The organic seed regulations framework in Europe – current status and recommendations for future development

Organic agriculture regulations, in particular European regulation EC 889/2008, prescribe the use of organically produced seed. For many cultivated plants, however, organic seed is often not available. This is mainly because investment in organic plant breeding and seed production has been low in the past. To bridge the gap between organic seed supply and demand, national and European regulations define certain circumstances under which organic producers are permitted to use non-organically produced seed. While the organic sector currently depends on these concessions, they also threaten to impede a further increase in the demand for organic seed, thereby potentially restraining present and future investment in organic seed production and plant breeding. We review the current status of the organic seed regulations framework by analysing key issues such as the role of the national derogation regimes, the role of expert groups, databases and seed prices. Key points are that (a) the situation of the organic seed sector has improved over the last few years; however, (b) reporting on organic seed to the EU by different countries needs to be harmonised; (c) the success of the organic seed sector depends critically on the implementation and improvement of national expert groups; and (d) to protect genetic diversity, the use of local varieties and landraces should not be impeded by organic seed regulations

The Detection of Low Mass Companions in Hyades Cluster Spectroscopic Binary Stars

We have observed a large sample of spectroscopic binary stars in the Hyades Cluster, using high resolution infrared spectroscopy to detect low mass companions. We combine our double-lined infrared measurements with well constrained orbital parameters from visible light single-lined observations to derive dynamical mass ratios. Using these results, along with photometry and theoretical mass-luminosity relationships, we estimate the masses of the individual components in our binaries. In this paper we present double-lined solutions for 25 binaries in our sample, with mass ratios from ~0.1-0.8. This corresponds to secondary masses as small as ~0.15 Msun. We include here our preliminary detection of the companion to vB 142, with a very small mass ratio of q=0.06+-0.04; this indicates that the companion may be a brown dwarf. This paper is an initial step in a program to produce distributions of mass ratio and secondary mass for Hyades cluster binaries with a wide range of periods, in order to better understand binary star formation. As such, our emphasis is on measuring these distributions, not on measuring precise orbital parameters for individual binaries.Comment: 36 pages, 8 figures, accepted for publication in The Astrophysical Journa

Manipulation and removal of defects in spontaneous optical patterns

Defects play an important role in a number of fields dealing with ordered structures. They are often described in terms of their topology, mutual interaction and their statistical characteristics. We demonstrate theoretically and experimentally the possibility of an active manipulation and removal of defects. We focus on the spontaneous formation of two-dimensional spatial structures in a nonlinear optical system, a liquid crystal light valve under single optical feedback. With increasing distance from threshold, the spontaneously formed hexagonal pattern becomes disordered and contains several defects. A scheme based on Fourier filtering allows us to remove defects and to restore spatial order. Starting without control, the controlled area is progressively expanded, such that defects are swept out of the active area.Comment: 4 pages, 4 figure

Lentiviral Vector-Mediated Correction of a Mouse Model of Leukocyte Adhesion Deficiency Type I

Leukocyte adhesion deficiency type I (LAD-I) is a primary immunodeficiency caused by mutations in the ITGB2 gene and is characterized by recurrent and life-threatening bacterial infections. These mutations lead to defective or absent expression of β2 integrins on the leukocyte surface, compromising adhesion and extravasation at sites of infection. Three different lentiviral vectors (LVs) conferring ubiquitous or preferential expression of CD18 in myeloid cells were constructed and tested in human and mouse LAD-I cells. All three hCD18-LVs restored CD18 and CD11a membrane expression in LAD-I patient-derived lymphoblastoid cells. Corrected cells recovered the ability to aggregate and bind to sICAM-1 after stimulation. All vectors induced stable hCD18 expression in hematopoietic cells from mice with a hypomorphic Itgb2 mutation (CD18(HYP)), both in vitro and in vivo after transplantation of corrected cells into primary and secondary CD18(HYP) recipients. hCD18(+) hematopoietic cells from transplanted CD18(HYP) mice also showed restoration of mCD11a surface co-expression. The analysis of in vivo neutrophil migration in CD18(HYP) mice subjected to two different inflammation models demonstrated that the LV-mediated gene therapy completely restored neutrophil extravasation in response to inflammatory stimuli. Finally, these vectors were able to correct the phenotype of human myeloid cells derived from CD34(+) progenitors defective in ITGB2 expression. These results support for the first time the use of hCD18-LVs for the treatment of LAD-I patients in clinical trials

Caby Photometry of the Hyades: Comparisons to the Field Stars

Intermediate-band photometry of the Hyades cluster on the Caby system is presented for dwarf stars ranging from spectral type A through late K. A mean hk, b-y relation is constructed using only single stars without anomalous atmospheres and compared to the field stars of the solar neighborhood. For the F dwarfs, the Hyades relation defines an approximate LOWER bound in the two-color diagram, consistent with an [Fe/H] between +0.10 and +0.15. These index-color diagrams follow the common convention of presenting stars with highest abundance at the bottom of the plot although the index values for the metal-rich stars are numerically larger. For field F dwarfs in the range [Fe/H] between +0.4 and -1.0, [Fe/H] = -5.6 delta-hk + 0.125, with no evidence for a color dependence in the slope. For the G and K dwarfs, the Hyades mean relation crosses the field star distribution in the two-color diagram, defining an approximate UPPER bound for the local disk stars. Stars found above the Hyades stars fall in at least one of three categories: [Fe/H] below -0.7, [Fe/H] above that of the Hyades, or chromospherically active. It is concluded that, contrary to the predictions of model atmospheres, the hk index for cool dwarfs at a given color hits a maximum value for stars below solar composition and, with increasing [Fe/H] above some critical value, declines. This trend is consistent, however, with the predictions from synthetic indices based upon much narrower Ca filters where the crossover is caused by the metallicity sensitivity of b-y.Comment: 13 pages, 9 eps figures, 1 tex table, 1 ascii tabl

Using natural resource inventory data to improve the management of dryland salinity in the Great Southern, Western Australia

The synoptic assessment of salinity risk and the likely costs and benefits associated with various management options is crucial to natural resource management decision-making in southern Australia. A variety of methods have been proposed and tested for assessing various aspects of salinity risks and costs, but no large region of Australia has ever had a comprehensive risk assessment across the range of biophysical and economic issues with forecasts of the effectiveness of different levels of intervention. This National Land and Water Resources Audit Implementation Project (referred to locally as Salt Scenarios 2020, or SS2020 for short) attempted to provide such an assessment (at a scale of around 1:100,000). The existing methods of monitoring and predicting salinity (based on variables derived from widely-available Landsat TM data and existing contour data; albeit with improved variable extraction from the DEMs) are being applied to the rest of the agricultural area of WA as part of the Land Monitor Project, funded in part by NHT. Collecting accurate contour data (2-metre) is a major part of the NHT project. This Audit project was proposed to allow other fundamental data sets, and especially groundwater levels from bore-hole data, to be used to significantly improve predictions in lower-rainfall areas as well as refine the predictions in the high rainfall areas. The Great Southern is an area of considerable economic and environmental value populated by 60,000 people. In 1996, it was estimated that about 30% of the cleared land and associated vegetation and water resources are at risk from becoming salt-affected over the next 30 years unless high-water use farming systems and farm forestry are adopted over large parts of the region(Ferdowsian et al., 1996). Four key questions arise with respect to the future of this region as affected by dryland salinity: •How large will the problem eventually be under current land practices? How large might it be in the year 2020? •What is at risk if the area under threat grows that large? •To what degree can we change the eventual extent of salinity with land use alternatives that are both feasible and available? •What are the costs and benefits of intervening with these alternative land uses? Ultimately, the SS2020 Project aimed to provide some guidance to state, regional and local planners and managers regarding salinity risk in the Great Southern. The analyses underpinning this guidance were based on similar data employed by NLWRA projects under Theme 2 – Dryland Salinit

On the determination of oxygen abundances in chromospherically active stars

We discuss oxygen abundances derived from [O I] 6300 and the O I triplet in stars spanning a wide range in chromospheric activity level, and show that these two indicators yield increasingly discrepant results with higher chromospheric/coronal activity measures. While the forbidden and permitted lines give fairly consistent results for solar-type disk dwarfs, spuriously high O I triplet abundances are observed in young Hyades and Pleiades stars, as well as in individual components of RS CVn binaries (up to 1.8 dex). The distinct behaviour of the [O I]-based abundances which consistently remain near-solar suggests that this phenomenon mostly results from large departures from LTE affecting the O I triplet at high activity level that are currently unaccounted for, but also possibly from a failure to adequately model the atmospheres of K-type stars. These results suggest that some caution should be exercised when interpreting oxygen abundances in active binaries or young open cluster stars.Comment: 8 pages, accepted for publication in A&

Reirradiation as part of a salvage treatment approach for progressive non-pontine pediatric high-grade gliomas: preliminary experiences from the German HIT-HGG study group

Background and purpose: The aim of the present analysis was to assess the feasibility, toxicity, and the tumor control of reirradiation as a salvage treatment for progressive pediatric non-pontine high-grade gliomas (HGG). Patients and methods: The database of the Reference Center for Radiation Oncology of the German HIT (HIT = German acronym for brain tumor) treatment network for childhood brain tumors was screened for children who were reirradiated for progressive non-pontine HGG. Results: We identified eight patients (WHO grade III: n = 5; WHO grade IV: n = 3) who underwent reirradiation between April 2006 and July 2012. Median age was 13.5 years at primary diagnosis and 14.8 years at first progression. All patients initially underwent surgery (incomplete resection, n = 7; biopsy, n = 1) followed by radiochemotherapy. Relapses occurred inside (n = 2), at the margin (n = 4), and outside of the preirradiated area (n = 2). In all patients, reirradiation was tolerated well without significant acute toxicity. Temporary clinical improvement and tumor regression on magnetic resonance imaging (MRI) following reirradiation was reported (n = 3). However, all patients finally died by disease progression. Median survival time was 26.2 months from initial diagnosis and 11.4 months after first progression. Median time interval between initial radiotherapy and first reirradiation was 9.0 months. In six patients, all macroscopic tumor deposits were reirradiated. In these patients, median progression-free (overall) survival from the start of reirradiation was 2.4 (4.6) months. Conclusion: Our analysis, although based on a limited patient number, suggests that reirradiation of progressive non-pontine HGG is feasible in children. Benefit in terms of quality of life and/or survival needs to be assessed in a prospective and ideally in a randomized manner

Reirradiation as part of a salvage treatment approach for progressive non-pontine pediatric high-grade gliomas: preliminary experiences from the German HIT-HGG study group

Background and purpose: The aim of the present analysis was to assess the feasibility, toxicity, and the tumor control of reirradiation as a salvage treatment for progressive pediatric non-pontine high-grade gliomas (HGG). Patients and methods: The database of the Reference Center for Radiation Oncology of the German HIT (HIT = German acronym for brain tumor) treatment network for childhood brain tumors was screened for children who were reirradiated for progressive non-pontine HGG. Results: We identified eight patients (WHO grade III: n = 5; WHO grade IV: n = 3) who underwent reirradiation between April 2006 and July 2012. Median age was 13.5 years at primary diagnosis and 14.8 years at first progression. All patients initially underwent surgery (incomplete resection, n = 7; biopsy, n = 1) followed by radiochemotherapy. Relapses occurred inside (n = 2), at the margin (n = 4), and outside of the preirradiated area (n = 2). In all patients, reirradiation was tolerated well without significant acute toxicity. Temporary clinical improvement and tumor regression on magnetic resonance imaging (MRI) following reirradiation was reported (n = 3). However, all patients finally died by disease progression. Median survival time was 26.2 months from initial diagnosis and 11.4 months after first progression. Median time interval between initial radiotherapy and first reirradiation was 9.0 months. In six patients, all macroscopic tumor deposits were reirradiated. In these patients, median progression-free (overall) survival from the start of reirradiation was 2.4 (4.6) months. Conclusion: Our analysis, although based on a limited patient number, suggests that reirradiation of progressive non-pontine HGG is feasible in children. Benefit in terms of quality of life and/or survival needs to be assessed in a prospective and ideally in a randomized manner