Factors Influencing Trust-Supporting Mechanisms in European Agri-Food Chains

The role of trust in eight selected agri-food chains in four EU countries is explored. The empirical analysis is based on a qualitative assessment of 28 expert interviews conducted in summer/autumn 2005. The findings suggest that trust is more pronounced among SMEs which are characterised by the existence of personal relationships between business partners. However, as is clear for pork breeders, if a source of distrust exists, trust may not fully develop. Also, if the general economic situation is difficult, the development of trust may be hampered, because all chain participants are struggling to command a share of a diminishing margin within the chain. Finally, if economic power is distributed unevenly, as is the case in Germany, Ireland, Spain and the UK where retailers dominate most chains, trust towards the more powerful may be limited.trust, economic relationships, EU, agri-food chains, Agribusiness,

The metal-rich nature of stars with planets

With the goal of confirming the metallicity "excess" present in stars with planetary-mass companions, we present in this paper a high-precision spectroscopic study of a sample of dwarfs included in the CORALIE extrasolar planet survey. The targets were chosen according to the basic criteria that 1) they formed part of a limited volume and 2) they did not present the signature of a planetary host companion. A few stars with planets were also observed and analysed; namely, HD 6434, HD 13445, HD 16141, HD 17051, HD 19994, HD 22049, HD 28185, HD 38529, HD 52265, HD 190228, HD 210277 and HD 217107. For some of these objects there had been no previous spectroscopic studies. The spectroscopic analysis was done using the same technique as in previous work on the metallicity of stars with planets, thereby permitting a direct comparison of the results. The work described in this paper thus represents the first uniform and unbiased comparison between stars with and without planetary-mass companions in a volume-limited sample. The results show that 1) stars with planets are significantly metal-rich, and 2) that the source of the metallicity is most probably "primordial". The results presented here may impose serious constraints on planetary system formation and evolution models.Comment: 14 pages, 7 figures, A&A in pres

Statistical properties of exoplanets II. Metallicity, orbital parameters, and space velocities

In this article we present a detailed spectroscopic analysis of more than 50 extra-solar planet host stars. Stellar atmospheric parameters and metallicities are derived using high resolution and high S/N spectra. The spectroscopy results, added to the previous studies, imply that we have access to a large and uniform sample of metallicities for about 80 planet hosts stars. We make use of this sample to confirm the metal-rich nature of stars with planets, and to show that the planetary frequency is rising as a function of the [Fe/H]. Furthermore, the source of this high metallicity is shown to have most probably an ``primordial'' source, confirming previous results. The comparison of the orbital properties (period and eccentricity) and minimum masses of the planets with the stellar properties also reveal some emerging but still not significant trends. These are discussed and some explanations are proposed. Finally, we show that the planet host stars included in the CORALIE survey have similar kinematical properties as the whole CORALIE volume-limited planet search sample. Planet hosts simply seem to occupy the metal-rich envelope of this latter population.Comment: 15 pages, 10 (eps) figures, Astronomy & Astrophysics, in pres

Quasar Feedback in the Ultraluminous Infrared Galaxy F11119+3257: Connecting the Accretion Disk Wind with the Large-Scale Molecular Outflow

In Tombesi et al. (2015), we reported the first direct evidence for a quasar accretion disk wind driving a massive molecular outflow. The target was F11119+3257, an ultraluminous infrared galaxy (ULIRG) with unambiguous type-1 quasar optical broad emission lines. The energetics of the accretion disk wind and molecular outflow were found to be consistent with the predictions of quasar feedback models where the molecular outflow is driven by a hot energy-conserving bubble inflated by the inner quasar accretion disk wind. However, this conclusion was uncertain because the energetics were estimated from the optically thick OH 119 um transition profile observed with Herschel. Here, we independently confirm the presence of the molecular outflow in F11119+3257, based on the detection of broad wings in the CO(1-0) profile derived from ALMA observations. The broad CO(1-0) line emission appears to be spatially extended on a scale of at least ~7 kpc from the center. Mass outflow rate, momentum flux, and mechanical power of (80-200) R_7^{-1} M_sun/yr, (1.5-3.0) R_7^{-1} L_AGN/c, and (0.15-0.40)% R_7^{-1} L_AGN are inferred from these data, assuming a CO-to-H_2 conversion factor appropriate for a ULIRG (R_7 is the radius of the outflow normalized to 7 kpc and L_AGN is the AGN luminosity). These rates are time-averaged over a flow time scale of 7x10^6 yrs. They are similar to the OH-based rates time-averaged over a flow time scale of 4x10^5 yrs, but about a factor 4 smaller than the local ("instantaneous"; <10^5 yrs) OH-based estimates cited in Tombesi et al. The implications of these new results are discussed in the context of time-variable quasar-mode feedback and galaxy evolution. The need for an energy-conserving bubble to explain the molecular outflow is also re-examined.Comment: 15 pages, 6 figures, 4 tables, accepted for publication in Ap

Prevalence, distribution and evolutionary significance of the IS629 insertion element in the stepwise emergence of Escherichia coli O157:H7

<p>Abstract</p> <p>Background</p> <p>Insertion elements (IS) are known to play an important role in the evolution and genomic diversification of <it>Escherichia coli </it>O157:H7 lineages. In particular, IS<it>629 </it>has been found in multiple copies in the <it>E. coli </it>O157:H7 genome and is one of the most prevalent IS in this serotype. It was recently shown that the lack of O157 antigen expression in two O rough <it>E. coli </it>O157:H7 strains was due to IS<it>629 </it>insertions at 2 different locations in the <it>gne </it>gene that is essential for the O antigen biosynthesis.</p> <p>Results</p> <p>The comparison of 4 <it>E. coli </it>O157:H7 genome and plasmid sequences showed numerous IS<it>629 </it>insertion sites, although not uniformly distributed among strains. Comparison of IS<it>629</it>s found in O157:H7 and O55:H7 showed the presence of at least three different IS<it>629 </it>sub-types. O157:H7 strains carry IS<it>629 </it>elements sub-type I and III whereby the ancestral O55:H7 carries sub-type II. Analysis of strains selected from various clonal groups defined on the <it>E. coli </it>O157:H7 stepwise evolution model showed that IS<it>629 </it>was not observed in sorbitol fermenting O157 (SFO157) clones that are on a divergent pathway in the emergence of O157:H7. This suggests that the absence of IS<it>629 </it>in SFO157 strains probably occurred during the divergence of this lineage, albeit it remains uncertain if it contributed, in part, to their divergence from other closely related strains.</p> <p>Conclusions</p> <p>The highly variable genomic locations of IS<it>629 </it>in O157:H7 strains of the A6 clonal complex indicates that this insertion element probably played an important role in genome plasticity and in the divergence of O157:H7 lineages.</p

Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars

Exo-planets are preferentially found around high metallicity main sequence stars. We aim at investigating whether evolved stars share this property, and what this tells about planet formation. Statistical tools and the basic concepts of stellar evolution theory are applied to published results as well as our own radial velocity and chemical analyses of evolved stars. We show that the metal distributions of planet-hosting (P-H) dwarfs and giants are different, and that the latter do not favor metal-rich systems. Rather, these stars follow the same age-metallicity relation as the giants without planets in our sample. The straightforward explanation is to attribute the difference between dwarfs and giants to the much larger masses of giants' convective envelopes. If the metal excess on the main sequence is due to pollution, the effects of dilution naturally explains why it is not observed among evolved stars. Although we cannot exclude other explanations, the lack of any preference for metal-rich systems among P-H giants could be a strong indication of the accretion of metal-rich material. We discuss further tests, as well as some predictions and consequences of this hypothesis.Comment: A&A, in pres

Carbon and Oxygen in Nearby Stars: Keys to Protoplanetary Disk Chemistry

We present carbon and oxygen abundances for 941 FGK stars-the largest such catalog to date. We find that planet-bearing systems are enriched in these elements. We self-consistently measure C/O, which is thought to play a key role in planet formation. We identify 46 stars with C/O \geq 1.00 as potential hosts of carbon-dominated exoplanets. We measure a downward trend in [O/Fe] versus [Fe/H] and find distinct trends in the thin and thick disks, supporting the work of Bensby et al. Finally, we measure sub-solar C/O = 0.40+0.11 - 0.07, for WASP-12, a surprising result as this star is host to a transiting hot Jupiter whose dayside atmosphere was recently reported to have C/O \geq 1 by Madhusudhan et al. Our measurements are based on 15,000 high signal-to-noise spectra taken with the Keck 1 telescope as part of the California Planet Search. We derive abundances from the [O I] and C I absorption lines at {\lambda} = 6300 and 6587 {\AA} using the SME spectral synthesizer.Comment: 108 pages (including appendix), 16 figures, 6 table

Ensambles de Aves Terrestres en Diferentes Paisajes Rurales: Un Estudio de Caso en las Pampas del Centro de Argentina

A combination of elements (e.g., crops and pasture lands, strips of roadside vegetation, woodlots, temporary wetlands) increases the heterogeneity of rural landscapes. Agricultural landscapes range from homogeneous, dominated by a single element (i.e., pure cropland or pure pastoral farming) to heterogeneous, dominated by two or more elements (i.e., mixed farming). In this study we characterized landbird assemblages in various agricultural landscapes (cropland, pastoral, and mixed landscapes) in the Pampas of central Argentina, surveying along transects to quantify species richness, composition, and abundance. Mixed landscapes were more heterogeneous than pastoral areas and cropland. Species richness, particularly of generalists, was greater in mixed landscapes. Richness of grassland specialists (species of increased conservation concern in the Pampas) was lower in croplands than in pastoral and mixed landscapes. An indicator-species analysis supported the association of some grassland specialists (Rhea americana, Asthenes hudsoni, Embernagra platensis, Pseudoleistes virescens) with pastoral landscapes. Our results suggest that maintaining landscape heterogeneity throughout the Pampas (i.e., mixed landscapes) is important for preserving species richness of birds. But several threatened grassland specialists inhabiting the Pampas, such as Rhea americana and Asthenes hudsoni, are found exclusively in pastoral landscapes, so the long-term survival of these species will depend on the conservation of this landscape type.La combinación de elementos del paisaje (e.g., cultivos, pastizales, vegetación de bordes de caminos, arboledas y humedales temporarios) incrementa la heterogeneidad y define diferentes tipos de paisajes rurales, desde paisajes homogéneos dominados por un único elemento (i.e., paisaje de cultivo o ganadero) hasta paisajes heterogéneos dominados por dos o más elementos (i.e., paisajes mixtos). En este estudio caracterizamos los ensambles de aves terrestres en diferentes tipos de paisajes rurales de la Pampa argentina (paisajes de cultivos, ganaderos y mixtos). Las aves terrestres fueron muestreadas con transectas para determinar la riqueza de especies, la composición y la abundancia en cada tipo de paisaje rural. El paisaje mixto tuvo una mayor heterogeneidad que los paisajes de cultivos y ganaderos. El paisaje mixto tuvo una mayor riqueza de especies que los paisajes de cultivos y ganaderos, en especial de especies generalistas. Por otro lado, el paisaje de cultivos tuvo la menor riqueza de especialistas de pastizal (aquellas con problemas de conservación en la Pampa) que los paisajes ganaderos y mixtos. Un análisis de especies indicadoras destacó la asociación entre algunas especies de pastizal (Rhea americana, Asthenes hudsoni, Embernagra platensis, Pseudoleistes virescens) y el paisaje ganadero. Nuestros resultados sugieren la importancia de mantener la heterogeneidad del paisaje en los agroecosistemas de la Pampa argentina (i.e., paisajes mixtos) para preservar la riqueza de aves. Sin embargo, cabe señalar que varias especies amenazadas de pastizal que habitan en los pastizales de las pampas, como R. americana y A. hudsoni, se encuentran exclusivamente en paisajes ganaderos, por lo que su supervivencia a largo plazo dependerá de la conservación de este tipo de paisaje.Fil: Codesido, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Gonzalez Fischer, Carlos Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bilenca, David Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Planetary Companions Around Two Solar Type Stars: HD 195019 and HD 217107

We have enlarged the sample of stars in the planet search at Lick Observatory. Doppler measurements of 82 new stars observed at Lick Observatory, with additional velocities from Keck Observatory, have revealed two new planet candidates. The G3V/IV star, HD 195019, exhibits Keplerian velocity variations with a period of 18.27 d, an orbital eccentricity of 0.03 +/- 0.03, and M sin i = 3.51 M_Jup. Based on a measurement of Ca II H&K emission, this star is chromospherically inactive. We estimate the metallicity of HD 195019 to be approximately solar from ubvy photometry. The second planet candidate was detected around HD 217107, a G7V star. This star exhibits a 7.12 d Keplerian period with eccentricity 0.14 +/- 0.05 and M sin i = 1.27 M_Jup. HD 217107 is also chromospherically inactive. The photometric metallicity is found to be [Fe/H] = +0.29 +/- 0.1 dex. Given the relatively short orbital period, the absence of tidal spin-up of HD 217107 provides a theoretical constraint on the upper limit of the companion mass of < 11 M_Jup.Comment: 15 pages, plus 6 figures. To appear in Jan 1999 PAS

The CoRoT primary target HD 52265: models and seismic tests

HD 52265 is the only known exoplanet-host star selected as a main target for the seismology programme of the CoRoT satellite. As such, it will be observed continuously during five months, which is of particular interest in the framework of planetary systems studies. This star was misclassified as a giant in the Bright Star Catalog, while it is more probably on the main-sequence or at the beginning of the subgiant branch. We performed an extensive analysis of this star, showing how asteroseismology may lead to a precise determination of its external parameters and internal structure. We first reviewed the observational constraints on the metallicity, the gravity and the effective temperature derived from the spectroscopic observations of HD 52265. We also derived its luminosity using the Hipparcos parallax. We computed the evolutionary tracks for models of various metallicities which cross the relevant observational error boxes in the gravity-effective temperature plane. We selected eight different stellar models which satisfy the observational constraints, computed their p-modes frequencies and analysed specific seismic tests. The possible models for HD 52265, which satisfy the constraints derived from the spectroscopic observations, are different in both their external and internal parameters. They lie either on the main sequence or at the beginning of the subgiant branch. The differences in the models lead to quite different properties of their oscillation frequencies. We give evidences of an interesting specific behaviour of these frequencies in case of helium-rich cores: the ``small separations'' may become negative and give constraints on the size of the core. We expect that the observations of this star by the CoRoT satellite wi ll allow choosing between these possible models.Comment: 11 pages, 7 figures, to be published in Astronomy and Astrophysic