Effect of nutrition survey 'cleaning criteria' on estimates of malnutrition prevalence and disease burden: secondary data analysis.

Tackling childhood malnutrition is a global health priority. A key indicator is the estimated prevalence of malnutrition, measured by nutrition surveys. Most aspects of survey design are standardised, but data 'cleaning criteria' are not. These aim to exclude extreme values which may represent measurement or data-entry errors. The effect of different cleaning criteria on malnutrition prevalence estimates was unknown. We applied five commonly used data cleaning criteria (WHO 2006; EPI-Info; WHO 1995 fixed; WHO 1995 flexible; SMART) to 21 national Demographic and Health Survey datasets. These included a total of 163,228 children, aged 6-59 months. We focused on wasting (low weight-for-height), a key indicator for treatment programmes. Choice of cleaning criteria had a marked effect: SMART were least inclusive, resulting in the lowest reported malnutrition prevalence, while WHO 2006 were most inclusive, resulting in the highest. Across the 21 countries, the proportion of records excluded was 3 to 5 times greater when using SMART compared to WHO 2006 criteria, resulting in differences in the estimated prevalence of total wasting of between 0.5 and 3.8%, and differences in severe wasting of 0.4-3.9%. The magnitude of difference was associated with the standard deviation of the survey sample, a statistic that can reflect both population heterogeneity and data quality. Using these results to estimate case-loads for treatment programmes resulted in large differences for all countries. Wasting prevalence and caseload estimations are strongly influenced by choice of cleaning criterion. Because key policy and programming decisions depend on these statistics, variations in analytical practice could lead to inconsistent and potentially inappropriate implementation of malnutrition treatment programmes. We therefore call for mandatory reporting of cleaning criteria use so that results can be compared and interpreted appropriately. International consensus is urgently needed regarding choice of criteria to improve the comparability of nutrition survey data

Economic growth and environmental quality: a meta-analysis of environmental Kuznets curve studies

Meta-analysis is used to investigate systematic variation across Environmental Kuznets Curve (EKC) studies. Based on 588 observations, modeling results indicate that data characteristics, study methods, estimation techniques, and the chosen environmental quality degradation measure all significantly affect the absence or presence of the EKC, and any predicted income turning points (ITPs). With respect to anthropogenic activity-related greenhouse gases, the evidence does not support the presence of an EKC.environmental Kuznets curve

Estudio histórico-epistemológico de la integral de una función de Leibniz a Riemann

En el presente trabajo se plantea una concepción de contexto en el que un elemento fundamental es el constituido por los sistemas de prácticas desarrollados por quienes se enfrentan a situaciones problémicas relacionadas con la matemática. Enmarcado en el enfoque ontosemiótico de la cognición matemática propuesto por Godino, Batanero, Font [2008] y otros, se concibe que el lenguaje desarrollado por los sujetos que hacen matemáticas, sus procedimientos, las propiedades que atribuyen a los objetos, sus formas de organización y los conceptos que reconocen, determinan, en buena medida, la actividad matemática que desarrollan al enfrentar nuevas situaciones problémicas. Tomando como sujeto a la comunidad de expertos, en esta ocasión mostramos elementos en la dirección señalada, para la construcción del objeto matemático “integral de una función”, siguiendo la línea de desarrollo iniciada por Leibniz a fines del Siglo XVII

Boosty-bit: Power for Pint-Sized Projects

In order to make it easier for hobbyists to create small portable microcontroller based electronics projects, I have created Boosty-bit, a tiny DC-DC boost convert that runs off a single alkaline battery cell (AA or AAA). The Boosty-bit converter can source up to 250mA @ 3.3v, making it ideal for many microcontroller based projects. In addition to power management, Boosty-bit is also physically small, allowing it to fit inside pen/marker-sized enclosures along with a AAA battery and a microcontroller. Boosty-bit aims to be the ideal solution for “makers” who desire portability and compact form factors in their projects

Courts and Political Parties: The Politics of Constitutional Review in Ecuador

The central argument of my dissertation is that political parties and timing influence constitutional judges' behavior in highly fragmented party systems under specific institutional conditions such as short term in office, the threat of impeachment, and the possibility of reappointment. Partisan influence on judges' decisions is selective, and it is dependent on institutional features. The carrots and sticks of appointment, reappointment, and impeachment may be useful tools for legislative coalitions to obtain judges' deferential behavior when terms of these judges are short and immediate reappointment is possible. However, politicians do not care about all cases of constitutional adjudication equally. Compared to the total number of constitutional review cases, only few decisions, generally about laws, attract politician's attention, are reported by the media as national issues, and mobilize pressure groups. In a fragmented party system, partisan influence is difficult to exercise given higher costs for the coalition to monitor and enforce judges' deferential behavior. Hence, a natural division emerges between politically important cases and standard cases without political pressure. Whereas some political variables help explain judicial votes on political cases, they have no influence on standard cases without political relevance. As a consequence, a constitutional judge may behave strategically on political cases and vote sincerely on standard cases

Thermal Analysis and Experiment Design for Seismic Performance Evaluation of Ice and Water Contaminated Friction Pendulum Bearings

Over the past few years, there have been several reports on water contaminated Friction Pendulum System (FPS) bearings across the country. Additionally, there is a concern in Alaska that water will freeze inside the bearing during the winter, potentially restraining the slider from moving along the bottom concave surface. The motivation for this project comes from the lack of experimental work to examine the effects of ice and water in FPS bearings.The objectives of the project are to assess the influence of water and ice contamination on the frictional properties and seismic response of FPS bearings, relative to uncontaminated bearings. This assessment may lead to modified analytical models to account for the effects of water and ice contamination, and recommendations to account for water and ice contamination in the design process and/or recommendations for mitigation. However, the scope of this thesis includes test setup and load frame design for shake table tests; and analysis and experiments to assess the feasibility, optimize the insulation arrangement, and estimate the time needed to freeze the water to a temperature of -30°F (239°K). A steel test frame was designed to transmit axial load to the bearing and to restrain the top plate of the bearing from displacement in all directions. The test frame consists of three pieces that form an “A”: 2 legs that are connected to rigid steel columns by a pin to allow for rotation, and 1 middle element that transmit axial load to the bearing. The frame was designed in accordance to AISC 360 to transmit an axial load of 100 kips to the bearing and to withstand a shear force of 23 kips, calculated using the maximum displacement capacity (11 in.) of Susitna Bridge bearing. A thermal finite volume model was developed to simulate the freezing process of a water-filled bearings placed inside an insulation box filled with dry ice. Two different approaches were used to model dry ice’s cooling capacity: Source Term and Temperature BC. In addition, two freezing tests were conducted to validate the results from the finite volume model. The freezing tests revealed that Source Term approach underestimates the dry ice cooling capacity while Temperature BC overestimates dry ice cooling capacity. Air gaps must be minimized in the final design of the insulation box, and insulation must be added above and below the bearing to achieve temperatures below -30°F or lower. The freezing tests also revealed that the insulation box needs to be refilled with dry ice after the water has changed phase from liquid to solid