1,142 research outputs found

    Preliminary studies on pigmentation and ultrastructure of microconidia of Neurospora crassa

    Get PDF
    Pigmentation and ultrastructure of microconidi

    Discovering the colours of industrial heritage characterisation of paint coatings from the powerplant at the Levada de Tomar

    Get PDF
    The paint coatings of three energy generators from the 20th-century powerplant at Levada de Tomar, Portugal, were investigated using micro-Raman and micro-X-ray fluorescence spectroscopies and scanning electron microscopy with energy dispersive spectroscopy. This multi-analytical approach was used to identify the colouring agents, thus providing a chronological chromatic pallet and allowing to infer on the use of the three energy generators. Together with traditional pigments like Prussian blue, red iron oxide, and carbon black, pigments used in industrial areas like copper phthalocyanine and toluidine red were identified as colouring agents. Complex paint systems of the oldest equipment (1924) were revealed as well as maintenance procedures of the equipment that worked during a longer time (1944–1990). Powdery carbon black layers, resulting from incomplete hydrocarbon combustion and present between metallic substrates and coating layers, suggested the inexistence of paint coatings replacement after the powerplant shutdown. The identification of magnetite as a corrosion product of iron alloy substrate revealed that corrosion developed after the engine shutdown and not during the operation period. The results obtained highlight the potentialities of scientific-based approach and Raman spectroscopy to the industrial heritage study, an emergent cultural area.publishersversionpublishe

    Coparenting Behaviors as Mediators between Postpartum Parental Depressive Symptoms and Toddler's Symptoms.

    Get PDF
    Postpartum parental depression, even of mild intensity and short duration, has negative consequences on child development, including increased externalizing and internalizing symptoms. Studies revealed that the links between parental depression and child development are mediated by parenting difficulties. On the other hand, the mediating role of problematic family-level relationships, such as low coparenting support and high conflict between the parents, has rarely been considered, although coparenting difficulties have been linked with both increased depressive symptoms in parents and increased symptoms in toddlers. In the present study, we proposed testing a comprehensive mediation model linking parental depression, coparenting, and child symptoms. At 3 months postpartum, a convenience sample of 69 parental couples completed the Edinburgh Postnatal Depression Scale. In addition, we assessed levels of coparenting support and conflict during a mother-father-infant play situation, the Lausanne Trilogue Play. At 18 months postpartum, both parents assessed child symptoms with the Symptom Checklist Questionnaire. The results showed that coparenting support mediated the links between parental depressive symptoms and child symptoms, but only for mothers: Maternal depressive symptoms were linked with lower coparenting support, which in turn predicted increased psychofunctional symptoms and behavior problems assessed by mothers. Although coparenting conflict behaviors were not predicted by parents' depressive symptoms, higher conflict was unexpectedly linked with fewer behavior problems assessed by both parents. The present study allowed us to unveil complex pathways between mild parental mood disturbances, family-level relationships, and child development in the first months of the child's life

    Strontium Stable Isotope Composition of Allende Fine-Grained Inclusions

    Get PDF
    Isotopic anomalies are departures from the laws of mass-dependent fractionation that cannot be explained by radioactive decay, cosmogenic effects, or exotic isotopic fractionation processes such as nuclear field shift or magnetic effects [1 and references therein]. These anomalies often have a nucleosynthetic origin and provide clues on the stellar origin and solar system processing of presolar dust. Anomalies are most often found in refractory elements of relatively low mass, so Sr is a prime target for study. The four stable isotopes of strontium are useful for discerning the various nucleosynthetic origins of early solar system building blocks and the timing of accretion processes. Strontium-84 is the least abundant (0.56%) of these isotopes, but is particularly significant in being a p-process only nuclide that is produced in core-collapse or type Ia supernovae [2,3]. The more abundant isotopes ^(86)Sr (9.86%), ^(87)Sr (7.00%) and ^(88)Sr (82.58%) are produced in s- and r-processes in asymptotic giant branch stars and other stellar types [4]. Additionally, ^(87)Sr is produced by ^(87)Rb decay in proportions that dominate over possible nucleosynthetic variations but provide timings of early solar system processes, most notably volatile element depletion [5-7]. Furthermore, variations in strontium isotopic ratios caused by high-temperature massdependent fractionation [8] are also important [9-12], as they provide insights into nebular and accretionary processes

    I-Xe studies of aqueous alteration in the Allende CAI Curious Marie

    Get PDF
    The Allende fine-grained inclusion Curious Marie is a unique CAI. It is depleted in uranium but contains large ^(235)U excess [1], providing new evidence that ^(247)Cm was alive in the Early Solar System, as has been previously suggested [2], and leading to an updated (^(247)Cm/^(235)U)initial ratio of (1.1±0.3)×10^(-4)

    Establishing the liquid phase equilibrium of angrites to constrain their petrogenesis

    Get PDF
    Angrites are a series of differentiat-ed meteorites, extremely silica undersaturated and with unusally high Ca and Al contents [1]. They are thought to originate from a small planetesimal parent body of ~ 100-200 km in radius ([2-3]), can be either plutonic (i.e., cumulates) or volcanic (often referred to as quenched) in origin, and their old formation ages (4 to 11 Myr after CAIs) have made them prime anchors to tie the relative chronologies inferred from short-lived radionuclides (e.g., Al-Mg, Mn-Cr, Hf-W) to the absolute Pb-Pb clock [4]. They are also the most vola-tile element-depleted meteorites available, displaying a K-depletion of a factor of 110 relative to CIs

    Developments in PF-HPLC (pneumatic-fluoropolymer high performance liquid chromatography)

    Get PDF
    Return missions are providing unique opportunities to deepen our knowledge of the formation and evolution of the solar system. The six Apollo missions have been critical in shaping our understanding of the Earth-Moon history [1], and the recent Genesis (solar wind; e.g., [2]), Stardust (cometary dust from Wild 2; e.g., [3,4]) and Hayabusa (dust from S-type asteroid from Itokawa; e.g., [5]) missions brought in a wealth of data
    corecore