Optimal two-point designs for the michaelis-menten model with heteroscedastic errors

We construct D-optimal designs for the Michaelis-Menten model when the variance of the response depends on the independent variable. However, this dependence is only partially known. A Bayesian approacn is used to find an optimal design by incorporating the prior lnformation about the variance structure. We demonstrate the method for a class of error variance structures and present efficiencies of these optimal designs under prior mis-specifications. In particular, we show that an erroneous assumption on the variance structure for the Michaelis-Menten model can have serious consequences.     

Mobility,Space and Power: On the Multiplicities of Seeing Mobility

Abstract

Mobility as a key modern phenomenon can be seen in multiple ways and this article raises the question of how mobility becomes visible and real through diverse ways of seeing mobility. Mobility’s different aspects appear and take place in particular spatial settings under the workings of diverse forms of power, and recognizing this informs us about the making of spatialised mobility. It is shown how mobility intermingles with perceptions, experiences and desires of the modern self. Such workings of power relate, among other things, to framing and imagining, practising and experiencing mobility. Capturing ways of seeing mobility thus widens our language for engaging with questions of mobility and its political and social reality and possible futures.     

阿赫玛托娃抒情诗歌的陌生化审美

俄罗斯白银时代女诗人阿赫玛托娃以写抒情诗见长.论题运用俄国形式主义文艺理论,从用词的背离与超常、情景的断裂与联想、诗歌的加密与解码三方面来探讨诗人抒情诗作的陌生化现象及其美学价值,认为陌生化手法是形成阿赫玛托娃创作个性与魅力的最重要原因之一,并指出其艺术形式的创新建立在对诗歌传统的继承之上.     

Aggregate Human Health Risk Assessment from Dust of Daily Life in the Urban Environment of Beijing

Because of the high emissions of polycyclic aromatic hydrocarbons (PAHs) into the environment by the increasing number of vehicles in Beijing and the absorption of these PAHs onto particulates, the performance of a preliminary health risk assessment of the aggregate exposure to PAHs of urban citizens in daily life is very important. Urban dust can be used to examine the aggregation of atmospheric particulates from local pollution sources over a long time period and the direct exposure of the urban human population. The environment's correlative with clothing, dining, residing, and traveling in urban daily life was assessed using exposure‐receptor‐oriented analysis. The multipathway exposure model was used to simulate the lifetime exposure of a female citizen to PAHs in dust. All of the PAH concentrations in dust for each behavior and its correlative environment in Beijing were acceptable because all of the carcinogenic risks of PAHs in the dust were approximately 1.0 × 10^–6. The dominant induced carcinogenic risks in the dust were Benzo(a)pyrene and Dibenzo(a,h)anthracene. The main carcinogenic risk routes for humans were dermal contact and oral intake, which contributed on average 99.78% of the risk. Indoor risk is especially important, as the decoration and height within the building were important impact factors for carcinogenic risk induced by indoor PAHs. For people living in an urban area, a healthy lifestyle includes less decoration per room, living on a low floor, wearing a respirator, and reducing exposed skin area when traveling.     

Association of serum calcium with serum sex steroid hormones in men in NHANES III

Abstract

Background: Bone is a positive regulator of male fertility, which indicates a link between regulation of bone remodeling and reproduction or more specifically a link between calcium and androgens. This possibly suggests how calcium is linked to prostate cancer development through its link with the reproductive system. We studied serum calcium and sex steroid hormones in the Third National Health and Nutrition Examination Survey (NHANES III).

Methods: Serum calcium and sex steroid hormones were measured for 1262 men in NHANES III. We calculated multivariable-adjusted geometric means of serum concentrations of total and estimated free testosterone and estradiol, androstanediol glucuronide (AAG), and sex hormone binding globulin (SHBG) by categories of calcium (lowest 5% [<1.16?mmol/L], mid 90%, top 5% [≥1.30?mmol/L]).

Results: Levels of total and free testosterone, total estradiol or AAG did not differ across categories of serum calcium. Adjusted SHBG concentrations were 36.4 for the bottom 5%, 34.2 for the mid 90% and 38.9?nmol/L for the top 5% of serum calcium (P_trend?=?0.006), free estradiol levels were 0.88, 0.92 and 0.80?pg/ml (P_trend?=?0.048).

Conclusions: This link between calcium and sex steroid hormones, in particular the U-shaped pattern with SHBG, may, in part, explain why observational studies have found a link between serum calcium and risk of prostate cancer.     

Spatial discrimination and classification maps

A method of constructing maps through spatial discrimination is given. The discrimination depends basically on the assumption of local spatial continuity, and a factorized covariance matrix. Given an autocovariance function, this formulation in particular, leads to a deeper insight into the pioneering work of Switzer (1980). Certain windows for the maps are examined, and choice of window size is discussed in relation to the classification error when the variables are dependent versus independent. When a training data is given, we give a method of estimating the parameters in the model. Some numerical examples are also given.     

译文读者对翻译行为的影响——以晚清小说的翻译为例

传统的翻译研究只重视原文与译文是否对等,直译意译孰是孰非等问题,忽视了译文读者及其阅读接受这一维。而以目的论为核心的德国功能派翻译理论则将目光转向翻译活动中译者的能动介入、译入语文化和接受者对翻译行为的影响上,翻译目的论肯定了译文读者的作用并强调了译文读者的重要性,给传统的翻译理论研究带来了新的视角和思路。该理论对研究晚清翻译小说,研究译文读者对翻译的选材、思想内容、语体风格和文本形式的影响,提供了一个新的视角。     

He—Ne激光差分吸收测量甲烷浓度

本文就甲烷对Ｈｅ—Ｎｅ激光３．３９２２μｍ，３．３９１２μｍ谱线的吸收系数进行了测量研究，设计了差分吸收模拟实验，并对测量系统误差进行了分析。     

钙敏感受体促进小鼠长骨的生长及软骨矿化

目的:探讨钙敏感受体(calcium sensing receptor,CaSR)对小鼠长骨及软骨矿化的直接作用?方法:利用骨移植的方法将出生后3 d同窝的野生型和CaSR基因敲除小鼠的股骨胫骨移植至同父母来源的8周龄的野生型小鼠背阔肌中?生长4周后,取出股骨和胫骨进行X线和组织学分析?结果:CaSR基因敲除小鼠骨骼生长严重阻滞,并且其生长板的软骨肥大细胞带显著宽于野生型小鼠的软骨肥大细胞带(P < 0.001)?结论:CaSR具有直接促进长骨生长的作用,并且能够促进肥大软骨细胞矿化和骨化?     

Stability and Bifurcations in a Model of Bacteria Immunity with Quorum Sensing

Quorum sensing, a widespread phenomenon in bacteria that is used to coordinate gene expression among local populations, intervenes in the competition between bacteria and the immune system. The domain of attraction of the bacteria-free equilibrium results from a linear matrix inequality optimization with a multivariate polynomial objective under constraints. The Bogdanov-Takens singularity and bifurcation, including a saddle-node bifurcation, a Hopf bifurcation, and a homoclinic bifurcation, are obtained from normal form theory. The normal form of a bifurcation is a simple dynamical system which is equivalent to all systems exhibiting this bifurcation.