Weed Management in Organic Farming in the New EU Member States and the Acceding Countries - Status Quo and Main Limitations

Under the EU Specific Support Action (SSA) Project CHANNEL (“Opening Channels of Communication between the Associated Candidate Countries and the EU in Ecological Farming”), a survey on the status quo in weed management was conducted in 15 new member and acceding EU states. The focus of the data collection was on three main aspects relevant for the understanding of the current situation, they are: i.) legal and administrative framework, ii.) status quo in practice and iii.) scientific basis. These aspects were covered by separate questionnaires, addressed to different authorities and target groups. The results of the weed management questionnaire for the target group “experts engaged in practical farming” are presented in this paper. The analysis allowed the identification of a small group of weeds as the main target species of organic weed management. Alien species were reported by almost all countries as an upcoming problem in organic farming. There was conformity among the different countries in regards to the choice of prevention tools, whereas an obvious lack of modern equipment available for practicing mechanical weed control was noted. Within the new EU member states and candidate countries, the economic constraints (lack of available machinery, lack of capital and high economic costs) were stated as the main limitations of weed management success. The economic costs of weed management in general, could not yet be covered by the market prices of organic products. Therefore, the economic pressure and the scope for improving weed management in practice are small. In most countries, the scientific sector (facilities, projects and advisory services) working on weed management issues in organic farming is relatively small. The lack of project funding in this area limits the research profoundly

High preindustrial δ13C in the deep Arctic Ocean: Implications for the interpretation of abrupt benthic δ13C excursions during the last glaciation

Only recently a strong air-sea signature of δ13C, i.e. δ13Cas, in modern bottom waters of the Atlantic sector of the Antarctic Ocean was revealed (Mackensen, 2012). This high southern δ13Cas may have been reduced in the Last Glacial Maximum, and parts of an ocean wide deep-water δ13CDIC lowering may be attributed to sea-ice formation with low-δ13Cas brine rejection and diminished air-sea gas exchange in the southern ocean. Low benthic δ13C values from the Nordic seas in cold stadials of the last glaciation have been attributed to brine formation, but little is known about the carbon isotopic composition of Arctic Ocean brines and deep-water masses. Here I show that today dissolved inorganic carbon (DIC) of bottom water in the deep Arctic Ocean is 13C enriched with mean δ13CDIC values of 1.2 ‰, whereas bottom waters bathing most of the continental margins with mean δ13CDIC values of about 0.8 ‰. This difference is also recorded in Recent epibenthic foraminiferal δ13C from the deep Arctic versus Greenland and Svalbard continental margins. It is in contrast, however, to the continental slope of the Laptev and East Siberian seas, where epibenthic δ13C is as high as in the deep basins. I conclude that (i) most of the shelves contributing to Arctic bottom water by brine rejection produce high-δ13Cas brine, and (ii) a strong δ13Cas signal from brine formation in polynyas today is masked by anthropogenically lowered atmospheric δ13CCO2. I then hypothesize that during stadials, when most of the Arctic Ocean was perennially sea-ice covered, less brine was produced, and that this cessation of brine rejection would have lowered bottom-water δ13C values in the Arctic Ocean and subsequently in the Nordic seas

Equilibria in overlapping generations models

Bibliography: pages vi-viii.Interest rates are fundamental in the explanation of equilibrium prices over time, because they provide the link between the present and the future. Capturing this dynamic feature, the overlapping generations model is particularly suitable to address the interest rate problem, as has been shown by Paul Samuelson, David Gale and Costas Azariadis. This thesis reviews their contribution to the theory of interest: with his consumption-loan model, Samuelson sets the analytical framework for subsequent research. Furthermore, he demonstrates that the optimal interest rate is unstable, implying that a competitive economy may fail to approach the social optimum. The Samuelson and classical sets of assumptions are consolidated in the intertemporal exchange model of Gale. Its equilibrium nature, however, ignores the sequential adjustment of disequilibrium interest rates to their equilibrium values. Consequently it is difficult to comment on the direction of causality involved in the interest rate determination, unless a clearing house is introduced which simultaneously resolves the starting-up, continuity and causality problems. Departing from the full certainty scenario, Azariadis analyses the existence and likelihood of self-fulfilling prophecies. It is shown that the implications of the economy's assumed Markovian structure are twofold: while facilitating the parametric treatment of the transition probabilities, it negates the question concerning the likelihood of sunspot equilibria. Within the specified framework it is impossible to explain how the economy arrives at such equilibria; it is only possible to identify the conditions that maintain (once they exist) these self-fulfilling prophecies

Modality-independent recruitment of inferior frontal cortex during speech processing in human infants

Despite increasing interest in the development of audiovisual speech perception in infancy, the underlying mechanisms and neural processes are still only poorly understood. In addition to regions in temporal cortex associated with speech processing and multimodal integration, such as superior temporal sulcus, left inferior frontal cortex (IFC) has been suggested to be critically involved in mapping information from different modalities during speech perception. To further illuminate the role of IFC during infant language learning and speech perception, the current study examined the processing of auditory, visual and audiovisual speech in 6-month-old infants using functional near-infrared spectroscopy (fNIRS). Our results revealed that infants recruit speech-sensitive regions in frontal cortex including IFC regardless of whether they processed unimodal or multimodal speech. We argue that IFC may play an important role in associating multimodal speech information during the early steps of language learning

Interferons and their potential in the treatment of ocular inflammation

Since their discovery in the 1950s interferons have been the scope of investigation in many diseases as therapeutic as well as pathogenetic factors. We know they have immune stimulatory and immune regulatory effects. This apparently counter-intuitive mechanism can be summarized as immunomodulatory action and seems to be very effective in a number of ocular inflammatory diseases. We review the current knowledge of interferons in immunity and autoimmunity and show their use in clinical ophthalmologic practice

Benthic Foraminiferal Oxygen Isotope Offsets Over The Last Glacial-Interglacial Cycle

The oxygen isotope (?18O) offset between contemporaneous benthic foraminiferal species is often assumed constant with time and geographic location. We present an inventory of benthic foraminiferal species ?18O offsets from the major ocean basins covering the last glacial-interglacial cycle, showing that of the twenty down-core records investigated, twelve show significant temporal changes in ?18O offsets that do not resemble stochastic variability. Some of the temporal changes may be related to kinetic fractionation effects causing deglacial/interglacial enrichment or glacial depletion in mainly infaunal species, but additional research is needed to confirm this. In addition to stratigraphic implications the finding of temporally varying offsets between co-existing benthic foraminiferal species could have implications for sea-level, deep water temperature, and regional deep water ?18O estimates

Towards sustainable artisanal fisheries for the common pool resource Spondylus (Bivalvia, Spondylidae) in Ecuador

The artisanal fishery for Spondylus has a very long tradition in Ecuador but developments in recent years have made it an excellent example of the rapid overharvesting of a Latin American shellfish fishery. In reaction to the declining population status, the Ecuadorian government enacted an official ban on the fishery in October 2009. The ban is intended to be kept in place at least until there is scientific information regarding stock status and basic population parameters that are necessary for a sustainable use of the resource. This study aims to provide the necessary knowledge base to develop a sustainable management program for Ecuadorian Spondylus stocks in the future. Our findings suggest that current population densities will not allow for a recovery without additional measures to support such recuperation. Nevertheless, the parameters we have calculated for growth and fecundity suggest that exploitation of Spondylus as a resource is generally possible when undertaken with caution. Under a precautionary approach it is crucial for a future management program to monitor densities of individuals closely, as this study identified recruitment failure as the main factor that has contributed to the collapse of the fishery in the past. Restoration efforts would be of high value for the local ecosystem as this study has also shown that Spondylus contributes significantly to the native biodiversity. Their shells provide a three dimensional habitat for a variety of drilling and non-drilling species that are not present without them, thus making Spondylus an important foundational species. Artisanal fisheries make a significant contribution to satisfying the increasing global demand for protein. It is dangerous to assume, that these fisheries operate sustainably per se and it is crucial to ensure that they do in the future. Sustainable solutions for artisanal overfishing are urgently needed, because tropical coastal communities are highly dependent on their local resources for their livelihoods and nutrition. The tools for successfully managing a common pool resource such as Spondylus through a co-management system are known we hope these are used in the future in conjunction with the findings of this study to prevent this iconic genus from disappearing

Abhandlungen der Herder-Gesellschaft und des Herder-Instituts zu Riga. Fünfter Band, Nr.8

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