2,014 research outputs found

    Tradition, Dynamics and Sustainability of Plant Species Composition and Management in Homegardens on Organic and Non-Organic Small Scale Farms in Alpine Eastern Tyrol, Austria

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    In Eastern Tyrol (Austria), homegardens are an integral part of the farming system. The aim of this paper is to present evidence for the development of gardening in the study area and to identify differences/similarities between gardens at organic and non-organic farms. In 1997 and 1998, in homegardens on 91 organic and 105 non-organic farms from 12 communities, occurrence and abundance of cultivated plant species were surveyed and interviews were carried out about garden history, management and plant use. For the factor organic/non-organic, differences between gardens were statistically tested. Garden management is similar in organic/non-organic gardens, except mixed cropping and the use of alternative remedies to combat diseases, both with significantly higher occurrence on organic farms. Popular innovations from organic farming did not have a strong and clearly visible impact on management of homegardens. The population of cultivated plant species, until the 1960s approx. 51; nowadays approx. 587 species in all gardens, and main use of garden produce has been in a process of change with an increase in importance of species used as food and for decoration, but with no significant differences concerning organic/non-organic. Women farmers gardening in Eastern Tyrol are highly sympathetic to the principles of organic farming, even on non-organic farms. Sustainability can be increased when methods from organic gardening are promoted and tested locally more effectively. Science and policy should recognize the work of women farmers who maintain homegardens with high agrobiodiversity as part of their culture

    Urban Organic Farming in Austria with the concept of Selbsternte ("self -harvest"): An agronomic and socio-economic analysis

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    In Vienna, consultants, organic farmers and green-minded consumers have developed a new concept of urban organic farming, called Selbsternte (`self-harvest'). Organic farmers prepare a plot of arable land (the Selbsternte plot) and sow or plant rows composed of 18-23 plant species. In mid-May the plots are divided into subplots that contain 2-6m of every sown species and are rented to so-called self-harvesters for a period of about 136 days. In 2002 Selbsternte was being practiced at 15 plots in Vienna or in neighboring cities, represented by 861 subplots, with a total area of 68,740m2, and managed by 12 organic farmers for 861 registered self-harvesters. At the Roter Berg plot, experimental subplots were established to evaluate yields and the value of the harvested produce, and interviews were conducted with 27 self-harvesters, the eight Selbsternte farmers and one Selbsternte consultant. The experimental subplots were managed in two different ways, namely, `with low intensity' (LIS) and `with high intensity' (HIS; meaning additional harrowing, mulching and sowing of additional plants). At the LIS 24.2 h and at the HIS 38.9 h of work were invested over 51 days. Monetary investment was US184fortheLISandUS184 for the LIS and US259 for the HIS subplots. The total harvest of fresh produce was: 163 kg/subplot for LIS and 208 kg/subplot for HIS subplots. The total value of the harvest at the HIS was US364forconventionalandUS364 for conventional and US766 for organic prices. All self- arvesters saw the rental of a subplot and the work as an activity of leisure. More than half of the self-harvesters reported `trying something new' at their subplots. The most frequently mentioned innovation for them was growing an unknown species. Twenty-five self-harvesters sowed 54 different, additional plant species. The motivating factors in establishing Selbsternte plots, as reported by all the farmers, were, primarily, better relations with consumers and work diversifcation, and only then were economic factors a consideration. The contribution of Selbsternte to income varied at the farms, being between 0 and 30% of the total farm income. As a main success factor, all of the farmers reported a close relationship between the self-harvesters and the farmers. Selbsternte subplots can be understood as small experimental stations where self-harvesters merge traditional horticultural techniques with urban ideas on permaculture, sustainable land use and participatory farming. Selbsternte has potential value for the improvement of urban agriculture, but also for the development of organic farming in general

    Fractional quantum Hall effect in CdTe

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    The fractional quantum Hall (FQH) effect is reported in a high mobility CdTe quantum well at mK temperatures. Fully-developed FQH states are observed at filling factor 4/3 and 5/3 and are found to be both spin-polarized ground state for which the lowest energy excitation is not a spin-flip. This can be accounted for by the relatively high intrinsic Zeeman energy in this single valley 2D electron gas. FQH minima are also observed in the first excited (N=1) Landau level at filling factor 7/3 and 8/3 for intermediate temperatures.Comment: Submitte

    Strong and Radiative Meson Decays in a Generalized Nambu--Jona-Lasinio Model

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    We investigate strong and radiative meson decays in a generalized Nambu--Jona-Lasinio model. The one loop order calculation provides a satisfactory agreement with the data for the mesonic spectrum and for radiative decays. Higher order effects for strong decays of ρ\rho and KK^* are estimated to be large. We also discuss the role of the flavour mixing determinantal interaction.Comment: 7 pages, LaTeX, 2 figs available upon request, CRN 92-4

    Quantum mutual information of an entangled state propagating through a fast-light medium

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    Although it is widely accepted that classical information cannot travel faster than the speed of light in vacuum, the behavior of quantum correlations and quantum information propagating through actively-pumped fast-light media has not been studied in detail. To investigate this behavior, we send one half of an entangled state of light through a gain-assisted fast-light medium and detect the remaining quantum correlations. We show that the quantum correlations can be advanced by a small fraction of the correlation time while the entanglement is preserved even in the presence of noise added by phase-insensitive gain. Additionally, although we observe an advance of the peak of the quantum mutual information between the modes, we find that the degradation of the mutual information due to the added noise appears to prevent an advancement of the leading edge. In contrast, we show that both the leading and trailing edges of the mutual information in a slow-light system can be significantly delayed

    Swiss ethnoveterinary knowledge on medicinal plants - a within-country comparison of Italian speaking regions with north-western German speaking regions

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    BACKGROUND: Ethnoveterinary knowledge in Europe may play an important role as a basis for sustainable treatment options for livestock. Aims of our study were (a) to compare the ethnoveterinary practices of two culturally and sociodemographically different regions of Switzerland, (b) to compare results with earlier ethnoveterinary studies conducted in Switzerland and in adjacent Italian regions and, (c) to evaluate possible reasons for regional differences in European ethnoveterinary medicine. METHODS: 25 interviews were conducted in 2014 in all Italian speaking regions (ItR) of Switzerland, and 31 interviews were held in five north-western German speaking Cantons (GeC). Semi-structured questionnaires were used to collect detailed information regarding plant species, mode of preparation, dosage, route of administration, category of use, origin of knowledge, frequency of use, and satisfaction with outcomes of the treatments. RESULTS: A total of 162 homemade remedies in ItR and 219 in GeC were reported, out of which 125 and 145, respectively, were reported to contain only one plant species (homemade single species herbal remedy report, HSHR). 44 ItR and 43 GeC plant species were reported to treat livestock, of which only a half were used in both regions. For each HSHR, we classified the treatment intention of all use reports (UR), leading to a total of 205 and 219 UR in ItR and GeC respectively. While cattle were the most often treated livestock species in both study regions, in ItR 40% of UR were administered to small ruminants. Main indications in both regions were gastrointestinal diseases and skin afflictions, but in ItR a high number of URs were reported as antiparasitics. URs were mainly handed down from the past generation, but in GeC the source of knowledge for 20% of URs were from courses. Regarding the used plant species, ItR showed a higher concordance with Swiss than Italian studies, but with some differences to all regions. A total of 22 (14 ItR; 8 GeC) plant species in this study have not been reported before in ethnoveterinary studies of Swiss and Italian alpine regions. CONCLUSIONS: ItR and GeC, show differences and similarities with respect to their own ethnoveterinary practices and earlier Swiss and Italian ethnoveterinary studies. Linguistic, geographical, as well as social and farm-structural conditions influence the regional ethnoveterinary knowledge. However, political borders seem to be more important than language or geographical barriers

    Manifestation of Quantum Chaos in Electronic Band Structures

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    We use semiconductors as an example to show that quantum chaos manifests itself in the energy spectrum of crystals. We analyze the {\it ab initio} band structure of silicon and the tight-binding spectrum of the alloy AlxGa1xAsAl_xGa_{1-x}As, and show that some of their statistical properties obey the universal predictions of quantum chaos derived from the theory of random matrices. Also, the Bloch momenta are interpreted as external, tunable, parameters, acting on the reduced (unit cell) Hamiltonian, in close analogy to Aharonov-Bohm fluxes threading a torus. They are used in the investigation of the parametric autocorrelator of crystal velocities. We find that our results are in good agreement with the universal curves recently proposed by Simons and coworkers.Comment: 15 pages with 6 Postscript figures included, RevTex-3, CMT-ERM/940
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