443 research outputs found

    A brief note on Early Abbasid stucco decoration. Madinat al-Far and the first Friday Mosque of Isfahan

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    The aim of this paper is to demonstrate how an in-depth study of the stucco decoration could be useful in dating different phases of the Early Abbasid period in the absence of other precise archaeological evidence. Two case studies are presented: the residence of Madinat al-Far in Syria and the Early Abbasid Mosque of Iṣfahān in Iran

    A matter of timing: the modern history of a ‘Sasanian’ silver plate from Rashy

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    After the recent publication of two previously unknown “Sasanian” silver plates depicting the renowned scene of the chariot of the Lunar God Mah, added to the other five known examples, this article reconsiders one specimen of this series of objects – here addressed as the “Rashy plate” –, the authenticity of which appears questionable. Three parameters are considered for discussing this plate: iconography, manufacturing technique and provenance, and all of them are contextualised in the period of the great exhibitions of Persian Art (between the 1930s and the 1960s). The outcome of these exhibitions, besides stimulating scholarly research on previously understudied artistic productions, was the consequent rising interest by museums and private collectors in art objects from the ancient Iranian world. The introduction of possible forgeries, such as the Rashy plate, coherently fits into this increasing demand of the art market

    Adult-type rhabdomyoma of the larynx: clinicopathologic study of an uncommon tumor in a rare location

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    Rhabdomyoma is an uncommon benign mesenchymal tumor with skeletal muscle differentiation that may occur either in the heart or in extra-cardiac sites. Even though the head and neck region is the most common area of extra-cardiac rhabdomyoma, the larynx is rarely involved. We present the case of an 85-year-old woman who reported a 10-day history of breathing difficulties, dysphagia and dysphonia. A computed tomography scan of the head and neck showed a contrast-enhanced, solid hypopharyngeal-laryngeal neoplasm with well-defined margins causing subtotal obliteration of the right pyriform sinus and a reduction in air lumen of the laryngeal vestibule. The patient underwent complete endoscopic removal of the lesion; histologic examination revealed an adult- type rhabdomyoma based on the histologic features and the immunoreactivity of the neoplastic cells for desmin, myoglobin and muscle-specific actin but not for cytokeratin, S-100, CD68R, chromogranin-A and synaptophysin. Since clinical and imaging features are not specific for rhabdomyoma, histologic examination and immunohistochemical analyses play a central role in the differential diagnosis of the adult-type rhabdomyoma from other laryngeal neoplasms. A correct diagnosis is mandatory to avoid inappropriate treatment

    eGEP Economic Model: Final Report on the Benefits, Costs and Financing of eGovernment

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    The Economic Study aims at assessing the impact of ICT within the Public Sector (PS) to Public Sector itself and to society. In particular, it provides the theoretical underpinning of the tangible elements presented in the Measurement Framework. The basic tenet of our model is that eGovernment programs result into an improvement of labour productivity in PS and, as a consequence, contribute to a number of intermediate outcomes (better services, cost savings, etc), and to the growth of GDP. Indeed, the contribution of PS to GDP can be adequately estimated as equal to the labour productivity of the public sector multiplied by the total number of public sector employees. As eGovernment represents the focus of our investigation, we make a ceteris paribus assumption and consider productivity increases linked only to the introduction of wider forms of eGovernment. Then we estimate PS productivity as a ratio between public sector output and the number of public sector employees. The model considers 5 main channels through which eGovernment projects increase PS productivity: the Market Enlargement or Smith’s Effect, the Substitution or Ricardo’s Effect, the Back-Office Reorganization Effect, the Investments-Led or Schumpeter’s Effect, and Other Take-Up Driven Effects. Given the large share of PS in European countries’ GDP, efficiency in the PAs is an objective per se and a major driver of international competitiveness and economic welfare: the growth of PS productivity is the first channel through which eGovernment enhances GDP growth. Then, two other effects depart from the growth of PS’s productivity: on the one hand, publicly provided goods and services contribute to welfare and are part of a country’s Gross Domestic Product, hence their growth should be accounted in national accounts (the second channel: growth of PS total output). Also, a more efficient public administration contributes directly to the efficiency of the economy as a whole and to the productivity of the Private Sector in particular, by stimulating innovation and the growth of the most competitive and innovative industries (the first, “indirect”, part of the third channel). Finally, eGovernment contributes to GDP growth due to its being part of Aggregate Demand, and its potential impact could further extend to multiplier and accelerator phenomena. Although the model’s foundations lie in a microeconomic analysis of single eGovernment projects and PAs, due to data limitations, following a macro approach, we have instead fit our model by aggregate data, so to produce tentative predictions for productivity and GDP behaviour in the next years, while providing a first validation of the proposed economic model. From this point of view, we can affirm that our results are encouraging, though it should be remarked that estimates are only partial, in many relevant theoretical effects could not be taken into account, and they are based on a rather short period of observation, therefore retaining a smaller statistical significance. Our estimates imply rather strong effects of eGovernment expenditure on PS productivity and GDP growth, even if we only consider the direct effect, i.e. we ignore the potential effect of the increased PS efficiency on the productivity of the private sector, and without even considering multiplier and/or accelerator effects. Our estimations imply that the projections on eGovernment expenditure provided by eGEP would lead by 2010 to a cumulative GDP growth at the EU-level of 1.5%. Furthermore, in a second scenario we also developed a simulation exercise to take into account the aggregate impact of both cost savings related to eProcurement and eGovernment expenditure on GDP growth for the period 2005-2010: if we assume that cost savings related to eProcurement would transfer in additional investments by PAs during the period 2005-2007, the overall GDP growth attributable to eGovernment in the period 2005-2010 can be estimated at 2%. Finally, from both the theoretical implications of the Economic Model and the empirical analysis employed in its validation procedure, we established that, in order to exploit eGovernment potential at its maximum level, it is necessary to work in three directions: increasing both the efficiency and the effectiveness of eGovernment inside Public Administrations and with reference to their main stakeholders (policy recommendations 1 to 4); promoting the diffusion of specific tools for performance measurement, together with a favourable cultural background (policy no. 5); setting-up a number of complementary policies, in order to foster the “take-up” effect, and finally promote productivity and growth. We identified five policy objectives connected to these three strategies: to share eGovernment goals, to address eGovernment towards shared objectives, to favour a performance-friendly environment within the Public Sector, to promote accessible and useful eGovernment services, to great a friendly financial framework for eGovernment, to make the performance measurement mandatory.public administrations; productivity growth; e-Government

    The economic performance of urban gardening in three European cities – examples from Ljubljana, Milan and London

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    Urban gardening is not a new phenomenon but it has received considerably more practical and academic interest in recent years. Studies on economic aspects such as crop yields, inputs and outputs of production, productivity, gross margins and the contribution to home economics are rare, especially in Europe. While urban gardening plays an important role in the Global South, its role in Western Europe for food productivity and home eco- nomics is currently under-researched. The aim of this study is to analyse European urban gardeners\u2019 economic performance and self-sufficiency on a household level, as well as to reach a better understanding of their con- tribution to food self-provision and food security in the metropolitan areas. In a study carried out in 2014 with on-site personal and with online questionnaires participated 180 urban gardeners from three case study cities (Ljubljana, Milan, and London). Results from the economic analysis showed that although for most urban gar- deners, profit is not their main motivation, the economic calculation shows that productivity in small urban plots can be comparable to market garden production. Urban gardeners are saving money, especially when, compared to retail prices for regular produce or organic produce, their input is included in the gross margin calculation. We conclude that, in the case-study cities, the self-provisional potential of urban gardeners\u2019 households to ade- quately cover the annual vegetable need of five-a-day servings can be met under three conditions: (1) sufficient garden size; (2) increased area productivity, and (3) sufficient labour-hour inputs

    Characterization of biocompatible scaffolds manufactured by fused filament fabrication of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate

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    We characterize poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) scaffolds for tissue repair and regeneration, manufactured by three-dimensional fused filament fabrication (FFF). PHBH belongs to the class of polyhydroxyalkanoates with interesting biodegradable and biocompatible capabilities, especially attractive for tissue engineering. Equally, FFF stands as a promising manufacturing technology for the production of custom-designed scaffolds. We address thermal, rheological and cytotoxicity properties of PHBH, placing special emphasis on the mechanical response of the printed material in a wide deformation range. Indeed, effective mechanical properties are assessed in both the linear and nonlinear regime. To warrant uniqueness of the material parameters, these are measured directly through digital image correlation, both in tension and compression, while experimental data fitting of finite-element analyses is only adopted for the determination of the second invariant coefficient in the nonlinear regime. Mechanical data are clearly porosity dependent, and they are given for both the cubic and the honeycomb infill pattern. Local strain spikes due to the presence of defects are observed and measured: those falling in the range 70\u2013100% lead to macro-crack development and, ultimately, to failure. Results suggest the significant potential attached to FFF printing of PHBH for customizable medical devices which are biocompatible and mechanically resilient

    Human umbilical cord blood-borne fibroblasts contain marrow niche precursors that form a bone/marrow organoid in vivo

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    Human umbilical cord blood (CB) has attracted much attention as a reservoir for functional hematopoietic stem and progenitor cells, and, recently, as a source of blood-borne fibroblasts (CB-BFs). Previously, we demonstrated that bone marrow stromal cell (BMSC) and CB-BF pellet cultures make cartilage in vitro. Furthermore, upon in vivo transplantation, BMSC pellets remodelled into miniature bone/marrow organoids. Using this in vivo model, we asked whether CB-BF populations that express characteristics of the hematopoietic stem cell (HSC) niche contain precursors that reform the niche. CB ossicles were regularly observed upon transplantation. Compared with BM ossicles, CB ossicles showed a predominance of red marrow over yellow marrow, as demonstrated by histomorphological analyses and the number of hematopoietic cells isolated within ossicles. Marrow cavities from CB and BM ossicles included donor-derived CD146-expressing osteoprogenitors and host-derived mature hematopoietic cells, clonogenic lineage-committed progenitors and HSCs. Furthermore, human CD34+ cells transplanted into ossicle-bearing mice engrafted and maintained human HSCs in the niche. Our data indicate that CB- BFs are able to recapitulate the conditions by which the bone marrow microenvironment is formed and establish complete HSC niches, which are functionally supportive of hematopoietic tissue

    Advances in geometrical parametrization and reduced order models and methods for computational fluid dynamics problems in applied sciences and engineering: overview and perspectives

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    Several problems in applied sciences and engineering require reduction techniques in order to allow computational tools to be employed in the daily practice, especially in iterative procedures such as optimization or sensitivity analysis. Reduced order methods need to face increasingly complex problems in computational mechanics, especially into a multiphysics setting. Several issues should be faced: stability of the approximation, efficient treatment of nonlinearities, uniqueness or possible bifurcations of the state solutions, proper coupling between fields, as well as offline-online computing, computational savings and certification of errors as measure of accuracy. Moreover, efficient geometrical parametrization techniques should be devised to efficiently face shape optimization problems, as well as shape reconstruction and shape assimilation problems. A related aspect deals with the management of parametrized interfaces in multiphysics problems, such as fluid-structure interaction problems, and also a domain decomposition based approach for complex parametrized networks. We present some illustrative industrial and biomedical problems as examples of recent advances on methodological developments. \ua9 The author
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