955 resultados para seek
Resumo:
This article focuses on the characteristics of persistent thin single-layer mixed-phase clouds. We seek to answer two important questions: (i) how does ice continually nucleate and precipitate from these clouds, without the available ice nuclei becoming depleted? (ii) how do the supercooled liquid droplets persist in spite of the net flux of water vapour to the growing ice crystals? These questions are answered quantitatively using in situ and radar observations of a long-lived mixed-phase cloud layer over the Chilbolton Observatory. Doppler radar measurements show that the top 500 m of cloud (the top 250 m of which is mixed-phase, with ice virga beneath) is turbulent and well-mixed, and the liquid water content is adiabatic. This well-mixed layer is bounded above and below by stable layers. This inhibits entrainment of fresh ice nuclei into the cloud layer, yet our in situ and radar observations show that a steady flux of ≈100 m−2s−1 ice crystals fell from the cloud over the course of ∼1 day. Comparing this flux to the concentration of conventional ice nuclei expected to be present within the well-mixed layer, we find that these nuclei would be depleted within less than 1 h. We therefore argue that nucleation in these persistent supercooled clouds is strongly time-dependent in nature, with droplets freezing slowly over many hours, significantly longer than the few seconds residence time of an ice nucleus counter. Once nucleated, the ice crystals are observed to grow primarily by vapour deposition, because of the low liquid water path (21 g m−2) yet vapour-rich environment. Evidence for this comes from high differential reflectivity in the radar observations, and in situ imaging of the crystals. The flux of vapour from liquid to ice is quantified from in situ measurements, and we show that this modest flux (3.3 g m−2h−1) can be readily offset by slow radiative cooling of the layer to space.
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Coupling a review of previous studies on the acquisition of grammatical aspects undertaken from contrasting paradigmatic views of second language acquisition (SLA) with new experimental data from L2 Portuguese, the present study contributes to this specific literature as well as general debates in L2 epistemology. We tested 31 adult English learners of L2 Portuguese across three experiments, examining the extent to which they had acquired the syntax and (subtle) semantics of grammatical aspect. Demonstrating that many individuals acquired target knowledge of what we contend is a poverty-of-the-stimulus semantic entailment related to the checking of aspectual features encoded in Portuguese preterit and imperfect morphology, namely, a [±accidental] distinction that obtains in a restricted subset of contexts, we conclude that UG-based approaches to SLA are in a better position to tap and gauge underlying morphosyntactic competence, since based on independent theoretical linguistic descriptions, they make falsifiable predictions that are amenable to empirical scrutiny, seek to describe and explain beyond performance, and can account for L2 convergence on poverty-of-the-stimulus knowledge as well as L2 variability/optionality.
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In recent years, the importance of the corporate brand has significantly grown and companies increasingly seek to strengthen their corporate brand. The corporate brand image can be strengthened through portfolio advertising as a technique of impression management. This mechanism works only if important variables are considered, such as the fit between product brands, the number of product brands as well as the processing depth of the consumers. Based on three experiments, the benefits of portfolio advertising for the corporate brand and its product brands are shown and practical implications are discussed.
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We study the degree to which Kraichnan–Leith–Batchelor (KLB) phenomenology describes two-dimensional energy cascades in α turbulence, governed by ∂θ/∂t+J(ψ,θ)=ν∇2θ+f, where θ=(−Δ)α/2ψ is generalized vorticity, and ψ^(k)=k−αθ^(k) in Fourier space. These models differ in spectral non-locality, and include surface quasigeostrophic flow (α=1), regular two-dimensional flow (α=2) and rotating shallow flow (α=3), which is the isotropic limit of a mantle convection model. We re-examine arguments for dual inverse energy and direct enstrophy cascades, including Fjørtoft analysis, which we extend to general α, and point out their limitations. Using an α-dependent eddy-damped quasinormal Markovian (EDQNM) closure, we seek self-similar inertial range solutions and study their characteristics. Our present focus is not on coherent structures, which the EDQNM filters out, but on any self-similar and approximately Gaussian turbulent component that may exist in the flow and be described by KLB phenomenology. For this, the EDQNM is an appropriate tool. Non-local triads contribute increasingly to the energy flux as α increases. More importantly, the energy cascade is downscale in the self-similar inertial range for 2.5<α<10. At α=2.5 and α=10, the KLB spectra correspond, respectively, to enstrophy and energy equipartition, and the triad energy transfers and flux vanish identically. Eddy turnover time and strain rate arguments suggest the inverse energy cascade should obey KLB phenomenology and be self-similar for α<4. However, downscale energy flux in the EDQNM self-similar inertial range for α>2.5 leads us to predict that any inverse cascade for α≥2.5 will not exhibit KLB phenomenology, and specifically the KLB energy spectrum. Numerical simulations confirm this: the inverse cascade energy spectrum for α≥2.5 is significantly steeper than the KLB prediction, while for α<2.5 we obtain the KLB spectrum.
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Both the EU’s Renewable Energy Directive (RED) and Article 7a of its Fuel Quality Directive (FQD) seek to reduce greenhouse gas (GHG) emissions from transport fuels. The RED mandates a 10% share of renewable energy in transport fuels by 2020, whilst the FQD requires a 6% reduction in GHG emissions (from a 2010 base) by the same date. In practice, it will mainly be biofuels that economic operators will use to meet these requirements, but the different approaches can lead to either the RED, or the FQD, acting as the binding constraint. A common set of environmental sustainability criteria apply to biofuels under both the RED and the FQD. In particular, biofuels have to demonstrate a 35% (later increasing to 50/60%) saving in life-cycle GHG emissions. This could be problematic in the World Trade Organization (WTO), as a non-compliant biofuel with a 34% emissions saving would probably be judged to be ‘like’ a compliant biofuel. A more economically rational way to reduce GHG emissions, and one that might attract greater public support, would be for the RED to reward emission reductions along the lines of the FQD. Moreover, this modification would probably make the provisions more acceptable in the WTO, as there would be a clearer link between policy measures and the objective of reductions in GHG emissions; and the combination of the revised RED and the FQD would lessen the commercial incentive to import biofuels with modest GHG emission savings, and thus reduce the risk of trade tension.
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Zinc (Zn)-deficient soils constrain rice (Oryza sativa) production and cause Zn malnutrition. The identification of Zn-deficiency-tolerant rice lines indicates that breeding might overcome these constraints. Here, we seek to identify processes underlying Zn-deficiency tolerance in rice at the physiological and transcriptional levels. A Zn-deficiency-tolerant line RIL46 acquires Zn more efficiently and produces more biomass than its nontolerant maternal line (IR74) at low Zn(ext) under field conditions. We tested if this was the result of increased expression of Zn(2+) transporters; increased root exudation of deoxymugineic acid (DMA) or low-molecular-weight organic acids (LMWOAs); and/or increased root production. Experiments were performed in field and controlled environment conditions. There was little genotypic variation in transcript abundance of Zn-responsive root Zn(2+)-transporters between the RIL46 and IR74. However, root exudation of DMA and LMWOA was greater in RIL46, coinciding with increased root expression of putative ligand-efflux genes. Adventitious root production was maintained in RIL46 at low Zn(ext), correlating with altered expression of root-specific auxin-responsive genes. Zinc-deficiency tolerance in RIL46 is most likely the result of maintenance of root growth, increased efflux of Zn ligands, and increased uptake of Zn-ligand complexes at low Zn(ext); these traits are potential breeding targets.
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In this paper we show how a seemingly unremarkable object – a cattle grid – has come to presence climate change in partial and contingent ways on the Lizard Peninsula, Cornwall, UK. We identify the cattle grid as an ‘anticipatory object’ through which conservation organisations seek to manage the future and adapt to climate change, but which at the same time presences that unthought-of future for others in the landscape. We explore the ways in which the cattle grid acts to presence something that is not only absent – climate change – but has uncertain imminence. We investigate the ways in which the cattle grid make climate relevant as an embodied and experiential process, a physical and intellectual artefact, and the means to imagine climate and the ways it might change. Drawing upon interpretative approaches informed by theorisations of materiality, presence and absence to understand climate change as a social phenomenon, we go beyond a consideration of this ordinary object defined by its function to consider how the object is experienced, the processes and practices through which people relate to it, and the ways in which social meaning accumulates around it. The empirical basis for this argument is provided by in-depth interviews with local representatives of Natural England, residents and farmers.
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Using annual observations on industrial production over the last three centuries, and on GDP over a 100-year period, we seek an historical perspective on the forecastability of these UK output measures. The series are dominated by strong upward trends, so we consider various specifications of this, including the local linear trend structural time-series model, which allows the level and slope of the trend to vary. Our results are not unduly sensitive to how the trend in the series is modelled: the average sizes of the forecast errors of all models, and the wide span of prediction intervals, attests to a great deal of uncertainty in the economic environment. It appears that, from an historical perspective, the postwar period has been relatively more forecastable.
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Final year research projects are an important part of undergraduate chemistry courses, allowing students to enhance transferable skills in teamworking, problem solving and presentations, at the same time as learning valuable practical skills. Several recent reports have highlighted the importance of research based studies as part of undergraduate courses. ‘We need to encourage universities to explore new models of curriculum. They should all incorporate research based study for undergraduates to cultivate awareness of research careers, to train students in research skills for employment, and to sustain the advantages of a research teaching connection,’ wrote Paul Ramsden from James Cook University, Australia, in a 2008 report for the UK’s Higher Education Academy.1 A 2010 report published by the Biopharma Skills Consortium – that promotes collaboration across the higher education sector in the area of biopharma – also stated that: ‘Companies seek recruits well placed to acclimatise quickly to the work environment. They are looking for recruits who can deploy a range of generic skills in the application of their knowledge.’2
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A glance along the finance shelves at any bookshop reveals a large number of books that seek to show readers how to ‘make a million’ or ‘beat the market’ with allegedly highly profitable equity trading strategies. This paper investigates whether useful trading strategies can be derived from popular books of investment strategy, with What Works on Wall Street by James P. O'Shaughnessy used as an example. Specifically, we test whether this strategy would have produced a similarly spectacular performance in the UK context as was demonstrated by the author for the US market. As part of our investigation, we highlight a general methodology for determining whether the observed superior performance of a trading rule could be attributed in part or in entirety to data mining. Overall, we find that the O'Shaughnessy rule performs reasonably well in the UK equity market, yielding higher returns than the FTSE All-Share Index, but lower returns than an equally weighted benchmark
Resumo:
Construction professional service (CPS) firms sell expertise and provide innovative solutions for projects founded on their knowledge, experience, and technical competences. Large CPS firms seeking to grow will often seek new opportunities in their domestic market and overseas by organic or inorganic growth through mergers, alliances, and acquisitions. Growth can also come from increasing market penetration through vertical, horizontal, and lateral diversification. Such growth, hopefully, leads to economies of scope and scale in the long term, but it can also lead to diseconomies, when the added cost of integration and the increased complexity of diversification no longer create tangible and intangible benefits. The aim of this research is to investigate the key influences impacting on the growth in scope and scale for large CPS firms. Qualitative data from the interviews were underpinned by secondary data from CPS firms’ annual reports and analysts’ findings. The findings showed five key influences on the scope and scale of a CPS firm: the importance of growth as a driver; the influence of the ownership of the firm on the decision for growth in scope and scale; the optimization of resources and capabilities; the need to serve changing clients’ needs; and the importance of localization. The research provides valuable insights into the growth strategies of international CPS firms. A major finding of the research is the influence of ownership on CPS firms’ growth strategies which has not been highlighted in previous research.
Resumo:
Enterprise Architecture (EA) has been recognised as an important tool in modern business management for closing the gap between strategy and its execution. The current literature implies that for EA to be successful, it should have clearly defined goals. However, the goals of different stakeholders are found to be different, even contradictory. In our explorative research, we seek an answer to the questions: What kind of goals are set for the EA implementation? How do the goals evolve during the time? Are the goals different among stakeholders? How do they affect the success of EA? We analysed an EA pilot conducted among eleven Finnish Higher Education Institutions (HEIs) in 2011. The goals of the pilot were gathered from three different stages of the pilot: before the pilot, during the pilot, and after the pilot, by means of a project plan, interviews during the pilot and a questionnaire after the pilot. The data was analysed using qualitative and quantitative methods. Eight distinct goals were recognised by the coding: Adopt EA Method, Build Information Systems, Business Development, Improve Reporting, Process Improvement, Quality Assurance, Reduce Complexity, and Understand the Big Picture. The success of the pilot was analysed statistically using the scale 1-5. Results revealed that goals set before the pilot were very different from those mentioned during the pilot, or after the pilot. Goals before the pilot were mostly related to expected benefits from the pilot, whereas the most important result was to adopt the EA method. Results can be explained by possibly different roles of respondents, which in turn were most likely caused by poor communication. Interestingly, goals mentioned by different stakeholders were not limited to their traditional areas of responsibility. For example, in some cases Chief Information Officers' goals were Quality Assurance and Process Improvement, whereas managers’ goals were Build Information Systems and Adopt EA Method. This could be a result of a good understanding of the meaning of EA, or stakeholders do not regard EA as their concern at all. It is also interesting to notice that regardless of the different perceptions of goals among stakeholders, all HEIs felt the pilot to be successful. Thus the research does not provide support to confirm the link between clear goals and success.
Resumo:
Purpose – The purpose of this paper is to examine the interaction between large Chinese firms as they internationalize and their home and host governments. Design/methodology/approach – The approach taken is that of an analysis of relevant literature and the application of a popular theoretical framework by Rugman and Verbeke to the case of Chinese firms as they expand abroad. Findings – First, the paper adapts a well-known business-government framework to analyze emerging economy issues, all in a Chinese context. Then the paper relates this analysis to the existing literature on the international expansion process of Chinese firms. The paper finds that in their attempt to seek strategic assets, Chinese multinational enterprises (MNEs) face conflicts with host countries and Western firms in which host government support for international competitiveness can be used as quasi protectionist defense mechanisms. Using the public policy and MNE framework, the paper examines several recent disputes and finds that Chinese MNEs have complementary goals with the Chinese state, but they have conflicting goals with Western governments. Originality/value – These findings have important academic research, managerial, and public policy implications.
Resumo:
This study investigates the determinants of cross-border capital flows into direct real estate markets. In particular, it investigates how existing institutional, regulatory and real estate specific barriers affect cross-border real estate inflows and outflows in a sample of 24 developed and emerging countries, and whether investors seek out targets with lower barriers and regulatory arbitrage. We do not find evidence of significant cross-border institutional or regulatory arbitrage in the real estate market. However, real estate market liquidity is found to be the most important driver of cross-border flows. While many of the institutional barriers included in this analysis do not appear to impact the level of real estate inflows significantly, their presence tends to suppress real estate capital outflows to other countries. Overall, easy access to financial markets, a good economic environment and transparent real estate markets may enhance real estate outflows, while returns and the macroeconomy are found to enhance domestic real estate investment.
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Nine of the compounds [M(L2−)(p-cymene)] (M = Ru, Os, L2− = 4,6-di-tert-butyl-N-aryl-o-amidophenolate) were prepared and structurally characterized (Ru complexes) as coordinatively unsaturated, formally 16 valence electron species. On L2−-ligand based oxidation to EPR-active iminosemiquinone radical complexes, the compounds seek to bind a donor atom (if available) from the N-aryl substituent, as structurally certified for thioether and selenoether functions, or from the donor solvent. Simulated cyclic voltammograms and spectroelectrochemistry at ambient and low temperatures in combination with DFT results confirm a square scheme behavior (ECEC mechanism) involving the Ln ligand as the main electron transfer site and the metal with fractional (δ) oxidation as the center for redox-activated coordination. Attempts to crystallize [Ru(Cym)(QSMe)](PF6) produced single crystals of [RuIII(QSMe •−)2](PF6) after apparent dissociation of the arene ligand.