Maize terpene synthase 1 impacts insect behavior via the production of monoterpene volatiles \u3ci\u3eβ\u3c/i\u3e-myrcene and linalool

Plant-derived volatiles are important mediators of plant-insect interactions as they can provide cues for host location and quality, or act as direct or indirect defense molecules. The volatiles produced by Zea mays (maize) include a range of terpenes, likely produced by several of the terpene synthases (TPS) present in maize. Determining the roles of specific terpene volatiles and individual TPSs in maize-insect interactions is challenging due to the promiscuous nature of TPSs in vitro and their potential for functional redundancy. In this study, we used metabolite GWAS of a sweetcorn diversity panel infested with Spodoptera frugiperda (fall armyworm) to identify genetic correlations between TPSs and individual volatiles. This analysis revealed a correlation between maize terpene synthase 1 (ZmTPS1) and emission of the monoterpene volatiles linalool and β-myrcene. Electroantennogram assays showed gravid S. frugiperda could detect both linalool and β-myrcene. Quantification of headspace volatiles in a maize tps1 loss-of-function mutant confirmed that ZmTPS1 is an important contributor to linalool and β-myrcene emission in maize. Furthermore, pairwise choice assays between tps1 mutant and wildtype plants showed that ZmTPS1, and by extension its volatile products, aid host location in the chewing insect S. frugiperda, yet repel the sap-sucking pest, Rhopalosiphum maidis (corn leaf aphid). On the other hand, ZmTPS1 had no impact on indirect defense via the recruitment of the parasitoid Cotesia marginiventris. ZmTPS1 is therefore an important mediator of the interactions between maize and its insect pests

Translation: The relative native

Translation by Julia Sauma and Martin Holbraad of: Viveiros de Castro, Eduardo (2002) "O Nativo Relativo." Mana, vol. 8, no. 1, p. 113-14

Profile and professional expectations of medical students in Mozambique: a longitudinal study

<p>Abstract</p> <p>Introduction</p> <p>This paper compares the socioeconomic profile of medical students registered at the Faculty of Medicine of Universidade Eduardo Mondlane (FM-UEM), Maputo, for the years 1998/99 and 2007/08.</p> <p>Case study</p> <p>The objective is to describe the medical students' social and geographical origins, expectations and perceived difficulties regarding their education and professional future. Data were collected through questionnaires administered to all medical students.</p> <p>Discussion and evaluation</p> <p>The response rate in 1998/99 was 51% (227/441) and 50% in 2007/08 (484/968).</p> <p>The main results reflect a doubling of the number of students enrolled for medical studies at the FM-UEM, associated with improved student performance (as reflected by failure rates). Nevertheless, satisfaction with the training received remains low and, now as before, students still identify lack of access to books or learning technology and inadequate teacher preparedness as major problems.</p> <p>Conclusions</p> <p>There is a high level of commitment to public sector service. However, students, as future doctors, have very high salary expectations that will not be met by current public sector salary scales. This is reflected in an increasing degree of orientation to double sector employment after graduation.</p

Sensitivity of wavepackets in jets to non-linear effects: the role of the critical layer

Linear instability waves, wavepackets, are key building blocks for the jet-noise problem. It has been shown in previous work that linear models correctly predict the evolution of axisymmetric wavepackets up to the end of the potential core. Beyond this station linear models fail to predict single-point statistics; they fail more broadly in the prediction of two-point properties such as coherence; and their underprediction of the radiated noise is believed to be associated with these errors. Non-linearity is the likely missing piece. But how might it be incorporated? What are the essential underlying mechanisms? Might it be amenable to a reduced-order modelling methodology? The work described in this paper is concerned with these questions. The non-linear interactions are considered as an "external" harmonic forcing of the standard linear model; the forcing can be viewed as comprising those Fourier components of the non-linear term of the Navier-Stokes equations which are most amplified by the linear wavepackets. This modelling framework is explored using three complementary problems in which we try to understand the relationship between "external" forcing, linear system and flow response. The response of an incompressible, two-dimensional, locally parallel, shear-flow to direct, spatially localised, harmonic forcing is first considered. A resolvant analysis is then performed, again in a locally parallel context, both for the incompressible, 2D problem and for a compressible axisymmetric shear-flow where the mean flow is taken from experiments. Finally, in order to incorporate the slow axial variation of the real jet, a novel approach is considered where 4D-Var data assimilation is applied using experimental data and the Parabolised Stability Equations (PSE-4D-Var). The objective of this third, data-driven, approach is to search for an optimal forcing that might improve the match between wavepaket solutions and measurements. In all of the problems considered the critical layer, where the phase speed of the wave is equal to the local mean velocity, is found to be relevant. It is at this point that the sensitivity of the linear waves to non-linearity is greatest. In the 2D, incompressible, problem the largest response is produced when the flow is forced in the vicinity of the critical layer. The resolvant analyses show optimal forcing modes that peak on the critical layer and the optimal response modes have a critical-layer structure. The PSE-4D-Var approach shows highest sensitivity near the critical layer. Furthermore, the structure of the forced perturbations are tilted in a manner that suggests an Orr-like mechanism. The ensemble of results suggest that the critical layer may play a central role in the modelling of wavepackets in subsonic turbulent jets, and indeed may be the key to remedying the deficiencies evoked above

Internal and near nozzle measurements of Engine Combustion Network "Spray G" gasoline direct injectors

[EN] Gasoline direct injection (GDI) sprays are complex multiphase flows. When compared to multi-hole diesel sprays, the plumes are closely spaced, and the sprays are more likely to interact. The effects of multi-jet interaction on entrainment and spray targeting can be influenced by small variations in the mass fluxes from the holes, which in turn depend on transients in the needle movement and small-scale details of the internal geometry. In this paper, we present a comprehensive overview of a multi-institutional effort to experimentally characterize the internal geometry and near-nozzle flow of the Engine Combustion Network (ECN) Spray G gasoline injector. In order to develop a complete pictitre of the near-nozzle flow, a standardized setup was shared between facilities. A wide range of techniques were employed, including both X-ray and visible-light diagnostics. The novel aspects of this work include both new experimental measurements, and a comparison of the results across different techniques and facilities. The breadth and depth of the data reveal phenomena which were not apparent from analysis of the individual data sets. We show that plume-to-plume variations in the mass fluxes from the holes can cause large-scale asymmetries in the entrainment field and spray structure. Both internal flow transients and small-scale geometric features can have an effect on the external flow. The sharp turning angle of the flow into the holes also causes an inward vectoring of the plumes relative to the hole drill angle, which increases with time due to entrainment of gas into a low-pressure region between the plumes. These factors increase the likelihood of spray collapse with longer injection durations.The X-ray experiments were performed at the 7-BM and 32-ID beam lines of the APS at Argonne National Laboratory. Use of the APS is supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-06CH11357. Research was also performed at the Combustion Research Facility, Sandia National Laboratories, Livermore, California. Sandia National Laboratories is managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy National Nuclear Security Administration under contract DE-NA-0003525.Duke, DJ.; Kastengren, AL.; Matusik, KE.; Swantek, AB.; Powell, CF.; Payri, R.; Vaquerizo, D.... (2017). Internal and near nozzle measurements of Engine Combustion Network "Spray G" gasoline direct injectors. Experimental Thermal and Fluid Science. 88:608-621. https://doi.org/10.1016/j.expthermflusci.2017.07.015S6086218

The training and professional expectations of medical students in Angola, Guinea-Bissau and Mozambique

<p>Abstract</p> <p>Background</p> <p>The purpose of this paper is to describe and analyze the professional expectations of medical students during the 2007-2008 academic year at the public medical schools of Angola, Guinea-Bissau and Mozambique, and to identify their social and geographical origins, their professional expectations and difficulties relating to their education and professional future.</p> <p>Methods</p> <p>Data were collected through a standardised questionnaire applied to all medical students registered during the 2007-2008 academic year.</p> <p>Results</p> <p>Students decide to study medicine at an early age. Relatives and friends seem to have an especially important influence in encouraging, reinforcing and promoting the desire to be a doctor.</p> <p>The degree of feminization of the student population differs among the different countries.</p> <p>Although most medical students are from outside the capital cities, expectations of getting into medical school are already associated with migration from the periphery to the capital city, even before entering medical education.</p> <p>Academic performance is poor. This seems to be related to difficulties in accessing materials, finances and insufficient high school preparation.</p> <p>Medical students recognize the public sector demand but their expectations are to combine public sector practice with private work, in order to improve their earnings. Salary expectations of students vary between the three countries.</p> <p>Approximately 75% want to train as hospital specialists and to follow a hospital-based career. A significant proportion is unsure about their future area of specialization, which for many students is equated with migration to study abroad.</p> <p>Conclusions</p> <p>Medical education is an important national investment, but the returns obtained are not as efficient as expected. Investments in high-school preparation, tutoring, and infrastructure are likely to have a significant impact on the success rate of medical schools. Special attention should be given to the socialization of students and the role model status of their teachers.</p> <p>In countries with scarce medical resources, the hospital orientation of students' expectations is understandable, although it should be associated with the development of skills to coordinate hospital work with the network of peripheral facilities. Developing a local postgraduate training capacity for doctors might be an important strategy to help retain medical doctors in the home country.</p

Intensity Modulated Radiotherapy (IMRT) and Fractionated Stereotactic Radiotherapy (FSRT) for children with head-and-neck-rhabdomyosarcoma

<p>Abstract</p> <p>Background</p> <p>The present study evaluates the outcome of 19 children with rhabdomyosarcoma of the head-and-neck region treated with Intensity Modulated Radiotherapy (IMRT) or Fractionated Stereotactic Radiotherapy (FSRT) between August 1995 and November 2005.</p> <p>Methods</p> <p>We treated 19 children with head-and-neck rhabdomyosarcoma with FSRT (n = 14) or IMRT (n = 5) as a part of multimodal therapy. Median age at the time of radiation therapy was 5 years (range 2–15 years). All children received systemic chemotherapy according to the German Soft Tissue Sarcoma Study protocols.</p> <p>Median size of treatment volume for RT was 93,4 ml. We applied a median total dose of 45 Gy (range 32 Gy – 54 Gy) using a median fractionation of 5 × 1,8 Gy/week (range 1,6 Gy – 1,8 Gy).</p> <p>The median time interval between primary diagnosis and radiation therapy was 5 months (range 3–9 months).</p> <p>Results</p> <p>After RT, the 3- and 5-year survival rate was 94%. The 3- and 5-year actuarial local control rate after RT was 89%.</p> <p>The actuarial freedom of distant metastases rate at 3- and 5-years was 89% for all patients.</p> <p>Radiotherapy was well tolerated in all children and could be completed without interruptions > 4 days. No toxicities >CTC grade 2 were observed. The median follow-up time after RT was 17 months.</p> <p>Conclusion</p> <p>IMRT and FSRT lead to excellent outcome in children with head-and-neck RMS with a low incidence of treatment-related side effects.</p