Turbulent mixing at a stable density interface : the variation of the buoyancy flux–gradient relation

Experiments conducted on mixing across a stable density interface in a turbulent Taylor–Couette flow show, for the first time, experimental evidence of an increase in mixing efficiency at large Richardson numbers. With increasing buoyancy gradient the buoyancy flux first passes a maximum, then decreases and at large values of the buoyancy gradient the flux increases again. Thus, the curve of buoyancy flux versus buoyancy gradient tends to be N-shaped (rather than simply bell shaped), a behaviour suggested by the model of Balmforth et al. (J. Fluid Mech. vol. 428, 1998, p. 349). The increase in mixing efficiency at large Richardson numbers is attributed to a scale separation of the eddies active in mixing at the interface; when the buoyancy gradient is large mean kinetic energy is injected at scales much smaller than the eddy size fixed by the gap width, thus decreasing the eddy turnover time. Observations show that there is no noticeable change in interface thickness when the mixing efficiency increases; it is the mixing mechanism that changes. The curves of buoyancy flux versus buoyancy gradient also show a large variability for identical experimental conditions. These variations occur at time scales one to two orders of magnitude larger than the eddy turnover time scale

Letters between Estelle Jensen and W. J. Kerr.

Letters concerning a position in the music department at the Agricultural College

Cytokinin and auxin intersection in root meristems

Cytokinin promotes cell differentiation in plant roots by repressing auxin transport and responses at the meristem boundary

MAGICC:A Project of the EU Lifelong Learning programme: Modularising Multilingual and Multicultural Academic Communication Competence

This report introduces the ERASMUS project of the EU Lifelong Learning programme MAGICC: Modularising Multilingual and Multicultural Academic Competences (2011-2014). Conceived as a complement to the CEFR, the project's main objective was to develop a framework and instruments that can be used to conceptualize and evaluate multilingual and multicultural academic communication competences. Through the Bologna Process, these competences have been becoming increasingly important to students in higher education and therefore need to be integrated as graduate learning outcomes at BA and MA level. To that end, MAGICC provides a conceptual framework, pedagogical scenarios, transparency tools, an academic e-portfolio and an executive summary for future employers.In the final assessment, the project received 9/10 from the Education, Audiovisual and Culture Executive Agency (EACEA) and was evaluated as an excellent project. Furthermore, experts from the Directorate-General for Education and Culture of the European Commission call it a success story.</p

Variance Calculations and the Bessel Kernel

In the Laguerre ensemble of N x N (positive) hermitian matrices, it is of interest both theoretically and for applications to quantum transport problems to compute the variance of a linear statistic, denoted var_N f, as N->infinity. Furthermore, this statistic often contains an additional parameter alpha for which the limit alpha->infinity is most interesting and most difficult to compute numerically. We derive exact expressions for both lim_{N->infinity} var_N f and lim_{alpha->infinity}lim_{N->infinity} var_N f.Comment: 7 pages; resubmitted to make postscript compatibl

Engendering Accountability: Gender Crimes Under International Criminal Law

Gender crimes, such as rape, sexual assault, sexual slavery, and forced prostitution, have always been perpetrated during war, yet the laws of war have been slow to acknowledge these crimes and to bring their perpetrators to justice. This article examines the response of the International Criminal Tribunals for the Former Yugoslavia and Rwanda to this lacuna in international law, and analyzes the mainly positive developments they have made in this area in relation to the definition of rape and to the prosecution of gender crimes as crimes against humanity, war crimes, grave breaches of the Geneva Conventions, and genocide. It also traces the procedural safeguards instituted to facilitate the prosecution of gender crimes. The authors consider the way in which these advances have been taken forward in the Statute of the International Criminal Court, and the usefulness of other responses, such as the truth commissions in Bosnia and Yugoslavia, and the gacaca courts in Rwanda

Development of a Short Trauma Screening Tool (STST) to Measure Child Trauma Symptoms: Establishing Content Validity

Purpose: The purpose of the study was to identify major symptom domain variables common to child trauma and create a prototype short trauma symptom screening tool (STST) intended for use in pediatric medical settings. Methods: This manuscript describes the first two phases of an on-going prospective mixed-method instrument development study. Phase 1 exploratory factor analysis was conducted with an archived LONGSCAN CBCL dataset to: (1) identify behavioral symptoms endorsed by children with known trauma exposure; and (2) generate a preliminary STST item pool. During Phase 2, researchers convened an expert panel (N = 10) and conducted Content Validity Index (CVI) procedures with the 20-item preliminary STST item pool, to further inform item retention, elimination and modification for an updated prototype STST. Findings: Expert quantitative scores yielded a CVI of 0.90 for the overall preliminary STST. The first two phases of this study assisted researchers with identifying 12 items that represent nine child trauma symptom domain variables, which include: (1) aggression/anger; (2) anxiety/fear; (3) sexual concerns; (4) elimination concerns; (5) somatic concerns; (6) depression; (7) dissociation; (8) physical acting out; and (9) dysregulation. Conclusions: The first two phases of STST development resulted in development of a brief, empirically-derived prototype screening tool that features 12 items operationalizing nine domains of child trauma symptoms. Developers can now advance to the next phase of STST development; feasibility assessment and psychometric testing

Auxin-sensitive Aux/IAA proteins mediate drought tolerance in Arabidopsis by regulating glucosinolate levels.

A detailed understanding of abiotic stress tolerance in plants is essential to provide food security in the face of increasingly harsh climatic conditions. Glucosinolates (GLSs) are secondary metabolites found in the Brassicaceae that protect plants from herbivory and pathogen attack. Here we report that in Arabidopsis, aliphatic GLS levels are regulated by the auxin-sensitive Aux/IAA repressors IAA5, IAA6, and IAA19. These proteins act in a transcriptional cascade that maintains expression of GLS levels when plants are exposed to drought conditions. Loss of IAA5/6/19 results in reduced GLS levels and decreased drought tolerance. Further, we show that this phenotype is associated with a defect in stomatal regulation. Application of GLS to the iaa5,6,19 mutants restores stomatal regulation and normal drought tolerance. GLS action is dependent on the receptor kinase GHR1, suggesting that GLS may signal via reactive oxygen species. These results provide a novel connection between auxin signaling, GLS levels and drought response