Carbon Dioxide Reforming with Natural Gas and Coal using Chemical Looping

Researchers are developing chemical looping technologies to convert of carbonaceous fuels to high value chemicals and/or electricity with minimal CO2 emission. These processes use a metal oxide or metal sulphate to partially or to fully oxidize the fuel source to the desired product while being regenerated with air and/or steam in a separate reactor. The chemical looping redox reaction pathway is capable of high product yield without the need for molecular oxygen and with minimal product separation costs. The Ohio State University is developing an advanced CO2 reforming using the chemical looping technique to produce syngas with carbonaceous fuels such as coal/biomass and natural gas. The OSU chemical looping reforming process uses an iron-based oxygen carrier (OC) in a co-current moving bed reactor for syngas generation. The OC circulates between two reactors, a reducer and oxidizer, allowing for the continuous production of syngas and regeneration of the OC, respectively. The present paper discusses the reaction mechanism for CO2 reforming with the OC and reducing fuel, process simulation studies for the integration of chemical looping reforming process with gas-to-liquid plant, and experimental studies conducted at the bench and 15 kWth sub-pilot scale. This presentation will focus on the theoretical thermodynamic rationale and validating experimental results for using a co-current moving bed reducer and an optimized iron-based OC particle

Two integrated and highly predictive functional analysis-based procedures for the classification of MSH6 variants in Lynch syndrome

Purpose: Variants in the DNA mismatch repair (MMR) gene MSH6, identified in individuals suspected of Lynch syndrome, are difficult to classify owing to the low cancer penetrance of defects in that gene. This not only obfuscates personalized health care but also the development of a rapid and reliable classification procedure that does not require clinical data. Methods: The complete in vitro MMR activity (CIMRA) assay was calibrated against clinically classified MSH6 variants and, employing Bayes’ rule, integrated with computational predictions of pathogenicity. To enable the validation of this two-component classification procedure we have employed a genetic screen to generate a large set of inactivating Msh6 variants, as proxies for pathogenic variants. Results: The genetic screen-derived variants established that the two-component classification procedure displays high sensitivities and specificities. Moreover, these inactivating variants enabled the direct reclassification of human variants of uncertain significance (VUS) as (likely) pathogenic. Conclusion: The two-component classification procedure and the genetic screens provide complementary approaches to rapidly and cost-effectively classify the large majority of human MSH6 variants. The approach followed here provides a template for the classification of variants in other disease-predisposing genes, facilitating the translation of personalized genomics into personalized health care

The Impact of Advocacy Organizations on Low-Income Housing Policy in U.S. Cities

Financial support for affordable housing competes with many other municipal priorities. This work seeks to explain the variation in support for affordable housing among U.S. cities with populations of 100,000 or more. Using multivariate statistical analysis, this research investigates political explanations for the level of city expenditures on housing and community with a particular interest in the influence of housing advocacy organizations (AOs). Data for the model were gathered from secondary sources, including the U.S. Census and the National Center for Charitable Statistics. Among other results, the analysis indicates that, on average, the political maturity of AOs has a statistically significant, positive effect on local housing and community development expenditures

Comparative 3D analyses and palaeoecology of giant early amphibians (Temnospondyli: Stereospondyli)

Macroevolutionary, palaeoecological and biomechanical analyses in deep time offer the possibility to decipher the structural constraints, ecomorphological patterns and evolutionary history of extinct groups. Here, 3D comparative biomechanical analyses of the extinct giant early amphibian group of stereospondyls together with living lissamphibians and crocodiles, shows that: i) stereospondyls had peculiar palaeoecological niches with proper bites and stress patterns very different than those of giant salamanders and crocodiles; ii) their extinction may be correlated with the appearance of neosuchians, which display morphofunctional innovations. Stereospondyls weathered the end-Permian mass extinction, re-radiated, acquired gigantic sizes and dominated (semi) aquatic ecosystems during the Triassic. Because these ecosystems are today occupied by crocodilians, and stereospondyls are extinct amphibians, their palaeobiology is a matter of an intensive debate: stereospondyls were a priori compared with putative living analogous such as giant salamanders and/or crocodilians and our new results try to close this debate.Peer ReviewedPostprint (published version

Using Shifts in Amino Acid Frequency and Substitution Rate to Identify Latent Structural Characters in Base-Excision Repair Enzymes

Protein evolution includes the birth and death of structural motifs. For example, a zinc finger or a salt bridge may be present in some, but not all, members of a protein family. We propose that such transitions are manifest in sequence phylogenies as concerted shifts in substitution rates of amino acids that are neighbors in a representative structure. First, we identified rate shifts in a quartet from the Fpg/Nei family of base excision repair enzymes using a method developed by Xun Gu and coworkers. We found the shifts to be spatially correlated, more precisely, associated with a flexible loop involved in bacterial Fpg substrate specificity. Consistent with our result, sequences and structures provide convincing evidence that this loop plays a very different role in other family members. Second, then, we developed a method for identifying latent protein structural characters (LSC) given a set of homologous sequences based on Gu's method and proximity in a high-resolution structure. Third, we identified LSC and assigned states of LSC to clades within the Fpg/Nei family of base excision repair enzymes. We describe seven LSC; an accompanying Proteopedia page (http://proteopedia.org/wiki/index.php/Fpg_Nei_Protein_Family) describes these in greater detail and facilitates 3D viewing. The LSC we found provided a surprisingly complete picture of the interaction of the protein with the DNA capturing familiar examples, such as a Zn finger, as well as more subtle interactions. Their preponderance is consistent with an important role as phylogenetic characters. Phylogenetic inference based on LSC provided convincing evidence of independent losses of Zn fingers. Structural motifs may serve as important phylogenetic characters and modeling transitions involving structural motifs may provide a much deeper understanding of protein evolution

Transcriptional Mutagenesis Induced by 8-Oxoguanine in Mammalian Cells

Most of the somatic cells of adult metazoans, including mammals, do not undergo continuous cycles of replication. Instead, they are quiescent and devote most of their metabolic activity to gene expression. The mutagenic consequences of exposure to DNA–damaging agents are well documented, but less is known about the impact of DNA lesions on transcription. To investigate this impact, we developed a luciferase-based expression system. This system consists of two types of construct composed of a DNA template containing an 8-oxoguanine, paired either with a thymine or a cytosine, placed at defined positions along the transcribed strand of the reporter gene. Analyses of luciferase gene expression from the two types of construct showed that efficient but error-prone transcriptional bypass of 8-oxoguanine occurred in vivo, and that this lesion was not repaired by the transcription-coupled repair machinery in mammalian cells. The analysis of luciferase activity expressed from 8OG:T-containing constructs indicated that the magnitude of erroneous transcription events involving 8-oxoguanine depended on the sequence contexts surrounding the lesion. Additionally, sequencing of the transcript population expressed from these constructs showed that RNA polymerase II mostly inserted an adenine opposite to 8-oxoguanine. Analysis of luciferase expression from 8OG:C-containing constructs showed that the generated aberrant mRNAs led to the production of mutant proteins with the potential to induce a long-term phenotypical change. These findings reveal that erroneous transcription over DNA lesions may induce phenotypical changes with the potential to alter the fate of non-replicating cells

3D bite modeling and feeding mechanics of the largest living amphibian, the Chinese Giant Salamander Andrias davidianus (Amphibia:Urodela)

Biting is an integral feature of the feeding mechanism for aquatic and terrestrial salamanders to capture, fix or immobilize elusive or struggling prey. However, little information is available on how it works and the functional implications of this biting system in amphibians although such approaches might be essential to understand feeding systems performed by early tetrapods. Herein, the skull biomechanics of the Chinese giant salamander, Andrias davidianus is investigated using 3D finite element analysis. The results reveal that the prey contact position is crucial for the structural performance of the skull, which is probably related to the lack of a bony bridge between the posterior end of the maxilla and the anterior quadrato-squamosal region. Giant salamanders perform asymmetrical strikes. These strikes are unusual and specialized behavior but might indeed be beneficial in such sit-and-wait or ambush-predators to capture laterally approaching prey. However, once captured by an asymmetrical strike, large, elusive and struggling prey have to be brought to the anterior jaw region to be subdued by a strong bite. Given their basal position within extant salamanders and theirPeer ReviewedPostprint (published version

Recognizing Jewish Children\u27s Literature For Forty Years: The Sydney Taylor Book Award

The Association of Jewish Libraries has been presenting a children\u27s book award for forty years. The author describes some of the history and background of the Sydney Taylor Book Award, as well as its mission of encouraging the publication of outstanding books of Jewish content for children and teens. A description of the award\u27s namesake and her importance to Jewish children\u27s literature is followed by a review of some of the books and authors that have been honored. These demonstrate the high standards of the Sydney Taylor Book Award Committee, as well as the quality of Jewish children\u27s literature. Prevalent themes and trends reflect the ever changing dynamic of contemporary Jewry

Changes in disability, self-rated health, comorbidities and psychological wellbeing in community-dwelling 75-95-year-old cohorts over two decades in Helsinki

Objective: To explore changes in self-reported disabilities, health, comorbidities and psychological wellbeing (PWB) in aged cohorts over two decades. Design, setting and subjects: Cross-sectional cohort studies with postal surveys were conducted among community-dwelling people aged 75, 80, 85, 90 and 95 years in 1989 (n = 660), 1999 (n = 2598) and 2009 (n = 1637) in Helsinki, Finland. Main outcome measures: Self-reported items on disability, self-rated health (SRH), diagnoses and PWB were compared between cohorts of the same age. Standardized mortality ratios (SMRs) were calculated for each study year to explore the representativeness of the samples compared to general population of same age. Results: A significantly lower proportion of the 75-85-year-olds of the later study years reported going outdoors daily, although this group had improvements in both SRH and PWB scores. The number of comorbidities increased over time among 75-85-year-olds. The only significant change that could be verified among 90- and 95-year-olds between 1999 and 2009, was the lower proportion of participants going outdoors daily. The trend of leveling-off in disabilities was not explained by the SMRs (0.90, 0.71 and 0.60 for 1989, 1999 and 2009). Conclusions: The latest older people's cohorts showed an end to previously reported improvements in disabilities, despite having favorable trends in SRH and PWB. Primary care may be faced with increasing need of appropriate services for their senior members.Peer reviewe