Multivariate reciprocal stationary Gaussian processes

AbstractIn this paper we examine the characterization of multivariate reciprocal stationary Gaussian processes in terms of their covariance matrix function. As an illustration, we identify all second-order reciprocal Gaussian processes

Особенности процесса распылительной сушки высоковлажной биомассы Spirulina platensis

Проведен комплекс исследований по распылительному обезвоживанию биомассы Spirulina platensis, включающий исследование кинетических особенностей обезвоживания и теплотехнологических параметров распылительного способа сушки. Получены опытные партии порошков, проведен анализ дисперсионных и структурно-механических характеристик полученных порошков, показано, что процесс обезвоживания осуществляется при достаточно “мягких” термических условиях.Проведено комплекс досліджень розпилювального зневоднення біомаси Spirulina platensis, стосовно кінетичних особливостей сушіння та теплотехнологічних параметрів розпилювального способу сушки. Отримано дослідні партії порошків, проведено аналіз дисперсних та структурно-механічних характеристик отриманих порошків, виявлено, що процес зневоднення здійснюється при достатньо “м’яких” термічних умовах.A complex investigation of the spray drying of Spirulina platensis biomass have been carried out, which included studying of the kinetic properties of the dehydration process as well as the heat exchanging technological parametrs of spray drying technique. By using a pilot dryer, development types of the dry powdered product have been obtained. A analysis of the dispersion and mechanical characteristics of the powdered product being obtained has been performed. It has been shown that the drying processes has to be carried out at fairly soft dehydration regimes

Deep incision in an Aptian carbonate succession indicates major sea-level fall in the Cretaceous

Long-term relative sea-level cycles (0 5 to 6 Myr) have yet to be fully understood for the Cretaceous. During the Aptian, in the northern Maestrat Basin (Eastern Iberian Peninsula), fault-controlled subsidence created depositional space, but eustasy governed changes in depositional trends. Relative sea-level history was reconstructed by sequence stratigraphic analysis. Two forced regressive stages of relative sea-level were recognized within three depositional sequences. The first stage is late Early Aptian age (intra Dufrenoyia furcata Zone) and is characterized by foreshore to upper shoreface sedimentary wedges, which occur detached from a highstand carbonate platform, and were deposited above basin marls. The amplitude of relative sea-level drop was in the order of tens of metres, with a duration of 2 km wide and cut 115 m down into the underlying Aptian succession. With the subsequent transgression, the incision was back-filled with peritidal to shallow subtidal deposits. The changes in depositional trends, lithofacies evolution and geometric relation of the stratigraphic units characterized are similar to those observed in coeval rocks within the Maestrat Basin, as well as in other correlative basins elsewhere. The pace and magnitude of the two relative sea-level drops identified fall within the glacio-eustatic domain. In the Maestrat Basin, terrestrial palynological studies provide evidence that the late Early and Late Aptian climate was cooler than the earliest part of the Early Aptian and the Albian Stage, which were characterized by warmer environmental conditions. The outcrops documented here are significant because they preserve the results of Aptian long-term sea-level trends that are often only recognizable on larger scales (i.e. seismic) such as for the Arabian Plate

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Métabolisme du plutonium

Le plutonium ne peut exister sous forme ionique à un pH physiologique. Il tire son individualité chimique du fait de la coexistence possible de plusieurs valences. L’étude du métabolisme général du plutonium est basée sur les complexes, car ils permettent d’obtenir l’isotope sous forme monodispersée. L’élimination est alors fonction de la stabilité in vivo du complexe. Deux phénomènes, captation cellulaire et hydrolyse, interviennent lors de la libération du plutonium dans l’organisme. L’étude des insolubles est plus complexe : dégradation locale touchant un pourcentage infime, suivie de transport avec arrêt au niveau des ganglions et du système réticulo-endothélial. Les sels dissociés du plutonium s’hydrolysent sur place; une fraction minime peut être prise en charge par les protéines plasmatiques. L’étude histologique montre, au niveau du foie la captation par la cellule de Kupfer et la cellule hépatique, au niveau de l’os la double rétention par le macrophage médullaire et par la trame osseuse, au niveau du rein la filtration glomérulaire et la réabsorption avec précipitation tubulaire. Le métabolisme du plutonium est ainsi régi par des phénomènes d’hydrolyse, de dégradation secondaire et de transport cellulaire