Genome-wide abnormalities in embryos: Origins and clinical consequences

Ploidy or genome-wide chromosomal anomalies such as triploidy, diploid/triploid mixoploidy, chimerism, and genome-wide uniparental disomy are the cause of molar pregnancies, embryonic lethality, and developmental disorders. While triploidy and genome-wide uniparental disomy can be ascribed to fertilization or meiotic errors, the mechanisms causing mixoploidy and chimerism remain shrouded in mystery. Different models have been proposed, but all remain hypothetical and controversial, are deduced from the developmental persistent genomic constitutions present in the sample studied and lack direct evidence. New single-cell genomic methodologies, such as single-cell genome-wide haplotyping, provide an extended view of the constitution of normal and abnormal embryos and have further pinpointed the existence of mixoploidy in cleavage-stage embryos. Based on those recent findings, we suggest that genome-wide anomalies, which persist in fetuses and patients, can for a large majority be explained by a noncanonical first zygotic cleavage event, during which maternal and paternal genomes in a single zygote, segregate to different blastomeres. This process, termed heterogoneic division, provides an overarching theoretical basis for the different presentations of mixoploidy and chimerism.     

The impact of CO2 capture in the power and heat sector on the emission of SO2, NOx,particulate matter,volatile organic compounds and NH3 in the European Union

This study quantifies the trade-offs and synergies between climate and air quality policy objectives for the European power and heat (P&H) sector. An overview is presented of the expected performance data of CO₂ capture systems implemented at P&H plants, and the expected emission of key air pollutants, being: SO₂, NO_X, NH₃, volatile organic compounds (VOCs) and particulate matter (PM). The CO₂ capture systems investigated include: post-combustion, oxyfuel combustion and pre-combustion capture.For all capture systems it was found that SO₂, NO_x and PM emissions are expected to be reduced or remain equal per unit of primary energy input compared to power plants without CO₂ capture. Increase in primary energy input as a result of the energy penalty for CO₂ capture may for some technologies and substances result in a net increase of emissions per kWh output. The emission of ammonia may increase by a factor of up to 45 per unit of primary energy input for post-combustion technologies. No data are available about the emission of VOCs from CO₂ capture technologies.A simple model was developed and applied to analyse the impact of CO₂ capture in the European P&H sector on the emission level of key air pollutants in 2030. Four scenarios were developed: one without CO₂ capture and three with one dominantly implemented CO₂ capture system, varying between: post-combustion, oxyfuel combustion and pre-combustion.The results showed a reduction in GHG emissions for the scenarios with CO₂ capture compared to the baseline scenario between 12% and 20% in the EU 27 region in 2030. NO_x emissions were 15% higher in the P&H sector in a scenario with predominantly post-combustion and lower when oxyfuel combustion (?16%) or pre-combustion (?20%) were implemented on a large scale. Large scale implementation of the post-combustion technology in 2030 may also result in significantly higher, i.e. increase by a factor of 28, NH₃ emissions compared to scenarios with other CO₂ capture options or without capture. SO₂ emissions were very low for all scenarios that include large scale implementation of CO₂ capture in 2030, i.e. a reduction varying between 27% and 41%. Particulate Matter emissions were found to be lower in the scenarios with CO₂ capture. The scenario with implementation of the oxyfuel technology showed the lowest PM emissions followed by the scenario with a significant share allocated to pre-combustion, respectively ?59% and ?31%. The scenario with post-combustion capture resulted in PM emissions varying between 35% reduction and 26% increase.     

The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers

Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy metals in soil and groundwater. This study reports the fate of Zn and Cd in sandy aquifers under a variety of plausible in-situ redox conditions that were induced by introduction of carbon and various electron acceptors in column experiments. Up to 100% Zn and Cd removal (from the liquid phase) was observed in all the four columns, however the mechanisms were different. Metal removal in column K1 (containing sulphate), was attributed to biological sulphate reduction and subsequent metal precipitation (as sulphides). In the presence of both nitrate and sulphate (K2), the former dominated the process, precipitating the heavy metals as hydroxides and/or carbonates. In the presence of sulphate, nitrate and supplemental iron (Fe(OH)(3)) (K3), metal removal was also due to precipitation as hydroxides and/or carbonates. In abiotic column, K4, (with supplemental iron (Fe(OH)(3)), but no nitrate), cation exchange with soil led to metal removal. The results obtained were modeled using the reactive transport model PHREEQC-2 to elucidate governing processes and to evaluate scenarios of organic carbon, sulphate and nitrate inputs.     

Ecological assessment of natural resources in agroecosystems of Dutch Lowland Peat area

In ecological assessment many abiotic and biotic indicators, reflecting the many facets of ecosystems, are used. Reporting on the state of the environment requires that information on separate indicators be integrated into comprehensive yardsticks or indices. In this paper we describe a method for assessing the quality of natural resources in agroecosystems and present a case study on the Dutch Lowland Peat area. Using a coherent set of physical, chemical, and biotic indicators, we compare the present situation with the long-term policy objective of strategic policy plans. Results are depicted in a radial plot. The present ecological quality of the Lowland Peat area has been found to deviate strongly from that of the desired state.     

Impact of Perceived Importance of Ecosystem Services and Stated Financial Constraints on Willingness to Pay for Riparian Meadow Restoration in Flanders (Belgium)

The strategic importance of ecosystem service valuation as an operational basis for policy decisions on natural restoration has been increasingly recognized in order to align the provision of ecosystem services with the expectation of human society. The contingent valuation method (CVM) is widely used to quantify various ecosystem services. However, two areas of concern arise: (1) whether people value specific functional ecosystem services and overlook some intrinsic aspects of natural restoration, and (2) whether people understand the temporal dimension of ecosystem services and payment schedules given in the contingent scenarios. Using a peri-urban riparian meadow restoration project in Flanders, Belgium as a case, we explored the impacts of residents’ perceived importance of various ecosystem services and stated financial constraints on their willingness-to-pay for the proposed restoration project employing the CVM. The results indicated that people tended to value all the benefits of riparian ecosystem restoration concurrently, although they accorded different importances to each individual category of ecosystem services. A longer payment scheme can help the respondents to think more about the flow of ecosystem services into future generations. A weak temporal embedding effect can be detected, which might be attributed to respondents’ concern about current financial constraints, rather than financial bindings associated with their income and perceived future financial constraints. This demonstrates the multidimensionality of respondents’ financial concerns in CV. This study sheds light on refining future CV studies, especially with regard to public expectation of ecosystem services and the temporal dimension of ecosystem services and payment schedules.     

Biological denitrification in drinking water treatment using the seaweed Gracilaria verrucosa as carbon source and biofilm carrier.

Chemical and microbiological aspects were investigated with regard to biological denitrification of drinking water using the seaweed Gracilaria verrucosa as the carbon and energy substrate and as physical support for the microbial flora in semibatch, fixed-bed reactors. Complete removal of nitrate (100 mg/L) was readily achieved without accumulation of nitrite. Microbiological analysis indicated that the effluent of the reactor contained high numbers of bacteria (>10(6)/mL total count). Among the 44 bacterial strains isolated directly from the samples or isolated after enrichment at 37 degrees C, 25 different fatty acid profiles were found, indicating a complex microflora, including potential pathogens.