971 resultados para Saint Kitts and Nevis
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
There are strong uncertainties regarding LAI dynamics in forest ecosystems in response to climate change. While empirical growth & yield models (G&YMs) provide good estimations of tree growth at the stand level on a yearly to decennial scale, process-based models (PBMs) use LAI dynamics as a key variable for enabling the accurate prediction of tree growth over short time scales. Bridging the gap between PBMs and G&YMs could improve the prediction of forest growth and, therefore, carbon, water and nutrient fluxes by combining modeling approaches at the stand level.Our study aimed to estimate monthly changes of leaf area in response to climate variations from sparse measurements of foliage area and biomass. A leaf population probabilistic model (SLCD) was designed to simulate foliage renewal. The leaf population was distributed in monthly cohorts, and the total population size was limited depending on forest age and productivity. Foliage dynamics were driven by a foliation function and the probabilities ruling leaf aging or fall. Their formulation depends on the forest environment.The model was applied to three tree species growing under contrasting climates and soil types. In tropical Brazilian evergreen broadleaf eucalypt plantations, the phenology was described using 8 parameters. A multi-objective evolutionary algorithm method (MOEA) was used to fit the model parameters on litterfall and LAI data over an entire stand rotation. Field measurements from a second eucalypt stand were used to validate the model. Seasonal LAI changes were accurately rendered for both sites (R-2 = 0.898 adjustment, R-2 = 0.698 validation). Litterfall production was correctly simulated (R-2 = 0.562, R-2 = 0.4018 validation) and may be improved by using additional validation data in future work. In two French temperate deciduous forests (beech and oak), we adapted phenological sub-modules of the CASTANEA model to simulate canopy dynamics, and SLCD was validated using LAI measurements. The phenological patterns were simulated with good accuracy in the two cases studied. However, IA/max was not accurately simulated in the beech forest, and further improvement is required.Our probabilistic approach is expected to contribute to improving predictions of LAI dynamics. The model formalism is general and suitable to broadleaf forests for a large range of ecological conditions. (C) 2014 Elsevier B.V. All rights reserved.
Resumo:
In savannah and tropical grasslands, which account for 60% of grasslands worldwide, a large share of ecosystem carbon is located below ground due to high root:shoot ratios. Temporal variations in soil CO2 efflux (R-S) were investigated in a grassland of coastal Congo over two years. The objectives were (1) to identify the main factors controlling seasonal variations in R-S and (2) to develop a semi-empirical model describing R-S and including a heterotrophic component (R-H) and an autotrophic component (R-A). Plant above-ground activity was found to exert strong control over soil respiration since 71% of seasonal R-S variability was explained by the quantity of photosynthetically active radiation absorbed (APAR) by the grass canopy. We tested an additive model including a parameter enabling R-S partitioning into R-A and R-H. Assumptions underlying this model were that R-A mainly depended on the amount of photosynthates allocated below ground and that microbial and root activity was mostly controlled by soil temperature and soil moisture. The model provided a reasonably good prediction of seasonal variations in R-S (R-2 = 0.85) which varied between 5.4 mu mol m(-2) s(-1) in the wet season and 0.9 mu mol m(-2) s(-1) at the end of the dry season. The model was subsequently used to obtain annual estimates of R-S, R-A and R-H. In accordance with results reported for other tropical grasslands, we estimated that R-H accounted for 44% of R-S, which represented a flux similar to the amount of carbon brought annually to the soil from below-ground litter production. Overall, this study opens up prospects for simulating the carbon budget of tropical grasslands on a large scale using remotely sensed data. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
It is not unknown that the evolution of firm theories has been developed along a path paved by an increasing awareness of the organizational structure importance. From the early “neoclassical” conceptualizations that intended the firm as a rational actor whose aim is to produce that amount of output, given the inputs at its disposal and in accordance to technological or environmental constraints, which maximizes the revenue (see Boulding, 1942 for a past mid century state of the art discussion) to the knowledge based theory of the firm (Nonaka & Takeuchi, 1995; Nonaka & Toyama, 2005), which recognizes in the firm a knnowledge creating entity, with specific organizational capabilities (Teece, 1996; Teece & Pisano, 1998) that allow to sustaine competitive advantages. Tracing back a map of the theory of the firm evolution, taking into account the several perspectives adopted in the history of thought, would take the length of many books. Because of that a more fruitful strategy is circumscribing the focus of the description of the literature evolution to one flow connected to a crucial question about the nature of firm’s behaviour and about the determinants of competitive advantages. In so doing I adopt a perspective that allows me to consider the organizational structure of the firm as an element according to which the different theories can be discriminated. The approach adopted starts by considering the drawbacks of the standard neoclassical theory of the firm. Discussing the most influential theoretical approaches I end up with a close examination of the knowledge based perspective of the firm. Within this perspective the firm is considered as a knowledge creating entity that produce and mange knowledge (Nonaka, Toyama, & Nagata, 2000; Nonaka & Toyama, 2005). In a knowledge intensive organization, knowledge is clearly embedded for the most part in the human capital of the individuals that compose such an organization. In a knowledge based organization, the management, in order to cope with knowledge intensive productions, ought to develop and accumulate capabilities that shape the organizational forms in a way that relies on “cross-functional processes, extensive delayering and empowerment” (Foss 2005, p.12). This mechanism contributes to determine the absorptive capacity of the firm towards specific technologies and, in so doing, it also shape the technological trajectories along which the firm moves. After having recognized the growing importance of the firm’s organizational structure in the theoretical literature concerning the firm theory, the subsequent point of the analysis is that of providing an overview of the changes that have been occurred at micro level to the firm’s organization of production. The economic actors have to deal with challenges posed by processes of internationalisation and globalization, increased and increasing competitive pressure of less developed countries on low value added production activities, changes in technologies and increased environmental turbulence and volatility. As a consequence, it has been widely recognized that the main organizational models of production that fitted well in the 20th century are now partially inadequate and processes aiming to reorganize production activities have been widespread across several economies in recent years. Recently, the emergence of a “new” form of production organization has been proposed both by scholars, practitioners and institutions: the most prominent characteristic of such a model is its recognition of the importance of employees commitment and involvement. As a consequence it is characterized by a strong accent on the human resource management and on those practices that aim to widen the autonomy and responsibility of the workers as well as increasing their commitment to the organization (Osterman, 1994; 2000; Lynch, 2007). This “model” of production organization is by many defined as High Performance Work System (HPWS). Despite the increasing diffusion of workplace practices that may be inscribed within the concept of HPWS in western countries’ companies, it is an hazard, to some extent, to speak about the emergence of a “new organizational paradigm”. The discussion about organizational changes and the diffusion of HPWP the focus cannot abstract from a discussion about the industrial relations systems, with a particular accent on the employment relationships, because of their relevance, in the same way as production organization, in determining two major outcomes of the firm: innovation and economic performances. The argument is treated starting from the issue of the Social Dialogue at macro level, both in an European perspective and Italian perspective. The model of interaction between the social parties has repercussions, at micro level, on the employment relationships, that is to say on the relations between union delegates and management or workers and management. Finding economic and social policies capable of sustaining growth and employment within a knowledge based scenario is likely to constitute the major challenge for the next generation of social pacts, which are the main social dialogue outcomes. As Acocella and Leoni (2007) put forward the social pacts may constitute an instrument to trade wage moderation for high intensity in ICT, organizational and human capital investments. Empirical evidence, especially focused on the micro level, about the positive relation between economic growth and new organizational designs coupled with ICT adoption and non adversarial industrial relations is growing. Partnership among social parties may become an instrument to enhance firm competitiveness. The outcome of the discussion is the integration of organizational changes and industrial relations elements within a unified framework: the HPWS. Such a choice may help in disentangling the potential existence of complementarities between these two aspects of the firm internal structure on economic and innovative performance. With the third chapter starts the more original part of the thesis. The data utilized in order to disentangle the relations between HPWS practices, innovation and economic performance refer to the manufacturing firms of the Reggio Emilia province with more than 50 employees. The data have been collected through face to face interviews both to management (199 respondents) and to union representatives (181 respondents). Coupled with the cross section datasets a further data source is constituted by longitudinal balance sheets (1994-2004). Collecting reliable data that in turn provide reliable results needs always a great effort to which are connected uncertain results. Data at micro level are often subjected to a trade off: the wider is the geographical context to which the population surveyed belong the lesser is the amount of information usually collected (low level of resolution); the narrower is the focus on specific geographical context, the higher is the amount of information usually collected (high level of resolution). For the Italian case the evidence about the diffusion of HPWP and their effects on firm performances is still scanty and usually limited to local level studies (Cristini, et al., 2003). The thesis is also devoted to the deepening of an argument of particular interest: the existence of complementarities between the HPWS practices. It has been widely shown by empirical evidence that when HPWP are adopted in bundles they are more likely to impact on firm’s performances than when adopted in isolation (Ichniowski, Prennushi, Shaw, 1997). Is it true also for the local production system of Reggio Emilia? The empirical analysis has the precise aim of providing evidence on the relations between the HPWS dimensions and the innovative and economic performances of the firm. As far as the first line of analysis is concerned it must to be stressed the fundamental role that innovation plays in the economy (Geroski & Machin, 1993; Stoneman & Kwoon 1994, 1996; OECD, 2005; EC, 2002). On this point the evidence goes from the traditional innovations, usually approximated by R&D investment expenditure or number of patents, to the introduction and adoption of ICT, in the recent years (Brynjolfsson & Hitt, 2000). If innovation is important then it is critical to analyse its determinants. In this work it is hypothesised that organizational changes and firm level industrial relations/employment relations aspects that can be put under the heading of HPWS, influence the propensity to innovate in product, process and quality of the firm. The general argument may goes as follow: changes in production management and work organization reconfigure the absorptive capacity of the firm towards specific technologies and, in so doing, they shape the technological trajectories along which the firm moves; cooperative industrial relations may lead to smother adoption of innovations, because not contrasted by unions. From the first empirical chapter emerges that the different types of innovations seem to respond in different ways to the HPWS variables. The underlying processes of product, process and quality innovations are likely to answer to different firm’s strategies and needs. Nevertheless, it is possible to extract some general results in terms of the most influencing HPWS factors on innovative performance. The main three aspects are training coverage, employees involvement and the diffusion of bonuses. These variables show persistent and significant relations with all the three innovation types. The same do the components having such variables at their inside. In sum the aspects of the HPWS influence the propensity to innovate of the firm. At the same time, emerges a quite neat (although not always strong) evidence of complementarities presence between HPWS practices. In terns of the complementarity issue it can be said that some specific complementarities exist. Training activities, when adopted and managed in bundles, are related to the propensity to innovate. Having a sound skill base may be an element that enhances the firm’s capacity to innovate. It may enhance both the capacity to absorbe exogenous innovation and the capacity to endogenously develop innovations. The presence and diffusion of bonuses and the employees involvement also spur innovative propensity. The former because of their incentive nature and the latter because direct workers participation may increase workers commitment to the organizationa and thus their willingness to support and suggest inovations. The other line of analysis provides results on the relation between HPWS and economic performances of the firm. There have been a bulk of international empirical studies on the relation between organizational changes and economic performance (Black & Lynch 2001; Zwick 2004; Janod & Saint-Martin 2004; Huselid 1995; Huselid & Becker 1996; Cappelli & Neumark 2001), while the works aiming to capture the relations between economic performance and unions or industrial relations aspects are quite scant (Addison & Belfield, 2001; Pencavel, 2003; Machin & Stewart, 1990; Addison, 2005). In the empirical analysis the integration of the two main areas of the HPWS represent a scarcely exploited approach in the panorama of both national and international empirical studies. As remarked by Addison “although most analysis of workers representation and employee involvement/high performance work practices have been conducted in isolation – while sometimes including the other as controls – research is beginning to consider their interactions” (Addison, 2005, p.407). The analysis conducted exploiting temporal lags between dependent and covariates, possibility given by the merger of cross section and panel data, provides evidence in favour of the existence of HPWS practices impact on firm’s economic performance, differently measured. Although it does not seem to emerge robust evidence on the existence of complementarities among HPWS aspects on performances there is evidence of a general positive influence of the single practices. The results are quite sensible to the time lags, inducing to hypothesize that time varying heterogeneity is an important factor in determining the impact of organizational changes on economic performance. The implications of the analysis can be of help both to management and local level policy makers. Although the results are not simply extendible to other local production systems it may be argued that for contexts similar to the Reggio Emilia province, characterized by the presence of small and medium enterprises organized in districts and by a deep rooted unionism, with strong supporting institutions, the results and the implications here obtained can also fit well. However, a hope for future researches on the subject treated in the present work is that of collecting good quality information over wider geographical areas, possibly at national level, and repeated in time. Only in this way it is possible to solve the Gordian knot about the linkages between innovation, performance, high performance work practices and industrial relations.
Resumo:
Quelle est la différence entre un flibustier et un pirate ? Ce projet de recherche est basé sur cette question enfantine. En fait, les historiens contemporains, qui ont consacré de nombreuses pages à la « piraterie » et à la « flibuste » de l’âge moderne, n’ont pas réussi à répondre à cette – apparemment – simple question. Les reconstructions et les théories développées, en fait, ont assimilé ces deux phénomènes, en traitant les deux termes comme de simples synonymes. Mais, si cela peut être considéré comme vrai aujourd’hui, il n'était pas au cours des XVIIème et XVIIIème siècles. À l'époque, pirate était équivalent de « hostis humani generis », et comme tel craint et persécuté. Les flibustiers, au contraire, ont été considérés comme l’un des groupes les plus importants dans les premiers établissements des îles de la Mer des Caraïbes. En outre, le terme flibustier, dans la correspondance des gouverneurs français, se réfère à un élément considéré comme essentiel pour la réussite du processus de construction de la colonie, et également cruciale pour la consolidation des établissements américains. C’est donc la relation spéciale entre les flibustiers et le Nouveau Monde est l’objet de cette thèse. En utilisant une approche historico-culturel, on a essayé de contextualiser le phénomène de la flibuste dans le « processus d’américanisation » des premières communautés européennes en Amérique. La relation étroite entre les colons des établissements français de Saint-Domingue (aujourd’hui Haïti) et les nombreux espaces - économique, militaire, diplomatique, social, humain - des Caraïbes a fait des flibustiers un élément fortement « américanisé ». Grâce à la lecture des documents d'archives et les mémoires des années entre 1684 et 1727, on a reconstruit la dynamique de la relation entre ce groupe et le contexte américain, avec une attention particulière à la dynamique culturelle et sociale.
Resumo:
We report four epidemiologically unrelated cases of KPC-carrying Klebsiella pneumoniae identified in Switzerland between May 2009 and November 2010. Three cases were transferred from Italy (two KPC-3, one KPC-2) and one from Greece (KPC-2). Resistance to colistin and doxycycline emerged in one KPC-3-carrying K. pneumoniae strain during therapy. These results demonstrate ongoing dissemination of KPC throughout Europe. Rapid and reliable identification of KPC and implementation of control measures is essential to limit spread.
Resumo:
Saint Margaret, as presented in the “Katherine Group” life of the virgin martyr, claims to have Christ’s “marks” and “seals” on her. Bringing together postmodern theories of body modification and Paul Zumthor’s concept of mouvance, this essay reads these marks as tattoos that consist of virtual (tattoo fantasies), oral (tattoo narratives), and written elements (the actual marks on skin). Margaret defends and empowers herself by claiming to possess Christ’s ownership tattoo. Her oppressor Olibrius, in turn, intends to overwrite that mark palimpsestically and hence to empower himself, not unlike slave-owners in antiquity. While the gruesome torture scenes suggest that Olibrius wins the upper hand in this contest, the outcome of the narrative instead proves that Margaret triumphs. She dies a virgin after defiantly appropriating, in her tattoo narrative, the torture marks as her own, divine tattoo.
Resumo:
A new examination of the textile fragments found in the Merovingian burials in the basilica of Saint Denis, near Paris, has recently underscored the diversity of fabrics used to make garments in which members of the royal court were buried. Among them, some woolens of fine quality had been dyed with indigotin. The most astonishing fibre found belongs to a mixed textile (not skin) with beaver fibers and wool. Silks contained shellfish purple and in one case kermes? Two dyestuffs associated with royalty and privilege. Along with this was large number of gold threads, probably produced locally and that were used in tablet-woven borders or for embroideries. In addition, several figured silks, of oriental origin, testify to the importance of this "foreign" material and the taste for textiles woven with complex techniques and probably what had originally had beautiful designs. Although none of these designs have been preserved and many colors have been greatly damaged, the technical characteristics of the remnants indicate proveniences as far as Byzantium, Sassanid Persia and the Chinese court. Such precious textiles show the high social status and political power of the Merovingian court, a testament to their ability to access such luxurious and costly textiles through diplomacy and/or trade with other powerful empires. The examination of these rare textiles along with other fine silks and luxury objects from the same period found in France expand our view of the fundamental role of textiles in the political sphere of this early period of European history.
Resumo:
A scintillation crystal can include Ln(1-y)REyX3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value at 0-1, and X represents a halogen. In an embodiment, the scintillation crystal is doped with a Group 1 element, a Group 2 element, or a mixt. thereof, and the scintillation crystal is formed from a melt having a concn. of such elements or mixt. thereof of at least ∼0.02%. In another embodiment, the scintillation crystal can have unexpectedly improved proportionality and unexpectedly improved energy resoln. properties. In a further embodiment, a radiation detection app. can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection app. can be useful in a variety of applications.
Resumo:
BACKGROUND: Infliximab (IFX) has been used for over a decade worldwide. Less is known about the natural history of IFX use beyond a few years and which patients are more likely to sustain benefits. METHODS: Patients with Crohn's disease (CD) exposed to IFX from Massachusetts General Hospital, Boston, Saint-Antoine Hospital, Paris, and the Swiss IBD Cohort Study were identified through retrospective and prospective data collection, complemented by chart abstraction of electronic medical records. We compared long-term users of IFX (>5 yr of treatment, long-term users of infliximab [LTUI]), with non-LTUI patients to identify prognostic factors. RESULTS: We pooled data on 1014 patients with CD from 3 different databases, of whom 250 were defined as LTUI. The comparison group comprised 290 patients with CD who discontinued IFX: 48 primary nonresponses, 95 loss of responses, and 147 adverse events. Factors associated with LTUI were colonic involvements and an earlier age at the start of IFX. The prevalence of active smokers and obese patients differed markedly, but inversely, between American and European centers but did not impact outcome. The discontinuation rate was stable around 3% to 6%, each year from years 3 to 10. CONCLUSIONS: Young age at start of IFX and colonic CD are factors associated with a beneficial long-term use of IFX. After 5 years of IFX, there is still a 3% to 5% discontinuation rate annually. Several factors associated with a good initial response such as nonsmoker and shorter disease duration at IFX initiation do not seem associated with a longer term response.