How robust are cross-country comparisons of PISA scores to the scaling model used?

The Programme for International Student Assessment (PISA) is an important international study of 15‐olds' knowledge and skills. New results are released every 3 years, and have a substantial impact upon education policy. Yet, despite its influence, the methodology underpinning PISA has received significant criticism. Much of this criticism has focused upon the psychometric scaling model used to create the proficiency scores. The aim of this article is to therefore investigate the robustness of cross‐country comparisons of PISA scores to subtle changes to the underlying scaling model used. This includes the specification of the item‐response model, whether the difficulty and discrimination of items are allowed to vary across countries (item‐by‐country interactions) and how test questions not reached by pupils are treated. Our key finding is that these technical choices make little substantive difference to the overall country‐level results

Rice-Infecting Pseudomonas Genomes Are Highly Accessorized and Harbor Multiple Putative Virulence Mechanisms to Cause Sheath Brown Rot

Sheath rot complex and seed discoloration in rice involve a number of pathogenic bacteria that cannot be associated with distinctive symptoms. These pathogens can easily travel on asymptomatic seeds and therefore represent a threat to rice cropping systems. Among the rice-infecting Pseudomonas, P. fuscovaginae has been associated with sheath brown rot disease in several rice growing areas around the world. The appearance of a similar Pseudomonas population, which here we named P. fuscovaginae-like, represents a perfect opportunity to understand common genomic features that can explain the infection mechanism in rice. We showed that the novel population is indeed closely related to P. fuscovaginae. A comparative genomics approach on eight rice-infecting Pseudomonas revealed heterogeneous genomes and a high number of strain-specific genes. The genomes of P. fuscovaginae-like harbor four secretion systems (Type I, II, III, and VI) and other important pathogenicity machinery that could probably facilitate rice colonization. We identified 123 core secreted proteins, most of which have strong signatures of positive selection suggesting functional adaptation. Transcript accumulation of putative pathogenicity-related genes during rice colonization revealed a concerted virulence mechanism. The study suggests that rice-infecting Pseudomonas causing sheath brown rot are intrinsically diverse and maintain a variable set of metabolic capabilities as a potential strategy to occupy a range of environments.Consortium for International Agricultural Research (CGIAR)Global Rice Science Partnership (GRiSP

Crop Ontology Governance and Stewardship Framework

A governance & stewardship framework for the Crop Ontology Project is required as this is a collaborative tool developed by a Community of Practice. Over the last 12 years of its existence, it has increased significantly in scope and use. Collecting and storing plant trait data and annotating the data with ontology terms is widely accepted by the crop science community to be critical to enable data interoperability and interexchange through tools such as the Breeding API (BrAPI). The Crop Ontology Community of Practice is organised around roles, curation principles and validation processes that require a formal description. A governance framework is defined by the various actors involved in the asset’s design, development and maintenance. It is complemented by a quality assurance process to ensure that trust levels, value creation, and sustainability objectives meet appropriate quality levels. The general principles underlying data governance are integrity, transparency, accountability and ownership, stewardship, standardization, change management and a robust data audit

How robust are cross-country comparisons of PISA scores to the scaling model used?

The Programme for International Student Assessment (PISA) is an important international study of 15‐olds' knowledge and skills. New results are released every 3 years, and have a substantial impact upon education policy. Yet, despite its influence, the methodology underpinning PISA has received significant criticism. Much of this criticism has focused upon the psychometric scaling model used to create the proficiency scores. The aim of this article is to therefore investigate the robustness of cross‐country comparisons of PISA scores to subtle changes to the underlying scaling model used. This includes the specification of the item‐response model, whether the difficulty and discrimination of items are allowed to vary across countries (item‐by‐country interactions) and how test questions not reached by pupils are treated. Our key finding is that these technical choices make little substantive difference to the overall country‐level results

The genome of rice-infecting <i>Pseudomonas</i> harbor high level of structural polymorphism.

<p>Global comparison of eight rice-infecting <i>Pseudomonas</i> draft genomes using BLASTn. The inner most ring corresponds to the genomic position at IRRI 6609. The second and third rings indicate G+C content and G+C skew, respectively. The rest of the rings indicate presence and absence portions of the eight rice-infecting <i>Pseudomonas</i> draft genomes against IRRI 6609. Solid colors represent genomic regions with hits while white spaced represent gaps. <i>P</i>. <i>fuscovaginae</i> (<i>Pfv</i>) and <i>P</i>. <i>fuscovaginae</i>-like (<i>Pfv</i>-like) strains are depicted. Sequence identity is related to color intensity. Also included are locations of four intact prophage insertions found in <i>Pfv</i>-like IRRI 6609 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139256#pone.0139256.s004" target="_blank">S4 Fig</a>). The global alignment was visualized using BRIG [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139256#pone.0139256.ref043" target="_blank">43</a>].</p

Nucleotide identity and percentage of orthologous genes obtained in rice-infecting <i>Pseudomonas</i> draft genomes compared to IRRI 6609

<p>^a Identity based on BLASTn results</p><p>Nucleotide identity and percentage of orthologous genes obtained in rice-infecting <i>Pseudomonas</i> draft genomes compared to IRRI 6609</p

Infection caused by <i>P</i>. <i>fuscovaginae</i>-like strain IRRI 7007 in <i>O</i>. <i>sativa</i> cv. Azucena.

<p><b>A)</b> Plants were inoculated at 45 days after transplanting using toothpick method. <b>B)</b> Symptom development along the sheath showing brown necrotic lesions. <b>C)</b> Discolored inner sheath. <b>D)</b> Poorly emerged panicles with brown to dark brown grains. <b>E)</b> Emerged panicles with discolored grains and progressive necrotic stripes at maturity stage.</p