Equilibration and thermal reversibility in mixtures of model OPV small-molecules and polymers

The thermal behaviour of small-molecule/polymer mixtures is of crucial significance in relation tothe operational stability of organic photovoltaics, and the equilibration (or otherwise) of domaincompositions and interfaces is of key importance for guiding design. Here, model phase-separatedmixtures of fullerene and polystyrene are studied in detail in a thin-film bilayer, to robustly examinewhether such systems satisfy two key requirements of thermodynamic equilibrium; (i) the attainment ofa state (at a given temperature) that minimises the free energy, independent of the starting state of thesystem, and (ii) the reversibility of transitions between such equilibrium states. In an extensive studyusing polystyrene molecular weights of 1.86, 4.73, and 278.2 kg mol1, depth profiles are measured as afunction of temperature using in situ neutron reflectivity, with initial sample composition profilescontaining layers that are either pure components or blends. Following thermal annealing at sufficientlyhigh temperatures we reproducibly observe changes in layer compositions, layer thicknesses andinterfacial roughnesses during temperature cycling that are reversible, irrespective of the startingcomposition profiles of the samples. This robust demonstration of equilibrium behaviour provides abenchmark for the understanding of mixing in small-molecule/polymer thin-films, with particularrelevance to the operation of organic photovoltaic device

Updating the Competency Profile and Examination Blueprint for Entry-Level Optometry in Canada

The Optometry Examining Board of Canada (formerly Canadian Examiners in Optometry) is a not-for-profit corporation that administers the entry-to-practice examination for optometrists in Canada in service to its members, the 10 provincial optometry regulators.   The described work resulted in an updated entry-level competency profile for optometry, together with an examination blueprint based upon indicators derived from the competencies. The project took place over the period May 2014 – September 2015 and involved the following steps:   Establishment of project teams Clarification of conceptual framework Development of proposed competencies Validation of competencies Development of indicators for each competency, consistent with the assessment methodologies used in the entry-to-practice examination Construction of an updated examination blueprin

A core outcomes set for clinical trials of interventions for young adults with type 1 diabetes: an international, multi-perspective Delphi consensus study

BACKGROUND: Achieving consensus from a range of relevant stakeholders about an agreed set of core outcomes to be measured and reported as a minimum in clinical trials has the potential to enhance evidence synthesis and make findings more relevant and applicable. Intervention research to improve outcomes for young adults with type 1 diabetes (T1DM) is hampered by inconsistent use of outcome measures. This population frequently struggles to manage their condition and reports suboptimal clinical outcomes. Our aim was to conduct an international, e-Delphi consensus study to identify a core outcome set (COS) that key stakeholders (young adults with T1DM, diabetes health professionals, diabetes researchers and diabetes policy makers) consider as essential outcomes for future intervention research. METHODS: Using a list of 87 outcomes generated from a published systematic review, we administered two online surveys to a sample of international key stakeholders. Participants in the first survey (survey 1; n = 132) and the second survey (survey 2; n = 81) rated the importance of the outcomes. Survey 2 participants received information on total mean rating for each outcome and a reminder of their personal outcome ratings from Survey 1. Survey 2 results were discussed at a consensus meeting and participants (n = 12: three young adults with T1DM, four diabetes health professionals, four diabetes researchers and one diabetes policy maker) voted on outcomes. Final core outcomes were included provided that 70% of consensus group participants voted for their inclusion. RESULTS: Eight core outcomes were agreed for inclusion in the final COS: measures of diabetes-related stress; diabetes-related quality of life; number of severe hypoglycaemic events; self-management behaviour; number of instances of diabetic ketoacidosis (DKA); objectively measured glycated haemoglobin (HbA1C); level of clinic engagement; and perceived level of control over diabetes. CONCLUSIONS: This study is the first to identify a COS for inclusion in future intervention trials to improve outcomes for young adults with T1DM. Use of this COS will improve the quality of future research and increase opportunities for evidence synthesis. Future research is necessary to identify the most robust outcome measure instruments

Habitat Associations of Fish Species of Greatest Conservation Need at Multiple Spatial Scales in Wadeable Iowa Streams

Fish and habitat data were collected from 84 wadeable stream reaches in the Mississippi River drainage of Iowa to predict the occurrences of seven fish species of greatest conservation need and to identify the relative importance of habitat variables measured at small (e.g., depth, velocity, and substrate) and large (e.g., stream order, elevation, and gradient) scales in terms of their influence on species occurrences. Multiple logistic regression analysis was used to predict fish species occurrences, starting with all possible combinations of variables (5 large-scale variables, 13 small-scale variables, and all 18 variables) but limiting the final models to a maximum of five variables. Akaike’s information criterion was used to rank candidate models, weight model parameters, and calculate model-averaged predictions. On average, the correct classification rate (CCR = 80%) and Cohen’s kappa (κ = 0.59) were greatest for multiple-scale models (i.e., those including both large-scale and small-scale variables), intermediate for small-scale models (CCR = 75%; κ = 0.49), and lowest for large-scale models (CCR = 73%; κ = 0.44). The occurrence of each species was associated with a unique combination of large-scale and small-scale variables. Our results support the necessity of understanding factors that constrain the distribution of fishes across spatial scales to ensure that management decisions and actions occur at the appropriate scale

Thiourea isosteres as anion receptors and transmembrane transporters

Compounds containing cyanoguanidine and 3-amino-1,2,4-benzothiadiazine-1,1-dioxide have been studied as anion receptors and transporters. Significant affinity for oxo-anions was observed in organic solution and the receptors were found to function as transmembrane chloride/nitrate antiporters with transport rates enhanced in the presence of valinomycin–K+ complex.<br/

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists