1000 resultados para Cent.


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The putative virulence and antimicrobial resistance gene contents of extended spectrum β-lactamase (ESBL)-positive E. coli (n=629) isolated between 2005 and 2009 from humans, animals and animal food products in Germany, The Netherlands and the UK were compared using a microarray approach to test the suitability of this approach with regard to determining their similarities. A selection of isolates (n=313) were also analysed by multilocus sequence typing (MLST). Isolates harbouring blaCTX-M-group-1 dominated (66%, n=418) and originated from both animals and cases of human infections in all three countries; 23% (n=144) of all isolates contained both blaCTX-M-group-1 and blaOXA-1-like genes, predominantly from humans (n=127) and UK cattle (n=15). The antimicrobial resistance and virulence gene profiles of this collection of isolates were highly diverse. A substantial number of human isolates (32%, n=87) did not share more than 40% similarity (based on the Jaccard coefficient) with animal isolates. A further 43% of human isolates from the three countries (n=117) were at least 40% similar to each other and to five isolates from UK cattle and one each from Dutch chicken meat and a German dog; the members of this group usually harboured genes such as mph(A), mrx, aac(6’)-Ib, catB3, blaOXA-1-like and blaCTX-M-group-1. forty-four per cent of the MLST-typed isolates in this group belonged to ST131 (n=18) and 22% to ST405 (n=9), all from humans. Among animal isolates subjected to MLST (n=258), only 1.2% (n=3) were more than 70% similar to human isolates in gene profiles and shared the same MLST clonal complex with the corresponding human isolates. The results suggest that minimising human-to-human transmission is essential to control the spread of ESBL-positive E. coli in humans.

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The literature on fiscal food policies focuses on their effectiveness in altering diets and improving health, while this paper focuses on their welfare costs. A formal welfare economics framework is developed to calculate the combined individualistic and distributional impacts of a tax-subsidy. Distributional characteristics of foods targeted by a tax tend to be concentrated in lower-income households. Further, consumption of fruit and vegetables tends to be concentrated in higher-income households; therefore, a subsidy on such foods increases regressivity. Aggregate welfare changes that result from a fiscal food policy are found to range from an increase of 1.41 per cent to a reduction of 2.06 per cent according to whether a subsidy is included, the degree of inequality aversion, and whether substitution among foods is allowed.

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Environmental building assessment tools have been developed to measure how well or poorly a building is performing, or likely to perform, against a declared set of criteria, or environmental considerations, in order to achieve sustainability principles. Knowledge of environmental building assessment tools is therefore important for successful design and construction of environmentally friendly buildings for countries. The purpose of the research is to investigate the knowledge and level of awareness of environmental building assessment tools among industry practitioners in Botswana. One hundred and seven paper-based questionnaires were delivered to industry practitioners, including architects, engineers, quantity surveyors, real estate developers and academics. Users were asked what they know about building assessment, whether they have used any building assessment tool in the past, and what they perceive as possible barriers to the implementation of environmental building assessment tools in Botswana. Sixty five were returned and statistical analysis, using IBM SPSS V19 software, was used for analysis. Almost 85 per cent of respondents indicate that they are extremely or moderately aware of environmental design. Furthermore, the results indicate that 32 per cent of respondents have gone through formal training, which suggests ‘reasonable knowledge’. This however does not correspond with the use of the tools on the ground as 69 per cent of practitioners report never to have used any environmental building assessment tool in any project. The study highlights the need to develop an assessment tool for Botswana to enhance knowledge and further improve the level of awareness of environmental issues relating to building design and construction.

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This paper reports an empirical study of the world’s 49 largest retail multinational enterprises (MNEs). Of these only one MNE is found to be a ‘global’ MNE, while five are ‘bi-regional’, i.e. with at least 20 per cent of sales in two parts of the ‘triad’ of the European Union, North America (NAFTA) and Asia. The remaining MNEs are either purely domestic or have sales in only their home-triad market. Thus, we conclude that the retail MNEs neither operate globally nor do they need global strategies. Instead, they are mainly regional MNEs and their focus is local, home-triad market-oriented.

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A method for the detection of O+ ion fluxes from topside soundings is described. The shape of the plasma scale-height profile is altered by such flows only at heights near the F2-peak, where ion-neutral drag is large. Model profiles are used to relate changes in scale height to the ratio (φ/φL) where φ is the field-aligned O+ flux (relative to the neutral air) and φL is the limiting value set by frictional drag. Values of (φ/φL) can then be determined to within a few per cent from experimental soundings, using the plasma temperature and its gradient (as deduced from the observed profile) and the MSIS model neutral temperature. It was found that 3700 topside profiles show departures from diffusive equilibrium, out of 10,000 used to obtain the global morphology of (φ/φL) near the sunspot minimum. Results reveal dynamic ion-flow effects such as the transequatorial breeze and the effects of the polar wind and protonospheric replenishment light-ion flows can be inferred.

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Intuition is an important and under-researched concept in information systems. Prior exploratory research has shown that that there is potential to characterize the use of intuition in academic information systems research. This paper extends this research to all of the available issues of two leading IS journals with the aim of reaching an approximation of theoretical saturation. Specifically, the entire text of MISQ and ISR was reviewed for the years 1990 through 2009 using searchable PDF versions of these publications. All references to intuition were coded on a basis consistent with Grounded Theory, interpreted as a gestalt and represented as a mind-map. In the period 1990-2009, 681 incidents of the use of "intuition", and related terms were found in the articles reviewed, representing a greater range of codes than prior research. In addition, codes were assigned to all issues of MIS Quarterly from commencement of publication to the end of the 2012 publication year to support the conjecture that coding saturation has been approximated. The most prominent use of the term of "intuition" was coded as "Intuition as Authority" in which intuition was used to validate a statement, research objective or a finding; representing approximately 34 per cent of codes assigned. In research articles where mathematical analysis was presented, researchers not infrequently commented on the degree to which a mathematical formulation was "intuitive"; this was the second most common coding representing approximately 16 per cent of the codes. The possibly most impactful use of the term "intuition" was "Intuition as Outcome", representing approximately 7 per cent of all coding, which characterized research results as adding to the intuitive understanding of a research topic or phenomena.This research aims to contribute to a greater theoretical understanding of the use of intuition in academic IS research publications. It provides potential benefits to practitioners by providing insight into the use of intuition in IS management, for example, emphasizing the emerging importance of "intuitive technology". Research directions include the creation of reflective and/or formative constructs for intuition in information systems research and the expansion of this novel research method to additional IS academic publications and topics.

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Purpose – The purpose of this paper is to examine the determinants of home-region strategy of the multinational subsidiary and the impact of such a strategy on its performance. The author draws upon new internalization theory to develop a theory-driven model and empirically tests the simultaneous relationships between home-region strategy and performance of the subsidiary. Design/methodology/approach – The author tests the model using a simultaneous equation statistical technique on an original, new data set of publicly listed multinational subsidiaries operating in the ASEAN region, with parent firms’ headquarters across the broad triad. Findings – There are three significant findings. The first finding is that subsidiary-level downstream knowledge (marketing advantages), and the geographic location of the subsidiary in the same home region as of the parent firm are key antecedents of a subsidiary’s home-region strategy. The second finding is that a subsidiary’s profitability reduces home-region orientation; however, home-region strategy has an insignificant effect on performance. The third finding is that these subsidiaries generate on average 92 per cent of their total sales in the home region (the Asia Pacific). Originality/value – The author advances the existing literature on the regional nature of parent-level multinational enterprises by demonstrating that their quasi-autonomous subsidiaries also operate mainly on a home-region basis.

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A key issue in UK railway history is whether the railway system was an efficient response to the traffic requirements of the economy. The UK railway system was constructed entirely by private enterprise with minimal state subsidies. This chapter considers whether the railway system was 'over-built' because the government ignored the advice of the Railway Committee of the Board of Trade. The chapter suggests that the system was over-built by about 35 per cent. The causes of this over-building are investigated and are found to be mainly social and political failures arising from distrust between MPs and civil servants and public pressure on local MPs to ensure that their constituencies were well served by railways.

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This continuing study of intragroup light in compact groups of galaxies aims to establish new constraints to models of formation and evolution of galaxy groups, specially of compact groups, which are a key part in the evolution of larger structures, such as clusters. In this paper we present three additional groups (HCG 15, 35 and 51) using deep wide-field B- and R-band images observed with the LAICA camera at the 3.5-m telescope at the Calar Alto observatory (CAHA). This instrument provides us with very stable flat-fielding, a mandatory condition for reliably measuring intragroup diffuse light. The images were analysed with the OV_WAV package, a wavelet technique that allows us to uncover the intragroup component in an unprecedented way. We have detected that 19, 15 and 26 per cent of the total light of HCG 15, 35 and 51, respectively, are in the diffuse component, with colours that are compatible with old stellar populations and with mean surface brightness that can be its low as 28.4 B mag arcsec(-2). Dynamical masses, crossing times and mass-to-light ratios were recalculated using the new group parameters. Also tidal features were analysed using the wavelet technique.

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A detailed study was performed for a sample of low-mass pre-main-sequence (PMS) stars, previously identified as weak-line T Tauri stars, which are compared to members of the Tucanae and Horologium Associations. Aiming to verify if there is any pattern of abundances when comparing the young stars at different phases, we selected objects in the range from 1 to 100 Myr, which covers most of PMS evolution. High-resolution optical spectra were acquired at European Southern Observatory and Observatorio do Pico dos Dias. The stellar fundamental parameters effective temperature and gravity were calculated by excitation and ionization equilibria of iron absorption lines. Chemical abundances were obtained via equivalent width calculations and spectral synthesis for 44 per cent of the sample, which shows metallicities within 0.5 dex solar. A classification was developed based on equivalent width of Li I 6708 angstrom and Ha lines and spectral types of the studied stars. This classification allowed a separation of the sample into categories that correspond to different evolutive stages in the PMS. The position of these stars in the Hertzsprung-Russell diagram was also inspected in order to estimate their ages and masses. Among the studied objects, it was verified that our sample actually contains seven weak-line T Tauri stars, three are Classical T Tauri, 12 are Fe/Ge PMS stars and 21 are post-T Tauri or young main-sequence stars. An estimation of circumstellar luminosity was obtained using a disc model to reproduce the observed spectral energy distribution. Most of the stars show low levels of circumstellar emission, corresponding to less than 30 per cent of the total emission.

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The study of Wolf-Rayet stars plays an important role in evolutionary theories of massive stars. Among these objects, similar to 20 per cent are known to be in binary systems and can therefore be used for the mass determination of these stars. Most of these systems are not spatially resolved and spectral lines can be used to constrain the orbital parameters. However, part of the emission may originate in the interaction zone between the stellar winds, modifying the line profiles and thus challenging us to use different models to interpret them. In this work, we analysed the He II lambda 4686 angstrom + C IV lambda 4658 angstrom blended lines of WR 30a (WO4+O5) assuming that part of the emission originate in the wind-wind interaction zone. In fact, this line presents a quiescent base profile, attributed to the WO wind, and a superposed excess, which varies with the orbital phase along the 4.6-d period. Under these assumptions, we were able to fit the excess spectral line profile and central velocity for all phases, except for the longest wavelengths, where a spectral line with constant velocity seems to be present. The fit parameters provide the eccentricity and inclination of the binary orbit, from which it is possible to constrain the stellar masses.

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We performed stellar population synthesis on the nuclear and extended regions of NGC 1068 by means of near-infrared spectroscopy to disentangle their spectral energy distribution components. This is the first time that such a technique is applied to the whole 0.8-2.4 mu m wavelength interval in this galaxy. NGC 1068 is one of the nearest and probably the most studied Seyfert 2 galaxy, becoming an excellent laboratory to study the interaction between black holes, the jets that they can produce and the medium in which they propagate. Our main result is that traces of young stellar population are found at similar to 100 pc south of the nucleus. The contribution of a power-law continuum in the centre is about 25 per cent, which is expected if the light is scattered from a Seyfert 1 nucleus. We find peaks in the contribution of the featureless continuum about 100-150 pc from the nucleus on both sides. They might be associated with regions where the jet encounters dense clouds. Further support to this scenario is given by the peaks of hot dust distribution found around these same regions and the H(2) emission-line profile, leading us to propose that the peaks might be associated to regions where stars are being formed. Hot dust also has an important contribution to the nuclear region, reinforcing the idea of the presence of a dense, circumnuclear torus in this galaxy. Cold dust appears mostly in the south direction, which supports the view that the south-west emission is behind the plane of the galaxy and is extinguished very likely by dust in the plane. Intermediate-age stellar population contributes significantly to the continuum, especially in the inner 200 pc.

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Cosmic shear requires high precision measurement of galaxy shapes in the presence of the observational point spread function (PSF) that smears out the image. The PSF must therefore be known for each galaxy to a high accuracy. However, for several reasons, the PSF is usually wavelength dependent; therefore, the differences between the spectral energy distribution of the observed objects introduce further complexity. In this paper, we investigate the effect of the wavelength dependence of the PSF, focusing on instruments in which the PSF size is dominated by the diffraction limit of the telescope and which use broad-band filters for shape measurement. We first calculate biases on cosmological parameter estimation from cosmic shear when the stellar PSF is used uncorrected. Using realistic galaxy and star spectral energy distributions and populations and a simple three-component circular PSF, we find that the colour dependence must be taken into account for the next generation of telescopes. We then consider two different methods for removing the effect: (i) the use of stars of the same colour as the galaxies and (ii) estimation of the galaxy spectral energy distribution using multiple colours and using a telescope model for the PSF. We find that both of these methods correct the effect to levels below the tolerances required for per cent level measurements of dark energy parameters. Comparison of the two methods favours the template-fitting method because its efficiency is less dependent on galaxy redshift than the broad-band colour method and takes full advantage of deeper photometry.

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Some observations of galaxies, and in particular dwarf galaxies, indicate a presence of cored density profiles in apparent contradiction with cusp profiles predicted by dark matter N-body simulations. We constructed an analytical model, using particle distribution functions (DFs), to show how a supernova (SN) explosion can transform a cusp density profile in a small-mass dark matter halo into a cored one. Considering the fact that an SN efficiently removes matter from the centre of the first haloes, we study the effect of mass removal through an SN perturbation in the DFs. We find that the transformation from a cusp into a cored profile occurs even for changes as small as 0.5 per cent of the total energy of the halo, which can be produced by the expulsion of matter caused by a single SN explosion.

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A numerous population of weak line galaxies (WLGs) is often left out of statistical studies on emission-line galaxies (ELGs) due to the absence of an adequate classification scheme, since classical diagnostic diagrams, such as [O iii]/H beta versus [N ii]/H alpha (the BPT diagram), require the measurement of at least four emission lines. This paper aims to remedy this situation by transposing the usual divisory lines between star-forming (SF) galaxies and active galactic nuclei (AGN) hosts and between Seyferts and LINERs to diagrams that are more economical in terms of line quality requirements. By doing this, we rescue from the classification limbo a substantial number of sources and modify the global census of ELGs. More specifically, (1) we use the Sloan Digital Sky Survey Data Release 7 to constitute a suitable sample of 280 000 ELGs, one-third of which are WLGs. (2) Galaxies with strong emission lines are classified using the widely applied criteria of Kewley et al., Kauffmann et al. and Stasinska et al. to distinguish SF galaxies and AGN hosts and Kewley et al. to distinguish Seyferts from LINERs. (3) We transpose these classification schemes to alternative diagrams keeping [N ii]/H alpha as a horizontal axis, but replacing H beta by a stronger line (H alpha or [O ii]), or substituting the ionization-level sensitive [O iii]/H beta ratio with the equivalent width of H alpha (W(H alpha)). Optimized equations for the transposed divisory lines are provided. (4) We show that nothing significant is lost in the translation, but that the new diagrams allow one to classify up to 50 per cent more ELGs. (5) Introducing WLGs in the census of galaxies in the local Universe increases the proportion of metal-rich SF galaxies and especially LINERs. In the course of this analysis, we were led to make the following points. (i) The Kewley et al. BPT line for galaxy classification is generally ill-used. (ii) Replacing [O iii]/H beta by W(H alpha) in the classification introduces a change in the philosophy of the distinction between LINERs and Seyferts, but not in its results. Because the W(H alpha) versus [N ii]/H alpha diagram can be applied to the largest sample of ELGs without loss of discriminating power between Seyferts and LINERs, we recommend its use in further studies. (iii) The dichotomy between Seyferts and LINERs is washed out by WLGs in the BPT plane, but it subsists in other diagnostic diagrams. This suggests that the right wing in the BPT diagram is indeed populated by at least two classes, tentatively identified with bona fide AGN and `retired` galaxies that have stopped forming stars and are ionized by their old stellar populations.