Optimal Estimation for Power of Variance with Application to Gene-Set Testing

Detecting differential expression of genes in genom research(e.g.,2019-nCoV)is not uncommon,due to the cost only small sample is employed to estimate a large number of variances(or their inverse)of variables simultaneously.However,the commonly used approaches perform unreliable.Borrowing information across different variables or priori information of variables,shrinkage estimation approaches are proposed and some optimal shrinkage estimators are obtained in the sense of asymptotic.In this paper,we focus on the setting of small sample and a likelihood-unbiased estimator for power of variances is given under the assumption that the variances are chi-squared distribution.Simulation reports show that the likelihood-unbiased estimators for variances and their inverse perform very well.In addition,application comparison and real data analysis indicate that the proposed estimator also works well.

Homogenization and trend analysis of 1960–2015 in situ sea surface temperature observations along the coast of China

Sea surface temperature(SST)measurements from 26 coastal hydrological stations of China during 1960–2015 were homogenized and analyzed in this study.The homogenous surface air temperature(SAT)series from meteorological stations which were highly correlated to SST series was used to construct the reference series.Monthly mean SST series were then derived and subjected to a statistical homogeneity test,called penalized maximal t test.Homogenized monthly mean SST series were obtained by adjusting all significant change points which were supported by historic metadata information.Results show that the majority of break points are caused by instrument change and station relocation,which accounts for about 61.3%and 24.2%of the total break points,respectively.The regionally averaged annual homogeneous SST series from the 26 stations shows a warming trend(0.19℃ per decade).This result is consistent with that based on the homogenized annual mean SAT at the same region(0.22℃ per decade),while the regionally averaged mean original SST series from the same stations shows a much weaker warming of 0.09℃ per decade for 1960–2015.This finding suggests that the effects of artificial change points on the result of trend analysis are remarkable,and the warming rate from original SST observations since 1960 may be underestimated.Thus a high quality homogenized observation is crucial for robust detection and assessment of regional climate change.Furthermore,the trends of the seasonal mean homogenized SST were also analyzed.This work confirmed that there was an asymmetric seasonal temperature trends in the Chinese coastal water in the past decades,with the largest warming rate occurring in winter.At last,the significant warming in winter and its relationships to the variability of three large-scale atmospheric modes were investigated.

Observation of Suicide Prevention in Hospitalized Patients with Depression Based on Taihe Emotion-distress Index

[Objectives]To reduce suicidal ideation and suicidal behavior through initial screening of patients with suicidal tendencies and implementing suicide prevention interventions during their hospitalization.[Methods]The Taihe Emotion-distress Index(THEI)was used to conduct pre-admission and post-discharge tests to explore the effects of suicide prevention measures during hospitalization on the alleviation of the disease and the reduction of suicidal behaviors.The study selected patients who were diagnosed with depression in the psychological outpatient department of Taihe Hospital from April 2019 to September 2019 and had to be hospitalized,including patients with moderate depressive episodes,severe depressive episodes with or without psychotic symptoms,and patients with suicidal thoughts and self-harming behaviors.[Results]The pre-admission and post-discharge test data of hospitalized patients were analyzed,and the non-parametric paired sample T test was carried out,and the result was P<0.05,showing that there are significant differences between the pre-admission and post-discharge test data.[Conclusions]The measures of suicide prevention intervention are effective to a certain extent.

An Approximate Hotelling T²-Test for Heteroscedastic One-Way MANOVA

In this paper, we consider the general linear hypothesis testing (GLHT) problem in heteroscedastic one-way MANOVA. The well-known Wald-type test statistic is used. Its null distribution is approximated by a Hotelling T2 distribution with one parameter estimated from the data, resulting in the so-called approximate Hotelling T2 (AHT) test. The AHT test is shown to be invariant under affine transformation, different choices of the contrast matrix specifying the same hypothesis, and different labeling schemes of the mean vectors. The AHT test can be simply conducted using the usual F-distribution. Simulation studies and real data applications show that the AHT test substantially outperforms the test of [1] and is comparable to the parametric bootstrap (PB) test of [2] for the multivariate k-sample Behrens-Fisher problem which is a special case of the GLHT problem in heteroscedastic one-way MANOVA.

Site and Regional Trend Analysis of Precipitation in Central Macedonia, Greece

The purpose of this paper is to investigate the trend of precipitation in Kilkis region (Greece) at the site and regional level in various time scales. At the site level, the precipitation trend was analyzed using three tests: 1) Mann-Kendall, 2) Sen’s T and 3) Spearman while the trend slope was estimated using the Sen’s estimator. At a regional level, nonparametric spatial tests such as Regional Average Mann-Kendall (RAMK) and BECD’s (Bootstrap Empirical Cumulative Distributions) were elaborated with and without the effect of cross correlation. The trend of precipitation was noticed generally downward at annual time scale and statistically significant at 5% level of significance only in only one station. The results of the analysis of trends at the regional level showed in total the influence of cross correlation in the time series since the number of trends detected is reduced when cross correlation is preserved. Precipitation data from 12 stations were used. The study results benefit water resource management, drought mitigation, socio-economic development, and sustainable agricultural planning in the region.

基于危机情景的领导素质理论的实证研究

领导科学理论的发展欠缺的是将领导者的素质和情景因素结合起来进行研究。本研究以危机情景为分类变量,应用逐步回归分析和单因素方差分析的方法,分析了不同危机情景下有效领导者之间的素质差异。从实证的角度验证了基于情景的领导素质理论研究的正确性和必要性。