Pulmonary Function Changes Associated with an Air Pollution Episode in January 1987

In January 1987, an air pollution episode occurred In central and western Europe. Levels of SO₂, NO₂, black smoke, sulphates and other components were elevated, with 24 hour average concentrations of SO₂ reaching a maximum of close to 300 μg/m3 In an area In the southeast of the Netherlands. Pulmonary function was measured In a group of children of 6- 12 years old at the end of the episode, and also two and three and a half weeks after the episode. A baseline lung function value was obtained about three months before the episode. Pulmonary function growth between baseline and retest dates was estimated from a simple growth model which was validated using measured pulmonary function growth data from a longitudinal study. A decline of pulmonary function (FVC, FEV₁ and PEF) from predicted baseline levels was observed, starting on the last day of the episode. Two weeks after the episode, FVC, FEV₁ PEF and MMEF were all decreased, and three and a half weeks after the episode, there was still a deficit compared to predicted baseline levels for FVC and FEV₁     

Preliminary assessment of risk of ozone impacts to maize (Zea mays) in southern Africa

Surface ozone concentrations in southern Africa exceed air quality guidelines set to protect agricultural crops. This paper addresses a knowledge gap by performing a preliminary assessment of potential ozone impacts on vegetation in southern African. Maize (Zea mays L.) is the receptor of interest in the main maize producing countries, i.e. South Africa, Zambia and Zimbabwe. Surface ozone concentrations are estimated for the growing season (October to April) using photochemical modelling. Hourly mean modelled ozone concentrations ranged between 19.7 and 31.2 ppb, while maximums range between 28.9 and 61.9 ppb, and are near 30 ppb over South Africa and Zambia, while in Zimbabwe, they exceed 40 ppb and translate into monthly AOT40 values of over 3,000 ppb h in five of the seven months of the growing season. This study suggests that surface ozone may pose a threat to agricultural production in southern African, particularly in Zimbabwe.     

Prenatal diagnosis,prediction of outcome and in utero therapy of isolated congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) can be associated with genetic or structural anomalies with poor prognosis. In isolated cases, survival is dependent on the degree of lung hypoplasia and liver position. Cases should be referred in utero to tertiary care centers familiar with this condition both for prediction of outcome as well as timed delivery. The best validated prognostic indicator is the lung area to head circumference ratio. Ultrasound is used to measure the lung area of the index case, which is then expressed as a proportion of what is expected normally (observed/expected LHR). When O/E LHR is < 25% survival chances are < 15%. Prenatal intervention, aiming to stimulate lung growth, can be achieved by temporary fetal endoscopic tracheal occlusion (FETO). A balloon is percutaneously inserted into the trachea at 26–28 weeks, and reversal of occlusion is planned at 34 weeks. Growing experience has demonstrated the feasibility and safety of the technique with a survival rate of about 50%. The lung response to, and outcome after FETO, is dependent on pre-existing lung size as well gestational age at birth. Early data show that FETO does not increase morbidity in survivors, when compared to historical controls. Several trials are currently under design. Copyright © 2008 John Wiley & Sons, Ltd.     

The use of magnetic resonance imaging in the prediction of birthweight

Extremes of fetal growth can increase adverse pregnancy outcomes, and this is equally applicable to single and multiple gestations. Traditionally, these cases have been identified using simple two-dimensional ultrasound which is quite limited by its low precision. Magnetic resonance imaging (MRI) has now been used for many years in obstetrics, mainly as an adjunct to ultrasound for congenital abnormalities and increasingly as part of the post-mortem examination. However, MRI can also be used to accurately assess fetal weight as first demonstrated by Baker et al in 1994, using body volumes rather than standard biometric measurements. This publication was followed by several others, all of which confirmed the superiority of MRI; however, despite this initial promise, the technique has never been successfully integrated into clinical practice. In this review, we provide an overview of the literature, detail the various techniques and formulas currently available, discuss the applicability to specific high-risk groups and present our vision for the future of MRI within clinical obstetrics.     

Prymnesium parvum Population Dynamics During Bloom Development: A Role Assessment of Grazers and Virus1

Schwierzke, Leslie, Daniel L. Roelke, Bryan W. Brooks, James P. Grover, Theodore W. Valenti, Jr., Mieke Lahousse, Carrie J. Miller, and James L. Pinckney, 2010. Prymnesium parvum Population Dynamics During Bloom Development: A Role Assessment of Grazers and Virus. Journal of the American Water Resources Association (JAWRA) 46(1):63-75. DOI: 10.1111/j.1752-1688.2009.00391.x Abstract: The toxic haptophyte Prymnesium parvum is a harmful alga known to cause fish-killing blooms that occur worldwide. In Texas (United States), P. parvum blooms occur in inland brackish water bodies and have increased in frequency and magnitude in recent years. In this study we conducted three consecutive field experiments (Lake Whitney) to investigate the influence of zooplankton and viruses on P. parvum bloom dynamics during the time of year when blooms are still typically active in Texas (early spring). A localized P. parvum bloom developed during our study that involved increasing levels of toxicity (based on Pimephales promelas and Daphnia magna bioassays). Only in our last experiment, during later stages of bloom development and under highly toxic conditions, did the presence of grazers show a statistically significant, negative effect on P. parvum population dynamics. During this experiment, a rotifer-dominated zooplankton community emerged, composed mostly of Notholca laurentiae, suggesting that this species was less sensitive than other grazers to toxins produced by P. parvum. Microzooplankton may have also been important at this time. Similarly, only our final experiment demonstrated a statistically significant, negative effect of viruses on P. parvum. This exploratory study, resulting in observed impacts on P. parvum populations by both grazers and virus, enhances our understanding of P. parvum ecology and highlights direction for future studies on resistance of zooplankton to prymnesin toxins and algal-virus interactions.