962 resultados para Donatello, 1386?-1466.
Resumo:
This conceptual paper argues that national differences in human resource management (HRM) matter and can be explained by cultural and institutional theories. We explore briefly the nature of each set of theories and some of the critiques that have been made of them. We argue that in general much of the differences in HRM between countries are determined by institutional factors, and that management has more influence over the effect of national cultural differences than it has over institutional differences and therefore in most cases the appropriate tests will be tests against institutional differences. Where institutions are less constraining, cultural differences may be the appropriate template.
Resumo:
Wall plaster sequences from the Neolithic town of Çatalhöyük have been analysed and compared to three types of natural sediment found in the vicinity of the site, using a range of analytical techniques. Block samples containing the plaster sequences were removed from the walls of several different buildings on the East Mound. Sub-samples were examined by IR spectroscopy, X-ray diffraction and X-ray fluorescence to determine the overall mineralogical and elemental composition, whilst thin sections were studied using optical polarising microscopy, IR Microscopy and Environmental Scanning Electron Microscopy with Energy Dispersive X-ray analysis. The results of this study have shown that there are two types of wall plaster found in the sequences and that the sediments used to produce these were obtained from at least two distinct sources. In particular, the presence of clay, calcite and magnesian calcite in the foundation plasters suggested that these were prepared predominantly from a marl source. On the other hand, the finishing plasters were found to contain dolomite with a small amount of clay and no calcite, revealing that softlime was used in their preparation. Whilst marl is located directly below and around Çatalhöyük, the nearest source of softlime is 6.5 km away, an indication that the latter was important to the Neolithic people, possibly due to the whiter colour (5Y 8/1) of this sediment. Furthermore, the same two plaster types were found on each wall of Building 49, the main building studied in this research, and in all five buildings investigated, suggesting that the use of these sources was an established practice for the inhabitants of several different households across the site.
Resumo:
Consideration of the geometrical features of the functional groups present in furosemide has enabled synthesis of a series of ternary co-crystals with predictable structural features, containing a robust asymmetric two-dimensional network.
Resumo:
In 2006 the UK government announced a move to zero carbon homes by 2016. The demand posed a major challenge to policy makers and construction professionals entailing a protracted process of policy design. The task of giving content to this target is used to explore the role of evidence in the policy process. Whereas much literature on policy and evidence treats evidence as an external input, independent of politics, this paper explores the ongoing mutual constitution of both. Drawing on theories of policy framing and the sociology of classification, the account follows the story of a policy for Zero Carbon Homes from the parameters and values used to specify the target. Particular attention is given to the role of Regulatory Impact Assessments (RIAs) and to the creation of a new policy venue, the Zero Carbon Hub. The analysis underlines the way in which the choices about how to model and measure the aims potentially transforms them, the importance of policy venues for transparency and the role of RIAs in the authorization of particular definitions. A more transparent, open approach to policy formulation is needed in which the framing of evidence is recognized as an integral part of the policy process.
Resumo:
An experimental search for crystalline forms of creatine including a variable temperature X-ray powder diffraction study has produced three polymorphs and a formic acid solvate. The crystal structures of creatine forms I and II were determined from X-ray powder diffraction data plus the creatine formic acid (1 : 1) solvate structure was obtained by single crystal X-ray diffraction methods. Evidence of a third polymorphic form of creatine obtained by rapid desolvation of creatine monohydrate is also presented. The results highlight the role of automated parallel crystallisation, slurry experiments and VT-XRPD as powerful techniques for effective physical form screening. They also highlight the importance of various complementary analytical techniques in structural characterisation and in achieving better understanding of the relationship between various solid-state forms. The structural relationships between various solid-state forms of creatine using the XPac method provided a rationale for the different relative stabilities of forms I and II of creatine with respect to the monohydrate form.
Resumo:
We analyze the interaction between university professors’ teaching quality and their research and administrative activities. Our sample is a high-quality individual panel data set from a medium size public Spanish university that allows us to avoid several types of biases frequently encountered in the literature. Although researchers teach roughly 20% more than non-researchers, their teaching quality is also 20% higher. Instructors with no research are 5 times more likely than the rest to be among the worst teachers. Over much of the relevant range, we find a nonlinear and positive relationship between research output and teaching quantity on teaching quality. Our conclusions may be useful for decision makers in universities and governments.
Resumo:
This paper uses a novel numerical optimization technique - robust optimization - that is well suited to solving the asset-liability management (ALM) problem for pension schemes. It requires the estimation of fewer stochastic parameters, reduces estimation risk and adopts a prudent approach to asset allocation. This study is the first to apply it to a real-world pension scheme, and the first ALM model of a pension scheme to maximise the Sharpe ratio. We disaggregate pension liabilities into three components - active members, deferred members and pensioners, and transform the optimal asset allocation into the scheme’s projected contribution rate. The robust optimization model is extended to include liabilities and used to derive optimal investment policies for the Universities Superannuation Scheme (USS), benchmarked against the Sharpe and Tint, Bayes-Stein, and Black-Litterman models as well as the actual USS investment decisions. Over a 144 month out-of-sample period robust optimization is superior to the four benchmarks across 20 performance criteria, and has a remarkably stable asset allocation – essentially fix-mix. These conclusions are supported by six robustness checks.
Resumo:
Aim Most vascular plants on Earth form mycorrhizae, a symbiotic relationship between plants and fungi. Despite the broad recognition of the importance of mycorrhizae for global carbon and nutrient cycling, we do not know how soil and climate variables relate to the intensity of colonization of plant roots by mycorrhizal fungi. Here we quantify the global patterns of these relationships. Location Global. Methods Data on plant root colonization intensities by the two dominant types of mycorrhizal fungi world-wide, arbuscular (4887 plant species in 233 sites) and ectomycorrhizal fungi (125 plant species in 92 sites), were compiled from published studies. Data for climatic and soil factors were extracted from global datasets. For a given mycorrhizal type, we calculated at each site the mean root colonization intensity by mycorrhizal fungi across all potentially mycorrhizal plant species found at the site, and subjected these data to generalized additive model regression analysis with environmental factors as predictor variables. Results We show for the first time that at the global scale the intensity of plant root colonization by arbuscular mycorrhizal fungi strongly relates to warm-season temperature, frost periods and soil carbon-to-nitrogen ratio, and is highest at sites featuring continental climates with mild summers and a high availability of soil nitrogen. In contrast, the intensity of ectomycorrhizal infection in plant roots is related to soil acidity, soil carbon-to-nitrogen ratio and seasonality of precipitation, and is highest at sites with acidic soils and relatively constant precipitation levels. Main conclusions We provide the first quantitative global maps of intensity of mycorrhizal colonization based on environmental drivers, and suggest that environmental changes will affect distinct types of mycorrhizae differently. Future analyses of the potential effects of environmental change on global carbon and nutrient cycling via mycorrhizal pathways will need to take into account the relationships discovered in this study.
Resumo:
Housebuilding firms vary across the world in size and in the scope of their activities. This variety may seem surprising in an industry with open technologies and ease of entry. While market and technological factors may go some way to explain such differences, much of the causes of variation lie in dissimilarities in regulatory and institutional frameworks. These themes are explored through a comparative analysis of the structure of the residential development industry in Australia, the UK and the USA and in analysis of firm size hierarchies. The firm concentration ratio is much higher in the UK than the other two countries and the reasons may lie in the geography of the country but also in the peculiarities of its planning system.
Resumo:
This paper reports findings from six field courses about student’s perceptions of iPads as mobile learning devices for fieldwork. Data were collected through surveys and focus groups. The key findings suggest that the multi-tool nature of the iPads and their portability were the main strengths. Students had some concerns over the safety of the iPads in adverse weather and rugged environments, though most of these concerns were eliminated after using the devices with protective cases. Reduced connectivity was found to be one of the main challenges for mobile learning. Finally, students and practitioners views of why they used the mobile devices for fieldwork did not align.
Resumo:
Trading commercial real estate involves a process of exchange that is costly and which occurs over an extended and uncertain period of time. This has consequences for the performance and risk of real estate investments. Most research on transaction times has occurred for residential rather than commercial real estate. We study the time taken to transact commercial real estate assets in the UK using a sample of 578 transactions over the period 2004 to 2013. We measure average time to transact from a buyer and seller perspective, distinguishing the search and due diligence phases of the process, and we conduct econometric analysis to explain variation in due diligence times between assets. The median time for purchase of real estate from introduction to completion was 104 days and the median time for sale from marketing to completion was 135 days. There is considerable variation around these times and results suggest that some of this variation is related to market state, type and quality of asset, and type of participants involved in the transaction. Our findings shed light on the drivers of liquidity at an individual asset level and can inform models that quantify the impact of uncertain time on market on real estate investment risk.
Resumo:
Recent empirical works on the within-sector impact of inward investments on domestic firms’ productivity have found rather robust evidence of no (or even negative) effects. We suggest that, among other reasons, a specification error might explain some of these results. A more general specification, which includes the usual one as a special case, is proposed. Using data on Italian manufacturing firms in 1992–2000, we find positive externalities only once we allow for the more flexible specification.
Resumo:
This article traces the intertextual relationships between Anya Ulinich’s graphic novel Lena Finkle’s Magic Barrel, Bernard Malamud’s short story ‘The Magic Barrel’ and a number of works by Philip Roth. Through these relationships and her construction of a number of variations on what Miriam Libicki has called a ‘gonzo self’ Ulinich explores the tensions between life and art, fact and fiction, and autobiography and the novel, mediating the aesthetic imperatives of what Roth has called the ‘written world’ and the ethical obligations of the ‘unwritten world’ in order to arrive at an authentic sense of herself as an artist and writer.
Resumo:
In experimental investigations of the effect of real incentives, accountability—the implicit or explicit expectation of a decision maker that she may have to justify her decisions in front of somebody else—is often confounded with the incentives themselves. This confounding of accountability with incentives makes causal attributions of any effects found problematic. We separate accountability and incentives, and find different effects. Accountability is found to reduce preference reversals between frames, for which incentives have no effect. Incentives on the other hand are found to reduce risk seeking for losses, where accountability has no effect. In a choice task between simple and compound events, accountability increases the preference for the simple event, while incentives have a weaker effect going in the opposite direction. It is thus shown that the confounding of accountability and incentives is relevant for studies on the effect of the latter, and that existing conclusions on the effect of incentives need to be reconsidered in light of this issue.