Structural-profiling of low molecular weight RNAs by nanopore trapping/translocation using Mycobacterium smegmatis porin A

Folding of RNA can produce elaborate tertiary structures, corresponding to their diverse roles in the regulation of biological activities. Direct observation of RNA structures at high resolution in their native form however remains a challenge. The large vestibule and the narrow constriction of a Mycobacterium smegmatis porin A (MspA) suggests a sensing mode called nanopore trapping/translocation, which clearly distinguishes between microRNA, small interfering RNA (siRNA), transfer RNA (tRNA) and 5 S ribosomal RNA (rRNA). To further profit from the acquired event characteristics, a custom machine learning algorithm is developed. Events from measurements with a mixture of RNA analytes can be automatically classified, reporting a general accuracy of ~93.4%. tRNAs, which possess a unique tertiary structure, report a highly distinguishable sensing feature, different from all other RNA types tested in this study. With this strategy, tRNAs from different sources are measured and a high structural conservation across different species is observed in single molecule.

Redetermination of the crystal structure of tetralithium octafluoridozirconate(IV), Li4ZrF8, from single-crystal X-ray data

Presented herein is the crystal-structure redetermination of Li4ZrF8 from single-crystal X-ray data. Alkali zirconium fluorides are important in nuclear-relevant technologies, and zirconium is commonly employed as an analogue for tetravalent f-block elements. The previous structure report of this species is based on powder X-ray data [Dugat et al. (1995). J. Solid State Chem. 120, 187–196] but there has never been a refined structure model from single-crystal data. The octafluoridozirconate moieties are held together by electrostatic attraction to lithium ions without sharing of fluoride sites between zirconium(IV) ions.

A CASE STUDY IN DOCUMENTATION PRODUCTION AS LEARNING TOOLS BENEFITTING MULTIPLE STAKEHOLDERS

The Fondation Strutt Foundation has taken on the conservation planning of the Strutt House as part of a P3 collaborative effort with the National Capital Commission (NCC). This paper will address three of the primary documents/data sets (documentary methodologies) being used on/for the Strutt House project. The Strutt House is a Recognized Federal Heritage Building and a significant example of Canadian modernist architecture. Stakeholder is a term often used in Architectural Projects reflecting an economic interest in success of the project. In conservation projects the stakeholder generally reflects social, cultural and/or economic interests in a given project. The Strutt House project has benefitted from stakeholders that have all been interested in the above, as well as the education of our future conservationists. The Strutt house was purchased from the architect’s daughter in 2010, and as part of the acquisition, a <i>Heritage Structure Report</i> was commissioned and produced by PTAH Consultants Inc., Architects. The report forms the first of the primary referenced documents of this paper, including: a comprehensive photographic record of existing conditions; and, a <i>building simulation model</i> of the house ‘as designed/built’. This HSR and the accompanying data/documents have been adopted as the basis of an evolving document in the development of the <i>Conservation Plan</i> including: additional heritage surveys and technologies; traditional drawings, photographic and video records; and, a series of workshops on the structural stabilization efforts, thermography scans, and smoke/blow-door (air pressure) testing. In 2016, Pierre Jouan, a Master’s thesis student from KU Leuvan, working with the Carleton University CIMS lab under the direction of Professor Mario Santana, and the FSF completed a <i>3-D scanning and photogrammetry</i> workshop on the Strutt House and created a building information model (BIM model) from the collected data. The three primary documentation processes being addressed in this paper are really a series of directed research or focussed investigations resulting in a collection of data sets resolved -or combined- into a document. They will assist in the development of the long-term Programming and Conservation Management Plan of the Strutt House.

An Expert System for Local Flood Response Coordination and Training

Flood response is an essential component of flood management to rescue people, reduce property loss, and limit the impact to the environment. Effective flood response depends on a sound coordination structure with unified responsibilities, smooth communications, and scalable response plans. An efficient coordination system, including command and management structures, is built on a thorough understanding of the responsibilities and actions of each role for delivering the response core capabilities. Collecting, sharing, using, and handling the knowledge require great efforts in knowledge management. To further enhance such efforts, an expert system for local flood response coordination and training (LFRS) was developed and introduced in this paper. LFRS can help emergency managers construct scalable, flexible, and adaptable coordination structures and support educating flood response entities, such as individuals, communities, nongovernmental organizations, private sector entities, and local governments. The output of the prototype expert system contains two CSV formatted reports as well as prompt screens. The operational structure report hierarchically depicts the crisscross linkages among all responders, their primary functions, and contact information. Another report summarizes the responsibilities and actions of a certain role of flood responders from commanders to individuals.

A DREAM DEFERRED?

The goal of this paper is to determine whether a privileged class position operates similarly in shaping Blacks’ and Whites’ beliefs about the causes of racial inequality. Existing studies have established that socioeconomic variation drives intraracial differences in commitments to individualistic and structural attributions. However, scholars have yet to determine whether Blacks and Whites positioned at some of the highest levels of the American class structure report corresponding beliefs about the roots of racial disparities. Pooled data from the 1985–2012 General Social Surveys indicate that class-based attitudinal differences are more prevalent and pronounced among Whites rather than Blacks. However, a privileged class position often operates similarly in shaping commitments to select structural attributions. The implications of the findings are discussed, and suggestions for future research are offered.

Crystal structure of [(1,2,3,4,11,12-η)-anthracene]tris(trimethylstannyl)cobalt(III)

The asymmetric unit of the title structure, [Co(η6-C14H10){Sn(CH3)3}3], contains two independent molecules. Each anthracene ligand is η6-coordinating to a CoIIIcation and is nearly planar [fold angles of 5.4 (3) and 9.7 (3)°], as would be expected for its behaving almost entirely as a donor to a high-oxidation-state metal center. The slight fold in each anthracene ligand gives rise to slightly longer Co—C bond lengths to the ring junction carbon atoms than to the other four. Each CoIIIcation is further coordinated by three Sn(CH3)3ligands, giving each molecule a three-legged piano-stool geometry. In each of the two independent molecules, the trio of SnMe3ligands are modeled as disordered over two positions, rotated by approximately 30%, such that the C atoms nearly overlap. In one molecule, the disorder ratio refined to 0.9365 (8):0.0635 (8), while that for the other refined to 0.9686 (8):0.0314 (8). The molecules are well separated, and thus no significant intermolecular interactions are observed. The compound is of interest as the first structure report of an η6-anthracene cobalt(III) complex.

Structural aspects of [NiFe]-hydrogenases

Enzymes that naturally contain an organometallic complex are highly rare. Hydrogenases commonly include iron carbonyl(s) at the active site and play central roles in the hydrogen metabolism of microorganisms. [NiFe]-hydrogenases that harbor an Ni-Fe(CN)2CO complex at the active site most widely exist among organisms, compared with the other two types, [FeFe]- and [Fe]-hydrogenases. Since the first crystal structure report in 1995, structural information of the Ni-Fe cluster with various redox/substrate-bound states has been obtained, although details of the reaction mechanisms are poorly understood. While the subunit composition, physiological function, and spectroscopic/biochemical properties of [NiFe]-hydrogenases are diverse, structural information of only a limited group of the enzymes is available so far. In this paper, structural aspects of [NiFe]-hydrogenases are reviewed and recent progresses in understanding the mechanism of an O2-tolerant property of limited members and active site assembling of [NiFe]-hydrogenases are described.