3,504 research outputs found
Information techniques for irrigation systems: Selected proceedings of the Second International Network Meeting on Information Techniques for Irrigation Systems held in Lahore/Bahawalnagar, Pakistan, 5-8 December 1994
Irrigation management / Irrigation systems / Decision support tools / Decision making / Information systems / Computer techniques / Models / Water management / Malaysia / Pakistan / Sri Lanka
Physiological responses to temperature in Merizodus soledadinus (Col., Carabidae), a subpolar carabid beetle invading sub-Antarctic islands
International audienceRecent human activities and rising air temperature have increased the vulnerability of sub-Antarctic islands to alien species. At the Kerguelen Islands, the predaceous ground beetle Merizodus soledadinus is the only invasive insect originating from the southern cold temperate area (native from Patagonia, Tierra del Fuego and Falkland Islands). This austral origin raises the question of the limits of its physiological tolerance and capability to withstand (1) global change and (2) warmer climates of archipelagos where its accidental transportation could be facilitated from the Kerguelen Islands (namely Amsterdam and Saint Paul). Using gas chromatography/mass spectrometry metabolomics, we compared metabotypes of adults exposed to different temperatures (0, 4, 8, 12, 16, 20 °C). All individuals survived after 2 weeks regardless of the temperature they were exposed to. The physiological changes observed were consistent with increased metabolic rate at increased temperatures, without extreme metabotypes that are characteristic of acute stress. First cues of sublethal stress were observed after prolonged exposure to 20 °C, a warm regime unrealistic for such duration in sub-Antarctic Islands. Overall, M. soledadinus’ thermal tolerance exceeded temperatures currently experienced in nature, suggesting that climate warming may boost its invasion by eliciting its activity and broadening habitat suitability in both invaded and still pristine islands. This thermal tolerance may allow survival aboard ships and development in sub-Antarctic islands with conditions warmer than the Kerguelen Islands, such as Amsterdam and St Paul. Stringent biosecurity measures are thus needed to prevent transfer from Kerguelen to these islands. The native range of this predaceous beetle limited to the Falkland Islands and southernmost South America may be partly constrained by factors other than temperature, such as desiccation, predation or competitio
Wind Forced Variability in Eddy Formation, Eddy Shedding, and the Separation of the East Australian Current
The East Australian Current (EAC), like many other subtropical western boundary currents, is believed to be penetrating further poleward in recent decades. Previous observational and model studies have used steady state dynamics to relate changes in the westerly winds to changes in the separation behavior of the EAC. As yet, little work has been undertaken on the impact of forcing variability on the EAC and Tasman Sea circulation. Here using an eddy‐permitting regional ocean model, we present a suite of simulations forced by the same time‐mean fields, but with different atmospheric and remote ocean variability. These eddy‐permitting results demonstrate the nonlinear response of the EAC to variable, nonstationary inhomogeneous forcing. These simulations show an EAC with high intrinsic variability and stochastic eddy shedding. We show that wind stress variability on time scales shorter than 56 days leads to increases in eddy shedding rates and southward eddy propagation, producing an increased transport and southward reach of the mean EAC extension. We adopt an energetics framework that shows the EAC extension changes to be coincident with an increase in offshore, upstream eddy variance (via increased barotropic instability) and increase in subsurface mean kinetic energy along the length of the EAC. The response of EAC separation to regional variable wind stress has important implications for both past and future climate change studies
Design and optimization of electrochemical microreactors for continuous electrosynthesis
The study focuses on the design and construction, as well as the theoretical and experimental optimization of electrochemical filter press microreactors for the electrosynthesis of molecules with a high added value. The main characteristics of these devices are firstly a high-specific electrochemical area to increase conversion and selectivity, and secondly the shape and size of themicrochannels designed for a uniform residence time distribution of the fluid. A heat exchanger is integrated into the microstructured electrode to rapidly remove (or supply) the heat required in exo- or endothermic reactions. The microreactors designed are used to perform-specific electrosynthesis reactions such as thermodynamically unfavorable reactions (continuous NADH regeneration), or reactions with high enthalpy changes
Coexpression, copurification, crystallization and preliminary X-ray analysis of a complex of ARL2-GTP and PDE delta
The small GTPase ARL2 (from Mus musculus) and an effector protein, the δ subunit of human cGMP phosphodiesterase (hPDE δ), were coexpressed and copurified from Escherichia coli as a stable complex. Coexpression significantly increased the otherwise low yield of PDE δ production in E. coli. The complex, which contains ARL2 in the activated GTP-bound form, was crystallized in two forms. The first belongs to the monoclinic space group P21, with unit-cell parameters a = 48.1, b = 45.7, c = 74.7 Å, β = 94.0° and one complex (39 kDa) in the asymmetric unit. Cryocooled crystals diffract to 2.3 Å using synchrotron radiation. The micro-focused X-ray beam at beamline ID13 (ESRF) allowed the use of very small crystals, which helped to overcome twinning and enabled the identification of a molecular-replacement solution. The second form recrystallized from the first one after several months. These crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 44.5, b = 65.4, c = 104.4 Å and one complex in the asymmetric unit. They diffracted to 1.8 Å using synchrotron radiation
Evaluating megaprojects: from the “iron triangle” to network mapping
Evaluation literature has paid relatively little attention to the specific needs of evaluating large, complex industrial and infrastructure projects, often called ‘megaprojects’. The abundant megaproject governance literature, in turn, has largely focused on the so-called ‘megaproject pathologies’, i.e. the chronic budget overruns, and failure of such projects to keep to timetables and deliver the expected social and economic benefits. This article draws on these two strands of literature, identifies shortcomings, and suggests potential pathways towards an improved evaluation of megaprojects. To counterbalance the current overemphasis on relatively narrowly defined accountability as the main function of megaproject evaluation, and the narrow definition of project success in megaproject evaluation, the article argues that conceptualizing megaprojects as dynamic and evolving networks would provide a useful basis for the design of an evaluation approach better able to promote learning and to address the socio economic aspects of megaprojects. A modified version of ‘network mapping’ is suggested as a possible framework for megaproject evaluation, with the exploration of the multiple accountability relationships as a central evaluation task, designed to reconcile learning and accountability as the central evaluation functions. The article highlights the role of evaluation as an ‘emergent’ property of spontaneous megaproject ‘governing’, and explores the challenges that this poses to the role of the evaluator
The explanatory variables of narrative transportation and consumer engagement with a transmedia consumption experience
Professionals in the cultural sector are increasingly designing transmedia narrative devices. By that new strategy, they expect to increase cultural consumption and attendance. Considering the central role of the narrative transportation during the transmedia experience, this article presents results about six anticipated antecedents of this process experienced by users of a transmedia device that combines digital and physical elements, and deals with the heritage history of a French province. The six variables tested are gender, age, level of education (to describe the socio-demographic profile), geographical proximity (to proxy the familiarity with the topic and contents of the story told in the transmedia device), cultural expertise (to refer to the whole acquaintance with cultural consumption), and relationship with technology (to score the propensity to adopt new technology). Regarding the consequence of the narrative transportation, the model focuses on the consumer engagement toward both the object of narration that is referring to the topic cultural professionals wants theirs visitors and viewers to discover, and the cultural genre (here the heritage and history of the region). This paper concludes with a discussion of our main results and limitations
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