ps2, the gene responsible for functional sterility in tomato, due to non-dehiscent anthers, is the result of a mutation in a novel polygalacturonase gene

The recessive mutation ps-2, which appeared spontaneously in tomato, confers functional male sterility due to non-dehiscent anthers. In this study, we isolated and characterized the PS-2 gene. A single nucleotide mutation in a novel tomato polygalacturonase gene is responsible for the ps-2 phenotype. The mutation in ps-2 is responsible for an alternative splicing during maturation of the pre-mRNA, which leads to an aberrant mRNA. Differentiation between ps-2 and wild type (PS-2) anthers only appears in the final developmental stage in which the stomium remains closed in the mutant. To our knowledge, this is the first functional sterility gene isolated in the Solanaceae family. The specific expression of the Arabidopsis homolog of PS-2 in the anther dehiscence zone suggests a conserved mode of action over the plant kingdom, which means that the repression of PS-2 homologs may be a potential way to introduce functional sterility in other specie

Thermal Density Functional Theory in Context

This chapter introduces thermal density functional theory, starting from the ground-state theory and assuming a background in quantum mechanics and statistical mechanics. We review the foundations of density functional theory (DFT) by illustrating some of its key reformulations. The basics of DFT for thermal ensembles are explained in this context, as are tools useful for analysis and development of approximations. We close by discussing some key ideas relating thermal DFT and the ground state. This review emphasizes thermal DFT's strengths as a consistent and general framework.Comment: Submitted to Spring Verlag as chapter in "Computational Challenges in Warm Dense Matter", F. Graziani et al. ed

Clockwise Torque of Sliding Hip Screws: Is There a Right Side?

OBJECTIVES: This study evaluated whether patients with a left-sided femoral neck fracture (FNF) treated with a sliding hip screw (SHS) had a higher implant failure rate than patients treated for a right-sided FNF. This was performed to determine the clinical relevance of the clockwise rotational torque of the femoral neck lag screw in a SHS, in relation to the rotational stability of left and right-sided FNFs after fixation. METHODS: Data were derived from the FAITH trial and Dutch Hip Fracture Audit (DHFA). Patients with a FNF, aged ≥50, treated with a SHS, with at least 3-month follow-up data available, were included. Implant failure was analyzed in a multivariable logistic regression model adjusted for age, sex, fracture displacement, prefracture living setting and functional mobility, and American Society for Anesthesiologists Class. RESULTS: One thousand seven hundred fifty patients were included, of which 944 (53.9%) had a left-sided and 806 (46.1%) a right-sided FNF. Implant failure occurred in 60 cases (3.4%), of which 31 were left-sided and 29 right-sided. No association between fracture side and implant failure was found [odds ratio (OR) for left vs. right 0.89, 95% confidence interval (CI) 0.52-1.52]. Female sex (OR 3.02, CI: 1.62-6.10), using a mobility aid (OR 2.02, CI 1.01-3.96) and a displaced fracture (OR 2.51, CI: 1.44-4.42), were associated with implant failure. CONCLUSIONS: This study could not substantiate the hypothesis that the biomechanics of the clockwise screw rotation of the SHS contributes to an increased risk of implant failure in left-sided FNFs compared with right-sided fractures. LEVEL OF EVIDENCE: Therapeutic Level II.See Instructions for Authors for a complete description of levels of evidence

Servicekosten bij winkelcentra in Nederland

In dit onderzoek zijn de servicekosten bij planmatig ontwikkelde winkelcentra onderzocht. Hierbij zijn de problemen die optreden in de markt geanalyseerd en zijn voor deze problemen door middel van literatuur- en empirisch onderzoek oplossingen en aanbevelingen gedefinieerd. Deze kunnen worden gebruikt bij het maken van (nieuwe) duidelijke afspraken tussen de verschillende stakeholders die met dit proces te maken krijgen danwel voor het opstellen van een verbeterde Leidraad voor Servicekosten bij winkelcentra.Real Estate ManagementReal Estate & HousingArchitecture and The Built Environmen

High-resolution fine mapping of ps-2, a mutated gene conferring functional male sterility in tomato due to non-dehiscent anthers

Functional male sterility is an important trait for the production of hybrid seeds. Among the genes coding for functional male sterility in tomato is the positional sterility gene ps-2. ps-2 is monogenic recessive, confers non-dehiscent anthers and is the most suitable for practical uses. In order to have tools for molecular-assisted selection (MAS) we fine mapped the ps-2 locus. This was done in an F2 segregating population derived from the interspecific cross between a functionally male sterile line (ps-2/ps-2; Solanum lycopersicum) and a functionally male fertile line (S. pimpinellifolium). Here we report the procedure that has led to the high-resolution fine mapping of the ps-2 locus in a 1.65 cM interval delimited by markers T0958 and T0635 on the short arm of Chromosome 4. The presence of many COS markers in the local high-resolution map allowed us to study the synteny between tomato and Arabidopsis at the ps-2 locus region. No obvious candidate gene for ps-2 was identified among the known functional male sterility genes in Arabidopsi

Assessing speaking in English: grading as an expression of teachers' subjectivity

Tendo em vista a expressiva literatura em Avaliação da Aprendizagem de Línguas, este artigo tem por objetivo compreender e discutir, a partir de estudos que tratam da confiabilidade (BROWN & BAILEY, 1984; BROWN, 2004; SCHOFFEN, 2009) e da avaliação da oralidade (BACHMAN, 1990; BORGES-ALMEIDA, 2009; QUEVEDO-CAMARGO, 2014; SCARAMUCCI, 2000), de que maneira os professores de inglês de um instituto de idiomas atribuem notas para mensurar o desempenho oral de seus alunos, considerando a adoção (ou não) de critérios previamente estabelecidos. Realizamos uma pesquisa qualitativa interpretativista, cujos dados foram coletados por meio de entrevistas semiestruturadas com cinco professores. Diante das discrepâncias entre as notas obtidas pelos alunos na avaliação da expressão oral, quais são os fatores que influenciam e reforçam essa constatação? Até que ponto a atribuição de notas na avaliação oral reflete o real desempenho do aluno? Em situações de turmas diferentes e professores distintos, como assegurar a confiabilidade da avaliação da produção oral de alunos de um mesmo nível de referência? Os resultados da investigação indicam a necessidade de adotar critérios previamente estabelecidos, uma vez que, por conta da excessiva subjetividade, os testes orais parecem não aferir o nível esperado de produção oral dos aprendizes e tampouco refletem a realidade de uso da língua.Taking into account the significant literature in Language Teaching Assessment, this article aims at understanding and discussing, based on studies about reliability (BROWN & BAILEY, 1984; BROWN, 2004; SCHOFFEN, 2009) and speaking assessment (BACHMAN, 1990; BORGES-ALMEIDA, 2009; QUEVEDO-CAMARGO, 2014; SCARAMUCCI, 2000), how English language teachers working in a language institute grade their students' oral performance, considering the adoption (or not) of previously established criteria. A qualitative-established criteria as, due to excessive subjectivity, oral tests do not seem to measure the students' expected level of oral performance, nor mirror language use reality