137 research outputs found

    Gesellschaftliche Leistungen der biologischen Landwirtschaft

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    Zusammenfassuung: In diesem Bericht werden die wissenschaftlichen Ergebnisse nationaler und internationaler Studien zu den gesellschaftlichen Leistungen des Biolandbaus zusammengefasst. Als Referenzen werden dabei sowohl die konventionelle wie auch die integrierte Landwirtschaft herangezogen. Es ist den Autoren bewusst, dass alle Landwirtschaftsmethoden in der Schweiz und im Ausland eine grosse Streubreite aufweisen, da der Einfluss der regionalen sozioökonomischen Rahmenbedingungen, der Standortfaktoren, der Betriebsleiter und der unterschiedlichen staatlichen und privaten Regulierungen gross ist. Trotzdem ergeben sich fĂŒr die verschiedenen Landwirtschaftsmethoden klare Unterschiede, die bei den agrarpolitischen Massnahmen berĂŒcksichtigt werden mĂŒssen. BezĂŒglich der positiven ExternalitĂ€ten weist der Biolandbau klare Mehrleistungen in der BiodiversitĂ€t auf. Dies sowohl auf der Ebene der Genetik, der Arten und besonders auch der Habitate. Deutlich sind die Mehrleistungen des Biolandbaus auch im Bereich des Humusaufbaus, was eine höhere CO2-Sequestrierung zur Folge hat. Obwohl eine dauerhafte Honorierung der Vermeidung negativer ExternalitĂ€ten im bisherigen Konzept der Weiterentwicklung des Direktzahlungssystems (WDZ) nicht vorgesehen ist, sind hier die Vorteile der biologischen Landwirtschaft betrĂ€chtlich. Dies betrifft die NĂ€hrstoff- und Pflanzenschutzmittelverluste in Grund- und OberflĂ€chengewĂ€sser sowie in andere Umweltkompartimente, der Verbrauch von nicht erneuerbarer Energie, die Emissionen von Klimagasen und die Belastungen mit Tiermedikamenten. Die nationalen und internationalen Studien zeigen auf, dass der Biolandbau sich besonders durch Systemwirkungen auszeichnet: erhöhte BiodiversitĂ€t, verbesserter Schutz des Bodens, wirksame Vermeidung von Umweltbelastungen, effiziente Nutzung von natĂŒrlichen Ressourcen, geringer Verbrauch nicht erneuerbarer Energie und verbessertes Tierwohl. Dies sind die Effekte von komplexen Response-Massnahmen der Betriebsleiter auf einfach zu kontrollierende EinschrĂ€nkungen und Verbote. Dadurch entstehen nicht zu unterschĂ€tzende Zusatzleistungen und Synergien bei der Erreichung der vom Bund definierten Ziele. Um den Mehrleistungen des Biolandbaus gerecht zu werden, schlagen die Autoren zwei neue Massnahmen vor: 1) BiodiversitĂ€tsbeitrag fĂŒr Acker, Sonderkulturen und intensive Wiesen und 2) CO2-SequestrationsbeitrĂ€ge. Damit sind aber die gesellschaftlich wichtigen Mehrleistungen des Biolandbaus noch nicht abgegolten. Bei der Vermeidung negativer ExternalitĂ€ten werden höhere umweltschutzrelevante Effekte erzielt. Diese können i) durch die EinfĂŒhrung eines negativen Anreizsystems nach dem Polluter-Pays-Principle (z.B. Stickstoffsteuer, CO2 - Abgabe), ii) durch ein höheres Einstiegsniveau bei den Cross-Compliance-Massnahmen fĂŒr alle Betriebe (ÖLNplus) oder iii) durch einen finanziellen Ausgleich fĂŒr die Mehrleistungen des Biolandbaus abgegolten werden. Die „Förderung des Biolandbaus“ als systemorientierte Massnahme macht auch nach dem Grundsatz des effizienten Einsatzes von Steuermitteln Sinn und stellt eine kosteneffektive Massnahme dar. Einerseits können damit die deutlich höheren positiven ExternalitĂ€ten abgegolten werden, andererseits wird die stĂ€rkere Vermeidung von negativen ExternalitĂ€ten genĂŒgend berĂŒcksichtigt

    Evolution of the Greater Caucasus Basement and Formation of the Main Caucasus Thrust, Georgia

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    Along the northern margin of the Arabia‐Eurasia collision zone in the western Greater Caucasus, the Main Caucasus Thrust (MCT) juxtaposes Paleozoic crystalline basement to the north against Mesozoic metasedimentary and volcaniclastic rocks to the south. The MCT is commonly assumed to be the trace of an active plate‐boundary scale structure that accommodates Arabia‐Eurasia convergence, but field data supporting this interpretation are equivocal. Here we investigate the deformation history of the rocks juxtaposed across the MCT in Georgia using field observations, microstructural analysis, U‐Pb and 40Ar/39Ar geochronology, and 40Ar/39Ar and (U‐Th)/He thermochronology. Zircon U‐Pb analyses show that Greater Caucasus crystalline rocks formed in the Early Paleozoic on the margin of Gondwana. Low‐pressure/temperature amphibolite‐facies metamorphism of these metasedimentary rocks and associated plutonism likely took place during Carboniferous accretion onto the Laurussian margin, as indicated by igneous and metamorphic zircon U‐Pb ages of ~330–310 Ma. 40Ar/39Ar ages of ~190–135 Ma from muscovite in a greenschist‐facies shear zone indicate that the MCT likely developed during Mesozoic inversion and/or rifting of the Caucasus Basin. A Mesozoic 40Ar/39Ar biotite age with release spectra indicating partial resetting and Cenozoic (<40 Ma) apatite and zircon (U‐Th)/He ages imply at least ~5–8 km of Greater Caucasus basement exhumation since ~10 Ma in response to Arabia‐Eurasia collision. Cenozoic reactivation of the MCT may have accommodated a fraction of this exhumation. However, Cenozoic zircon (U‐Th)/He ages in both the hanging wall and footwall of the MCT require partitioning a substantial component of this deformation onto structures to the south.Plain Language SummaryCollisions between continents cause deformation of the Earth’s crust and the uplift of large mountain ranges like the Himalayas. Large faults often form to accommodate this deformation and may help bring rocks once buried at great depths up to the surface of the Earth. The Greater Caucasus Mountains form the northernmost part of a zone of deformation due to the ongoing collision between the Arabian and Eurasian continents. The Main Caucasus Thrust (MCT) is a fault juxtaposing old igneous and metamorphic (crystalline) rocks against younger rocks that has often been assumed to be a major means of accommodating Arabia‐Eurasia collision. This study examines the history of rocks along the MCT with a combination of field work, study of microscopic deformation in rocks, and dating of rock formation and cooling. The crystalline rocks were added to the margins of present‐day Eurasia about 330–310 million years ago, and the MCT first formed about 190–135 million years ago. The MCT is likely at most one of many structures accommodating present‐day Arabia‐Eurasia collision.Key PointsAmphibolite‐facies metamorphism and plutonism in the Greater Caucasus basement took place ~330–310 MaThe Main Caucasus Thrust formed as a greenschist‐facies shear zone during Caucasus Basin inversion and/or rifting (~190–135 Ma)The Main Caucasus Thrust may have helped facilitate a portion of at least 5–8 km of basement exhumation during Arabia‐Eurasia collisionPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/1/tect21292-sup-0002-2019TC005828-ts01.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/2/tect21292-sup-0006-2019TC005828-ts05.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/3/tect21292_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/4/tect21292-sup-0003-2019TC005828-ts02.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/5/tect21292-sup-0005-2019TC005828-ts04.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/6/tect21292.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154626/7/tect21292-sup-0004-2019TC005828-ts03.pd

    Permian high-temperature metamorphism in the Western Alps (NW Italy)

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    During the late Palaeozoic, lithospheric thinning in part of the Alpine realm caused high-temperature low-to-medium pressure metamorphism and partial melting in the lower crust. Permian metamorphism and magmatism has extensively been recorded and dated in the Central, Eastern, and Southern Alps. However, Permian metamorphic ages in the Western Alps so far are constrained by very few and sparsely distributed data. The present study fills this gap. We present U/Pb ages of metamorphic zircon from several Adria-derived continental units now situated in the Western Alps, defining a range between 286 and 266 Ma. Trace element thermometry yields temperatures of 580-890°C from Ti-in-zircon and 630-850°C from Zr-in-rutile for Permian metamorphic rims. These temperature estimates, together with preserved mineral assemblages (garnet-prismatic sillimanite-biotite-plagioclase-quartz-K-feldspar-rutile), define pervasive upper-amphibolite to granulite facies conditions for Permian metamorphism. U/Pb ages from this study are similar to Permian ages reported for the Ivrea Zone in the Southern Alps and Austroalpine units in the Central and Eastern Alps. Regional comparison across the former Adriatic and European margin reveals a complex pattern of ages reported from late Palaeozoic magmatic and metamorphic rocks (and relics thereof): two late Variscan age groups (~330 and ~300 Ma) are followed seamlessly by a broad range of Permian ages (300-250 Ma). The former are associated with late-orogenic collapse; in samples from this study these are weakly represented. Clearly, dominant is the Permian group, which is related to crustal thinning, hinting to a possible initiation of continental rifting along a passive margin

    The Presidency and the Executive Branch in Latin America: What We Know and What We Need to Know

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    The presidential politics literature depicts presidents either as all- powerful actors or figureheads and seeks to explain outcomes accordingly. Th e president and the executive branch are nonetheless usually treated as black boxes, particularly i n developing countries, even though the presidency has evolved into an extremely complex branch of government. While these developments have been studied in the U nited States, far less i s known in other countries, particularly in Latin America, where presi dential systems have been considered the source of all goods and evils. To help close the knowledge gap and explore differences in policymaking characteristics not only between Latin America and the US but also across Latin American countries, this paper s ummarizes the vast literature on the organization and resources of the Executive Branch in the Americas and sets a research agenda for the study of Latin American presidencies.Fil: Bonvecchi, Alejandro. Universidad Torcuato Di Tella. Departamento de Ciencia PolĂ­tica y Estudios Internacionales; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Scartascini, Juan Carlos. Banco Interamericano de Desarrollo; Estados Unido

    Empirical Legal Studies Before 1940: A Bibliographic Essay

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    The modern empirical legal studies movement has well-known antecedents in the law and society and law and economics traditions of the latter half of the 20th century. Less well known is the body of empirical research on legal phenomena from the period prior to World War II. This paper is an extensive bibliographic essay that surveys the English language empirical legal research from approximately 1940 and earlier. The essay is arranged around the themes in the research: criminal justice, civil justice (general studies of civil litigation, auto accident litigation and compensation, divorce, small claims, jurisdiction and procedure, civil juries), debt and bankruptcy, banking, appellate courts, legal needs, legal profession (including legal education), and judicial staffing and selection. Accompanying the essay is an extensive bibliography of research articles, books, and reports
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