Die Soziale Innovationskraft des Ökologischen Landbaus – zwischen Main Stream und Gesellschaftlichem Wandel

In this article we present a conceptual framework to describe and assess how conversion towards organic farming can qualify as a social innovation (SI). For that we critically analyze the current concepts on SI and add insights from Practice Theory (PT) to create an instrument to apply the idea of SI within the context of organic agrofood-systems. We introduce an example and conclude with a summary of the added value of an extended concept of SI using insights from PT

Locally constrained homomorphisms on graphs of bounded treewidth and bounded degree.

A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its restriction to the neighborhood of every vertex of G is bijective, surjective, or injective, respectively. We prove that the problems of testing whether a given graph G allows a homomorphism to a given graph H that is locally bijective, surjective, or injective, respectively, are NP-complete, even when G has pathwidth at most 5, 4 or 2, respectively, or when both G and H have maximum degree 3. We complement these hardness results by showing that the three problems are polynomial-time solvable if G has bounded treewidth and in addition G or H has bounded maximum degree

Early cadmium-induced effects on reactive oxygen species production, cell viability and membrane electrical potential in grapevine roots

Cadmium (Cd) is one of the most worldwide concerned metal pollutants. It is able to induce reactive oxygen species production through indirect mechanisms causing oxidative stress. Vitis vinifera roots were treated with 100 μM Cd for 0-180 min or 20-100 μM Cd for 24 h. Fluorescence confocal microscopy showed elevated hydrogen peroxide and superoxide levels in the apical root segments. Two phases (after 30 min and 24 h) of the superoxide raised levels were observed. This was accompanied by the decrease in root cell viability. Cd in concentrations between 0.005-10 mM induced significant, but different changes in membrane electrical potential (EM) of the root epidermal cells. The low concentrations of Cd (0.005-0.01 mM) caused transient EM hyperpolarization followed by depolarization, whereas by higher concentrations (0.05-5.0 mM) EM was depolarized. In any case, the depolarization or hyperpolarization were only transient up to 5 mM Cd concentration indicating that the plasma membrane function was not irreversibly destroyed. Hyperpolarization of EM induced by fusicoccin (FC) was completely suppressed only in the presence of 10 mM Cd pointing to the inhibition of H+-ATPase. The results suggest that the Cd interactions, depending on cellular development, result in activation of a complex of various mechanisms such as peroxide and hydrogen peroxide production, which in turn may be a more probable reason for the root cell responses to Cd toxicity than the transient EM changes

Dissimilar responses of membrane potential (EM), permeability properties and respiration to cadmium and nickel in maize root cells

The short-term treatment with Cd2+ and Ni2+ triggered transient depolarization of transplasma membrane potential (EM) in the outer cortical root cells of two maize cultivars (cv. Premia and cv. Blitz), however, both metals changed the EM in a quantitatively different way. The magnitude and duration of EM depolarization were concentration dependent and were greater in the metal susceptible cv. Blitz. The highest EM depolarization was recorded with simultaneous application of Cd2+ + Ni2+ in both maize cultivars. The EM depolarization induced by Cd2+ or Cd2+ + Ni2+ but not Ni2+ alone was accompanied with a tremendous increase of membrane conductivity, but it was not accompanied with the effect of heavy metals (HM) on respiration. Simultaneous application of fusiccocin (FC) with Cd2+ or Cd2+ + Ni2+ during the EM depolarization, inability of FC to stop the depolarization by FC-enhanced proton extrusion and rapid restoration of EM, suggested a transient inhibition of the plasma membrane H+-ATPase by these toxic metals. Our data support the opinion that differences in the effects of the studied ions were not the result of their direct action on PM, but rather of their different influence on intracellular processes within root cells

Instability of misoprostol tablets stored outside the blister: a potential serious concern for clinical outcome in medical abortion

Misoprostol (Cytotec) is recognised to be effective for many gynaecological indications including termination of pregnancy, management of miscarriage and postpartum haemorrhage. Although not licensed for such indications, it has been used for these purposes by millions of women throughout the world. Misoprostol tablets are most often packaged as multiple tablets within an aluminium strip, each within an individual alveolus. When an alveolus is opened, tablets will be exposed to atmospheric conditions

The N-methyl-d-aspartate receptor antagonist CPP alters synapse and spine structure and impairs long-term potentiation and long-term depression induced morphological plasticity in dentate gyrus of the awake rat

Long-term morphological synaptic changes associated with homosynaptic long-term potentiation (LTP) and heterosynaptic long-term depression (LTD) in vivo, in awake adult rats were analyzed using three-dimensional (3-D) reconstructions of electron microscope images of ultrathin serial sections from the molecular layer of the dentate gyrus. For the first time in morphological studies, the specificity of the effects of LTP and LTD on both spine and synapse ultrastructure was determined using an N-methyl-d-aspartate (NMDA) receptor antagonist CPP (3-[(R)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid). There were no differences in synaptic density 24 h after LTP or LTD induction, and CPP alone had no effect on synaptic density. LTP increased significantly the proportion of mushroom spines, whereas LTD increased the proportion of thin spines, and both LTP and LTD decreased stubby spine number. Both LTP and LTD increased significantly spine head evaginations (spinules) into synaptic boutons and CPP blocked these changes. Synaptic boutons were smaller after LTD, indicating a pre-synaptic effect. Interestingly, CPP alone decreased bouton and mushroom spine volumes, as well as post-synaptic density (PSD) volume of mushroom spines.These data show similarities, but also some clear differences, between the effects of LTP and LTD on spine and synaptic morphology. Although CPP blocks both LTP and LTD, and impairs most morphological changes in spines and synapses, CPP alone was shown to exert effects on aspects of spine and synaptic structure

The marine myxosporean Sigmomyxa sphaerica (Thélohan, 1895) gen. n., comb. n. (syn. Myxidium sphaericum) from garfish (Belone belone (L.)) uses the polychaete Nereis pelagica L. as invertebrate host

Sigmomyxa sphaerica (Thélohan, 1892) gen. n. (Myxozoa, Myxosporea) with myxosporean stages in the gall bladder of Belone belone (L.) (Teleostei, Belonidae) uses the polychaete Nereis pelagica L. (Nereidae) from shallow water in the northern Øresund, Denmark, as invertebrate host. The nearly spherical tetractinomyxon-type actinospores of S. sphaerica differ from those of two species of Ellipsomyxa which also use Nereis spp. as invertebrate host. Pansporocysts of S. sphaerica were not seen. S. sphaerica is redescribed on the basis of myxospore stages from B. belone and actinospores from N. pelagica, and the phylogenetic affinities examined on the basis of ribosomal small subunit gene sequences. S. sphaerica is closest related to Ellipsomyxa spp., and is not congeneric with morphologically similar Myxidium spp. from gadids. This is the fifth elucidated two-host life cycle of a marine myxozoan

The Rest-frame Optical Colors of 99,000 SDSS Galaxies

We synthesize the rest-frame Stroemgren colors using SDSS spectra for 99,088 galaxies selected from Data Release 1. This narrow-band ~200 AA photometric system (uz, vz, bz, yz), first designed for the determination of effective temperature, metallicity and gravity of stars, measures the continuum spectral slope of galaxies in the rest-frame 3200-5800 AA wavelength range. Galaxies form a remarkably narrow locus (~0.03 mag) in the resulting color-color diagram. The Bruzual & Charlot population synthesis models suggest that the position of a galaxy along this locus is controlled by a degenerate combination of metallicity and age of the dominant stellar population. Galaxy distribution along the locus is bimodal, with the local minimum corresponding to an ~1 Gyr old single stellar population. The position perpendicular to the locus is independent of metallicity and age, and reflects the galaxy's dust content, as implied by both the models and the statistics of IRAS detections. A comparison of this locus with the galaxy locus in the H_delta-D_n(4000) diagram, utilized by Kauffmann et al. (2003) to estimate stellar masses, reveals a tight correlation, although the two analyzed spectral ranges barely overlap. Overall, the galaxy spectral energy distribution in the entire UV to near-IR range can be described as a single-parameter family with an accuracy of 0.1 mag, or better. This nearly one-dimensional distribution of galaxies in the multi-dimensional space of measured parameters strongly supports the conclusion of Yip et al. (2004), based on a principal component analysis, that SDSS galaxy spectra can be described by a small number of eigenspectra. Apparently, the contributions of stellar populations that dominate the optical emission from galaxies are combined in a simple and well-defined way.Comment: Accepted for publication in MNRAS; 19 pages, 28 color figure

Global Conformational Dynamics of a Y-Family DNA Polymerase during Catalysis

High-resolution analysis of protein, and DNA conformational changes during DNA polymerization, established relationships between the enzymatic function and conformational dynamics of individual domains for a DNA polymerase