Evaluation of lot-to-lot repeatability and effect of assay media choice in the recombinant Factor C assay

Measurement of environmental endotoxin exposures is complicated by variability encountered using current biological assay methods arising in part from lot-to-lot variability of the Limulus-amebocyte lysate (LAL) reagents. Therefore, we investigated the lot-to-lot repeatability of commercially available recombinant Factor C (rFC) kits as an alternative to LAL. Specifically, we compared endotoxin estimates obtained from rFC assay of twenty indoor dust samples, using four different extraction and assay media, to endotoxin estimates previously obtained by Limulus amebocyte lysate (LAL) assay and amounts of 3-hydroxy fatty acids (3-OHFA) in lipopolysaccharide (LPS) using gas-chromatography mass spectroscopy (GC-MS). We found that lot-to-lot variability of the rFC assay kits does not significantly alter endotoxin estimates in house dust samples when performed using three of the four assay media tested and that choice of assay media significantly altered endotoxin estimates obtained by rFC assay of house dust samples. Our findings demonstrate lot-to-lot reproducibility of rFC assay of environmental samples and suggest that use of rFC assay performed with Tris buffer or water as the extraction and assay medium for measurement of endotoxin in dust samples may be a suitable choice for developing a standardized methodology.     

Comparison of external costs between dry tomb and bioreactor landfills: taking intergenerational effects seriously.

Dry tomb and bioreactor landfills were analyzed with respect to their external costs in an intergenerational cost-benefit analysis in a partial framework which enabled a sounder comparison to be carried out between these two technologies from a socio-economic viewpoint. Obviously, this approach was only a first step for building a comprehensive basis of any environmental as well as fiscal policy in the field of waste management. All external costs are identified and evaluated in three different scenarios, corresponding to a worst case, a best guess and a best case. Obviously, discounting is crucial with respect to an intergenerational perspective. Generation-adjusted discounting (GAD) was applied to take into account equity as well as efficiency criteria, in order to deal with three different types of uncertainties that are decisive in waste policy decisions: a physical uncertainty is captured by introducing our three different scenarios; a macroeconomic uncertainty is taken into consideration by calculating present values using different real growth rates; and a microeconomic uncertainty is taken into account by considering individual peculiarities reflected in their subjective time preference rate. The findings show, that whenever there is a low real GDP growth of less than 1%, the bioreactor is generally superior to the dry tomb (lower present values of external costs). This statement becomes more valid as the growth rate decreases. However, whenever there are high positive growth rates, it is the dry tomb technology which is superior to the bioreactor system.     

Controversies in antenatal corticosteroid treatment

Antenatal corticosteroids are now established as one of the cornerstones of therapy in the prevention of neonatal morbidity and mortality prior to preterm birth. Although this practice is widely accepted, a significant number of controversies exist. This review explores the knowledge gaps regarding the use of antenatal corticosteroids in the preterm, late preterm and term populations. Furthermore, the role of antenatal corticosteroids in special populations, such as diabetes, multiple pregnancies and periviable gestations, where high-quality data from randomized controlled trials are lacking, is also considered.     

Fixism and conservation science

The field of biodiversity conservation has recently been criticized as relying on a fixist view of the living world in which existing species constitute at the same time targets of conservation efforts and static states of reference, which is in apparent disagreement with evolutionary dynamics. We reviewed the prominent role of species as conservation units and the common benchmark approach to conservation that aims to use past biodiversity as a reference to conserve current biodiversity. We found that the species approach is justified by the discrepancy between the time scales of macroevolution and human influence and that biodiversity benchmarks are based on reference processes rather than fixed reference states. Overall, we argue that the ethical and theoretical frameworks underlying conservation research are based on macroevolutionary processes, such as extinction dynamics. Current species, phylogenetic, community, and functional conservation approaches constitute short‐term responses to short‐term human effects on these reference processes, and these approaches are consistent with evolutionary principles.     

Disaster safety nets for developing countries: Extending public—private partnerships

In developed countries, public—private partnerships involving insurance companies and governments often provide security against the human and economic losses of disasters. These partnerships, however, are neither available nor affordable in most highly exposed developing countries. In this paper we examine recent innovations in financial risk management that extend traditional public—private partnerships to include NGOs, international financial institutions and other donors. Importantly, these partnerships provide secure financial arrangements to low-income communities before disasters strike and thus relieve the uncertainty and anxiety of depending on ad hoc post-disaster aid for recovery and even survival. We examine three examples of extended partnerships: the Turkish Catastrophe Insurance Pool; the Andhra Pradesh microinsurance program and an index-based weather derivative for farmers facing drought in Malawi.     

WATER SUPPLY AND URBAN GROWTH PLANNING: A PARTNERSHIP1

ABSTRACT As urban expansion outstrips water supplies, the usual solution is to build pipelines to bring in water from sources farther afield. Such water supplies may act as either a leader of urban development or as a follower. In either case, this engineering approach to the provision of water has fostered less than optimal utilization of regional water and land resources for urban growth. More efficient utilization of these resources is achieved when water supply development and urban growth planning are conjoint activities. Water supply planners and land use planners, working together, are able to generate and evaluate the full range of urban development options, including water demand management through conservation. Preferred regional growth plans are achieved using the best mix of water supply and urban growth. The result is a reduced rate of water supply development and a reduction of urban expansion on prime lands. This partnership approach is demonstrated for the Calgary Region under two levels of water conservation.     

Determination and assessment of total mercury levels in local, frozen and canned fish in Lebanon

Fish is an important constituent of the Lebanese diet. However, very little attention in our area is given to bring awareness regarding the effect of the toxicity of mercury (Hg) mainly through fish consumption. This study aimed to report analytical data on total mercury levels in several fish species for the first time in thirty years and to also made individuals aware of the presence and danger from exposure to mercury through fish consumption. Fish samples were selected from local Lebanese markets and fisheries and included 94 samples of which were fresh, frozen, processed, and canned fish. All values were reported as microgram of mercury per gram of fish based on wet weight. The level of mercury ranged from 0.0190 to 0.5700 μg/g in fresh samples, 0.0059 to 0.0665 μg/g in frozen samples, and 0.0305 to 0.1190 μg/g in canned samples. The data clearly showed that higher levels of mercury were detected in local fresh fish as opposed to other types thus placing consumers at higher risk from mercury exposure. Moreover, the data revealed that Mallifa (yellowstripe barracuda/Sphyraena chrysotaenia), Sargous (white seabream/Diplodus sargus), Ghobbos (bogue/Boops hoops), and shrimp (Penaeus sp.) were among the types containing the highest amounts of mercury. On the other hand, processed fish such as fish fillet, fish burger, small shrimp and crab are found to contain lower levels of mercury and are associated with lower exposure risks to mercury. Lebanese population should therefore, be aware to consume limited amounts of fresh local fish to minimize exposure to mercury.