Endemic goiter in school children of Salta Province, Argentina

The Province of Salta, located in the northwest of Argentina, showed severe endemic goiter-cretinism. The purpose of our work, therefore, was to evaluate the results of the iodized salt prophylaxis measure implemented since 1963. In 1980-1981 the prevalence of goiter was determined in 16,935 school children whose ages ranged from four to 15 years. The urinary iodine/creatinine index was also determined in a subsample of 401 children. Findings revealed that the goiter prevalence in the Province was 16.1%. In 10 Departments of the Province, those with greater socioeconomic development and denser population, the prevalences found were below 10%, limit established as endemic. In the remaining 13 Departments, especially in those less developed--where mountainous regions make their access difficult and hence, their populations consume non-iodized salt obtained from natural salt basins--values exceeded this limit. The average ioduria was 104.0 micrograms I/g Cr, with 4.5% presenting values below 25 micrograms. After 20 years of prophylaxis, endemic goiter has therefore been partially eradicated. It is suggested, however, that consumption of iodized salt and, even the supply of iodized oil in those areas where prevalence is high, be recommended.     

Service aged 69 and 115 kV XLPE cables

Five 69 kV XLPE cables, 6 to 23 years in service and two old vintage cables from storage plus a 115 kV XLPE cable from service together with a spare cable from the same production, kept in storage, were evaluated. All components of the cables were found to show little signs of deterioration except for AC breakdown. The 69 kV XLPE cable from service has breakdown levels ranging from 10.2 to 18.2 kV/mm, the spare cable 15.0 to 17.7 kV/mm compared to 27.2 kV/mm, the only previously reported value for a new cable. The 115 kV XLPE cable had a breakdown level of 16 kV/mm and the spare 10 kV/mm. The above cables are low-stress cables. Most modern cables operate at higher voltage stresses, taking advantage of cleaner insulations with smoother shields and moisture barriers. Caution is advised in using older, low-stress cables placed in storage     

Categorization of Lung Morphology Based on FRC and Height: Computer Simulations of Aerosol Deposition

The aim of this study was to compare the human subject experimental measurements of particle deposition within the lungs using the aerosol bolus technique with the results of analytical modeling as a basis for assessing the influence of lung morphology on inhaled particle deposition patterns. A methodology for scaling the lung morphology, based on a classic symmetric dichotomous model, as a function of both functional residual capacity and height of the investigated population is presented. Because of the availability of deposition data for male and female lung morphologies, these were used as an example to address the importance of adjusting lung morphology in calculating the aerosol deposition rates. In order to represent the 2 groups based on gender enrolled in the experimental study, 2 lung morphologies have been built. An analytical and mechanistic model was used to mimic the bolus delivery technique and simulate the aerosol deposition in each of the 2 groups. Predicted results were compared with experimental data for both total deposition fraction and bolus recovery (fraction of exhaled particles compared with inhaled particles) for 3 flow rates and 3 particle sizes. Good agreement was found between theoretical and measured data, showing the primary importance of the differentiation of the lung morphology to predict the aerosol deposition within human lungs. This study presents a morphological lung model that is adaptable to specific populations (e.g., gender or race), groups (e.g., a clinical study population), or even individuals.

Copyright 2012 American Association for Aerosol Research     

Recent advances in autonomic communications [Guest Editorial]

The nine papers in this special issue focus on recent advances in autonomic communications. This issue addresses four areas in which autonomics play a central role: network architectures, traffic management, monitoring, and resource management.     

Indeterminacy in the estimation of flow rate and transport functions from tracer experiments in closed circulations

The interpretation of tracer experiments in closed circulating systems is studied from the viewpoint of applied probability theory. It is shown that basic quantities and characteristics of the system, such as mean round time and its variability as well as the average volumetric flow rate cannot be extracted from the tracer response even if two concentration histories — one at the injection site and one at an arbitrary location on the same flow path—are simultaneously recorded. The observed tracer responses are compatible with many feasible underlying round-time distributions (transport functions) and a many-one correspondence rather than a one-one correspondence between circulation time probability density and concentration history is shown to exist. This indeterminacy is inherent and stems from the recirculation within the system. A value that can be determined is the maximum flow consistent with the measurements; any value below this maximum leads to feasible round-time distribution functions. The theory presented in this study leads to estimation procedures—pertaining to maximum feasible flow—which are completely free of prior distribution assumptions.     

Track-based self-supervised classification of dynamic obstacles

This work introduces a self-supervised architecture for robust classification of moving obstacles in urban environments. Our approach presents a hierarchical scheme that relies on the stability of a subset of features given by a sensor to perform an initial robust classification based on unsupervised techniques. The obtained results are used as labels to train a set of supervised classifiers. The outcomes obtained with the second sensor can be used for higher level tasks such as segmentation or to refine the within-clusters discrimination. The proposed architecture is evaluated for a particular realization based on range and visual information which produces track-based labeling that is then employed to train supervised modules that perform instantaneous classification. Experiments show that the system is able to achieve 95% classification accuracy and to maintain the performance through on-line retraining when working conditions change.     

Analysis of peg-hole automated pre-assembly engagement search

The paper presents the main characteristics of search strategies used for automated pre-assembly engagement. The handling of such operations is described through an experimental set-up. Finally, experimental results are used to facilitate the decision-making process for correct automated engagement prior to the assembly insertion stage. The multi peg-hole system for preassembly engagement as a more complex system is discussed.