Application of Multivariate Geostatistics in Environmental Epidemiology: Case Study from Houston, Texas

This study represents an example of investigating the associations between the joint exposure to ozone (O3) and particulate matter of sizes less than or equal to 2.5 micrometers in aerodynamic diameter (PM2.5) and cardiovascular disease (CVD) emergency room (ER) visits and chronic obstructive pulmonary disease (COPD) ER visits using multivariate geostatistics in Houston, Texas, from 2004 to 2009. Analyses showed lack of strong pair-wise association among the predictors of O3, PM2.5, wind speed, relative humidity, and temperature. Whereas CVD and COPD ER visits exhibited a strong positive correlation. Both outcomes drastically increased from 2006 possibly due to immigration from neighboring locations. Parametric testing showed that the data differed significantly between the years. Multivariate multiple regression results on the 2009 data showed that PM2.5, relative humidity, and temperature were significant to both CVD and COPD ER visits. Codispersion coefficients were constant which justified the assumption of intrinsic correlation. That is, our predictors had strong influence on the spatial variability of CVD and COPD ER visits. This multivariate geostatistics approach predicted an increase of 34% in CVD ER visits and 24% increase in COPD ER visits, which calls for more attention from policy makers. The use of multivariate geostatistics analyses enabled us to successfully detect the effects of risk factors on both outcomes.

Relative Contribution of Different Source Categories to Ozone Exceedances in the Houston-Galveston-Brazoria Area

The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepare the emission files for five different source combination cases (Base case, Biogenic, Area + Biogenic, Mobile + Biogenic, Low-level Point + Biogenic). These emission files are used to perform photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx), and the results are analyzed with Visual Environment for Rich Data Interpretation (VERDI) tool. The daily maximum ozone concentrations and individual contributions of the source categories were analyzed over a 15-day study period between June 1-15, 2012, at three locations (University of Houston-Sugarland, Bayland Park and Conroe). Biogenic sources contributed an average of 49.7% ± 12.8%, 43.1% ± 12.0%, and 39.9% ± 9.28% at Sugarland, Bayland Park and Conroe sites respectively, indicating the significance of isoprene emissions from the vegetation in northeast Houston. On peak ozone days, contribution of Mobile + Biogenic source category averages about 80.1% ± 12.6%, 79.9% ± 6.50%, and 75.9% ± 10.9% at Sugarland, Bayland Park and Conroe sites respectively, indicating the dominance of mobile source NOX emissions and the necessity for regulatory focus on mobile source emissions control.

Air Quality Impact of Biomass Co-Firing with Coal at a Power Plant in the Greater Houston Area

The Houston-Galveston-Brazoria (HGB) area of Texas is a moderate nonattainment region for ozone, and has a history of severe summer ozone episodes. W. A. Parish power plant (WAP) located in the greater Houston area is the largest coal and natural gas based electricity generating unit (EGU) in Texas. Forest residue is an abundant renewable resource, and can be used to offset coal usage at EGUs. This study evaluates the impact of co-firing 5%, 10%, and 15% (energy-basis) of forest residue at WAP on the air quality of the HGB area. Photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx) was conducted to investigate the air quality at three air quality monitoring sites (C696, C53, C556) in the HGB area, under two source scenarios (all-sources, point + biogenic sources). Significant reduction of SO2 and O3 was observed for 10% and 15% co-firing ratios at monitoring station (C696) close to WAP. The maximum reduction of ozone observed for 15% co-firing is 4.7% and 6.3% for all-sources and point + biogenic sources scenarios respectively. The reduction in other criteria air pollutants is not significant at all locations. The overall results from this study indicate that biomass co-firing at WAP would not lead to a significant reduction in ozone concentrations in the region during periods of peak ozone.

Houston16:A stable geodetic reference frame for subsidence and faulting study in the Houston metropolitan area,Texas,U.S.

Houston,Texas,is one of the earliest regions to employ continuous GPS technology for land subsidence monitoring.Currently,there are over 200 permanent GPS stations located in the greater Houston area.The need for a consistent and stable reference frame to precisely interpret local ground deformation has become critically important since the 1990s,because of the significant spreading of subsidence.We have established a stable Houston reference frame,designated Houston16,using publicly available GPS observations(>5 years)from 15 Continuously Operating Reference Stations(CORS)located outside of the greater Houston area.Applications of the reference frame in subsidence and faulting studies are demonstrated in this article.Houston16 is aligned in origin and scale with the International GNSS Reference Frame of 2008(IGS08).A 7-parameter method was employed to transform the GPS-derived positional time series from IGS08 to Houston16.The primary product of this study is the seven parameters for transforming Earth-Centered-Earth-Fixed XYZ coordinates from IGS08 to Houston16.The frame stability of Houston16 is approximately 1 mm/year.Houston16 will be updated every few years to mitigate degradation of the frame’s stability with time and to synchronize with future updates of the IGS reference frame.

Age, Race and Gender Spatiotemporal Disparities of COPD Emergency Room Visits in Houston, Texas

Chronic obstructive pulmonary disease (COPD) is one of the major causes of morbidity and mortality in the United State. The investigation of the continuing increase in its prevalence and mortality has increased attempts to further understand its causes and how to manage it. Understanding the spatial and temporal distribution of COPD emergency room (ER) visits in Harris County (Houston) can guide these efforts in a uniform yet diverse setting like this one. The objectives of this study were to identify the temporal and spatial variations of COPD emergency room visits adjusted by age, gender, ethnicity, day of the week, month, and year, and to estimate the odds ratio of COPD emergency room visits adjusted by the six risk factors. The dataset used were extracted from two resources: ER Utilization Study and Harris County centroid coordinates. Exploratory statistical analyses were conducted to study the spatiotemporal disparities and investigate associations. Logistic regression was performed to estimate the odds ratio of COPD primary diagnosis adjusted for age, race, gender, day of the week, month, and year. The number of COPD ER visits kept increasing from 2004 throughout 2009 but there was a significant increase after the year 2005. Spring and summer had lower visits compared to winter and autumn. Lowest visits were during June and July and higher during December and January. Tuesdays had the highest number of visits compared to the remaining days of the week with Saturdays having had the lowest number of visits. Temporal analyses show the continuous increase in COPD ER visits in Houston as well as the consistent spatial disparities between zip regions. After adjustment for age, race, gender, day of the week, month, and year, there were statistically significant associations between emergency room chronic obstructive pulmonary disease diagnoses in Houston, Texas, with these six predictors.

ZTE USA Announces Its First Corporate Partnership and Consumer Marketing Push in Conjunction with the Houston Rockets

5 October 2013, Houston--The Houston Rockets and ZTE USA, the fastest-growing smartphone provider in the United States, announced that ZTE will be the official smartphone of the Houston Rockets for the 2013-14 NBA season. This is the first partnership of its kind for ZTE globally and the first big consumer marketing push in the United States since the company entered the country 15 years ago.

Combining innovative science and policy to improve air quality in cities with refining and chemicals manufacturing： The case study of Houston, Texas, USA

In Houston, a combination of urban emissions from a city of 4 million people, coupled with emissions from extensive petroleum refining and chemical manufacturing, leads to conditions for photochemistry that are unique in the United States, and historically, the city had experienced some of the highest ozone concentrations recorded in the United States. Large air quality field studies （the Texas Air Quality Studies or TexAQS I and II） were conducted to determine root causes of the high ozone concentrations. Hundreds of air quality investigators, from around the world, deployed instruments on aircraft, on ships, and at fixed ground sites to make extensive air quality measurements; detailed photochemical modeling was used to interpret and assess the implications of the measurements. The Texas Air Quality Studies revealed that both continuous and episodic emissions of light alkenes, which came to be called highly reactive volatile organic compounds, played a critical role in the formation of ozone and other photochemical oxidants in the region. Under- standing and quantifying the role of these emissions in regional air quality required innovations in characterizing emissions and in photochemical modeling. Reducing emissions required innovative policy approaches. These coupled scientific and policy innovations are described, and the result, substantially cleaner air for Houston, is documented. The lessons learned from the Houston air quality experience are relevant to cities with similar population and industrial profiles around the world.

Study of narrow waterways congestion based on automatic identification system(AIS)data:A case study of Houston Ship Channel

Using automatic identification system(AIS)data,this article first has extended the definition of three widely used roadway congestion indices to maritime transportation systems(MTS),traffic speed index(TSI),traffic rate index(TRI),and dwell time index(DTI).Next,a methodology is developed to measure the indices based on AIS data,considering various factors,including path geometry,time of day,and the type and size of vessels,and finally the method has been applied to the AIS data of the Houston Ship Channel(HSC)to evaluate the applicability in real cases.The results show that although average TSI and TRI cannot represent waterway congestion,the real-time values(rather than the average)at the micro level can help finding location,time,and severity of traffic congestion.Besides,while TSI and TRI have shortcomings,both average and real-time dwell time index(DTI)can quantify traffic congestion and highlight severity in different waterway segments for different types of vessels.When congestion happens at some narrow waterways,vessels need to wait at sea buoy or docks,thus dwell time index(DTI)can quantify traffic congestion better than in-transit indices such as travel speed,TSI.According to HSC DTI,most tankers experience long waiting times at the sea buoy and Galveston Bay,while cargo vessels experience delays at Bayport and Barbour’s Cut terminals.This paper helps the decision-makers quantify congestion in different sections of a waterway and provides measures to compare congestion for national competing projects at different waterways.

Reality Check of U.S.Unilateral Demand for China to Close Houston Consulate General

On July 21,the U.S.made a unilateral provocation by making the outrageous demand that China close its consulate general in Houston.By doing so,the U.S.has grossly violated international law,the basic norms of international relations,and relevant provisions of the China-U.S.Consular Convention,and gravely damaged China-U.S.relations.

Houston 捷克现代化的浪漫史诗

在欧洲历史当中,捷克的过去不为世人所重视。然而本月在休斯顿艺术馆揭幕的捷克历史艺术展览,展开了引人入胜的历史回溯旅程。以捷克现代化为主题的展览,陈列出休斯顿慈善家古伦夫妇收藏、一百五十多位捷克前卫艺术家的标志性作品,涉猎别具一次大战后时期色彩的抽象画作和拼画,刻画了这段不为世所知的章节。艺术馆的主任表示,二十世纪的捷克艺术对于欧洲的现代化具重要的意义,而这次的藏品细腻的表现当时先锋艺术的张狂想象力。

中国山东平原区和美国大休斯顿地区地面沉降监测与防控对比

中国山东省平原区和美国大休斯顿地区都存在过量开采地下水引发的地面沉降问题,休斯顿积累了100多年的监测成果和50多年防控经验,与山东省平原区30多年来的地面沉降监测与防控经验具有一定的相似性。为进一步推动和加强山东省地面沉降监测与防治、地下水资源管理、数字赋能和数据共享,文章对两个地区的地面沉降成因、监测技术、地下水管理和地面沉降防控进行了对比分析。结果表明:过度抽取地下水是导致地面沉降的主要原因,两地都采取了以限制地下水开采为主的地面沉降管理措施,当前沉降面积和沉降速率都趋于减小;两地目前使用的监测方法和技术基本相同,主要使用精密水准测量、分层标或深孔伸缩仪、全球卫星定位系统和干涉合成孔径雷达技术,观测点的密度和监测频次都在逐步增加。然而,两地在观测数据的管理和共享方面存在很大差异。休斯顿地区的地面沉降管理部门主要负责采集数据和协调数据共享,不承担观测数据的处理和研究任务,所有的观测数据都向社会开放,基于观测数据的研究工作主要由美国地质调查局和大学的研究团体承担,研究成果公开发表;山东平原区的地面沉降和地下水位监测由自然资源和水利部门承担,下属的事业单位承担野外观测、数据保管、数据分析和研究,为制定地下水管理规章制度提供科技支撑,部门间的数据共享和整合存在一定困难,限制了对地面沉降的深入系统研究。

动态风险型的奥斯顿保险经济价值模型

Houston模型[1]没有风险分析,魏力仁[2]将他推广到风险分析的情况,并从两个角度对保险费率的取值进行了讨论。本文在[2]的基础上将Houston模型推广到动态的情形。Houston模型已被经济发达国家的企业采纳作为投保决策的参考依据。随着经济改革深入发展,我国企业也将面临一个经营投保决策问题。所以Houstort模型的研究有着它的现实意义。

波浪环境中作业起重船悬吊载荷的摆振分析

针对在波浪中作业的起重船,同时考虑趸船横摇和吊臂回转,分析了悬吊载荷的摆振。运用多体动力学的休斯敦方法,建立了系统的动力学方程,计算得到了各种工况下载荷摆振的运动轨迹,据此给出了安全作业的有关建议。

借鉴休斯敦经验推进资源枯竭型城市转型——以甘肃省白银市为例

以甘肃省白银市为例,借鉴休斯敦经验,为白银实现转型提供建议。随着自然资源的枯竭,许多资源型城市陷入"矿竭城衰"的境地。路径依赖作用贯穿于资源枯竭型城市区域产业结构的形成和发展过程中。休斯敦是美国典型的依托石油资源发展起来的城市,20世纪60年代以来通过转型已成为美国第四大城市,为我国资源型城市转型提供了丰富的经验。

休斯顿临终关怀院花园

临终关怀对于正在步入老龄化社会的中国意义重大,临终关怀花园有着鲜明的特点与功能,在临终关怀运动中发挥着重要作用。美国休斯顿临终关怀院花园是一座经过专业设计、建设实施并得到很好维护的临终关怀花园。对休斯顿临终关怀院花园的介绍与研究,有助于加深对临终关怀花园这一特殊类型的康复性景观的认识,可以为中国该类型景观的发展提供借鉴。

大型综合医院设立临床医学研究所的思考——来自美国休斯敦卫理公会医院研究所的启示

为了解国外当前大型综合医院临床医学研究所的发展建设情况,作者走访了世界著名的美国休斯敦卫理公会医院研究所,深入了解其历史背景、基础设施、转化医学、科研教育和管理运营机制等内容,以期为医院乃至国内临床医学研究所建设提供发展思路。

“布鲁斯-方言”批评理论与“黑人性”表述

当代美国非裔文学批评家休斯顿·A.贝克的"布鲁斯-方言"批评理论以黑人的布鲁斯和方言土语解构了西方主流批评话语及其文本模式,拓宽了人们对文学批评及文化的视野,并彰显出黑人文学独具特色的言说方式和"黑人性"特征,为美国非裔文学批评和文本解读提供了强有力的理论依据和有效模式。

美国休斯敦大学图书馆数字学术服务实施路径及启示

在阐述数字学术服务的定义、演进历程的基础上,通过典型案例法介绍美国休斯敦大学图书馆数字学术服务的具体实施路径,总结其经验,并从扫描环境,深度调研;制定规划,分步实施;转变角色,提升能力;注重评估,形成长效等方面提出对我国高校图书馆实施数字学术服务的启示。

美国休斯顿大学本科生科研“REU计划”的实践与启示——以休斯顿大学计算机系为例

以美国休斯顿大学计算机系本科生科研"REU计划"为例,介绍了"REU计划"的申请、内容、实践等在培养本科生科研能力方面的情况,同时得出四点启示,旨在为我国研究型高校在探索提高本科生科研能力方面提供一些有益的借鉴和参考。

火箭队22连胜成因分析

通过分析火箭队22场连胜中有关数据,我们可以得出这样的结论:取得如此战绩并非靠的是运气,而是火箭队在阿德尔曼率领已经有了长足的进步,具备了相当的实力。