The cost of publicly financed dental care in relation to community water fluoridation in Texas

Dental caries lead to children being less ready to learn and results in diminished productivity in the classroom. Tooth decay causes pain and infection, leading to impaired chewing, speech, and facial expression, in addition to a loss in self-esteem. There have been many studies supporting the safety and efficacy of community water fluoridation in reducing dental caries. Water fluoridation has been identified by the Centers for Disease Control and Prevention as one of 10 great public health achievements of the 20th century. The decline in the prevalence and severity of tooth decay in the United States during the past 60 years has been attributed largely to the increased use of fluoride; in particular, the widespread utilization of community water fluoridation. However, in the decades since fluoridation was first introduced, reductions in dental caries have declined, most likely due to the presence of other sources of fluoride. Questions have been raised regarding the need to continue to fluoridate community water supplies in the face of possible excessive exposure to fluoride. Nevertheless, dental caries continue to be a significant public health burden throughout the world, including the United States, especially among low-income and disadvantaged populations. Although many poor children receive their dental care through Medicaid, the percentage of Texas children with untreated dental caries continues to exceed the U.S. average and is well above Healthy People 2010 goals, even as state Medicaid expenditures continue to rise. The objective of this study is to determine the relationship between Medicaid dental expenditures and community water fluoridation levels in Texas counties. By examining this relationship, the cost-effectiveness of community water fluoridation in the Texas pediatric Medicaid beneficiary population, as measured by publicly financed dental care expenditures, may be ascertained.^

BLOOD PRESSURE CHANGES IN RELATION TO DEMOGRAPHIC, ANTHROPOMETRIC, AND SEXUAL MATURATION VARIABLES IN U.S. HEALTH EXAMINATION SURVEY OF CHILDREN AND YOUTHS (UNITED STATES)

The determinants of change in blood pressure during childhood and adolescence were studied in a cohort of U.S. national probability sample of 2146 children examined on two occasions during the Health Examination Survey. Significant negative correlations between the initial level and the subsequent changes in blood pressure were observed. The multiple regression analyses showed that the major determinants of systolic blood pressure (SBP) change were change in weight, baseline SBP, and baseline upper arm girth. Race, time interval between examinations, baseline age, and height change were also significant determinants in SBP change. For the change in diastolic blood pressure (DBP), baseline DBP, baseline weight, and weight change were the major determinants. Baseline SBP, time interval and race were also significant determinants. Sexual maturation variables were also considered in the subgroup analysis for girls. Weight change was the most important predictor of the change in SBP for the group of girls who were still in the pre-menarchal or pre-breast maturation status at the time of the follow-up examination, and who had started to menstruate or to develop breast maturation at sometime between the two examinations. Baseline triceps skinfold thickness or initial SBP were more important variables than weight change for the group of girls who had already experienced menarche or breast maturation at the time of the initial survey. For the total group, pubic hair maturation was found to be a significant predictor of SBP change at the 5% significance level. The importance of weight change and baseline weight for the changes in blood pressure warrants further study. ^

C. H. Chalmers.- Bacteriología de la leche. (Bacteria in relation to the milk supply). 271 pp., 3ª ed., 1945, reimpresa en 1949. Editado por Edward Arnol & Co., Londres

Fil: H. G. C..

Export Restrictions in relation to Extractive Industries

A new E15 Think Piece by Ilaria Espa produced under the E15Initiative (E15). Implemented jointly by the International Centre for Trade and Sustainable Development (ICTSD) and the World Economic Forum, the E15 convenes world-class experts and institutions to generate strategic analysis and recommendations for government, business and civil society geared towards strengthening the global trade system. This paper considers concrete policy options to better regulate the use of export restrictions in relation to extractive industries. It briefly describes recent trends in the use of export restrictions on mineral and energy resources. It gives an account of the main shortcomings in the WTO legal treatment of export restrictions. It accordingly discusses possible avenues for reforming existing WTO disciplines in the interest of secure access to supplies, while still taking into account the need to preserve some policy space for host countries to use such measures as legitimate development tools.

Brown trout redd superimposition in relation to spawning habitat availability

The relationship between redd superimposition and spawning habitat availability was investigated in the brown trout (Salmo trutta L.) population inhabiting the river Castril (Granada, Spain). Redd surveys were conducted in 24 river sections to estimate the rate of redd superimposition. Used and available microhabitat was evaluated to compute the suitable spawning habitat (SSH) for brown trout. After analysing the microhabitat characteristics positively selected by females, SSH was defined as an area that met all the following five requirements: water depth between 10 and 50 cm, mean water velocity between 30 and 60 cm s)1, bottom water velocity between 15 and 60 cm s)1, substrate size between 4 and 30 mm and no embeddedness. Simple regression analyses showed that redd superimposition was not correlated with redd numbers, SSH or redd density. A simulation-based analysis was performed to estimate the superimposition rate if redds were randomly placed inside the SSH. This analysis revealed that the observed superimposition rate was higher than expected in 23 of 24 instances, this difference being significant (P menor que 0.05) in eight instances and right at the limit of statistical significance (P = 0.05) in another eight instances. Redd superimposition was high in sections with high redd density. High superimposition however was not exclusive to sections with high redd density and was found in moderate- and low-redd-density sections. This suggests that factors other than habitat availability are also responsible for redd superimposition. We argue that female preference for spawning over previously excavated redds may be the most likely explanation for high superimposition at lower densities.

Variation of PM2.5 concentrations in relation to street washing activities

Several studies conducted in urban areas have pointed out that road dust resuspension contributes significantly to PM concentration levels. Street washing is one of the methods proposed to reduce resuspended road dust contributions to ambient PM concentrations. As resuspended particles are mainly found in the coarse mode, published studies investigating the effects of street washing have focused on PM10 size fraction. As the PM2.5 mass fraction of particles originating from mechanical abrasion processes may still be significant we conducted a study in order to evaluate the effects of street washing on the mitigation of resuspension of fine particles. The PM2.5 mass concentration data were examined and integrated with the occurrence of street washing activities. In addition, the effect of the meteorological variability, traffic flow and street washing activities, on ambient PM2.5 levels was valuated by means of a multivariate regression model. The results revealed that traffic low is the most important factor that controls PM2.5 hourly concentrations while street washing activities did not influence fine particle mass levels.