High-resolution Late Pleistocene paleomagnetic secular variation record from Laguna Potrok Aike, Southern Patagonia (Argentina): preliminary results from the ICDP-PASADO drilling

PosterHere we present preliminary results of a high-resolution full vector paleomagnetic reconstruction from the southernmost continental scientific drilling site Laguna Potrok Aike, Argentina (52°S). Magnetic analyses of the long PASADO-ICDP composite record are currently underway at the Sedimentary paleomagnetism laboratory of the Institut des sciences de la mer de Rimouski (ISMER) and reveal high quality paleomagnetic dat

Human trafficking: Coding a crime hampered by imprecise language

Este trabajo tiene como finalidad exponer un breve análisis, aunque complejo y detallado, del delito de trata de personas desde una perspectiva lógica y comparativa que dilucide con mayor énfasis los problemas de codificación. Se introducirán los preceptos principales que identifican a todo ordenamiento jurídico y la diferencia entre ellos.Facultad de Ciencias Jurídicas y Sociale

La trata de personas: la codificación de un delito entorpecido por un lenguaje poco preciso

   Durante años, la trata de personas, a pesar de considerarse uno de los delitos más importantes y antiguos de la sociedad, ha sido pasada a un segundo plano en la codificación de nuestro código penal dejando como consecuencia una redacción inconsistente e incompleta. Y es que resulta incomprensible cómo es que un delito que atenta a los principales derechos humanos pueda ser pasado desapercibido a lo largo de la historia penal y social de nuestro país, y que haya comenzado a tomar relevancia la necesidad de un reparo social y legislativo recién en el siglo XXI

High-resolution paleomagnetic records from Laguna Potrok Aike (Patagonia, Argentina) for the last 16,000 years

Holocene and Late-glacial records documenting variations in direction and intensity of the geomagnetic field during the last 16,000 cal. BP are presented for Southern Patagonia. This continuous high-resolution terrestrial record from Laguna Potrok Aike (51°58´S, 70°23´W) was recovered within the SALSA(South Argentinean Lake Sediment Archives and modeling) project. Mineral magnetic measurements indicate that pseudo single-domain magnetite is the major carrier of the remanence allowing the reliable determination of stable natural remanent magnetization inclinations and declinations from alternatingfield demagnetization and principal component analysis. Paleomagnetic secular variation records reveal most of the familiar features of declination and inclination that have previously been reported in other records from South Argentina but conspicuous centennial-scale differences are also observed. The results illustrate the potential of paleosecular variations records for dating sedimentary sequences in southern South America.Fil: Gogorza, Claudia Susana. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Irurzun, Maria Alicia. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Sinito, Ana Maria. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Lisé Pronovost, Agathe. Université du Québec a Montreal; CanadáFil: St Onge, Guillaume. Université du Québec a Montreal; CanadáFil: Haberzettl, Torsten. Universitat Jena; AlemaniaFil: Ohlendorf, Christian. Universitat de Bremen; AlemaniaFil: Kastner, Stephanie. Universitat de Bremen; AlemaniaFil: Zolitschka, Bernd. Universitat de Bremen; Alemani

Climatic influence of the latest Antarctic isotope maximum of the last glacial period (AIM4) on Southern Patagonia

This paper presents the first detailed paleoclimate reconstruction of the latest Antarctic isotope maximum (AIM4, ~ 33–29 ka cal. BP) at 52°S in continental southeastern Argentine Patagonia. High-resolution sedimentological and geochemical analyses of sediments from the maar lake Potrok Aike (PTA) reveal a decrease in the thickness of flood-induced turbidites and a series of wind burst deposits during AIM4, both pointing to increasingly drier conditions. This interpretation is also supported by a significant amount of runoff-driven micropumices incorporated within the sediments that suggests a lower lake level with canyons incising thick tephra deposits around the lake. Increased gustiness and/or dust availability in southeast Patagonia, together with intensified Antarctic circumpolar circulation in the Drake Passage, dust deposition in the Scotia Sea and in Antarctica ice shelf, are consistent with a southward shift of the Southern Westerly Winds (SWW) during the AIM4. In contrast to other warmer AIMs, the SWW during the AIM4 did not migrate far enough south to generate upwelling in the Southern Ocean and they did not reach 52°S in SE Patagonia, as revealed by unchanged values of the rock-magnetic proxy of wind intensity obtained from the same PTA core. Nevertheless, the SWW displacement during AIM4 imposed drier conditions at 52°S in southeast Patagonia likely by blocking precipitation from the Atlantic Ocean, in a way similar to modern seasonal variations and the other Antarctic warm events. -- Keywords : Southern Westerly Winds ; Micro X-ray fluorescence ; Microfacies ; Micropumices ; Dust ; Flood

Forschendes Lernen. Konzeptuelle Grundlagen und Potenziale digitaler Medien

Im folgenden Artikel wird dargelegt, was unter dem Konzept des forschenden Lernens zu verstehen ist und welche Einsatzmöglichkeiten sich für das forschende Lernen im Kontext Universität ergeben. Dabei werden speziell diejenigen Merkmale theoretisch herausgearbeitet, die aus Lehrendenperspektive Anknüpfungspunkte für einen prozessbegleitenden Medieneinsatz bieten. Exemplarisch wird eine Lehrveranstaltung angeführt, die auf Fallebene zeigt, wie ein forschungsorientiertes Seminar um digitale Medien angereichert werden kann und welche Chancen und Grenzen sich bei der selbstgesteuerten Verwendung digitaler Medienangebote ergeben. Die Evaluation des Seminars zeigt, dass die Studierenden einen großen Lernzuwachs erleben, jedoch teilweise durch die Offenheit des Lernens überfordert sind. Diese und andere Gründe führen dazu, dass die von Lehrenden vorgeschlagenen Medienangebote selten bis kaum genutzt werden. Zudem sehen Lernende die Qualität virtuell distribuierter Inhalte kritisch, was sich auf die Akzeptanz und die Nutzung der vorhandenen digitalen Medienangebote auswirkt. (DIPF/Orig.

Rainforest response to glacial terminations before and after human arrival in Lutruwita (Tasmania)

Limited understanding of how Indigenous people have created and managed the Australian landscape continues to have repercussions on how landscapes are culturally interpreted and managed today. Addressing this is critically important as climate change is increasing the frequency and intensity of wildfires, whilst challenging the objectives, methods and efficacy of contemporary landscape management practices. Here we compare the palaeoecology of vegetation changes across glacial to interglacial states before (Termination II) and after (Termination I) human occupation of the cool temperate rainforests of western Lutruwita (Tasmania). Sediment from Darwin Crater (Termination II) and Lake Selina (Termination I) were analysed using radiometric dating, fossil pollen, charcoal, geochemical, environmental magnetic and sedimentary methods to produce a comprehensive reconstruction of vegetation and landscape dynamics. Results show marked differences in the rainforest response to the transition from glacial to interglacial climates before and after human arrival at c. 43,000 years ago (ka). In the absence of human disturbance, Phyllocladus aspleniifolius-Nothofagus cunninghamii lowland rainforest taxa dominated the last interglacial period (∼77% of the pollen sum) but was reduced in the current interglacial (∼41%) and largely replaced by Gymnoschoenus sphaerocephalus buttongrass moorland (10–23%). This demonstrates the legacy of Indigenous Palawa managed landscapes, primarily using fire to promote landscape openness and prevent the dominance of an ecologically climax rainforest community, until their forced removal via invasion and colonisation ca. 1806

Reconciling 22,000 years of landscape openness in a renowned wilderness

Here, we explore the profound impact of the Tasmanian Aboriginal (Palawa) people on Tasmanian landscapes by examining a 22,000-year record of landscape change from Lake Selina in western Tasmania, Australia. We analysed a sediment core for palaeoecological proxies, namely, pollen (vegetation), charcoal (fire), and geochemical data (landscape weathering). This study reveals that the contemporary landscape is a product of Palawa people’s intentional and strategic fire management practices characterised by fire-dependent buttongrass moorland and the absence of climax rainforest. Specifically, our data show that rainforest failed to re-establish a dominance at Lake Selina following the end of the Last Glacial Maximum, as temperature and moisture increased as a result of Palawa cultural fire for at least 18,000 years. This finding challenges the long-held notion that Tasmania’s wilderness is a product of the absence of human activity. Rather, archaeological sites across western and central Tasmania demonstrate long term presence, with some of the highest artefact and faunal bone densities in the world. The study contributes to the recognition of Tasmania’s west as a cultural landscape shaped by generations of Aboriginal care for Country and fire practices

Dredging and canal gate technologies in Portus, the ancient harbour of Rome, reconstructed from event stratigraphy and multi-proxy sediment analysis

Ancient harbours are rich archives of human-environment interaction. However, dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events. Portus, the maritime harbour of Rome at the height of the Roman Empire, was a port complex composed of basins and canals connecting the commercial harbour to Rome via the Tiber River. Sediment core CPS1 in the narrowest of these canals, Canale Traverso, is located centrally in what was the capital city's commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year. Here we use piston coring, high-resolution core scanning and a multi-proxy sediment analysis including for the first time paleo- and rock-magnetism, and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy. The method allowed precise identification of major reworked events, including a dredged deposit and a hyperpycnal deposit, which improve the chronostratigraphy and water depth reconstruction, and sheds light on harbour technologies at the height of the Roman Empire. A debris layer with abundant ceramic fragments and rocks marks the decommissioning of Canale Traverso and provides a new chronostratigraphic marker at Portus. Multi-proxy riverine input signatures point to the possible use of canal gate technology for water flow management

Myosin5a tail associates directly with Rab3A-containing compartments in neurons

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Society for Biochemistry and Molecular Biology. The definitive version was published in Journal of Biological Chemistry, 286 (2011): 14352-14361, doi:10.1074/jbc.M110.187286.Myosin-Va (Myo5a) is a motor protein associated with synaptic vesicles (SVs) but the mechanism by which it interacts has not yet been identified. A potential class of binding partners are Rab GTPases and Rab3A is known to associate with SVs and is involved in SV trafficking. We performed experiments to determine whether Rab3A interacts with Myo5a and whether it is required for transport of neuronal vesicles. In vitro motility assays performed with axoplasm from the squid giant axon showed a requirement for a Rab GTPase in Myo5a-dependent vesicle transport. Furthermore, mouse recombinant Myo5a tail revealed that it associated with Rab3A in rat brain synaptosomal preparations in vitro and the association was confirmed by immunofluorescence imaging of primary neurons isolated from the frontal cortex of mouse brains. Synaptosomal Rab3A was retained on recombinant GST-tagged Myo5a tail affinity columns in a GTP-dependent manner. Finally, the direct interaction of Myo5a and Rab3A was determined by sedimentation v e l o c i t y analytical ultracentrifugation using recombinant mouse Myo5a tail and human Rab3A. When both proteins were incubated in the presence of 1 mM GTPγS, Myo5a tail and Rab3A formed a complex and a direct interaction was observed. Further analysis revealed that GTP-bound Rab3A interacts with both the monomeric and dimeric species of the Myo5a tail. However, the interaction between Myo5a tail and nucleotidefree Rab3A did not occur. Thus, our results show that Myo5a and Rab3A are direct binding partners and interact on SVs and that the Myo5a/Rab3A complex is involved in transport of neuronal vesicles