The association between stunting and overweight in Latin American and Caribbean preschool children

BACKGROUND: Although some segments of the population continue to suffer from undernutrition, other groups exhibit excess weight gain, resulting in the coexistence of undernutrition and obesity and leading to a dual nutritional burden. OBJECTIVE: To explore the association between stunting and overweight in preschool children from Latin American and Caribbean countries. METHODS: We analyzed cross-sectional data from children 0 to 5 years of age from 79 nationally representative surveys, compiled by the World Health Organization (WHO) Global Database on Child Growth and Malnutrition. This database defines stunting as low height-for-age and overweight as high weight-for-height. These variables were explored with the use of simple and multiple regression models. RESULTS: There were significant differences between subregions in the prevalence of stunting: the prevalence was 7.4% in the Caribbean, 11.3% in South America, and 20.4% in Central America (p < .001). In contrast, the estimated prevalence of overweight was similar between subregions. The overall prevalence rates of stunting and overweight in Latin America and the Caribbean in the year 2000 were 13.7% and 4.3%, respectively. We found an inverse relationship (r = -0.3) between the prevalence rates of overweight and stunting, overall and within subregions. South America exhibited the highest slope and intercept on the regression of overweight on stunting. CONCLUSIONS: Different subregions of Latin America and the Caribbean have different prevalence rates of childhood stunting but similar prevalence rates of overweight. There is an inverse relationship between stunting and overweight. The South American subregion had the highest increase and prevalence of overweight of the Latin American region.     

Plasma-assisted Co/Zr-metal organic framework catalysis of CO_2 hydrogenation:influence of Co precursors

In this study, Co/Zr-metal organic framework(MOF) precursors were obtained by a roomtemperature liquid-phase precipitation method and the equivalent-volume impregnation method,respectively, using a Zr-MOF as the support, and Co/Zr-MOF-M and Co/Zr-MOF-N catalysts were prepared after calcination in a hydrogen–argon mixture gases(V_(Ar):V_(H_2)= 9: 1) at 350 °C for 2 h. The catalytic activities of the prepared samples for CO_2 methanation under atmosphericpressure cold plasma were studied. The results showed that Co/Zr-MOF-M had a good synergistic effect with cold plasma. At a discharge power of 13.0 W, V_(H_2):V_(CO_2)= 4: 1 and a gas flow rate of 30 ml·min~(-1), the CO_2 conversion was 58.9% and the CH_4 selectivity reached 94.7%,which was higher than for Co/Zr-MOF-N under plasma(CO_2 conversion 24.8%, CH_4 selectivity 9.8%). X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N_2 adsorption and desorption(Brunauer–Emmett–Teller) and x-ray photoelectron spectroscopy analysis results showed that Co/Zr-MOF-M and Co/Zr-MOF-N retained a good Zr-MOF framework structure, and the Co oxide was uniformly dispersed on the surface of the Zr-MOF. Compared with Co/Zr-MOF-N, the Co/Zr-MOF-M catalyst has a larger specific surface area and higher Co~(2+)/Cototaland Co/Zr ratios. Additionally, the Co oxide in Co/ZrMOF-M is distributed on the surface of the Zr-MOF in the form of porous particles, which may be the main reason why the catalytic activity of Co/Zr-MOF-M is higher than that of Co/ZrMOF-N.     

斜直井眼中钻柱的动力学特性分析

为研究和控制钻柱动力学特性,分析斜直井眼中全井钻柱的受力变形特点,建立了钻柱动力学模型,利用节点迭代法解决了利用整体有限元法计算钻柱动力学特性较困难的问题,并应用节点迭代有限元法研究了钻柱的涡动轨迹和涡动速度等动力学特性。在转盘转速为120 r/min时,在给定的钻柱结构下,井深5256 m处的涡动速度达252 r/min,井深261~732 m处的钻柱应力波动幅值约为15 MPa。结果表明,钻柱内的这种应力波动或涡动特征是导致钻柱失效的重要因素,控制钻柱内的动态应力水平对钻柱失效事故的降低十分重要。     

玻璃包覆合金微丝的微波磁性能分析及模拟

基于无限长的单畴圆柱体的微波进动方程,推导了玻璃包覆磁性合金微丝内芯区的微波磁导率,模拟了Fe基合金微丝外壳区的微波磁导率并分析了合金微丝外壳区自然铁磁共振频率的影响因素.根据理论分析结果,模拟了典型的玻璃包覆磁性合金微丝内芯区和外壳区的微波相对复磁导率以及几何尺寸改变时玻璃包覆合金微丝的自然铁磁共振频率的变化规律,探讨了几何尺寸对玻璃包覆磁性合金微丝的自然铁磁共振频率的影响规律.结果表明,微丝合金内芯的自然铁磁共振频率主要依赖于合金的饱和磁化强度,Fe基合金微丝合金外壳层的自然铁磁共振频率依赖于磁各向异性等效场,自然铁磁共振频率可以通过改变合金微丝的几何尺寸而控制.     

锅炉炉膛按需吹灰方法的实现

针对锅炉运行效率和锅炉受热面吹灰的关连性,介绍了日本松浦电厂通过设置锅炉水冷壁内、外壁温测量装置完善锅炉炉膛受热面污染度状态监测,实现炉膛按需吹灰的自动控制方法,可为国内相关技术开发提供参考。     

中间仓储式制粉系统的防爆安全分析

介绍了负压中间仓储式制粉系统的构成,从中间仓储式制粉系统设备及煤质特性两方面对煤粉爆炸原因及制粉系统的防爆安全进行分析,并从实践角度提出了防止制粉系统爆炸的措施。     

非最小相位线性系统的自适应建模

自适应逆控制（Adaptive Inverse Control）把自适应滤波器技术较好地应用到控制领域中,较传统控制方法有诸多优点和研究价值。对非最小相位对象的自适应逆控制,一般需要先进行稳定性分析,保证其稳定性前提下进行控制。课题着重研究了非最小相位线性系统的自适应建模这一环节。首先介绍了自适应滤波器理论的相关知识,接下来讨论自适应控制的建模原理,并完成线性非最小相位对象的自适应建模,最后进行计算机仿真,演示实验结装。     

基于Windows平台的自动化设备软件发布方法

介绍了一种基于Windows操作系统的自动化测试设备软件的发布方法,用Visual C＋＋开发了配置ODBC（开放的数据库互连）数据源和卸载ODBC数据源的程序。EasySetup是一种制作安装程序的工具软件,高效易用。用它制作的安装程序在安装开始前、安装完成后或卸载前可以自动执行相关文件（．bat、．exe、．reg）并进行授权管理、修改注册表或配置ODBC数据源等工作。     

A patient-mounted robotic platform for CT-scan guided procedures

In this paper, we present a novel robotic assistant dedicated to medical interventions under computed tomography scan guidance. This compact and lightweight patient-mounted robot is designed so as to fulfill the requirements of most interventional radiology procedures. It is built from an original 5 DOF parallel structure with a semispherical workspace, particularly well suited to CT-scan interventional procedures. The specifications, the design, and the choice of compatible technological solutions are detailed. A preclinical evaluation is presented, with the registration of the robot in the CT-scan.     

Compact charge and capacitance modeling of undoped ultra-thin body (UTB) SOI MOSFETs

We present an analytic, explicit and continuous charge model for a long-channel UTB (ultra-thin body) SOI (silicon-on-insulator) MOSFET, from which analytical expressions of the total capacitances are obtained. Our model is valid from below to well above threshold, without suffering from discontinuities between the regimes. It is based on a unified charge control model derived from Poisson’s equation. The drain-current, charge and capacitances expressions result in continuous explicit functions of the applied bias.The calculated capacitance characteristics are validated by 2D numerical simulations showing a very good agreement for different silicon film thicknesses.