In situ lifetimes and kinetics of a reductive whey barrier and an oxidative ORC barrier in the subsurface

Permeable reactive barriers (PRB) are being used to engineer favorable field conditions for in-situ remediation efforts. Two redox adjustment barriers were installed to facilitate a 10-month research effort on the fate and transport of MTBE (methyl tert-butyl ether) at a site called the Michigan Integrated Remediation Technology Laboratory (MIRTL). Thirty kilograms of whey were injected as a slurry into an unconfined aquifer to establish an upgradient reductive zone to reduce O2 concentration in the vicinity of a contaminant injection source. To minimize the impact of contaminant release, 363 kg of oxygen release compound (ORC) were placed in the aquifer as a downgradient oxidative barrier. Dissolved oxygen and other chemical species were monitored in the field to evaluate the effectiveness of this technology. A transient one-dimensional advective-dispersive-reaction (ADR) model was proposed to simulate the dissolved oxygen transport. The equations were solved with commonly encountered PRB initial and constant/variable boundary conditions. No similar previous solution was found in the literature. The in-situ lifetimes, based on variable source loading, were estimated to be 1,661 and 514 days for the whey barrier and ORC barrier, respectively. Estimates based on either maximum O2 consumption/production or measured O2 curves were found to under- or overestimate the lifetime of the barriers. The pseudo-first-order rate constant of whey depletion was estimated to be 0.303/d with a dissolution rate of 0.04/d. The oxygen release rate constant in the ORC barrier was estimated to be 0.03/d. This paper provides a means to design and predict the performance of reactive redox barriers, especially when only limited field data are available.     

Experiences of Trauma and DNA Methylation Profiles among African American Mothers and Children

Potentially traumatic experiences have been associated with chronic diseases. Epigenetic mechanisms, including DNA methylation (DNAm), have been proposed as an explanation for this association. We examined the association of experiences of trauma with epigenome-wide DNAm among African American mothers (n = 236) and their children aged 3–5 years (n = 232; N = 500), using the Life Events Checklist-5 (LEC) and Traumatic Events Screening Inventory—Parent Report Revised (TESI-PRR). We identified no DNAm sites significantly associated with potentially traumatic experience scores in mothers. One CpG site on the ENOX1 gene was methylome-wide-significant in children (FDR-corrected q-value = 0.05) from the TESI-PRR. This protein-coding gene is associated with mental illness, including unipolar depression, bipolar, and schizophrenia. Future research should further examine the associations between childhood trauma, DNAm, and health outcomes among this understudied and high-risk group. Findings from such longitudinal research may inform clinical and translational approaches to prevent adverse health outcomes associated with epigenetic changes.     

Quantification and interpretation of total petroleum hydrocarbons in sediment samples by a GC/MS method and comparison with EPA 418.1 and a rapid field method.

Total petroleum hydrocarbons (TPH) as a lumped parameter can be easily and rapidly measured or monitored. Despite interpretational problems, it has become an accepted regulatory benchmark used widely to evaluate the extent of petroleum product contamination. Three currently used methods (GC/MS, conventional EPA 418.1, and a rapid field method PetroFLAG) were performed to quantify the TPH content in samples collected from a site contaminated by transformer oil. To standardize the method and improve the comparability of TPH data, crucial GC-based quantification issues were examined, e.g., quantification based on internal standards (ISTD) vs external standards (ESTD), single vs multiple ISTD, and various area integration approaches. The interpretation of hydrocarbon chromatographic results was examined in the context of field samples. The performance of the GC/MS method was compared with those of EPA 418.1 and PetroFLAG. As a result, it was observed that the ISTD quantification method was preferred to the ESTD method, multiple ISTD might be better than single ISTD, and three different area integration approaches did not have a significant effect on TPH results. Evaluation of the chromatograms between a reference sample and three unknown samples showed that the extent of contamination varied appreciably with sample depth. It was also found that there existed a good positive correlation between GC/MS and both EPA 418.1 and PetroFLAG, and that EPA 418.1 produced the higher overall estimate while GC/MS and PetroFLAG resulted in lower, more statistically comparable TPH values.     

Sequential chemical oxidation and aerobic biodegradation of equivalent carbon number-based hydrocarbon fractions in jet fuel

Remediation of petroleum mixtures is complicated by the differing environmental degradabilities of hundreds of individual hydrocarbons in the mixtures. By grouping the individual hydrocarbons into a few fractions based on equivalent carbon number (EC), the present study examined the chemical and biological degradation of the fractions. With or without prechemical oxidation (25 days) by three oxidants (KMnO4, H202, MgO2), sterile and live microcosms were constituted with aquifer samples for aerobic biodegradation (134 days) of JP-4 jet fuel. Eighty-seven hydrocarbons were recovered and grouped into nine EC fractions. The apparent removal and actual transformation rate constants were estimated for both chemical and biological degradations. The data show that prechemical oxidations facilitated removal of total petroleum hydrocarbons (TPH) (up to 80%) within shorter times (<50 days) than biological alone. KMnO4 and H202 were better oxidants in terms of mass reduction in shorter times yet to some extent inhibited the subsequent microbial activity. MgO2 was a moderate oxidant with less inhibition of microbial activity. Selective degradation of the EC fractions was observed for both chemical and biological processes. The biological processes were much less effective than the prechemical oxidations in transforming aromatic fractions, the more toxic fractions. The favorable substrates (i.e., aliphatic EC approximately 10) for microbial growth were also those most subject to chemical oxidation. The results suggest that for remediation of petroleum contaminants, sequential chemical and biological technologies may surpass biological alone and more moderate oxidants such as MgO2 may be better candidates. More work is needed on the optimal dose and residence time for applied oxidants and on the application to engineering design and formulation of cleanup standards.     

Incidence in diverse pig populations of an IGF2 mutation with potential influence on meat quality and quantity: An assay based on real time PCR (RT-PCR)

IGF2, insulin-like growth factor 2, is implicated in myogenesis and lean meat content. A mutation in a single base (A for G substitution) of the gene for IGF2 (position 3072 in intron 3) has been recently described as the cause of a major QTL effect on muscle growth in pigs [Van Laere, A. S, Nguyen, M., Braunschweig, M., Nezer, C., Collete, C., & Moreau, L. et al. (2003). Nature, 425, 832-836]. We describe here a rapid assay based on real time PCR (RT-PCR) to detect this mutation. We have evaluated the incidence of the mutation in commercial pig crosses, in three populations of purebred Iberian or Iberian×Duroc crosses, and in cured meat products and wild boars. The incidence of the mutation varies among these groups. Penetrance of the A mutation is about 80% in the commercial population. Purebred Iberian pigs were all homozygous G/G whereas crosses of Iberian pigs were heterozygous (90%) or homozygous A/A (10%). The implications of this gene for the selection of Iberian pigs are discussed.     

Practical experiences in the usage of MIDAS in the logistics domain

International Journal on Software Tools for Technology Transfer - In this paper, we present the experience in the usage of MIDAS, an integrated framework for Service Oriented Architecture (SOA)...     

Sediment oxygen demand fractionation, kinetics and reduced chemical substances

Observations of the kinetics and fractionation of sediment oxygen demand (SOD) are reported on six cores from two shallow, freshwater lakes. These measurements were made by batch respirometry on discrete sub-cores which were handled to minimize aerial oxidation. The kinetics of oxygen uptake were measured for periods ranging from 1 to 24 h. Four parallel sediment samples were processed to differentiate oxygen uptake arising from chemical, biological and sulfidic origins. The SOD values ranged from 0.05 to 5.24 mg g⁻¹ wet sediment and the major portion of the oxygen demand resulted from chemical reactions. Reduced soluble species in sediment pore waters were calculated to account for less than 10% of the total SOD. Approx. 28% of the SOD was due to the reaction of sulfide minerals. The remainder of the demand resulted from the oxidation of organic matter and reduced metallic minerals associated with surfaces. Bulk sediment parameters (% volatile solids, organic carbon and acid-soluble sulfide) showed significant correlations with corresponding SOD fractions. Total SOD rates were adequately described by an apparent first order rate equation. Rates were found to be significantly greater in the upper 20 cm of sediment than they were in deeper samples. The relationships between sediment composition, SOD magnitude and oxygen uptake rates provide valuable insights for engineering applications of the results to dredging operations.     

A real time PCR (RT-PCR) alternative assay to detect the T/C mutation in position 1843 of the ryanodine receptor gene

The discovery of the causal mutation of malignant hyperthermia in pigs, a T for C substitution in base 1843 of the ryanodine receptor gene, opened the door to selection procedures based on the analysis of ryanodine receptor genotype based on PCR amplification of the region containing base 1843, subsequent digestion with specific restriction enzymes of the amplified DNA fragment, and electrophoretic analysis of the resulting bands. In this paper, we describe an assay that allows analysis of the three possible genotypes of the ryanodine receptor gene using real time PCR to amplify and detect them in a single step. Results obtained with the RT-PCR assay described in this work match 100% with those obtained using traditional PCR methods. RT-PCR methods are cheaper and faster than traditional ones allowing one to genotype up to 384 samples in a single run.     

胡安·布斯盖兹的城市项目

加泰罗尼亚建筑师、城市规划师胡安·布斯盖兹在教学、城市理论方面有大量的出版著作和城市设计实践,特别是在欧洲。这些组成了他统一的批判性城市作品,并为他赢得了多种奖项,其中包括由于城市公共空间设计而于2011年获得荷兰伊拉斯谟奖,评委认为公共空间的设计是满足人民福祉的一项基本因素。布斯盖兹在巴塞罗那建筑学院讲授城市主义课程。他在1968年同曼努埃尔·德·索拉-莫拉莱斯及其他城市主义专题的讲师共同成立了巴塞罗那城市主