Field testing of strategies for fire blight control in organic fruit growing

In organic fruit growing effective control strategies are needed to prevent blossom infections by the fire blight pathogen Erwinia amylovora. Many potential control agents are under discussion and have been tested in vitro and in vivo. 19 out of 27 tested preparations showed a high efficacy against E. amylovora in vitro. Nevertheless, on detached apple blossoms only 7 of them led to a symptom reduction by more than 50%. In six field trials conducted according to the EPPO guideline PP1/166(3) BlossomProtect (82%), Myco-sin (65%) and Funguran (58%) had the highest efficiency. In 2006 and 2007, strategies to integrate BlossomProtect in spray schedules of organic apple production have been tested. The use of sulphur or lime-sulphur before or after BlossomProtect did not influence the efficiency of BlossomProtect, which showed that fire blight control is possible without compromising apple scab control. The addition of Cutisan to BlossomProtect reduced fruit russet. An alternating use of BlossomProtect and Myco-sin was shown to be possible

Why we need to see the dark matter to understand the dark energy

The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents separately without making strong assumptions.Comment: 4 pages, to be published in the Journal of Physics: Conference Series as a contribution to the 2007 Europhysics Conference on High Energy Physic

Control of apple scab by curative applications of biocontrol agents

In organic apple growing protective applications with copper, sulphur or lime sulphur are used for apple scab control. Protective applications have to be repeated when new leaves unfold. The timing of protective sprays depends on the weather forecast. If forecasted infection conditions fail to appear, treatments were for nothing. With curative control agents available, the number of treatments could be reduced. In greenhouse trials we tested control agents for their protective and curative efficiency against apple scab after artificial inoculation of potted apple trees. Applications were done 2 hours before inoculation, 5 hours after inoculation on wet leaves, 5 hours after inoculation during simulated rainfall or 24 hours after inoculation on wet or dry leaves. The optimal time of application differed between the preparations tested. Vitisan and OmniProtect had their highest activity when sprayed curative 24 hours after inoculation. Combinations were found, which revealed a high efficiency against apple scab from 2h before to 24 hours after inoculation. In a field trial apple scab was effectively controlled by curative applications of OmniProtect

Finite difference time domain calculations of antenna mutual coupling

The Finite Difference Time Domain (FDTD) technique was applied to a wide variety of electromagnetic analysis problems, including shielding and scattering. However, the method has not been exclusively applied to antennas. Here, calculations of self and mutual admittances between wire antennas are made using FDTD and compared with results obtained during the method of moments. The agreement is quite good, indicating the possibilities for FDTD application to antenna impedance and coupling

Observational constraint on the fourth derivative of the inflaton potential

We consider the flow-equations for the 3 slow-roll parameters n_S (scalar spectral index), r (tensor to scalar ratio), and dn_S/dlnk (running of the spectral index). We show that the combination of these flow-equations with the observational bounds from cosmic microwave background and large scale structure allows one to put a lower bound on the fourth derivative of the inflationary potential, M_P^4(V''''/V) > -0.02.Comment: 3 pages, 3 figure

FDTD modeling of thin impedance sheets

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods

Prolonged elevations in haemostatic and rheological responses following psychological stress in low socioeconomic status men and women

Low socioeconomic status (SES) and psychological stress are associated with increased risk of coronary heart disease, and both may influence haemostatic responses. Von Willebrand factor (vWF), Factor VIII, plasma viscosity, haematocrit, blood viscosity, tissue plasminogen activator (t-PA) and fibrin D- dimer were measured at rest and following stressful tasks in 238 middle-aged British civil servants. SES was defined by grade of employment. Lower SES was associated with higher resting vWF, Factor VIII and plasma viscosity. Psychological stress stimulated increases in haemostatic and rheological factors. Initial stress responses did not vary with SES, but Factor VIII, plasma viscosity and blood viscosity remained more elevated 45 minutes post-stress in lower SES participants. High blood pressure stress reactivity was also associated with greater haemostatic responses. We conclude that lower SES is characterised by more prolonged elevations in procoagulant responses following psychological stress, and that these processes might contribute to increased cardiac risk

‘Making space’ in Cairo: Expatriate movements and spatial practices

This paper examines what it means to be an ‘expatriate’ in Cairo through the lens of movement and space-making. Inquiring into a set of migrant (im)mobilities, spatial practices, relations, and imaginations, it argues that as a ‘spatialised’ identity category ‘expatriate’ narrates and enacts migratory privileges linked to wider hierarchies of social difference. It contributes to a growing literature examining the social and political dimensions of ‘expatriate’ migration and further engages scholarship thinking space and movement in relational and socio-historical terms. Rather than denoting an easily distinguishable group of migrants, ‘expatriate’ emerged as a contingent and ambiguous category of practice. As such, ‘expatriate’ stands in a productive relationship with privileged movement and socio-spatial processes. Like other migrants, respondents skillfully navigated the global differences in wealth, power and status they were presented with. Yet, unlike many other migrants, they did so from a privileged position within the global power-geometries of international migration. Migrants’ personal geographies were further shaped by how bodies were racialised and gendered in entangled, intersecting and sometimes counter-intuitive ways. This diversity and complexity of ‘expatriate’ geographies highlights the necessity of intersectional and situated analyses of privilege