Multiple melt bodies fed the AD 2011 eruption of Puyehue-Cordon Caulle, Chile

Artículo de publicación ISIWithin the volcanological community there is a growing awareness that many large-to smallscale, point-source eruptive events can be fed by multiple melt bodies rather than from a single magma reservoir. In this study, glass shard major-and trace-element compositions were determined from tephra systematically sampled from the outset of the Puyehue-Corden Caulle (PCC) eruption (similar to 1 km(3)) in southern Chile which commenced on June 4th, 2011. Three distinct but cogenetic magma bodies were simultaneously tapped during the paroxysmal phase of this eruption. These are readily identified by clear compositional gaps in CaO, and by Sr/Zr and Sr/Y ratios, resulting from dominantly plagioclase extraction at slightly different pressures, with incompatible elements controlled by zircon crystallisation. Our results clearly demonstrate the utility of glass shard major-and trace-element data in defining the contribution of multiple magma bodies to an explosive eruption. The complex spatial association of the PCC fissure zone with the Liquine-Ofqui Fault zone was likely an influential factor that impeded the ascent of the parent magma and allowed the formation of discrete melt bodies within the sub-volcanic system that continued to independently fractionate.Argentine PIP CONICET 2011 0311 FONCYT PICT 2010 2046 Iniciativa Cientifica Milenio grants P02-51 NC120066 Chilean Fondecyt 115146

Spatial working memory is enhanced in children by differential outcomes

Working memory (WM) is essential to academic achievement. Any enhancement of WM abilities may improve children's school performance. We tested the usefulness of the differential outcomes procedure (DOP) to enhance typically developing children's performance on a spatial WM task. The DOP involves a conditional discriminative learning task in which a correct choice response to a specific stimulus-stimulus association is reinforced with a particular reinforcer (outcome). We adapted a spatial memory task to be used with the DOP. Participants had to learn and retain in their WM four target locations of eight possible locations where a shape could be presented. Two groups of 5- and 7-year-old children performed the low-attentional version of the spatial task, and an additional group of 7-year-old children performed the high-attentional version. The results showed that compared with the standard non-differential outcomes procedure (NOP), the DOP produced better memory-based performance in 5-year-old children with the low-attentional task and in 7-year-old children with the high-attentional task. Additionally, delay intervals impaired performance in the NOP but not in the DOP. These findings suggest that the DOP may be a useful complement to other WM intervention programs targeted to improve children's academic performance at school

The independent group looks at London's west end

In the early 1950s, British culture was dominated by welfare-state visions of urban reconstruction. These projections of a stable civic society were premised on a particular way of looking at and reading the metropolitan environment. At odds with this project, the Independent Group's discussions and collaborative work developed an alternative urban semiology, which found the city to be already rich in visual resources for fashioning a more profound form of social democracy. Soon, this critical engagement would develop in different directions, represented here by Lawrence Alloway's commentary on Piccadilly Circus in his essay 'City Notes' and the London footage inserted by John McHale into his film for the Smithsons' Berlin Hauptstadt project (both 1959). By the end of the 1950s, members of the erstwhile Independent Group had produced two contrasting critical accounts of how the metropolitan centre should be looked at, which challenged the strictures of post-war reconstruction in distinct and conflicting ways. © The Author(s), 2013

Foliar lead uptake by lettuce exposed to atmospheric fallouts

Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

Dimensions of a Projection Column and Architecture of VPM and POm Axons in Rat Vibrissal Cortex

This is the first article in a series of 3 studies that investigate the anatomical determinants of thalamocortical (TC) input to excitatory neurons in a cortical column of rat primary somatosensory cortex (S1). S1 receives 2 major types of TC inputs, lemiscal and paralemniscal. Lemiscal axons arise from the ventral posteromedial nucleus (VPM) of the thalamus, whereas paralemniscal fibers originate in the posteromedial nucleus (POm). While these 2 TC projections are largely complementary in L4, overlap in other cortical layers is still a matter of debate. VPM and POm axons were specifically labeled in the same rat by virus-mediated expression of different fluorescent proteins. We show that columnar and septal projection patterns are maintained throughout most of the cortical depth with a lower degree of separation in infragranular layers, where TC axons form bands along rows. Finally, we present anatomical dimensions of “TC projection domains” for a standard column in S1

Tephrochronology

Tephrochronology is the use of primary, characterized tephras or cryptotephras as chronostratigraphic marker beds to connect and synchronize geological, paleoenvironmental, or archaeological sequences or events, or soils/paleosols, and, uniquely, to transfer relative or numerical ages or dates to them using stratigraphic and age information together with mineralogical and geochemical compositional data, especially from individual glass-shard analyses, obtained for the tephra/cryptotephra deposits. To function as an age-equivalent correlation and chronostratigraphic dating tool, tephrochronology may be undertaken in three steps: (i) mapping and describing tephras and determining their stratigraphic relationships, (ii) characterizing tephras or cryptotephras in the laboratory, and (iii) dating them using a wide range of geochronological methods. Tephrochronology is also an important tool in volcanology, informing studies on volcanic petrology, volcano eruption histories and hazards, and volcano-climate forcing. Although limitations and challenges remain, multidisciplinary applications of tephrochronology continue to grow markedly

Accumulation of Rhodopsin in Late Endosomes Triggers Photoreceptor Cell Degeneration

Progressive retinal degeneration is the underlying feature of many human retinal dystrophies. Previous work using Drosophila as a model system and analysis of specific mutations in human rhodopsin have uncovered a connection between rhodopsin endocytosis and retinal degeneration. In these mutants, rhodopsin and its regulatory protein arrestin form stable complexes, and endocytosis of these complexes causes photoreceptor cell death. In this study we show that the internalized rhodopsin is not degraded in the lysosome but instead accumulates in the late endosomes. Using mutants that are defective in late endosome to lysosome trafficking, we were able to show that rhodopsin accumulates in endosomal compartments in these mutants and leads to light-dependent retinal degeneration. Moreover, we also show that in dying photoreceptors the internalized rhodopsin is not degraded but instead shows characteristics of insoluble proteins. Together these data implicate buildup of rhodopsin in the late endosomal system as a novel trigger of death of photoreceptor neurons

Mid- to late Pliocene (3.3-2.6 Ma) global sea-level fluctuations recorded on a continental shelf transect, Whanganui Basin, New Zealand

We present a similar to 900 m-thick, mid- (3.3-3.0 Ma) to late Pliocene (3.0-2.6 Ma), shallow-marine, cyclical sedimentary succession from Whanganui Basin, New Zealand that identifies paleobathymetric changes, during a warmer-than-present interval of Earth history, relevant to future climate change. Our approach applies lithofacies, sequence stratigraphy and benthic foraminiferal analyses to two continuously-cored drillholes integrated with new and existing outcrop studies. We construct a depositional model of orbitally-paced, global sea-level changes on a wave-graded continental shelf. Unlike many previous studies, these shelf sediments were not eroded during sea-level lowstands and thus provide the potential to reconstruct the full amplitude of glacial-interglacial sea-level change. Paleobathymetric interpretations are underpinned by analysis of extant benthic foraminiferal census data and a statistical correlation with the distribution of modern taxa. In general, water depths derived from foraminiferal Modern Analogue Technique (MAT), are consistent with variability recorded by lithofacies. The inferred sea-level cycles co-vary with a qualitative climate record reconstructed from a census of extant pollen and spores, and a modern temperature relationship. A high -resolution age model is established using magnetostratigraphy constrained by biostratigraphy, and the dating and correlation of tephra. This integrated chronostratigraphy allows the recognition of 23 individual sedimentary cycles, that are correlated across the paleo-shelf and a possible "one-to-one" relationship is made to deep-ocean benthic oxygen isotope (delta O-18) records. In general water depth changes were paced by similar to 20 kyr duration between 3.3 and 3.0 Ma, after which cycle duration is similar to 40 kyr during the late Pliocene (3.0-2.6 Ma). This record provides a future opportunity to evaluate the amplitude and frequency of global, Pliocene glacioeustatic sea-level change, independent of the global benthic delta O-18 record. (C) 2018 Elsevier Ltd. All rights reserve

Gender Socialization in Chinese Kindergartens: Teachers’ Contributions

Teacher-child interactions and peer exchanges were observed once a week for 10 months in four kindergartens in Hong Kong, China. A total of 206 anecdotes/scenes considered representative of the gender-related experiences of 109 4-year-old Chinese children in these kindergartens were analyzed. Descriptive codes, generated iteratively were clustered, categorized, integrated, recoded and recategorized and led to the identification of two major themes related to the socialization practices of teachers: Gendered Kindergarten Routines and Perpetuation of Gender Stereotypes. Findings indicated that these early years’ educational contexts were not gender neutral. Teachers interacted with boys significantly more than girls. They also subtly conveyed traditional Chinese gender values through their repeated use of gendered routines in the kindergartens and their behaviors reflected gender stereotypes

Bioavailability in soils

The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr