Carbon isotope discrimination of arctic and boreal biomes inferred from remote atmospheric measurements and a biosphere-atmosphere model

Estimating discrimination against ^(13)C during photosynthesis at landscape, regional, and biome scales is difficult because of large-scale variability in plant stress, vegetation composition, and photosynthetic pathway. Here we present estimates of ^(13)C discrimination for northern biomes based on a biosphere-atmosphere model and on National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory and Institute of Arctic and Alpine Research remote flask measurements. With our inversion approach, we solved for three ecophysiological parameters of the northern biosphere (^(13)C discrimination, a net primary production light use efficiency, and a temperature sensitivity of heterotrophic respiration (a Q10 factor)) that provided a best fit between modeled and observed δ^(13)C and CO_2. In our analysis we attempted to explicitly correct for fossil fuel emissions, remote C4 ecosystem fluxes, ocean exchange, and isotopic disequilibria of terrestrial heterotrophic respiration caused by the Suess effect. We obtained a photosynthetic discrimination for arctic and boreal biomes between 19.0 and 19.6‰. Our inversion analysis suggests that Q10 and light use efficiency values that minimize the cost function covary. The optimal light use efficiency was 0.47 gC MJ^(−1) photosynthetically active radiation, and the optimal Q10 value was 1.52. Fossil fuel and ocean exchange contributed proportionally more to month-to-month changes in the atmospheric growth rate of δ^(13)C and CO_2 during winter months, suggesting that remote atmospheric observations during the summer may yield more precise estimates of the isotopic composition of the biosphere

Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments

Background: Individuals with Down syndrome (DS) and individuals with Williams syndrome (WS) have poor navigation skills, which impact their potential to become independent. Two aspects of navigation were investigated in these groups, using virtual environments (VE): route knowledge (the ability to learn the way from A to B by following a fixed sequence of turns) and configural knowledge (knowledge of the spatial relationships between places within an environment). Methods: Typically developing (TD) children aged 5 to 11 years (N = 93), individuals with DS (N = 29) and individuals with WS (N = 20) were presented with a sparse and a rich VE grid maze. Within each maze, participants were asked to learn a route from A to B and a route from A to C before being asked to find a novel shortcut from B to C. Results: Performance was broadly similar across sparse and rich mazes. The majority of participants were able to learn novel routes, with poorest performance in the DS group, but the ability to find a shortcut, our measure of configural knowledge, was limited for all three groups. That is, 59 % TD participants successfully found a shortcut, compared to 10 % participants with DS and 35 % participants with WS. Differences in the underlying mechanisms associated with route knowledge and configural knowledge and in the developmental trajectories of performance across groups were observed. Only the TD participants walked a shorter distance in the last shortcut trial compared to the first, indicative of increased configural knowledge across trials. The DS group often used an alternative strategy to get from B to C, summing the two taught routes together. Conclusions: Our findings demonstrate impaired configural knowledge in DS and in WS, with the strongest deficit in DS. This suggests that these groups rely on a rigid route knowledge based method for navigating and as a result are likely to get lost easily. Route knowledge was also impaired in both DS and WS groups and was related to different underlying processes across all three groups. These are discussed with reference to limitations in attention and/or visuo-spatial processing in the atypical groups

Marine and coastal ecosystem services on the science–policy–practice nexus: challenges and opportunities from 11 European case studies

We compared and contrasted 11 European case studies to identify challenges and opportunitiestoward the operationalization of marine and coastal ecosystem service (MCES) assessments inEurope. This work is the output of a panel convened by the Marine Working Group of theEcosystemServices Partnership in September 2016. TheMCES assessments were used to (1) addressmultiple policy objectives simultaneously, (2) interpret EU-wide policies to smaller scales and (3)inform local decision-making. Most of the studies did inform decision makers, but only in a fewcases, the outputswere applied or informed decision-making. Significant limitations among the 11assessments were the absence of shared understanding of the ES concept, data and knowledgegaps, difficulties in accounting for marine social–ecological systems complexity and partial stakeholderinvolvement. The findings of the expert panel call for continuous involvement of MCES ‘endusers’, integrated knowledge onmarine social–ecological systems, defining thresholds to MCES useand raising awareness to the general public. Such improvements at the intersection of science,policy and practice are essential starting points toward building a stronger science foundationsupporting management of European marine ecosystems

Valorização do patrimônio científico e tecnológico brasileiro: descobrindo conjuntos de objetos de C&T pelo Brasil

Most of Brazil's science and technology (S&T) heritage has yet to be tracked down. The knowledge amassed on the topic is still limited, and there is a real risk that Brazilian science and technology objects may already have been modernized or discarded. A research project was developed in the last four years including several initiatives to preserve this kind of heritage, as such: a national survey to build up a picture of the current state of this heritage; studies concerning heritage protection legislation of some countries, including Brazil; and two case studies of collections of S&T objects (Observatório do Valongo and Colégio Pedro II). This paper presents an overview of the results obtained in the several initiatives of preservation undertaken. The survey is divided into different areas of knowledge and different time frames. As such, we are interested in sets of objects from the exact sciences, the different engineering specialties, as well as geography, geology and oceanography, which were manufactured in or before the 1960s. A registration form was prepared which was adapted from a form used in surveys of collections of this kind in Portugal. Sets of objects have been identified at museums, universities and research institutes. From the results, it could be observed that: the best preserved collections are at the few museums devoted to the area, but the universities hold most of the artifacts and the overwhelming majority of the objects were made in the twentieth century.A maior parte dos bens que constituem o patrimônio cultural da Ciência e Tecnologia (C&T) está para ser descoberta. O conhecimento acumulado sobre o tema ainda é limitado e há um risco real de que os objetos já tenham sido modernizados ou descartados. Nos últimos quatro anos, desenvolveu-se um projeto de pesquisa, envolvendo várias iniciativas para preservar este tipo de patrimônio: um levantamento nacional para construir um panorama do estado atual desse patrimônio; estudos sobre a legislação de proteção ao patrimônio de alguns países, inclusive o Brasil; e dois estudos de caso de coleções de objetos de C&T (Observatório do Valongo e Colégio Pedro II, ambos no Rio de Janeiro). Este artigo apresenta uma visão geral dos resultados obtidos e, em especial, dos levantamentos de conjuntos de objetos de C&T. Utilizou-se um recorte em relação a áreas do conhecimento e período histórico, compreendendo objetos pertencentes à s ciências exatas, à s diferentes especialidades de engenharia, bem como geografia, geologia e oceanografia, e fabricados até 1960. A partir da adaptação de um formulário usado em pesquisas similares em Portugal, elaborou-se uma ficha de registro, que permitiu identificar conjuntos de objetos em museus, universidades e institutos de pesquisa. Pôde-se, com isso, observar que as coleções mais bem preservadas estão nos poucos museus dedicados à área, enquanto as universidades detêm a maior parte dos artefatos, e que a esmagadora maioria dos objetos foi produzida no século XX

Implementation of Advanced Information Services to European Inland Waterways Transport: A socio-Economic Perspective

info:eu-repo/semantics/publishe

Regulation of liver metabolism by the hepatic nerves

In the isolated rat liver perfused as usual via the portal vein, joint electrical stimulation of the nerve fibers around the artery and the portal vein in the liver hilus increased glucose output, shifted lactate uptake to output, decreased urea and glutamine formation as well as ammonia uptake, reduced ketone body production, lowered oxygen uptake and reduced perfusion flow simultaneously changing the intrahepatic flow distribution; it was accompanied by an overflow of noradrenaline into the hepatic vein. All effects were mediated predominantly via alpha-receptors; they were dependent on extracellular calcium. In livers perfused both via the artery and the portal vein, separate stimulation of the plexus at the common hepatic artery or at the portal vein caused similar effects on glucose and lactate balance and on perfusion flow. Arterial stimulation caused the higher metabolic responses and alterations not only in arterial but also 'transhepaticly' in portal flow, and conversely, portal flow elicited the smaller metabolic responses and alterations in both portal and 'transhepaticly' arterial flow. If sympathetic nerve actions were blocked using alpha- and beta-antagonists, the resulting parasympathetic stimulation increased glucose uptake in the presence of insulin and antagonized the glucagon stimulated glucose release, both alone and more strongly in the presence of insulin. The sympathetic nerves may act directly at the parenchymal cells or indirectly via an overflow of neurotransmitter from the vasculature into the sinusoids or via hemodynamic changes. Experiments with the smooth muscle relaxant sodium nitroprusside and with retrograde flow indicate that neither hemodynamic changes nor noradrenaline overflow from the vasculature can play a major role in the mechanism of action of sympathetic liver nerves on glucose and lactate metabolism. Comparative studies with perfused livers of rats, guinea pigs and tupaias are in line with the view that in the rat the sympathetic nerves act via contacts with only a few periportal hepatocytes, from where the signal is propagated through gap junctions, while in guinea pig and tupaia the nerves act via contacts with almost all parenchymal cells. Sympathetic nerve stimulation of the perfused rat liver caused an increase in the activity of glycogen phosphorylase and a decrease of glycogen synthase, but left the activity of pyruvate kinase unaltered; fructose 2,6-bisphosphate and cAMP were only slightly enhanced.(ABSTRACT TRUNCATED AT 400 WORDS