• 【关于差异表达基因的鉴定: 改进Affymetrix微阵列基因表达数据的广义F统计量。】 复制标题 收藏 收藏
    DOI:10.1016/j.compbiolchem.2006.06.002 复制DOI
    作者列表:Lai Y
    BACKGROUND & AIMS: :It has been shown that the generalized F-statistics can give satisfactory performances in identifying differentially expressed genes with microarray data. However, for some complex diseases, it is still possible to identify a high proportion of false positives because of the modest differential expressions of disease related genes and the systematic noises of microarrays. The main purpose of this study is to develop statistical methods for Affymetrix microarray gene expression data so that the impact on false positives from non-expressed genes can be reduced. I proposed two novel generalized F-statistics for identifying differentially expressed genes and a novel approach for estimating adjusting factors. The proposed statistical methods systematically combine filtering of non-expressed genes and identification of differentially expressed genes. For comparison, the discussed statistical methods were applied to an experimental data set for a type 2 diabetes study. In both two- and three-sample analyses, the proposed statistics showed improvement on the control of false positives.
    背景与目标: : 已经表明,广义F统计量可以在用微阵列数据鉴定差异表达基因方面提供令人满意的性能。然而,对于一些复杂的疾病,由于疾病相关基因的适度差异表达和微阵列的系统噪声,仍然有可能识别出高比例的假阳性。这项研究的主要目的是开发Affymetrix微阵列基因表达数据的统计方法,以便可以减少对非表达基因假阳性的影响。我提出了两种新颖的通用F统计量来识别差异表达的基因,以及一种估计调整因子的新方法。所提出的统计方法系统地结合了非表达基因的过滤和差异表达基因的鉴定。为了进行比较,将讨论的统计方法应用于2型糖尿病研究的实验数据集。在两样本和三样本分析中,建议的统计数据均显示出对假阳性的控制有所改善。
  • 【[产后避孕: 对600名患者进行产后控制,其中129名患者]。】 复制标题 收藏 收藏
    DOI:10.1016/j.gyobfe.2013.07.017 复制DOI
    作者列表:Blangis F,Lopes P,Branger B,Garnier P,Philippe HJ,Ploteau S
    BACKGROUND & AIMS: OBJECTIVE:To draw a parallel between the contraceptive methods prescribed in the post-natal ward and the contraceptive methods taken by patients during their postnatal visit. PATIENTS AND METHODS:This piece of work draws information from a prospective 10 weeks study at a University Teaching Hospital post-natal ward on the contraception that is prescribed upon leaving the maternity ward and also at the time of the post-natal visit. RESULTS:From the 600 cases studied, the analysis is about 129 patients reviewed in the post-natal visit. The percentage of loss was 78.5%. A hormonal contraceptive pill was prescribed to 73.5% of women (441 patients) after birth in which 63.5% had microprogestative pills. At the earliest, the IUD was given at about 5.4 weeks postpartum. At the time of the postnatal visit, compliance was bad for one third of women with either estrogen plus progestin methods, microprogestative or natural methods. Women who chose a barrier method were only 45.5% to follow this choice, the others left without contraception. DISCUSSION AND CONCLUSION:The prescription of postpartum contraception was followed by only 66.6% of women. In order to prescribe a more effective contraceptive method, we must improve the prescriber's timing in sharing contraceptive information and completeness of the contraceptive methods offered.
    背景与目标:
  • 【在先前剖宫产的妇女中同时进行铜T插入与医学终止妊娠。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Gupta I,Mahajan U,Sawhney H
    BACKGROUND & AIMS: :The event rates up to 1 year after insertion of a Copper-T IUD were compared in 76 women who had 1 or more cesarean sections, and were given their IUD immediately after medical termination of pregnancy, and in 76 women matched for age and parity but normal vaginal deliveries. The cesarean group had abortion performed under general anesthesia; the vaginal group had iv diazepam and paracervical block. All subjects were less than 11 weeks gestation. They were followed up at 7 days, 6 weeks, and 3 monthly intervals for 1 year. No perforations or pregnancies occurred. Incomplete abortion caused expulsion in 2.6% of women in both groups, and removal in 6.5 and 5.3%, in the cesarean and control groups respectively, and was responsible for most discontinuations. It was concluded that IUD insertion is safe after medical termination of pregnancy in women with a history of cesarean section, depending on the skill of the surgeon.
    背景与目标: : 比较了76名剖宫产1次或更多次,并在医学终止妊娠后立即给予宫内节育器的妇女和76名年龄和胎次匹配但阴道分娩正常的妇女插入铜-T宫内节育器后1年的事件发生率。剖宫产组在全麻下进行人工流产术; 阴道组静脉注射安定和宫颈旁阻滞。所有受试者妊娠均少于11周。对他们进行了7天,6周和3个月的随访,为期1年。没有发生穿孔或怀孕。不完全流产导致两组2.6% 的妇女被驱逐,剖宫产组和对照组分别在6.5和5.3% 中被驱逐,这是大多数中止的原因。结论是,根据外科医生的技能,有剖宫产史的妇女在医学终止妊娠后插入宫内节育器是安全的。
  • 【增加同步性可能会促进癫痫发作的终止: 来自癫痫持续状态的证据。】 复制标题 收藏 收藏
    DOI:10.1016/j.clinph.2007.06.006 复制DOI
    作者列表:Schindler K,Elger CE,Lehnertz K
    BACKGROUND & AIMS: OBJECTIVE:To test whether increasing synchronization of neuronal activity might be causally related to seizure termination. METHODS:Neuronal synchronization was assessed by the relative changes of the eigenvalue spectrum of the equal-time correlation matrix computed from a short window sliding along multi-channel EEGs, recorded with either intracranial or surface electrodes. RESULTS:Synchronization dynamics of six status epilepticus EEG recordings from six patients were assessed. In all six recordings EEG synchronization fluctuated around relatively low levels during ongoing epileptiform activity. Synchronization only persistently increased before, or in one case, at the end of status epilepticus. Ongoing seizure activity stopped without pharmacological intervention in one patient. In four of the five other cases, the persistent increase of synchronization followed administration of anticonvulsant drugs. CONCLUSIONS:Our findings support the hypothesis that increasing synchronization of neuronal activity may be considered as an emergent self-regulatory mechanism for seizure termination. SIGNIFICANCE:The traditional concept is challenged that increasing neuronal synchronization during epileptic seizures is always pathological and should be suppressed. On the contrary, our findings imply that therapeutic interventions to increase synchronization during seizures might be beneficial.
    背景与目标:
  • 【多次或分层评分者间协定研究中AC1统计量的同质性得分测试和常见AC1的估计。】 复制标题 收藏 收藏
    DOI:10.1186/s12874-019-0887-5 复制DOI
    作者列表:Honda C,Ohyama T
    BACKGROUND & AIMS: BACKGROUND:Cohen's κ coefficient is often used as an index to measure the agreement of inter-rater determinations. However, κ varies greatly depending on the marginal distribution of the target population and overestimates the probability of agreement occurring by chance. To overcome these limitations, an alternative and more stable agreement coefficient was proposed, referred to as Gwet's AC1. When it is desired to combine results from multiple agreement studies, such as in a meta-analysis, or to perform stratified analysis with subject covariates that affect agreement, it is of interest to compare several agreement coefficients and present a common agreement index. A homogeneity test of κ was developed; however, there are no reports on homogeneity tests for AC1 or on an estimator of common AC1. In this article, a homogeneity score test for AC1 is therefore derived, in the case of two raters with binary outcomes from K independent strata and its performance is investigated. An estimation of the common AC1 between strata and its confidence intervals is also discussed. METHODS:Two homogeneity tests are provided: a score test and a goodness-of-fit test. In this study, the confidence intervals are derived by asymptotic, Fisher's Z transformation and profile variance methods. Monte Carlo simulation studies were conducted to examine the validity of the proposed methods. An example using clinical data is also provided. RESULTS:Type I error rates of the proposed score test were close to the nominal level when conducting simulations with small and moderate sample sizes. The confidence intervals based on Fisher's Z transformation and the profile variance method provided coverage levels close to nominal over a wide range of parameter combination. CONCLUSIONS:The method proposed in this study is considered to be useful for summarizing evaluations of consistency performed in multiple or stratified inter-rater agreement studies, for meta-analysis of reports from multiple groups and for stratified analysis.
    背景与目标:
  • 【输精管,男性避孕的一个部位: 概述。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Lohiya NK,Manivannan B,Mishra PK,Pathak N
    BACKGROUND & AIMS: :The vas deferens is a site which can be exploited for male contraception without undue side effects. The only effective technique available for male contraception is vasectomy, being practiced world wide, despite that it is a permanent surgical procedure and its successful reversal is not assured. Although no-scalpel vasectomy minimizes surgical procedures, the fate of its reversal is akin to that of vasectomy. Several occlusive and non-occlusive vasal procedures which claim to be reversible without surgical intervention, possess more disadvantages than advantages. Vas occlusion with plug, 'Shug' or medical grade silicone rubber, although claimed to produce reversible azoospermia without affecting spermatogenesis, requires skilled microsurgery for their implantation and later removal. RISUG, a non-sclerotic polymer styrene maleic anhydride (SMA), could be more advantageous than vasectomy and other vas occlusive procedures in that it could be a totally non-invasive procedure by "no-scalpel injection" and "non-invasive reversal". It is claimed to offer long-term contraception without adverse side effects and also to be possible as a male spacing method by repeated vas occlusion and non-invasive reversal. The drug is currently under multicentre Phase III clinical trial.
    背景与目标: : 输精管是一个可以用于男性避孕的部位,没有过度的副作用。唯一可用于男性避孕的有效技术是输精管切除术,尽管它是一种永久性的外科手术,并且不能保证其成功逆转。尽管无手术刀输精管切除术可最大程度地减少外科手术,但其逆转的命运类似于输精管切除术。几种闭塞性和非闭塞性血管手术声称无需手术干预即可逆转,其缺点多于优点。尽管据称会产生可逆的无精子症而不影响精子发生,但需要熟练的显微外科手术才能将其植入并随后取出。RISUG是一种非硬化聚合物苯乙烯马来酸酐 (SMA),可能比输精管切除术和其他输精管闭塞手术更有利,因为它可以通过 “无手术刀注射” 和 “非侵入性逆转” 完全是非侵入性的手术。据称可以提供长期避孕而没有不良副作用,并且可以通过反复的vas闭塞和非侵入性逆转作为男性间隔方法。该药物目前正在进行多中心III期临床试验。
  • 【RNA聚合酶II与Sen1-dependent转录终止之间的动力学竞争。】 复制标题 收藏 收藏
    DOI:10.1016/j.molcel.2012.10.014 复制DOI
    作者列表:Hazelbaker DZ,Marquardt S,Wlotzka W,Buratowski S
    BACKGROUND & AIMS: :The essential helicase-like protein Sen1 mediates termination of RNA Polymerase II (Pol II) transcription at snoRNAs and other noncoding RNAs in yeast. A mutation in the Pol II subunit Rpb1 that increases the elongation rate increases read-through transcription at Sen1-mediated terminators. Termination and growth defects in sen1 mutant cells are partially suppressed by a slowly transcribing Pol II mutant and are exacerbated by a faster-transcribing Pol II mutant. Deletion of the nuclear exosome subunit Rrp6 allows visualization of noncoding RNA intermediates that are terminated but not yet processed. Sen1 mutants or faster-transcribing Pol II increase the average lengths of preprocessed snoRNA, CUT, and SUT transcripts, while slowed Pol II transcription produces shorter transcripts. These connections between transcription rate and Sen1 activity support a model whereby kinetic competition between elongating Pol II and Sen1 helicase establishes the temporal and spatial window for early Pol II termination.
    背景与目标: : 必需的解旋酶样蛋白Sen1介导RNA聚合酶II (Pol II) 在酵母中的snoRNAs和其他非编码RNA上的转录终止。增加伸长率的Pol II亚基Rpb1中的突变增加了Sen1-mediated终止子处的通读转录。缓慢转录的Pol II突变体部分抑制了sen1突变细胞中的终止和生长缺陷,而转录速度较快的Pol II突变体则加剧了这种缺陷。删除核外泌体亚基Rrp6允许可视化终止但尚未处理的非编码RNA中间体。Sen1突变体或转录速度较快的Pol II增加了预处理的snoRNA,CUT和SUT转录物的平均长度,而减慢Pol II转录速度会产生较短的转录物。转录速率与Sen1活性之间的这些联系支持了一个模型,该模型使延长的Pol II和Sen1解旋酶之间的动力学竞争建立了早期Pol II终止的时间和空间窗口。
  • 【用过氧化氢终止有毒的亚历山大花。】 复制标题 收藏 收藏
    DOI:10.1016/j.hal.2013.10.017 复制DOI
    作者列表:Burson A,Matthijs HC,de Bruijne W,Talens R,Hoogenboom R,Gerssen A,Visser PM,Stomp M,Steur K,van Scheppingen Y,Huisman J
    BACKGROUND & AIMS: :The dinoflagellate Alexandrium ostenfeldii is a well-known harmful algal species that can potentially cause paralytic shellfish poisoning (PSP). Usually A. ostenfeldii occurs in low background concentrations only, but in August of 2012 an exceptionally dense bloom of more than 1millioncellsL-1 occurred in the brackish Ouwerkerkse Kreek in The Netherlands. The A. ostenfeldii bloom produced both saxitoxins and spirolides, and is held responsible for the death of a dog with a high saxitoxin stomach content. The Ouwerkerkse Kreek routinely discharges its water into the adjacent Oosterschelde estuary, and an immediate reduction of the bloom was required to avoid contamination of extensive shellfish grounds. Previously, treatment of infected waters with hydrogen peroxide (H2O2) successfully suppressed cyanobacterial blooms in lakes. Therefore, we adapted this treatment to eradicate the Alexandrium bloom using a three-step approach. First, we investigated the required H2O2 dosage in laboratory experiments with A. ostenfeldii. Second, we tested the method in a small, isolated canal adjacent to the Ouwerkerkse Kreek. Finally, we brought 50mgL-1 of H2O2 into the entire creek system with a special device, called a water harrow, for optimal dispersal of the added H2O2. Concentrations of both vegetative cells and pellicle cysts declined by 99.8% within 48h, and PSP toxin concentrations in the water were reduced below local regulatory levels of 15μgL-1. Zooplankton were strongly affected by the H2O2 treatment, but impacts on macroinvertebrates and fish were minimal. A key advantage of this method is that the added H2O2 decays to water and oxygen within a few days, which enables rapid recovery of the system after the treatment. This is the first successful field application of H2O2 to suppress a marine harmful algal bloom, although Alexandrium spp. reoccurred at lower concentrations in the following year. The results show that H2O2 treatment provides an effective emergency management option to mitigate toxic Alexandrium blooms, especially when immediate action is required.
    背景与目标: : 鞭毛虫亚历山大菌是一种众所周知的有害藻类,可能会导致麻痹性贝类中毒 (PSP)。通常,A。ostenfeldii仅在低背景浓度下发生,但在8月2012年,荷兰微咸的Ouwerkerkse Kreek出现了超过100万细胞sl-1的异常密集的开花。A. ostenfeldii开花同时产生saxitoxin和spirolides,并对具有高saxitoxin胃含量的狗的死亡负责。Ouwerkerkse Kreek通常将其水排入相邻的Oosterschelde河口,并且需要立即减少水华,以避免污染广泛的贝类地面。以前,用过氧化氢 (H2O2) 处理受感染的水成功地抑制了湖泊中的蓝藻水华。因此,我们采用三步方法对这种治疗方法进行了调整,以根除亚历山大花。首先,我们在实验室实验中研究了所需的H2O2剂量。其次,我们在Ouwerkerkse Kreek附近的一条孤立的小运河中测试了该方法。最后,我们使用一种称为耙的特殊装置将50mgL-1的H2O2引入整个creek系统,以最佳分散添加的H2O2。营养细胞和膜囊肿的浓度在48小时内均下降了99.8%,并且水中的PSP毒素浓度降低到15μgl-1的局部调节水平以下。H2O2处理对浮游动物的影响很大,但对大型无脊椎动物和鱼类的影响很小。这种方法的一个关键优点是,添加的H2O2在几天内就会衰变成水和氧气,这使得处理后系统能够快速恢复。尽管亚历山大菌属 (Alexandrium spp),但这是首次成功地将H2O2应用于抑制海洋有害藻华。第二年再次以较低的浓度出现。结果表明,H2O2处理提供了一种有效的应急管理选择,以减轻有毒的亚历山大花,尤其是在需要立即采取行动时。
  • 【SGK1.1降低了由Kainic酸引起的癫痫发作的严重程度,并导致癫痫发作的迅速终止。】 复制标题 收藏 收藏
    DOI:10.1093/cercor/bhz302 复制DOI
    作者列表:Armas-Capote N,Maglio LE,Pérez-Atencio L,Martin-Batista E,Reboreda A,Barios JA,Hernandez G,Alvarez de la Rosa D,Lamas JA,Barrio LC,Giraldez T
    BACKGROUND & AIMS: :Approaches to control epilepsy, one of the most important idiopathic brain disorders, are of great importance for public health. We have previously shown that in sympathetic neurons the neuronal isoform of the serum and glucocorticoid-regulated kinase (SGK1.1) increases the M-current, a well-known target for seizure control. The effect of SGK1.1 activation on kainate-induced seizures and neuronal excitability was studied in transgenic mice that express a permanently active form of the kinase, using electroencephalogram recordings and electrophysiological measurements in hippocampal brain slices. Our results demonstrate that SGK1.1 activation leads to reduced seizure severity and lower mortality rates following status epilepticus, in an M-current-dependent manner. EEG is characterized by reduced number, shorter duration, and early termination of kainate-induced seizures in the hippocampus and cortex. Hippocampal neurons show decreased excitability associated to increased M-current, without altering basal synaptic transmission or other neuronal properties. Altogether, our results reveal a novel and selective anticonvulsant pathway that promptly terminates seizures, suggesting that SGK1.1 activation can be a potent factor to secure the brain against permanent neuronal damage associated to epilepsy.
    背景与目标: : 控制癫痫的方法是最重要的特发性脑部疾病之一,对公共卫生至关重要。我们以前已经表明,在交感神经元中,血清和糖皮质激素调节激酶 (SGK1.1) 的神经元同工型会增加M电流,这是控制癫痫发作的众所周知的靶标。在表达激酶永久活性形式的转基因小鼠中,使用脑电图记录和电生理测量在海马脑切片中研究了SGK1.1激活对海藻酸盐诱导的癫痫发作和神经元兴奋性的影响。我们的结果表明,SGK1.1激活以M电流依赖性方式导致癫痫持续状态后癫痫发作严重程度降低和死亡率降低。脑电图的特征是海马和皮层海藻酸盐诱发的癫痫发作的数量减少,持续时间缩短和提前终止。海马神经元表现出与M电流增加相关的兴奋性降低,而没有改变基底突触传递或其他神经元特性。总之,我们的结果揭示了一种新颖的选择性抗惊厥途径,可迅速终止癫痫发作,这表明SGK1.1激活可能是确保大脑免受与癫痫相关的永久性神经元损伤的有效因素。
  • 【在DNA复制终止和有丝分裂过程中CUL-2LRR-1和UBXN-3驱动复制体的拆卸。】 复制标题 收藏 收藏
    DOI:10.1038/ncb3500 复制DOI
    作者列表:Sonneville R,Moreno SP,Knebel A,Johnson C,Hastie CJ,Gartner A,Gambus A,Labib K
    BACKGROUND & AIMS: :Replisome disassembly is the final step of DNA replication in eukaryotes, involving the ubiquitylation and CDC48-dependent dissolution of the CMG helicase (CDC45-MCM-GINS). Using Caenorhabditis elegans early embryos and Xenopus laevis egg extracts, we show that the E3 ligase CUL-2LRR-1 associates with the replisome and drives ubiquitylation and disassembly of CMG, together with the CDC-48 cofactors UFD-1 and NPL-4. Removal of CMG from chromatin in frog egg extracts requires CUL2 neddylation, and our data identify chromatin recruitment of CUL2LRR1 as a key regulated step during DNA replication termination. Interestingly, however, CMG persists on chromatin until prophase in worms that lack CUL-2LRR-1, but is then removed by a mitotic pathway that requires the CDC-48 cofactor UBXN-3, orthologous to the human tumour suppressor FAF1. Partial inactivation of lrr-1 and ubxn-3 leads to synthetic lethality, suggesting future approaches by which a deeper understanding of CMG disassembly in metazoa could be exploited therapeutically.
    背景与目标: : repisome拆卸是真核生物中DNA复制的最后一步,涉及CMG解旋酶 (CDC45-MCM-GINS) 的泛素化和CDC48-dependent溶解。使用秀丽隐杆线虫早期胚胎和非洲爪蟾卵提取物,我们表明E3连接酶CUL-2LRR-1与复制体结合,并驱动CMG的泛素化和分解,以及CDC-48辅因子的UFD-1和NPL-4。从青蛙卵提取物中的染色质中去除CMG需要CUL2染色,我们的数据确定CUL2LRR1的染色质募集是DNA复制终止过程中的关键调节步骤。然而,有趣的是,CMG在染色质上持续存在,直到缺乏CUL-2LRR-1的蠕虫中出现前期,但随后被需要CDC-48辅因子UBXN-3 (与人类肿瘤抑制因子faf1同源) 的有丝分裂途径去除。lrr-1和ubxn-3的部分失活会导致合成的杀伤力,这表明了未来的方法,通过这些方法可以在治疗上更深入地了解后生动物中CMG的分解。
  • 【ABM临床方案 #13: 母乳喂养期间避孕。】 复制标题 收藏 收藏
    DOI:10.1089/bfm.2006.1.43 复制DOI
    作者列表:Academy of Breastfeeding Medicine Protocol Committee.
    BACKGROUND & AIMS: :A central goal of the Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may influence breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.
    背景与目标: : 母乳喂养医学研究院的中心目标是制定临床方案,以管理可能影响母乳喂养成功的常见医学问题。这些协议仅作为母乳喂养母亲和婴儿护理的指南,并不划定专属疗程或作为医疗护理标准。根据个别患者的需要,治疗的变化可能是适当的。
  • 【地震统计数据因台风驱动的侵蚀而改变。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-020-67865-y 复制DOI
    作者列表:Steer P,Jeandet L,Cubas N,Marc O,Meunier P,Simoes M,Cattin R,Shyu JBH,Mouyen M,Liang WT,Theunissen T,Chiang SH,Hovius N
    BACKGROUND & AIMS: :Tectonics and climate-driven surface processes govern the evolution of Earth's surface topography. Topographic change in turn influences lithospheric deformation, but the elementary scale at which this feedback can be effective is unclear. Here we show that it operates in a single weather-driven erosion event. In 2009, typhoon Morakot delivered ~ 3 m of precipitation in southern Taiwan, causing exceptional landsliding and erosion. This event was followed by a step increase in the shallow (< 15 km depth) earthquake frequency lasting at least 2.5 years. Also, the scaling of earthquake magnitude and frequency underwent a sudden increase in the area where mass wasting was most intense. These observations suggest that the progressive removal of landslide debris by rivers from southern Taiwan has acted to increase the crustal stress rate to the extent that earthquake activity was demonstrably affected. Our study offers the first evidence of the impact of a single weather-driven erosion event on tectonics.
    背景与目标: : 构造和气候驱动的表面过程控制着地球表面地形的演变。地形变化反过来会影响岩石圈变形,但是这种反馈有效的基本尺度尚不清楚。在这里,我们表明它在单个天气驱动的侵蚀事件中运行。2009年,台风莫拉克 (Morakot) 在台湾南部地区产生了约3 m的降水,造成了异常的滑坡和侵蚀。此事件之后,持续至少2.5年的浅 (<15千米深度) 地震频率逐步增加。此外,在大规模浪费最严重的地区,地震震级和频率的规模突然增加。这些观察结果表明,台湾南部河流对滑坡碎片的逐步清除已导致地壳应力速率增加,以至于地震活动受到明显影响。我们的研究提供了单个天气驱动的侵蚀事件对构造的影响的第一个证据。
  • 【多重插补的多参数检验统计量的评价】 复制标题 收藏 收藏
    DOI:10.1080/00273171.2017.1298432 复制DOI
    作者列表:Liu Y,Enders CK
    BACKGROUND & AIMS: :In Ordinary Least Square regression, researchers often are interested in knowing whether a set of parameters is different from zero. With complete data, this could be achieved using the gain in prediction test, hierarchical multiple regression, or an omnibus F test. However, in substantive research scenarios, missing data often exist. In the context of multiple imputation, one of the current state-of-art missing data strategies, there are several different analogous multi-parameter tests of the joint significance of a set of parameters, and these multi-parameter test statistics can be referenced to various distributions to make statistical inferences. However, little is known about the performance of these tests, and virtually no research study has compared the Type 1 error rates and statistical power of these tests in scenarios that are typical of behavioral science data (e.g., small to moderate samples, etc.). This paper uses Monte Carlo simulation techniques to examine the performance of these multi-parameter test statistics for multiple imputation under a variety of realistic conditions. We provide a number of practical recommendations for substantive researchers based on the simulation results, and illustrate the calculation of these test statistics with an empirical example.
    背景与目标: : 在普通的最小二乘回归中,研究人员通常对知道一组参数是否与零不同感兴趣。使用完整的数据,可以使用预测测试中的增益,分层多元回归或综合f检验来实现。然而,在实质性研究场景中,经常存在缺失的数据。在当前最先进的缺失数据策略之一的多重插补的背景下,对一组参数的联合显著性有几种不同的类比多参数检验,这些多参数检验统计量可以参考各种分布进行统计推断。然而,对这些测试的性能知之甚少,并且几乎没有研究研究在行为科学数据的典型场景 (例如,小到中等样本等) 中比较了这些测试的类型1错误率和统计能力。本文使用蒙特卡洛模拟技术来检验这些多参数测试统计量在多种现实条件下的多次插补的性能。我们根据模拟结果为实质性研究人员提供了一些实用的建议,并通过一个实证示例说明了这些测试统计量的计算。
  • 【一例需要终止妊娠的脓疱疮。】 复制标题 收藏 收藏
    DOI:10.1177/0300060520933811 复制DOI
    作者列表:Yao X,Zhang X,Peng M,Wang H,Meng Y,Chen Y
    BACKGROUND & AIMS: :Impetigo herpetiformis is a rare variant of generalized pustular psoriasis that occurs during pregnancy or is triggered by pregnancy, often in association with hypocalcemia. This condition is associated with increased maternal and fetal morbidity and mortality. We report a 29-year-old pregnant woman who presented to hospital at the gestational age of 20 weeks with widespread erythema covered with pustules that coalesced to form lakes of pus. She did not respond to corticosteroids, immunosuppressants, or phototherapy. Finally, intra-amniotic injection of ethacridine lactate was administered to terminate the pregnancy, and the patient showed complete recovery in 3 months. Insight from this case report may facilitate optimal management of this relatively rare entity.
    背景与目标: : 脓疱疮是一种罕见的广泛性脓疱型牛皮癣,发生在怀孕期间或由怀孕触发,通常与低钙血症有关。这种情况与孕产妇和胎儿的发病率和死亡率增加有关。我们报告了一名29岁的孕妇,她在20周的胎龄就诊,出现了广泛的红斑,上面覆盖着脓疱,并合并形成了脓湖。她对皮质类固醇,免疫抑制剂或光疗无反应。最后,羊膜内注射乳酸依沙啶终止妊娠,患者在3个月内完全康复。从该病例报告中获得的见解可能有助于对该相对罕见的实体进行最佳管理。
  • 【基于非参数模拟的统计数据,用于检测普通谱系中的链接。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Davis S,Schroeder M,Goldin LR,Weeks DE
    BACKGROUND & AIMS: We present here four nonparametric statistics for linkage analysis that test whether pairs of affected relatives share marker alleles more often than expected. These statistics are based on simulating the null distribution of a given statistic conditional on the unaffecteds' marker genotypes. Each statistic uses a different measure of marker sharingthe SimAPM statistic uses the simulation-based affected-pedigree-member measure based on identity-by-state (IBS) sharing. The SimKIN (kinship) measure is 1.0 for identity-by-descent (IBD) sharing, 0.0 for no IBD status sharing, and the kinship coefficient when the IBD status is ambiguous. The simulation-based IBD (SimIBD) statistic uses a recursive algorithm to determine the probability of two affecteds sharing a specific allele IBD. The SimISO statistic is identical to SimIBD, except that it also measures marker similarity between unaffected pairs. We evaluated our statistics on data simulated under different two-locus disease models, comparing our results to those obtained with several other nonparametric statistics. Use of IBD information produces dramatic increases in power over the SimAPM method, which uses only IBS information. The power of our best statistic in most cases meets or exceeds the power of the other nonparametric statistics. Furthermore, our statistics perform comparisons between all affected relative pairs within general pedigrees and are not restricted to sib pairs or nuclear families.

    背景与目标: 我们在这里提供了四个用于连锁分析的非参数统计数据,这些统计数据测试了受影响的亲戚对是否比预期的更频繁地共享标记等位基因。这些统计信息基于模拟给定统计信息的空分布,条件是未受影响的标记基因型。每个统计量使用不同的标记共享度量SimAPM统计量使用基于身份状态 (IBS) 共享的基于模拟的受影响谱系成员度量。SimKIN (亲属关系) 度量对于按血统身份 (IBD) 共享是1.0的,0.0对于没有IBD状态共享,并且当IBD状态不明确时是亲属系数。基于模拟的IBD (SimIBD) 统计量使用递归算法来确定两个情感共享特定等位基因IBD的概率。SimISO统计量与SimIBD相同,不同之处在于它还测量了未受影响的对之间的标记相似性。我们评估了在不同的两基因座疾病模型下模拟的数据的统计数据,并将我们的结果与其他几种非参数统计数据进行了比较。与仅使用IBS信息的SimAPM方法不同,使用IBD信息会大大提高功率。在大多数情况下,我们最好的统计量的能力达到或超过其他非参数统计量的能力。此外,我们的统计数据在一般谱系内所有受影响的相对对之间进行比较,并且不仅限于同胞对或核心家庭。

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