Reconsidering the current stratigraphy of the Alpine Lateglacial

The sedimentary and morphological evidence for Lateglacial glacier fluctuations in the Lienz area provides a strong case against the currently used pentapartite stratigraphic subdivision of the Alpine Lateglacial (ALG; c. 19–11.7 ka) i.e. the timespan between the Würmian Pleniglacial (= Alpine Last Glacial Maximum; AlpLGM) and the beginning of the Holocene. The results of comprehensive geological mapping (including the detection of mass movements) supported by geochronological data and pollen analysis revealed that the ALG- record of the Schobergruppe mountains and the Lienz Dolomites can be subdivided into four unconformity-bounded (allostratgraphic) units which are linked to three climatostratigraphically-defined phases of glacier activity. Delta deposits and till of local glaciers document the phase of ice-decay after the AlpLGM. Between this period and the Bølling/Allerød (B/A) interstadial only one glacier stabilisation with massive end moraines, correlated with the Gschnitz stadial, is evident. Multiple end moraines prove the presence of very active glacier tongues during the Younger Dryas aged Egesen stadial. The 10Be exposure dating of an end moraine, previously attributed to the Daun stadial (pre-B/A interstadial) based on ΔELA values, provided an age of 12.8 ± 0.6 ka indicating it is of Younger Dryas age. This case highlights the pitfalls of the commonly used ΔELA-based stratigraphic ALG subdivision and the subsequent derivation of palaeoclimatic implications. ΔELAs are still considered as a useful tool for correlation on the local scale e.g. in one mountain group with a quite comparable topography and lithology and taking into account the limitations, especially the impact of debris cover. However, our results show that a stratigraphic correlation across the whole Alpine chain via ΔELAs is not a successful approach potentially leading to bias and, eventually, to circular arguments.researc

A ~180,000years sedimentation history of a perialpine overdeepened glacial trough (Wehntal, N-Switzerland)

A 30m-deep drill core from a glacially overdeepened trough in Northern Switzerland recovered a ~180ka old sedimentary succession that provides new insights into the timing and nature of erosion-sedimentation processes in the Swiss lowlands. The luminescence-dated stratigraphic succession starts at the bottom of the core with laminated carbonate-rich lake sediments reflecting deposition in a proglacial lake between ~180 and 130ka ago (Marine Isotope Stage MIS 6). Anomalies in geotechnical properties and the occurrence of deformation structures suggest temporary ice contact around 140ka. Up-core, organic content increases in the lake deposits indicating a warming of climate. These sediments are overlain by a peat deposit characterised by pollen assemblages typical of the late Eemian (MIS 5e). An abrupt transition following this interglacial encompasses a likely hiatus and probably marks a sudden lowering of the water level. The peat unit is overlain by deposits of a cold unproductive lake dated to late MIS 5 and MIS 4, which do not show any direct influence from glaciers. An upper peat unit, the so-called >, previously encountered in construction pits, interrupts this cold lacustrine phase and marks more temperate climatic conditions between 60 and 45ka (MIS 3). In the upper part of the core, a succession of fluvial and alluvial deposits documents the Late Glacial and Holocene sedimentation in the basin. The sedimentary succession at Wehntal confirms that the glaciation during MIS 6 did not apparently cause the overdeepening of the valley, as the lacustrine basin fill covering most of MIS 6 is still preserved. Consequently, erosion of the basin is most likely linked to an older glaciation. This study shows that new dating techniques combined with palaeoenvironmental interpretations of sediments from such overdeepened troughs provide valuable insights into the past glacial histor

Sortimentos de Pinus elliottii Engelm para a região da Serra do Sudeste do estado do Rio Grande do Sul, Brasil.

In the present work the assortments of the of Pinus elliottii Engelm, with a view to the formation of assortments and tables of asssortments for regional use in the Serra do Sudeste, State of  Rio Grande do Sul were studied. Thus, the development of stem taper for the medium tree and for diameter class and the formation of assortments were studied. Furthermore tables of assortments for regional use were developed. The polynomial models of 5th degree showed good adjustment and statistical precision, with relative diameter (di/d)  as dependent variable and relative height (hi/h) as independent variable. Its integration allowed to estimate absolute and relative volumes of the assortments which were classified and expressed in percentage of the volume and number of corresponding logs. Thus, in order to quantify  commercial volume of the tree, the minimum diameter of 7 cm outside bark at the small end of the tree and for sawlog timber a diameter of 14 cm outside bark were considered. These results are integrated in tables of optimized assortments for individual trees.No presente trabalho foi estudada a forma do tronco de Pinus elliottii Engelm, para formação de sortimentos e confecção de tabelas para uso na região da Serra do Sudeste do Estado do Rio Grande do Sul. A forma do tronco foi ajustada com boa precisão estatística por um polinômio de 5º grau, tendo como variáveis dependentes os diâmetros relativos (di/d) e como variáveis independentes as alturas relativas (hi/h). A integração do polinômio permitiu estimar os volumes absolutos e relativos dos sortimentos, sendo estes classificados e expressos em percentagem do volume e em número de toras correspondentes. Para isso, foi considerado, para quantificar o volume total aproveitável da árvore, o diâmetro mínimo de 7 cm com casca e para o volume de toras para a serraria, o diâmetro de 14 cm com casca, ambos tomados na ponta fina da tora. Esses resultados deram origem a tabelas de sortimentos otimizadas para árvores individuais

Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes

Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag–Magnetite and Au–Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surface-enhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag–Magnetite and Au–Magnetite nanostructures that is very similar to that of other composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles.Peer Reviewe

PRODUÇÃO DE Eucalyptus grandis Hill ex Maiden EM DIFERENTES INTENSIDADES DE DESBASTE

O efeito de diferentes intensidades de desbaste sobre a produção Eucalyptus grandis Hill ex Maiden implantado no ano de 1981, em espaçamento inicial de 3,0 x 2,0 metros, na região de Cachoeira do Sul, Rio Grande do Sul, foi estudado com delineamento de blocos ao acaso, com duas repetições e quatro tratamentos: testemunha, sem desbastes, manutenção de 40%, 50% e 60% da área basal da testemunha, constando-se diferença significativa entre os tratamentos, ao nível de 5% de probabilidade. A produção máxima (756,3 m3cc/ha) foi obtida na testemunha, sem desbaste, que não diferiu estatísticamente de 639,6 m3cc/ha, obtido no tratamento com manutenção de 60% da área basal da testemunha, porém diferiu dos tratamentos com manutenção de 50% e 40% da área basal da testemunha. A redução da área basal incrementou a concentração das freqüências nas maiores classes de diâmetro, deslocando a distribuição para a direita, porém com perdas expressivas de produção total e acréscimo significativo no diâmetro. A manutenção de 60% da área basal da testemunha permitiu as menores perdas de produção, cerca de 15,4%, e um ganho de 6,4cm ou 23,9% em incremento diamétrico das árvores remanescentes quando comparado com a testemunha, sem desbaste

Holzreste von spätglazialen Kiefern aus der tiefgründigen und tonreichen Permanentrutschung ‚Spiegelberg’, Kanton Schwyz (Schweiz)

Die Hauptstrasse Nr. 8 zwischen Schwyz und Sattel verläuft durch aktive und tiefgründige Permanentrutschungen. Im lehmigen, matrix-gestützten Gehängeschutt der Rutschung ‚Spiegelberg’ wurde zwischen 1979–81 die Gütschbrücke erstellt (LK: 690.314/211.943; 670 m ü.M.) und unter Anwendung von Gründungsschutzschächten im unterlagernden Fels fundiert. Beim Aushub des Schutzschachtes für den Pfeiler WL-Nord wurden in der Tiefe von 25 m bzw. 38 m unter Oberkante Terrain zwei Nadelbaumfragmente gefunden. Letzterer Holzfund lag wenige Meter über der Felsoberfläche. Die 14C-Altersdatierung der Holzfunde (beide Pinus sylvestris) ergaben kalibrierte Altersspannen zwischen 11.690–11.270 cal. a BP (2s) am Übergang vom Grönland Stadial 1 (GS-1; ‚Jüngere Dryas’) zum Holozän bzw. 13.830–13.640 cal. a BP (2s) zu Beginn der spätglazialen Wärmeschwankung GI-1c (Grönland Interstadial 1c; ‚Allerød’). Die vorliegenden Daten zeigen, dass die Hanginstabilitäten bei ‚Spiegelberg’ nach dem Zerfall des letzteiszeitlichen Muota/Reussgletschers zu Beginn des Spätglazials eingesetzt haben mussten, und die Waldkiefer schon kurz nach den Kälterückschlägen des GI-1d (‚Aegelsee-Schwankung’) bzw. des GS-1 am nördlichen Alpenrand präsent war.researc

Minimizing attosecond CEP jitter by carrier envelope phase tuning

Minimizing the CEP jitter of isolated attosecond pulses (IAP) will be important for future applications. This jitter is experimentally and theoretically investigated and can be minimized when the driving pulse is near its Fourier limit but with slightly negative chirp. Thus, understanding and characterization of the CEP jitter of IAPs is a first step towards exact control of the electric field of IAP pulses

Shaping Mediterranean landscapes:The cultural impact of anthropogenic fires in Tyrrhenian southern Tuscany during the Iron and Middle Ages (800–450 BC / AD 650–1300)

Charcoal analysis, applied in sediment facies analysis of the Pecora river palaeochannel (Tyrrhenian southern Tuscany, Italy), detected the occurrence of past fire events in two different fluvial landforms at 800–450 BC and again at AD 650–1300. Taking place in a central Mediterranean district adequately studied through palaeoenvironmental and archaeological research, the investigation determined land changes, time phases and socio-economic driving forces involved in dynamic processes of fire. The fire sequences had purely anthropogenic origins and were linked to forest opening and reduction by local communities. Introduced by the Etruscans, fires dated to 800–450 BC involved mainly the forest cover on the hilly slopes, ensuring agricultural exploitation. From AD 650, fires contributed to Medieval upstream reclamation and vegetation clearing of flat swamplands. From AD 850 to 1050, the use of fire spread over a wider area in the river valley, increasing arable lands. Between AD 1150 and 1300, fires belonged to a regional forest clearance phase. Medieval fire episodes had a paramount importance in shaping and determining the character of the Tuscan Mediterranean landscape. From AD 850, Medieval fire clearing influenced regional vegetation history contributing to the decline of the dominant deciduous Quercus woodland. Open habitats became the new form of a clearly detectable agricultural landscape from AD 950. The use of fire clearing and the resulting landscape changes in the Pecora river valley depended on the political strategies adopted by Medieval authorities and marked, in fact, the progression of a cultural landscape still characterizing central Tyrrhenian Italy