新生代农民工保安的生存状态分析——以北京市为例

农民工保安是流动人口中的一群从事特殊职业的青年群体,在城市经济建设、社会发展中发挥着特殊的作用。农民工保安受教育水平低、收入低、消费低、生活满意度低,但工作辛苦、生活单调、对未来缺少明确的个人规划。难以融入当地社会。     

Genetic variants in 5p13.2 and 7q21.1 are associated with treatment for benign prostatic hyperplasia with the α-adrenergic receptor antagonist

Background: The etiology of benign prostatic hyperplasia (BPH) has not been well established. The preferred medical treatment for many men with symptomatic benign prostatic hyperplasia is either an α-adrenergic receptor antagonist (α-blocker), or a 5α-reductase inhibitor. Single nucleotide polymorphism (SNP) is a powerful tool for successful implementation of individualized treatment.

Methods: Eighteen SNPs associated with drug efficacy in a Chinese population were genotyped in 790 BPH cases (330 aggressive and 460 non-aggressive BPH cases) and 1008 controls. All BPH patients were treated with α-adrenergic blockers for at least 9 months. We tested the associations between tagging single nucleotide polymorphism and BPH risk/aggressiveness, clinical characteristics at baseline, including the International Prostate Symptom Score (IPSS) and total prostate volume, and changes in clinical characteristics after treatment.

Results: There were nine SNPs associated with BPH risk, clinical progression and therapeutic effect. (1) There were nine tSNPs been chosen in CYP3A4, CYP3A5 and RANBP3L genes. (2) The SNP, rs16902947 in RANBP3L at 5p13.2 (p?=?.01), was significantly associated with BPH. (3) We found two SNPs, rs16902947 in RANBP3L at 5p13.2 (p?=?.0388) and rs4646437 in CYP3A4 at 7q21.1 (p?=?.0325), associated with drug effect. (4) Allele “G” for rs16902947 was found to be risk alleles for BPH risk (OR=?2.357, 95%CI 1.01–1.48). The “A” allele of rs4646437 was associated with lower IPSS at baseline (β=??0.4232, p=?.03255).

Conclusions: rs16902947, rs16902947 and rs4646437 single nucleotide polymorphisms are significantly associated with the clinical characteristics of benign prostatic hyperplasia and the efficacy of benign prostatic hyperplasia treatment.     

珠三角自主创新示范区空间发展的理论基础与策略建议

我国自主创新示范区自2009年开始建设以来,逐渐从高新区的"升级版"演变为区域创新联动的新引擎。珠三角自主创新示范区涉及多个城市的不同空间载体,偏向技术创新领域,创新资源的集聚及创新网络日渐成熟,但创新主体单一,且创新要素相互间联系不足。区域创新体系理论强调各种基本要素的相互作用,强调区域政策对区域资产的动员和网络关系的建设。开放式创新成为创新发展模式的新趋势,在空间上具有很强的空间集聚态势,同时与传统核心城市分离,并具有时空的延续性。由此,未来珠三角自主创新示范区的空间发展策略将围绕"加速要素流动,网聚优势集群"这一核心而提出。     

An FPTAS for generalized absolute 1-center problem in vertex-weighted graphs

Given a vertex-weighted undirected connected graph \(G = (V, E, \ell , \rho )\), where each edge \(e \in E\) has a length \(\ell (e) > 0\) and each vertex \(v \in V\) has a weight \(\rho (v) > 0\), a subset \(T \subseteq V\) of vertices and a set S containing all the points on edges in a subset \(E' \subseteq E\) of edges, the generalized absolute 1-center problem (GA1CP), an extension of the classic vertex-weighted absolute 1-center problem (A1CP), asks to find a point from S such that the longest weighted shortest path distance in G from it to T is minimized. This paper presents a simple FPTAS for GA1CP by traversing the edges in \(E'\) using a positive real number as step size. The FPTAS takes \(O( |E| |V| + |V|^2 \log \log |V| + \frac{1}{\epsilon } |E'| |T| {\mathcal {R}})\) time, where \({\mathcal {R}}\) is an input parameter size of the problem instance, for any given \(\epsilon > 0\). For instances with a small input parameter size \({\mathcal {R}}\), applying the FPTAS with \(\epsilon = \Theta (1)\) to the classic vertex-weighted A1CP can produce a \((1 + \Theta (1))\)-approximation in at most O(|E| |V|) time when the distance matrix is known and \(O(|E| |V| + |V|^2 \log \log |V|)\) time when the distance matrix is unknown, which are smaller than Kariv and Hakimi’s \(O(|E| |V| \log |V|)\)-time algorithm and \(O(|E| |V| \log |V| + |V|^3)\)-time algorithm, respectively.     

Complete moment convergence of moving-average process generated by a class of random variables

In this article, we establish the complete moment convergence of a moving-average process generated by a class of random variables satisfying the Rosenthal-type maximal inequality and the week mean dominating condition. On the one hand, we give the correct proof for the case p = 1 in Ko (2015 Ko, M.H. (2015). Complete moment convergence of moving average process generated by a class of random variables. J. Inequalities Appl. 2015(1):1–9. Article ID 225.[Crossref], [Web of Science ®] , [Google Scholar]); on the other hand, we also consider the case αp = 1 which was not considered in Ko (2015 Ko, M.H. (2015). Complete moment convergence of moving average process generated by a class of random variables. J. Inequalities Appl. 2015(1):1–9. Article ID 225.[Crossref], [Web of Science ®] , [Google Scholar]). The results obtained in this article generalize some corresponding ones for some dependent sequences.     

On the skewness of extreme order statistics from heterogeneous samples

The effect of heterogeneity on order statistics has attracted much attention in recent decades. In this paper, we study the skewness of extreme order statistics from heterogeneous samples in the scale models according to star ordering. It is shown that, without any restriction on the scale parameters, the skewness of extreme order statistics from heterogeneous samples is larger than that from homogeneous samples. We further extend this study to the multiple-outlier scale models. Some examples and applications are highlighted as well.     

A generalized Bayesian nonlinear mixed‐effects regression model for zero‐inflated longitudinal count data in tuberculosis trials

In this paper, we investigate Bayesian generalized nonlinear mixed‐effects (NLME) regression models for zero‐inflated longitudinal count data. The methodology is motivated by and applied to colony forming unit (CFU) counts in extended bactericidal activity tuberculosis (TB) trials. Furthermore, for model comparisons, we present a generalized method for calculating the marginal likelihoods required to determine Bayes factors. A simulation study shows that the proposed zero‐inflated negative binomial regression model has good accuracy, precision, and credibility interval coverage. In contrast, conventional normal NLME regression models applied to log‐transformed count data, which handle zero counts as left censored values, may yield credibility intervals that undercover the true bactericidal activity of anti‐TB drugs. We therefore recommend that zero‐inflated NLME regression models should be fitted to CFU count on the original scale, as an alternative to conventional normal NLME regression models on the logarithmic scale.     

Model‐free causal inference of binary experimental data

For binary experimental data, we discuss randomization‐based inferential procedures that do not need to invoke any modeling assumptions. In addition to the classical method of moments, we also introduce model‐free likelihood and Bayesian methods based solely on the physical randomization without any hypothetical super population assumptions about the potential outcomes. These estimators have some properties superior to moment‐based ones such as only giving estimates in regions of feasible support. Due to the lack of identification of the causal model, we also propose a sensitivity analysis approach that allows for the characterization of the impact of the association between the potential outcomes on statistical inference.     

应当关注度量技术供给与需求关系的统计指标

应当关注度量技术供给与需求关系的统计指标丁晓良牛文元ＡＢＳＴＲＡＣＴＴｈｅｐａｐｅｒｄｉｓｃｕｓｓｅｓｆｒｏｍｔｈｒｅｅａｓｐｅｃｔｓｔｈａｔｔｈｅｓｔａｔｉｓｔｉｃａｌｉｎｄｉｃａｔｏｒｓｒｅｆｌｅｃｔｉｎｇｔｈｅｍｅａｓｕｒｅｍｅｎｔｏｆｒｅｌａ...     

OPTIMAL AGRICULTURAL POLICY: SMALL GAINS?

Agricultural subsidies distort the allocation of workers across sectors, and may keep too many workers in agriculture. We use a general equilibrium model with endogenous sector selection calibrated to the U.S. economy to assess the efficiency loss and redistribution effect of the current transfer system. Eliminating current subsidies has two main effects: (1) small efficiency gains (around 4% of agricultural output) and (2) a corresponding rise in the price of agricultural goods. We find high-productivity farmers to be the main beneficiaries of the existing policies, although some of the transfers generate a redistribution effect toward low-productivity agents, which extends beyond the agricultural sector. (JEL H21, H25, H30, J24, J31, J43)