MR imaging of the fetal musculoskeletal system

Magnetic resonance imaging (MRI) appears to be increasingly used, in addition to standard ultrasonography for the diagnosis of abnormalities in utero. Previous studies have recently drawn attention to the technical refinement of MRI to visualize the fetal bones and muscles. Beyond commonly used T2-weighted MRI, echoplanar, thick-slab T2-weighted and dynamic sequences, and three-dimensional MRI techniques, are about to provide new imaging insights into the normal and the pathological musculoskeletal system of the fetus. This review emphasizes the potential significance of MRI in the visualization of the fetal musculoskeletal system. © 2012 John Wiley & Sons, Ltd.     

Aspekte der Phytoremediation organischer Schadstoffe

Phytoremediation is the quite novel technique of cleaning polluted sites through the use of plants. Phytoremediation methods are comparatively cheap, are accepted by the public and are ecologically advantageous, compared to common technological approaches. Until today, there have been only a few examples for successful applications. One reason is that the processes occurring are complex, and a full clean up may require many years. Plants have an influence on the water balance of a site, they change redox potential and pH, and stimulate microbial activity of the soil. These indirect influences may accelerate degradation in the root zone or reduce the leaching of compounds into the groundwater. Compounds taken up into plants may be metabolised, accumulate, or volatilise into air. Based on these processes, several phytoremediation methods have been developed: Phytoextraction, rhizofiltration, phytostabilisation, rhizound phytodegradation, pump and tree, land farming, phytovolatilisation, hydraulic control and even more. Already in use are plants (and here mainly willows, poplars and grasses) for the degradation of petroleum products, aromatic hydrocarbons (BTEX), chlorinated solvents, explosives and cyanides. Phytotoxicity and pollutants mass balance have rarely been documented carefully. Often, the success of the projects was not controlled, and only estimates can be made about the applicability and the potential of phytoremediation. This lack of experience about possibilities and limitations seems to be a hindrance for a broader use of these techniques.     

Sequentielle Schwermetallextraktion aus Staubniederschl?gen und Stra?ensedimenten Teil I: Sequentielle Schwermetallextraktion von Mikroproben

Für die Anwendung der sequentiellen Schwermetallextraktion auf Proben, die nur im Milligramm-Bereich erhalten werden k?nnen (Mikroproben, wie z. B. Staubniederschl?ge), wurde die Methode vonZeien &Brümmer (1989) weiterentwickelt. Der Extraktionsma?stab wurde um den Faktor 1∶100 verringert und die Reproduzierbarkeit des Verfahrens mit variablen Probenmengen um 20mg und einem Extraktionsvolumen von 500 μl mit Hilfe von Standardb?den nachgewiesen. M?gliche Einflüsse variabler Extraktionsverh?ltnisse (Verh?ltnis von Probenmenge zu Extraktionsvolumen) sowie eine aufwendige Vorbehandlung von Staubproben, die nach der Bergerhoff-Methode (VDI 2119/2, 1972) gesammelt wurden, lagen bei diesen Untersuchungen weitgehend im Variationsbereich des Verfahrens. Die sequentielle Extraktion kann folglich zur Untersuchung der Mobilisierbarkeit von Schwermetallen auch aus Mikroproben mit variablen Probenmengen eingesetzt werden. Mit Hilfe dieses Verfahrens wurden die Mobilisierbarkeiten von Zink, Kupfer und Blei der Schluff- und Tonfraktion von Stra?ensedimenten mit Staubniederschl?gen an zwei urbanen Standorten mit unterschiedlicher, verkehrsbedingter Schwermetallbelastung verglichen. Diese Untersuchungen werden in Teil 2 (“Sequentielle Schwermetallextraktion von st?dtischen St?uben”) vorgestellt.     

Lower thermal capacity limits of the common brown shrimp (Crangon crangon,L.)

Brown shrimp (Crangon crangon, L.) are subjected to a huge annual temperature range, and certain thermal conditions during winter have been identified to affect the brown shrimp population. Despite that, little is known about its thermal biology with regard to critically low temperatures. In the present study, we determined the critical thermal minima (CT_min) and the critical lethal minima (CL_min) of male and female brown shrimp of different body sizes in laboratory-based experiments. For the CT_min trials, shrimp were acclimated to 4.0, 9.0, and 14.0 °C and exposed to a cooling rate of ?0.2 °C min^?1. In the CL_min trials, brown shrimp were exposed to a cooling rate of ?1.0 °C day^?1 without prior thermal acclimation. Acclimation temperature significantly affected the temperature tolerance of brown shrimp (p < 0.001). CT_min among the experimental groups just varied slightly, and no clear effect of gender or body size was observed. In the CL_min trials, brown shrimp even tolerated the coldest temperature of ?1.7 °C that could be established in the experimental setup. However, we observed a negative relationship between temperature and reactivity within the range of 7.0 and 1.0 °C that was determined by means of the flicking response. This relationship suddenly broke between 1.0 and 0.0 °C where an abrupt drop in the reactivity of the shrimp became apparent. The results of this study revealed that brown shrimp hold a wider thermal range as originally reported and that it can cope with subzero temperatures. Implications of low-temperature tolerance are discussed in the context of the brown shrimp’s ecology as well as stock assessment.     

Economic benefits from decreased mercury emissions: Projections for 2020

Anthropogenic processes have increased the exposure of humans and wildlife to toxic methyl mercury (MeHg). Mercury emissions will increase by about 25% between 2005 and 2020, if the present trajectory is maintained. A global assessment of societal damages caused by the ingestion of methyl mercury, based merely on loss of IQ (Intelligence Quotient), suggests that the annual cost will be approximately US$3.7 billion (2005 dollars) in 2020. The corresponding cost of damages resulting from the inhalation of methyl mercury is estimated at US$2.9 million (2005 dollars). Under a higher degree of emission control such as in the case of the Extended Emission Control (EXEC) and the Maximum Feasible Technological Reduction (MFTR) scenarios, total emissions could decrease in the period 2005–2020 by about 50–60%. The corresponding annual benefits in 2020 are estimated to be about US$1.8–2.2 billion (2005 dollars). Large economic benefits can be achieved by reducing global mercury emissions.     

Estimating Watershed Level Nonagricultural Pesticide Use From Golf Courses Using Geospatial Methods1

Abstract: Limited information exists on pesticide use for nonagricultural purposes, making it difficult to estimate pesticide loadings from nonagricultural sources to surface water and to conduct environmental risk assessments. A method was developed to estimate the amount of pesticide use on recreational turf grasses, specifically golf course turf grasses, for watersheds located throughout the conterminous United States (U.S.). The approach estimates pesticide use: (1) based on the area of recreational turf grasses (used as a surrogate for turf associated with golf courses) within the watershed, which was derived from maps of land cover, and (2) from data on the location and average treatable area of golf courses. The area of golf course turf grasses determined from these two methods was used to calculate the percentage of each watershed planted in golf course turf grass (percent crop area, or PCA). Turf‐grass PCAs derived from the two methods were used with recommended application rates provided on pesticide labels to estimate total pesticide use on recreational turf within 1,606 watersheds associated with surface‐water sources of drinking water. These pesticide use estimates made from label rates and PCAs were compared to use estimates from industry sales data on the amount of each pesticide sold for use within the watershed. The PCAs derived from the land‐cover data had an average value of 0.4% of a watershed with minimum of 0.01% and a maximum of 9.8%, whereas the PCA values that are based on the number of golf courses in a watershed had an average of 0.3% of a watershed with a minimum of <0.01% and a maximum of 14.2%. Both the land‐cover method and the number of golf courses method produced similar PCA distributions, suggesting that either technique may be used to provide a PCA estimate for recreational turf. The average and maximum PCAs generally correlated to watershed size, with the highest PCAs estimated for small watersheds. Using watershed specific PCAs, combined with label rates, resulted in greater than two orders of magnitude over‐estimation of the pesticide use compared to estimates from sales data.