Effect of metal micro-structuring on the mechanical behavior of polymer–metal laser T-joints

AbstractThe metal was locally structured by pulsed laser radiation producing microscopic patterns on its surface. In a second step the opposite side of the micro-structured metal was irradiated by a continuous wave (CW) fiber laser to achieve the mechanical interlock between the two materials. A tight relationship between the microstructure parameters and pull-out test performance was observed. The greatest strength was achieved when the distance between subsequent grooves was minimized. The T-joint mechanical performance did not reveal any significant dependence on the considered range of joining areas. The morphological and topographical features of the detached surfaces showed that the micro-structured grooves were completely filled during the laser conductive joining process. Different alignment angles of patterns produced different failure modes although there was no evidence of an additional mechanical interlock

Ice cave reveals environmental forcing of long-term Pyrenean tree line dynamics

1. Tree lines are supposed to react sensitively to the current global change. However, the lack of a long-term (millennial) perspective on tree line shifts in the Pyrenees prevents understanding the underlying ecosystem dynamics and processes. 2. We combine multiproxy palaeoecological analyses (fossil pollen, spores, conifer stomata, plant macrofossils, and ordination) from an outstanding ice cave deposit located in the alpine belt c. 200 m above current tree line (Armeña-A294 Ice Cave, 2, 238 m a.s.l.), to assess for the first time in the Pyrenees, tree line dynamics, and ecosystem resilience to climate changes 5, 700–2, 200 (cal.) years ago. 3. The tree line ecotone was located at the cave altitude from 5, 700 to 4, 650 cal year bp, when vegetation consisted of open Pinus uncinata Ramond ex DC and Betula spp. Woodlands and timberline were very close to the site. Subsequently, tree line slightly raised and timberline reached the ice cave altitude, exceeding its today''s uppermost limit by c. 300–400 m during more than four centuries (4, 650 and 4, 200 cal year bp) at the end of the Holocene Thermal Maximum. After 4, 200 cal year bp, alpine tundra communities dominated by Dryas octopetala L. expanded while tree line descended, most likely as a consequence of the Neoglacial cooling. Prehistoric livestock raising likely reinforced climate cooling impacts at 3, 450–3, 250 cal year bp. Finally, a tree line ecotone developed around the cave that was on its turn replaced by alpine communities during the past 2, 000 years. 4. Synthesis. The long-term Pyrenean tree line ecotone sensitivity suggests that rising temperatures will trigger future P. uncinata and Betula expansions to higher elevations, replacing arctic–alpine plant species. Climate change is causing the rapid melting of the cave ice; rescue investigations would be urgently needed to exploit its unique ecological information

A theoretical introduction to “Combinatory SYBR®Green qPCR Screening”, a matrix-based approach for the detection of materials derived from genetically modified plants

The detection of genetically modified (GM) materials in food and feed products is a complex multi-step analytical process invoking screening, identification, and often quantification of the genetically modified organisms (GMO) present in a sample. “Combinatory qPCR SYBR®Green screening” (CoSYPS) is a matrix-based approach for determining the presence of GM plant materials in products. The CoSYPS decision-support system (DSS) interprets the analytical results of SYBR®GREEN qPCR analysis based on four values: the Ct- and Tm values and the LOD and LOQ for each method. A theoretical explanation of the different concepts applied in CoSYPS analysis is given (GMO Universe, “Prime number tracing”, matrix/combinatory approach) and documented using the RoundUp Ready soy GTS40-3-2 as an example. By applying a limited set of SYBR®GREEN qPCR methods and through application of a newly developed “prime number”-based algorithm, the nature of subsets of corresponding GMO in a sample can be determined. Together, these analyses provide guidance for semi-quantitative estimation of GMO presence in a food and feed product

Escenarios, tempo e indicadores paleoambientales para la identificación del Antropoceno en el paisaje vegetal del Pirineo Central (NE Iberia) [Scenarios, timing and paleo-environmental indicators for the identification of Anthropocene in the vegetal landscape of the Central Pyrenees (NE Iberia)]

El Antropoceno puede considerarse como el origen de la configuración paisajística actual, y en relación a la vegetación, como el periodo en el que la intervención humana es el agente principal de los cambios que se producen de forma clara, intensa y permanente en el tiempo. En este trabajo se recopilan y comparan datos de secuencias palinológicas y de microcarbones, ocupaciones de yacimientos arqueológicos y dataciones de paleoincendios localizados en el Pirineo central, además de información documental, exponiendo una reflexión sobre las supuestas evidencias que promulgan una deforestación temprana y el uso del fuego de origen antrópico como señal inequívoca de intervención humana y surgimiento de los paisajes culturales desde hace milenios. En realidad, lo que se constata es una alta diversidad temporal y espacial entre todos los indicios, y sólo a partir de la Baja Edad Media (últimos 700 años, 1300 AD), los indicadores y valores de los mismos ofrecen auténtico consenso sobre el inicio de cambios consistentes y duraderos que marcarían el inicio del Antropoceno. The Anthropocene is related to the origin of current landscape configuration, and in terms of vegetation, with the consideration of human action as main forcing of clear, intense and permanent changes through time. In this paper we compile and compare data from palynological sequences, microcharcoal records, archaeological sites and radiocarbon dates from palaeofires located in the central Pyrenees besides historical documents, and we argue that some evidences related to early deforestation processes and use of human fire are not so clear than some authors point. Conversely, indicators of unequivocal human use and the origin of cultural landscapes are located only a few centuries and not a few millennia ago. In fact, high temporal and spatial variability is recorded until the Middle Ages (last 700 years, 1300 AD), when a series of consistent and permanent changes suggest the onset of the Anthropocene