Monthly Archives: June 2013

Online water quality sensor networks increase detection likelihood and decrease mean time to detection

Lina Perelman, Avi Ostfeld. Operation of remote mobile sensors for security of drinking water distribution systems. Water Research, Volume 47, Issue 13, 1 September 2013, Pages 4217–4226

The deployment of fixed online water quality sensors in water distribution systems has been recognized as one of the key components of contamination warning systems for securing public health. This study proposes to explore how the inclusion of mobile sensors for inline monitoring of various water quality parameters (e.g., residual chlorine, pH) can enhance water distribution system security. Mobile sensors equipped with sampling, sensing, data acquisition, wireless transmission and power generation systems are being designed, fabricated, and tested, and prototypes are expected to be released in the very near future. This study initiates the development of a theoretical framework for modeling mobile sensor movement in water distribution systems and integrating the sensory data collected from stationary and non-stationary sensor nodes to increase system security. The methodology is applied and demonstrated on two benchmark networks. Performance of different sensor network designs are compared for fixed and combined fixed and mobile sensor networks. Results indicate that complementing online sensor networks with inline monitoring can increase detection likelihood and decrease mean time to detection.

Click here for full paper (fee).

Toothpaste must be used correctly to avoid dental fluorosis

Nascimento HA, Ferreira JM, Granville-Garcia AF, Costa EM, Cavalcante AL, Sampaio FC. Estimation of toothpaste fluoride intake in preschool children. Braz Dent J. 2013;24(2). pii: S0103-64402013000200142. doi: 10.1590/0103-6440201302087.

The objective of this study was to estimate the intake of toothpaste fluoride used by children aged 2 to 6 years (n=87) treated at a hospital of a medium-sized city (Campina Grande, PB) in the Northeastern region of Brazil. Data regarding sociodemographic characteristics of families and children’s toothbrushing were collected from questionnaire-based interviews with parents/guardians, and the amount of fluoride used during toothbrushing was estimated using a precision scale for assessment of the risk of dental fluorosis, considering a cutoff value of 0.07 mgF/kg body weight/day. Fluoride content in the toothpastes was analyzed using a specific fluoride electrode. Data were analyzed using descriptive and inferential statistics using the chi-square and Fisher’s exact tests (α=0.05). Considering the use of the derice, the risk of fluorosis in the children was 19.5%. There was significant association (p<0.05) between the risk of fluorosis, brushing frequency, type of derice and who performed the child’s oral hygiene. It was concluded that a high percentage of children in the studied sample used toothpaste inappropriately and were at risk of developing dental fluorosis.

Click here for full paper (Open Source).

“…CO2 content has had essentially nothing to do with earth’s near-surface air temperature throughout the entire Holocene,”

A new analysis finds that the Medieval Warming Period was global and unrelated to CO2.  Click here or image below.

report cover

Wind Turbine kills rarely seen White-throated Needletail

“There hasn’t been a sighting of a White-throated Needletail in the United  Kingdom for 22 years, so nearly 80 birdwatchers flocked to Scotland this week to  get a look, the Telegraph reported.  But instead of enjoying the world’s  fastest flying bird soaring, they watched it fly into the small blade of a wind  turbine and die.”

Click here for the complete story….

Who is responsible for children’s fluoride intake and dental health?

This study examined the effectiveness of fluoride salt administered to selected children in two public schools. The so called “public health” officials took the responsibility to conduct the study. I generally have no problem with this, except if the ultimate responsbility for children’s health is taken from parents. Of course, there are differing circumstances of children (e.g., children who are the responsibiity of a state) that must be taken into consideration. Perhaps failure in this case was the lack of parental attention given to the dental health of their childat home, rather than relying on the school officials.

Wennhall I, Hajem S, Ilros S, Ridell K, Ekstrand KR, Twetman S. Fluoridated salt for caries prevention and control – a 2-year field study in a disadvantaged community. Int J Paediatr Dent. 2013 Jun 20. doi: 10.1111/ipd.12045

BACKGROUND: Salt fluoridation is considered a cost-effective community strategy for reducing caries.

AIM: To evaluate the effect of school-based and domestic distribution of F-salt to school children residing in a disadvantaged community.

DESIGN: Seven hundred and thirty-three schoolchildren (12-14 years), attending two public schools, were enrolled; one was assigned to intervention (IS), whereas the other served as reference (RS). Subjects in IS were given access to F-salt (250 ppm F) in marked jars at school lunch and through free supply for domestic use. The 2-year caries increment and progression rate, assessed from bitewing radiographs, was scored. Information on diet, oral hygiene, and fluoride exposure was collected through a baseline questionnaire.

RESULTS: The dropout rate was high (IS 27%; RS 18%). At baseline, the IS children displayed more unfavourable risk factors and a higher caries experience than RS children. There were no significant differences in total caries increment or proximal progression rate between the two schools. A negative correlation (r = -0.29; P < 0.05) between the amount of delivered salt and the caries progression rate was, however, noted. No side effects were reported.

CONCLUSIONS: F-salt was not effective in this setting. Still, the findings indicate that salt may be a beneficial source of fluoride in schoolchildren provided that compliance can be secured.

Aging solar radiation screens on weather stations cause large positive bias

G. Lopardo, F. Bertiglia, S. Curci, G. Roggero, A. Merlone. Comparative analysis of the influence of solar radiation screen ageing on temperature measurements by means of weather stations. International Journal of Climatology DOI: 10.1002/joc.3765

Solar radiation screens play a key role in automatic weather stations (AWS) performances. In this work, screen ageing effects on temperature measurements are examined. Paired temperature observations, traceable to national standards and with a well-defined uncertainty budget, were performed employing two naturally ventilated weather stations equipped with identical sensors and different only for their working time. Three different tests were carried out employing different aged AWSs: a 5-year-old AWS (AWS5) was compared with a new device (AWS0), a 1 year old (AWS1) was compared with both a 3 years old (AWS3) and a new one devices (AWS00). Due to solar and weather conditions exposure a degradation of the screen reflective coating is evident for the older AWSs (5 and 3 years old) and so a qualitative estimation of how different conditions of ageing affect the temperature drift was done. During the comparison 0 to 5 and 1 to 3-year-old screens, significant temperature differences were recorded at different times of the day. The differences, wider than the uncertainty amplitude, demonstrate a systematic effect. The temperature measured with the older screen is larger, and the maximum instantaneous difference was 1.63 °C (for 0–5 years comparison) in daytime hours. During night-time the two AWS’s measure the same temperature (within the uncertainty amplitude). This behaviour, increasing with increasing solar radiation intensity and decreasing with increasing wind speed, is attributed to a radiative heating effect. The screen ageing has compromised the shield effectiveness introducing a significant change in the temperature evaluation. The experimental results of a further comparison, between 0- and 1-year-old screens, confirm the same conclusion showing a negligible ageing effect, within the uncertainty amplitude.

Click here for full paper (fee).

White House climate report is a stretch too far….

This White House report is not representative of the issues and assumptions necessary to make such a statement…..Indeed, this as utopian policy  propaganda. (click here for a good discussion) For example, the state reports start by saying:

“We have a moral obligation to leave our children a planet that’s not polluted or damaged,”

Does anyone believe that such a utopian ideal is achievable, and should drive all other decisions, and even trump a person’s ability to earn a living and provide for their family?

This example report (click here or see below) for California is almost silly.

California Fact Sheet