Multicolour photometry of the M0V+M5V eclipsing binary V405 And

We present multicolour photometry and modelling of the active eclipsing binary star V405 And. The components of 0.2 and 0.5 solar masses are just below and above the theoretical limit of the full convection, that is thought to be around 0.3 solar mass. The light curves are compositions of constant and variable features: the distorted shape of the components (about 25%), a small eclipse, and mainly of spots (about 75%) and flares.Comment: 4 pages, 2 figures, 1 table, proceedings of Cool Stars 15, St Andrews, July 2008, to be published in the Conference Proceedings Series of the AIP; typo in Table 1. (value of rotation period) correcte

Performance and selection of winter durum wheat genotypes in different European conventional and organic fields

Sustainability is a key factor for the future of agriculture. Productivity in agriculture has more than tripled in developed countries since the 1950s. Beyond the success of plant breeding, the increased use of inorganic fertilizers, application of pesticides, and spread of irrigation also contributed to this success. However, impressive yield increases started to decline in the 1980s because of the lack of sustainability. One of the most beneficial ways to increase sustainability is organic agriculture. In such agro-ecosystem-based holistic production systems the prerequisite of successful farming is the availability of crop genotypes that perform well. However, selection of winter durum wheat for sub-optimal growing conditions is still mainly neglected, and the organic seed market also lacks of information on credibly tested winter durum varieties suitable for organic agriculture

A linear-time algorithm for finding a complete graph minor in a dense graph

Let g(t) be the minimum number such that every graph G with average degree d(G) \geq g(t) contains a K_{t}-minor. Such a function is known to exist, as originally shown by Mader. Kostochka and Thomason independently proved that g(t) \in \Theta(t*sqrt{log t}). This article shows that for all fixed \epsilon > 0 and fixed sufficiently large t \geq t(\epsilon), if d(G) \geq (2+\epsilon)g(t) then we can find this K_{t}-minor in linear time. This improves a previous result by Reed and Wood who gave a linear-time algorithm when d(G) \geq 2^{t-2}.Comment: 6 pages, 0 figures; Clarification added in several places, no change to arguments or result

REFORMING PILLAR 2 –TOWARDS SIGNIFICANT AND SUSTAINABLE RURAL DEVELOPMENT?

With the ongoing “Health Check” and the decisions needed for after 2013, the Common Agricultural Policy is likely to see another major reform and an increase in compulsory modulation. By employing a regional model, this paper compares the long-term impact of spending along the Pillar 2 Axes in NUTS3 areas on selected indicators of sustainability in several peripheral areas across Europe. The four case study areas are: Pinzgau-Pongau (a tourism-dominated alpine area in Austria), the Wetterau (an urbanised industrial area in Germany), Gorenjska (a tourism and manufacturing dominated area in Slovenia) and Caithness-Sutherland (a remote area in Scotland). The results suggest although devolution in European rural development policy has taken over the last 10 years, there is further need to restore place-based stewardship of public goods and services as well as private investments across rural areas in the European Union. Increasing the importance of Axis 2 and Axis 3 measures (part of CAP Pillar 2) therefore seems an obvious choice for the future. Furthermore, it is clear that the effects of wider societal trends such as the decreasing importance of agriculture, commuting and migration, can be weakened or amplified by EU funding but can not be reversed or significantly changed.CAP, Pillar 2, rural development, Agricultural and Food Policy, R15, Q18, Q01,

The contact binary VW Cephei revisited: surface activity and period variation

Context. Despite the fact that VW Cephei is one of the well-studied contact binaries in the literature, there is no fully consistent model available that can explain every observed property of this system. Aims. Our motivation is to obtain new spectra along with photometric measurements, to analyze what kind of changes may have happened in the system in the past two decades, and to propose new ideas for explaining them. Methods. For the period analysis we determined 10 new times of minima from our light curves, and constructed a new O$-$C diagram of the system. Radial velocities of the components were determined using the cross-correlation technique. The light curves and radial velocities were modelled simultaneously with the PHOEBE code. All observed spectra were compared to synthetic spectra and equivalent widths of the H$\alpha$ line were measured on their differences. Results. We have re-determined the physical parameters of the system according to our new light curve and spectral models. We confirm that the primary component is more active than the secondary, and there is a correlation between spottedness and the chromospheric activity. We propose that flip-flop phenomenon occurring on the primary component could be a possible explanation of the observed nature of the activity. To explain the period variation of VW Cep, we test two previously suggested scenarios: presence of a fourth body in the system, and the Applegate-mechanism caused by periodic magnetic activity. We conclude that although none of these mechanisms can be ruled out entirely, the available data suggest that mass transfer with a slowly decreasing rate gives the most likely explanation for the period variation of VW Cep.Comment: 13 pages, 18 figures, 9 tables, accepted for publication in Astronomy and Astrophysic

Influência de luz na infecção da ferrugem da videira (Phakopsora euvitis).

O objetivo deste trabalho foi avaliar o efeito luz na infecção de P. euvitis.Suplemento, ref. 097, Edição dos Resumos do XXX Congresso Paulista de Fitopatologia, Botucatu, fev. 2007