394 research outputs found

    Landscape and its possible “new” relevance: ethics and some forgotten narratives on human mobility

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    This article aims to provide a reinterpretation of the concept of landscape and to investigate, in some respects, its possible “new” relevance. More specifically, the analysis of “new” theoretical resources of landscape – “new” as they are yet to be explored – is linked here to an alternative interpretation of some neglected pathways of its history. I argue that the possible “new” relevance of landscape also lies in some forgotten ethical narratives on mobility that it has inherited from its chorographic roots, which I outline by re-reading some ancient and 16th-century sources. In fact, I try to show that, by virtue of this chorographic legacy, landscape may represent today a critical and destabilizing perspective, able to undermine the striated and hegemonic certainties of modern thought through the lens of human mobility and its association with an ethical conception of happiness. The final section of the article is dedicated to the theoretical contributions that the chorographic side of landscape can provide to some contemporary reflections on mobility and to geographical ideas of ethics. These theoretical contributions are regarded as an integral part of the possible “new” relevance of landscape.</p

    Investigations on offshore wind turbine inflow modelling using numerical weather prediction coupled with local-scale computational fluid dynamics

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    The computational power available nowadays to industry and research paves the way to increasingly more accurate systems for the wind resource prediction. A promising approach is to support the mesoscale numerical weather prediction (NWP) with high fidelity computational fluid dynamics (CFD). This approach aims at increasing the spatial resolution of the wind prediction by not only accounting for the complex and multiphysics aspects of the atmosphere over a large geographical region, but also including the effects of the fine scale turbulence and the interaction of the wind flow with the sea surface. In this work, we test a set of model setups for both the mesoscale (NWP) and local scale (CFD) simulations employed in a multi-scale modelling framework. The method comprises a one-way coupling interface to define boundary conditions for the local scale simulation (based on the Reynolds Averaged Navier–Stokes equations) using the mesoscale wind given by the NWP system. The wind prediction in an offshore site is compared with LiDAR measurements, testing a set of mesoscale planetary boundary layer schemes, and different model choices for the local scale simulation, which include steady and unsteady approaches for simulation and boundary conditions, different turbulence closure constants, and the effect of the wave motion of the sea surface. The resulting wind is then used for the simulation of a large wind turbine, showing how a realistic wind profile and an ideal exponential law profile lead to different predictions of wind turbine rotor performance and loads

    The role of fundamental solution in Potential and Regularity Theory for subelliptic PDE

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    In this survey we consider a general Hormander type operator, represented as a sum of squares of vector fields plus a drift and we outline the central role of the fundamental solution in developing Potential and Regularity Theory for solutions of related PDEs. After recalling the Gaussian behavior at infinity of the kernel, we show some mean value formulas on the level sets of the fundamental solution, which are the starting point to obtain a comprehensive parallel of the classical Potential Theory. Then we show that a precise knowledge of the fundamental solution leads to global regularity results, namely estimates at the boundary or on the whole space. Finally in the problem of regularity of non linear differential equations we need an ad hoc modification of the parametrix method, based on the properties of the fundamental solution of an approximating problem

    Is age more than manual material handling associated with lumbar vertebral body and disc changes? A cross-sectional multicentre MRI study

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    Conflicting evidence exists to what extent manual material handling (MMH) causes lumbar disc disease, lack of evidence exist that this effect takes place especially at L5-S1 level, where the greatest moment occurs. The aim was to assess if lumbar vertebral body and disc changes are more common in people whose job involves significant MMH and, if so, to evaluate if lumbar vertebral body and disc changes are more prevalent in the lower part of the lumbar spine (L4-L5 and L5-S1)

    "Is this case of a very rare disease work-related?" A review of reported cases of Pacinian neuroma.

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    Objective In response to a request for a medicolegal opinion from an orthopaedic technician with pacinian neuroma of the hand, we conducted a systematic review of reported cases designed to assess whether this rare disease could be considered to be work-related.Methods We used Medline, Embase, Google Scholar, Google, and a manual search to identify reports of histologically confirmed pacinian neuroma of the hand manifesting after 15 years of age. Cases with available information (from article/authors) on personal history were considered eligible. We tabulated information on age/gender; localization and histopathologic features; signs/symptoms; history of local trauma; occupation, sports/hobbies or other physical exposures; right- or left-handedness; and outcome.Results We found 44 eligible cases (including the present referral). Of these, 21 (48%) followed a trauma [<6 months from onset/presentation (N=7); 0.5\u20132 years from onset (N=6); 652 years from onset (N=7); and timing unknown (N=1)] involving the same anatomic site. Three of these 21 traumas definitely occurred at work, and a further 2 cases occurred at the site of definite work-related repetitive microtrauma.Conclusions The results reinforce the concept that pacinian neuroma of the hand can follow local trauma or repetitive microtrauma. Implicated traumas were either recent or remote, and they sometimes occurred while performing manual tasks at work. We concluded that the referred case could plausibly be considered work-related

    Wake interaction in offshore wind farms with mesoscale derived inflow condition and sea waves

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    Numerical simulation is an indispensable tool for the design and optimization of wind farms layout and control strategies for energy loss reduction. Achieving consistent simulation results is strongly related to the definition of reliable weather and sea conditions, as well as the use of accurate computational fluid dynamics (CFD) models for the simulation of the wind turbines and wakes. Thus, we present a case study aiming to evaluate the wake-rotor interaction between offshore multi-MW wind turbines modelled using the Actuator Line Model (ALM) and realistic wind inflow conditions. In particular, the interaction between two DTU10 wind turbines is studied for two orientations of the upstream turbine rotor, simulating the use of a yaw-based wake control strategy. Realistic wind inflow conditions are obtained using a multi-scale approach, where the wind field is firstly computed using mesoscale numerical weather prediction (NWP). Then, the mesoscale vertical wind profile is used to define the wind velocity and turbulence boundary conditions for the high-fidelity CFD simulations. Sea waves motion is also imposed using a dynamic mesh approach to investigate the interaction between sea waves, surface boundary layer, and wind turbine wakes and loads

    Potential theory results for a class of PDOs admitting a global fundamental solution

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    We outline several results of Potential Theory for a class of linear par-tial differential operators L of the second order in divergence form. Under essentially the sole assumption of hypoellipticity, we present a non-invariant homogeneous Harnack inequality for L; under different geometrical assumptions on L (mainly, under global doubling/Poincar\ue9 assumptions), it is described how to obtainan invariant, non-homogeneous Harnack inequality. When L is equipped with a global fundamental solution \u393, further Potential Theory results are available (such as the Strong Maximum Principle). We present some assumptions on L ensuring that such a \u393 exists

    Recommendations of the 2007 Healthy Lifestyle Forum to Help Combat Childhood Obesity

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    Senator Guy Barnett has held eight Healthy Lifestyle Forums to Help Combat Childhood Obesity since entering the Senate in 2002. The most recent forum, held on 20 June 2007 at Australian Parliament House Canberra, brought together approximately 60 concerned members of health care, academia, industry and public health to develop useful interventions and ideas for fighting childhood obesity. This report details the recommendations of the groups convened. They were asked to consider actions in the key areas of: clinical/health care system monitoring/benchmarking infant and early childhood schools and the wider community, and industry and private sector solutions

    Multi-imaging investigation to evaluate the relationship between serum cystatin c and features of atherosclerosis in Non-ST-Segment elevation acute coronary syndrome

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    Objectives: High cystatin C(CysC) levels are associated with impaired cardiovascular outcome. Whether CysC levels are independently related to the atherosclerosis burden is still controversial. Methods: We enrolled 31 non-ST-segment elevation acute coronary syndrome patients undergoing percutaneous coronary intervention. Patients were divided into 2 groups on the basis of median value of serum CysC. Using the high CysC group as a dependent variable, univariable and multivariable analyses were used to evaluate the association between CysC and three different features of atherosclerosis: 1) coronary plaque vulnerability as assessed by optical coherence tomography (OCT), 2) coronary artery calcium (CAC) by means of computed tomography scan, and 3) aortic wall metabolic activity, as assessed using 18 F-Fluorodeoxyglucose-positron emission tomography ( 18 F-FDG-PET). Results: After univariable and multivariable analyses, 18 F-FDG uptake in the descending aorta (DA) was independently associated with a low level of CysC [(Odds Ratio = 0.02; 95%CI 0.0004-0.89; p = 0.044; 18 F-FDG uptake measured as averaged maximum target to blood ratio); (Odds Ratio = 0.89; 95%CI 0.82-0.98, p = 0.025; 18 F-FDG uptake measured as number of active slices)]. No trend was found for the association between CysC and characteristics of OCT-assessed coronary plaque vulnerability or CAC score. Conclusions: In patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), 18 F-FDG uptake in the DA was associated with a low level of serum CysC. There was no relation between CysC levels and OCT-assessed coronary plaque vulnerability or CAC score. These findings suggest that high levels of CysC may not be considered as independent markers of atherosclerosis

    Harnack inequality for fractional sub-Laplacians in Carnot groups

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    In this paper we prove an invariant Harnack inequality on Carnot-Carath\'eodory balls for fractional powers of sub-Laplacians in Carnot groups. The proof relies on an "abstract" formulation of a technique recently introduced by Caffarelli and Silvestre. In addition, we write explicitly the Poisson kernel for a class of degenerate subelliptic equations in product-type Carnot groups
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