?
    CONCLUSIONS: Phthalates, a class of ubiquitous chemicals, showed an association with altered placental weight, placental vascular resistance (PVR), and placental efficiency.
    BACKGROUND: Only a few epidemiological studies have assessed the effects of phenols and phthalates on placental health. Their results were affected by exposure measurement errors linked to the rapid excretion of these compounds and the reliance on a limited number of spot urine samples to assess exposure.
    UNASSIGNED: A prospective mother-child cohort, with improved exposure assessment for non-persistent chemicals, recruited participants between 2014 and 2017. Sample size ranged between 355 (placental parameters measured at birth: placental weight and placental-to-fetal weight ratio (PFR): a proxy for placental efficiency) and 426 (placental parameters measured during pregnancy: placental thickness and vascular resistance).
    METHODS: Phenols (four parabens, two bisphenols, triclosan, and benzophenone-3), 13 phthalate metabolites, and two non-phthalate plasticizer metabolites were measured in within-subject pools of repeated urine samples collected during the second and third trimesters of pregnancy (median = 21 samples/trimester/woman). Placental thickness and PVR were measured during pregnancy. The placenta was weighed at birth and the PFR was computed. Both adjusted linear regression and Bayesian Kernel Machine Regression were used to evaluate associations between phenols and phthalates (alone or as a mixture) and placental parameters. Effect modification by child sex was also investigated.
    RESULTS: Several phthalate metabolites were negatively associated with placental outcomes. Monobenzyl phthalate (MBzP) concentrations, during the second and third trimesters of pregnancy, were associated with a decrease in both placental weight at birth (β = -20.1 g [95% CI: -37.8; -2.5] and β = -17.4 g [95% CI: -33.2; -1.6], for second and third trimester, respectively) and PFR (β = -0.5 [95% CI: -1, -0.1] and β = -0.5 [95% CI: -0.9, -0.1], for the second and third trimester, respectively). Additionally, MBzP was negatively associated with PVR during the third trimester (β= -0.9 [95% CI: -1.8; 0.1]). Mono-n-butyl phthalate (MnBP), was negatively associated with PVR in both trimesters (β = -1.3, 95% CI: [-2.3, -0.2], and β = -1.2, 95% CI: [-2.4, -0.03], for the second and third trimester, respectively). After stratification for child sex, Σ diisononyl phthalate (DiNP) (either second or third-trimester exposures, depending on the outcomes considered) was associated with decreased PVR in the third trimester, as well as decreased placental weight and PFR in males. No associations were observed for phenol biomarkers.
    CONCLUSIONS: False positives cannot be ruled out. Therefore, chemicals that were associated with multiple outcomes (MnBP and DiNP) or reported in existing literature as associated with placental outcomes (MBzP) should be considered as the main results.
    CONCLUSIONS: Our results are consistent with in vitro studies showing that phthalates target peroxisome proliferator-activated receptor γ, in the family of nuclear receptors involved in key placental development processes such as trophoblast proliferation, migration, and invasion. In addition to placental weight at birth, we studied placental parameters during pregnancy, which could provide a broader view of how environmental chemicals affect maternal-fetal exchanges over the course of pregnancy. Our findings contribute to the increasing evidence indicating adverse impacts of phthalate exposure on placental health.
    BACKGROUND: This work was supported by the French Research Agency-ANR (MEMORI project ANR-21-CE34-0022). The SEPAGES cohort was supported by the European Research Council (N°311765-E-DOHaD), the European Community\'s Seventh Framework Programme (FP7/2007-206-N°308333-892 HELIX), the European Union\'s Horizon 2020 research and innovation programme (N° 874583 ATHLETE Project, N°825712 OBERON Project), the French Research Agency-ANR (PAPER project ANR-12-PDOC-0029-01, SHALCOH project ANR-14-CE21-0007, ANR-15-IDEX-02 and ANR-15-IDEX5, GUMME project ANR-18-CE36-005, ETAPE project ANR-18-CE36-0005-EDeN project ANR-19-CE36-0003-01), the French Agency for Food, Environmental and Occupational Health & Safety-ANSES (CNAP project EST-2016-121, PENDORE project EST-2016-121, HyPAxE project EST-2019/1/039, PENDALIRE project EST-2022-169), the Plan Cancer (Canc\'Air project), the French Cancer Research Foundation Association de Recherche sur le Cancer-ARC, the French Endowment Fund AGIR for chronic diseases-APMC (projects PRENAPAR, LCI-FOT, DysCard), the French Endowment Fund for Respiratory Health, the French Fund-Fondation de France (CLIMATHES-00081169, SEPAGES 5-00099903, ELEMENTUM-00124527). N.J. was supported by a doctoral fellowship from the University Grenoble Alpes. V.M. was supported by a Sara Borrell postdoctoral research contract (CD22/00176), granted by Instituto de Salud Carlos III (Spain) and NextGenerationEU funds. The authors declare no conflict of interest.
    BACKGROUND: ClinicalTrials.gov NCT02852499.
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  • 文章类型: Journal Article
    背景:超重和肥胖是全球主要的慢性疾病。环境酚被认为是导致体重变化的内分泌干扰物;然而,混合酚对肥胖的影响尚不明确.
    方法:使用国家健康和营养调查中成年人的数据,这项研究研究了四种酚类对肥胖的单独和联合作用。传统逻辑回归和两个混合模型(加权分位数和(WQS)回归和贝叶斯核机回归(BKMR))的组合用于评估酚类在肥胖发展中的作用。通过平行中介模型分析了胆固醇对这些作用的潜在中介作用。
    结果:结果表明,除三氯生外,单酚与肥胖呈负相关(P值<0.05)。WQS指数与一般肥胖(β:0.770,95%CI:0.644~0.919,P值=0.004)和腹型肥胖(β:0.781,95%CI:0.658~0.928,P值=0.004)呈负相关。始终如一,BKMR模型证明了酚类对肥胖的显著联合负面影响.平行介导分析显示,高密度脂蛋白介导了所有四种单酚对肥胖的影响,而低密度脂蛋白仅介导苯酚-3与肥胖之间的关联。此外,胆固醇充当混合酚与肥胖之间关联的介体。暴露于单一和混合酚与肥胖显著负相关。胆固醇介导单一和混合环境酚与肥胖的关联。
    结论:评估混合酚的潜在公共卫生风险有助于将这些信息纳入实际的健康建议和指导。
    BACKGROUND: Overweight and obesity are among the leading chronic diseases worldwide. Environmental phenols have been renowned as endocrine disruptors that contribute to weight changes; however, the effects of exposure to mixed phenols on obesity are not well established.
    METHODS: Using data from adults in National Health and Nutrition Examination Survey, this study examined the individual and combined effects of four phenols on obesity. A combination of traditional logistic regression and two mixed models (weighted quantile sum (WQS) regression and Bayesian kernel-machine regression (BKMR)) were used together to assess the role of phenols in the development of obesity. The potential mediation of cholesterol on these effects was analyzed through a parallel mediation model.
    RESULTS: The results demonstrated that solitary phenols except triclosan were inversely associated with obesity (P-value < 0.05). The WQS index was also negatively correlated with general obesity (β: 0.770, 95% CI: 0.644-0.919, P-value = 0.004) and abdominal obesity (β: 0.781, 95% CI: 0.658-0.928, P-value = 0.004). Consistently, the BKMR model demonstrated the significant joint negative effects of phenols on obesity. The parallel mediation analysis revealed that high-density lipoprotein mediated the effects of all four single phenols on obesity, whereas low-density lipoprotein only mediated the association between benzophenol-3 and obesity. Moreover, Cholesterol acts as a mediator of the association between mixed phenols and obesity. Exposure to single and mixed phenols significantly and negatively correlated with obesity. Cholesterol mediated the association of single and mixed environmental phenols with obesity.
    CONCLUSIONS: Assessing the potential public health risks of mixed phenols helps to incorporate this information into practical health advice and guidance.
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  • 文章类型: Journal Article
    我们介绍了一个基于混合理论的数学模型,旨在描述肿瘤微环境中的肿瘤-免疫系统相互作用。这些方程解释了肿瘤扩张的几何形状,以及免疫细胞的位移,由扩散和趋化机制驱动。他们还考虑了营养和氧气供应方面的限制。数值调查分析了不同建模假设和参数的影响。根据参数,该模型可以重现消除,平衡或逃逸阶段,它确定了氧气/营养供应在塑造肿瘤生长中的关键作用。此外,抗肿瘤免疫细胞是控制肿瘤生长的关键因素,保持平衡,而原瘤细胞有利于逃逸和肿瘤扩张。
    We introduce a mathematical model based on mixture theory intended to describe the tumor-immune system interactions within the tumor microenvironment. The equations account for the geometry of the tumor expansion, and the displacement of the immune cells, driven by diffusion and chemotactic mechanisms. They also take into account the constraints in terms of nutrient and oxygen supply. The numerical investigations analyze the impact of the different modeling assumptions and parameters. Depending on the parameters, the model can reproduce elimination, equilibrium or escape phases and it identifies a critical role of oxygen/nutrient supply in shaping the tumor growth. In addition, antitumor immune cells are key factors in controlling tumor growth, maintaining an equilibrium while protumor cells favor escape and tumor expansion.
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  • 文章类型: Journal Article
    传统上,较差的理解者被认为具有低于平均水平的阅读理解,平均范围单词阅读,和两者之间的差异。虽然口语在理解较差的人中往往很低,阅读是一个复杂的特征,异质性可能不会被群体水平的比较所发现。
    我们采用了预先注册的数据驱动方法来识别较差的理解者,并检查他们的困难是否存在多个不同的认知特征。潜在混合模型从雅芳父母和儿童纵向研究中确定了6846名儿童的阅读概况,基于8-9岁的阅读和听力理解评估。第二个混合模型检查了弱理解者认知特征的变化,使用阅读的措施,语言,工作记忆,非语言能力,和注意力不集中。
    预注册模型未识别出较差的综合能力。然而,通过额外控制整体能力,出现了一个6类模型,该模型包含了理解力相对较弱的配置文件(N=947,13.83%)。这些孩子中的大多数在良好的段落阅读的背景下阅读理解能力较弱,伴随着词汇和非语言能力的弱点。在其他认知障碍的情况下,一个小组显示出更严重的理解困难。
    阅读的特定组成部分中的孤立损伤很少见,然而,数据驱动的方法可以用来识别理解力相对较弱的儿童。在这个群体中,词汇和非语言能力一直很弱,对于一部分儿童来说,更广泛的认知困难也很明显。这些发现表明,理解力差是连续体的最佳特征,并考虑了影响严重程度的多种风险。
    UNASSIGNED: Poor comprehenders are traditionally identified as having below-average reading comprehension, average-range word reading, and a discrepancy between the two. While oral language tends to be low in poor comprehenders, reading is a complex trait and heterogeneity may go undetected by group-level comparisons.
    UNASSIGNED: We took a preregistered data-driven approach to identify poor comprehenders and examine whether multiple distinct cognitive profiles underlie their difficulties. Latent mixture modelling identified reading profiles in 6846 children from the Avon Longitudinal Study of Parents and Children, based on reading and listening comprehension assessments at 8-9 years. A second mixture model examined variation in the cognitive profiles of weak comprehenders, using measures of reading, language, working memory, nonverbal ability, and inattention.
    UNASSIGNED: A poor comprehender profile was not identified by the preregistered model. However, by additionally controlling for overall ability, a 6-class model emerged that incorporated a profile with relatively weak comprehension (N = 947, 13.83%). Most of these children had weak reading comprehension in the context of good passage reading, accompanied by weaknesses in vocabulary and nonverbal ability. A small subgroup showed more severe comprehension difficulties in the context of additional cognitive impairments.
    UNASSIGNED: Isolated impairments in specific components of reading are rare, yet a data-driven approach can be used to identify children with relatively weak comprehension. Vocabulary and nonverbal ability were most consistently weak within this group, with broader cognitive difficulties also apparent for a subset of children. These findings suggest that poor comprehension is best characterised along a continuum, and considered in light of multiple risks that influence severity.
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  • 文章类型: Journal Article
    在没有金标准检验的情况下,对诊断检验数据采用贝叶斯潜类分析时,通常假设任何未知的测试敏感性和特异性在不同人群中是恒定的。实际上,这种假设对于模型的可识别性通常是必要的。然而,有一些实际情况,根据测试的类型和疾病的性质,这个假设可能不是真的。我们提供了一个使用显微镜凝集试验诊断肉牛中钩端螺旋体感染的案例研究,这强烈表明,敏感性尤其在牧群之间有所不同。我们开发并拟合了一种替代模型,在该模型中,敏感性与群体内患病率相关,并讨论统计和流行病学的影响。
    When Bayesian latent class analysis is used for diagnostic test data in the absence of a gold standard test, it is common to assume that any unknown test sensitivities and specificities are constant across different populations. Indeed this assumption is often necessary for model identifiability. However there are a number of practical situations, depending on the type of test and the nature of the disease, where this assumption may not be true. We present a case study of using a microscopic agglutination test to diagnose leptospiroris infection in beef cattle, which strongly suggests that sensitivity in particular varies among herds. We develop and fit an alternative model in which sensitivity is related to within-herd prevalence, and discuss the statistical and epidemiological implications.
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  • 文章类型: Journal Article
    抗菌素耐药性正在成为全世界公共卫生的主要威胁。研究人员正试图通过开发新的抗生素和针对患者的治疗方法来进行对比。在第二种情况下,全基因组测序在两个方面产生了巨大的影响:第一,进行全基因组测序变得越来越便宜和快捷,这使得它在标准表型测试方面具有竞争力;第二,在统计学上可以将抗性的表型模式与基因组中的特定突变联系起来。因此,现在有可能开发与特定抗生素抗性相关的基因组变异目录,以提高抗性预测和建议治疗。至关重要的是要有可靠的方法来识别与抗性相关的突变并不断更新可用的目录。这项工作提出了一种通用方法来研究最小抑制浓度分布,并鉴定对抗菌药物具有不同抗性的菌株簇。一旦识别出集群并将菌株分配给每个集群,可以采用回归方法以高统计能力鉴定与耐药相关的突变。该方法适用于一种新的96孔微量滴定板,用于检测结核分枝杆菌。
    Antimicrobial resistance is becoming a major threat to public health throughout the world. Researchers are attempting to contrast it by developing both new antibiotics and patient-specific treatments. In the second case, whole-genome sequencing has had a huge impact in two ways: first, it is becoming cheaper and faster to perform whole-genome sequencing, and this makes it competitive with respect to standard phenotypic tests; second, it is possible to statistically associate the phenotypic patterns of resistance to specific mutations in the genome. Therefore, it is now possible to develop catalogues of genomic variants associated with resistance to specific antibiotics, in order to improve prediction of resistance and suggest treatments. It is essential to have robust methods for identifying mutations associated to resistance and continuously updating the available catalogues. This work proposes a general method to study minimal inhibitory concentration distributions and to identify clusters of strains showing different levels of resistance to antimicrobials. Once the clusters are identified and strains allocated to each of them, it is possible to perform regression method to identify with high statistical power the mutations associated with resistance. The method is applied to a new 96-well microtiter plate used for testing Mycobacterium tuberculosis.
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  • 文章类型: Journal Article
    在许多医疗保健和社会科学应用中,有关单位的信息分散在多个数据文件中。跨文件链接记录对于估计感兴趣的关联是必要的。常见的记录链接算法仅依赖于出现在所有文件中的链接变量之间的相似性。此外,对链接文件的分析通常会忽略错误或丢失链接可能导致的错误。贝叶斯记录链接方法允许链接误差的自然传播,通过联合采样联动结构和模型参数。我们扩展了现有的贝叶斯记录链接方法,以整合所链接的每个文件所独有的变量之间的关联。我们通过分析显示,使用模拟,所提出的方法可以改善链接过程,并且可以得出准确的推论。我们应用该方法将车轮上的膳食接受者与Medicare参保记录联系起来。
    In many healthcare and social science applications, information about units is dispersed across multiple data files. Linking records across files is necessary to estimate the associations of interest. Common record linkage algorithms only rely on similarities between linking variables that appear in all the files. Moreover, analysis of linked files often ignores errors that may arise from incorrect or missed links. Bayesian record linking methods allow for natural propagation of linkage error, by jointly sampling the linkage structure and the model parameters. We extend an existing Bayesian record linkage method to integrate associations between variables exclusive to each file being linked. We show analytically, and using simulations, that the proposed method can improve the linking process, and can result in accurate inferences. We apply the method to link Meals on Wheels recipients to Medicare enrollment records.
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  • 文章类型: Journal Article
    在不同场景中建立有限数量的样本和分割对象之间的关系是少射分割中的主要挑战。然而,许多以前的工作忽略了关键的支持-查询集交互和需要探索的更深层次的信息。当面对复杂的场景时,这种监督可能会导致模型失败,比如模糊的边界。为了解决这个问题,提出了一种利用抑制和聚焦概念的双工网络,以有效地抑制背景并聚焦于前景。我们的网络包括动态卷积以增强支持-查询交互和原型匹配结构,以从支持和查询中完全提取信息。所提出的模型称为动态原型混合卷积网络(DPMC)。为了最大限度地减少冗余信息的影响,我们在DPMC中加入了一个混合注意模块,称为双层注意增强卷积模块(DAAConv)。该模块使网络能够更加专注于前台信息。我们在PASCAL-5i和COCO-20i数据集上的实验表明,DPMC和DAAConv的性能平均优于传统的基于原型的方法5-8%。
    Establishing the relationship between a limited number of samples and segmented objects in diverse scenarios is the primary challenge in few-shot segmentation. However, many previous works overlooked the crucial support-query set interaction and the deeper information that needs to be explored. This oversight can lead to model failure when confronted with complex scenarios, such as ambiguous boundaries. To solve this problem, a duplex network that utilizes the suppression and focus concept is proposed to effectively suppress the background and focus on the foreground. Our network includes dynamic convolution to enhance the support-query interaction and a prototype match structure to fully extract information from support and query. The proposed model is called dynamic prototype mixture convolutional networks (DPMC). To minimize the impact of redundant information, we have incorporated a hybrid attentional module called double-layer attention augmented convolutional module (DAAConv) into DPMC. This module enables the network to concentrate more on foreground information. Our experiments on PASCAL-5i and COCO-20i datasets suggested that DPMC and DAAConv outperform traditional prototype-based methods by up to 5-8% on average.
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