320 research outputs found
Accessible path finding for historic urban environments: feature extraction and vectorization from point clouds
Sidewalk inventory is a topic whose importance is increasing together with the widespread use of smart city management. In order to manage the city properly and to make informed decisions, it is necessary to know the real conditions of the city. Furthermore, when planning and calculating cultural routes within the city, these routes must take into account the specific needs of all users. Therefore, it is important to know the conditions of the city’s sidewalk network and also their physical and geometrical characteristics. Typically, sidewalk network are generated basing on existing cartographic data, and sidewalk attributes are gathered through crowdsourcing. In this paper, the sidewalk network of an historic city was produced starting from point cloud data. The point cloud was semantically segmented in ”roads” and ”sidewalks”, and then the cluster of points of sidewalks surfaces were used to compute sidewalk attributes and to generate a vector layer composed of nodes and edges. The vector layer was then used to compute accessible paths between Points of Interest, using QGIS. The tests made on a real case study, the historic city and UNESCO site of Sabbioneta (Italy), shows a vectorization accuracy of 98.7%. In future, the vector layers and the computed paths could be used to generate maps for city planners, and to develop web or mobile phones routing apps.Ministerio de Ciencia e Innovación | Ref. RYC2020-029193-
Integration of infrared thermography and photogrammetric surveying of built landscape
The thermal analysis of buildings represents a key-step for reduction of energy consumption, also in the case of Cultural Heritage. Here the complexity of the constructions and the adopted materials might require special analysis and tailored solutions. Infrared Thermography (IRT) is an important non-destructive investigation technique that may aid in the thermal analysis of buildings. The paper reports the application of IRT on a listed building, belonging to the Cultural Heritage and to a residential one, as a demonstration that IRT is a suitable and convenient tool for analysing the existing buildings. The purposes of the analysis are the assessment of the damages and energy efficiency of the building envelope. Since in many cases the complex geometry of historic constructions may involve the thermal analysis, the integration of IRT and accurate 3D models were developed during the latest years. Here authors propose a solution based on the up-to-date photogrammetric solutions for purely image-based 3D modelling, including automatic image orientation/sensor calibration using Structure-from-Motion and dense matching. Thus, an almost fully automatic pipeline for the generation of accurate 3D models showing the temperatures on a building skin in a realistic manner is described, where the only manual task is given by the measurement of a few common points for co-registration of RGB and IR photogrammetric projects.Xunta de Galicia | Ref. ED481B 2016/079-
A deep learning approach for the recognition of urban ground pavements in historical sites
Urban management is a topic of great interest for local administrators, particularly because it is strongly connected to smart city issues and can have a great impact on making cities more sustainable. In particular, thinking about the management of the physical accessibility of cities, the possibility of automating data collection in urban areas is of great interest. Focusing then on historical centres and urban areas of cities and historical sites, it can be noted that their ground surfaces are generally characterised by the use of a multitude of different pavements. To strengthen the management of such urban areas, a comprehensive mapping of the different pavements can be very useful. In this paper, the survey of a historical city (Sabbioneta, in northern Italy) carried out with a Mobile Mapping System (MMS) was used as a starting point. The approach here presented exploit Deep Learning (DL) to classify the different pavings. Firstly, the points belonging to the ground surfaces of the point cloud were selected and the point cloud was rasterised. Then the raster images were used to perform a material classification using the Deep Learning approach, implementing U-Net coupled with ResNet 18. Five different classes of materials were identified, namely sampietrini, bricks, cobblestone, stone, asphalt. The average accuracy of the result is 94%.Xunta de Galicia | Ref. ED481B-2019-061Xunta de Galicia | Ref. ED431C 2020/01Ministerio de Ciencia e Innovación | Ref. PID2019-105221RB-C43Ministerio de Ciencia e Innovación | Ref. RYC2020-029193-
Specialized pro-resolvin mediators induce cell growth and improve wound repair in intestinal epithelial Caco-2 cell cultures.
Specialized pro-resolvin mediators (SPMs) are a superfamily of bioactive molecules synthesized from polyunsaturated fatty acids (arachidonic, eicosapentaenoic and docosahexaenoic acids) that include resolvins, protectins and maresins. These metabolites are important to control the resolution phase of inflammation and the epithelial repair, which is essential in restoring the mucosal barriers. Unfortunately, the effects of SPMs on intestinal epithelial cell growth remain poorly understood. Caco-2 cell were used as intestinal epithelial cell model. Cell growth/DNA synthesis, cell signalling pathways, western blot and wound repair assay were performed. Our data demonstrated that SPMs such as lipoxin LxA4, resolvin (Rv) E1, RvD1, protectin D 1 and maresin 1 were able to enhance intestinal epithelial Caco-2 cell growth and DNA synthesis. Furthermore, our results provide evidence that these effects of RvE1 and RvD1 were associated with a pertussis toxin-sensitive G protein-coupled receptor, and that leukotriene B4 receptor 2 could be involved, at least in part, in these effects of RvE1/RvD1. Moreover, these mitogenic effects induced by SPMs were dependent on the ERK 1/2 and p38 MAPK pathways as well as phospholipase C and protein kinase C activation. Thus, these mitogenic effects of RvE1/RvD1 on intestinal epithelial cells could be involved in this signalling circuit involved in wounded epithelium and the catabasis process. Keywords: Lipoxin; Maresin; Protectin; Resolvin; Wound closure
The effect of salt fusion processing variables on structural, physicochemical and biological properties of poly(glycerol sebacate) scaffolds
"This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Polymeric Materials and Polymeric Biomaterials on SEP 21 2020, available online: https://www.tandfonline.com/doi/full/10.1080/00914037.2019.1636247"[EN] Poly(glycerol sebacate), PGS, is a biodegradable elastomer recently proposed in the form of scaffolds for cardiac, vascular, cartilage or neural applications. In the present work, several processing variables for the fabrication of PGS scaffolds by the salt fusion method were systematically studied, namely the pre-polymer/porogen ratio, the salt particles average size, use of tetrahydrofuran to dissolve the pre-polymer for its injection in the porogen template, and the curing pressure. The effect of these variables on their structural, mechanical and biological properties was assessed to select those leading to optimal ones in terms of their potential performance in tissue engineering applications.The authors acknowledge Spanish Ministerio de Economia y Competitividad through DPI2015-65401-C3-2-R project. The authors acknowledge the assistance and advice of the Electron Microscopy Service of the Universitat Politecnica de Valencia (Spain).Vilariño, G.; Muñoz-Santa, A.; Conejero-Garcia, Á.; Vallés Lluch, A. (2020). The effect of salt fusion processing variables on structural, physicochemical and biological properties of poly(glycerol sebacate) scaffolds. International Journal of Polymeric Materials. 69(14):938-945. https://doi.org/10.1080/00914037.2019.1636247S9389456914Fung, Y.-C. (1993). Bioviscoelastic Solids. Biomechanics, 242-320. doi:10.1007/978-1-4757-2257-4_7Chiang, B., Kim, Y. C., Doty, A. C., Grossniklaus, H. E., Schwendeman, S. P., & Prausnitz, M. R. (2016). Sustained reduction of intraocular pressure by supraciliary delivery of brimonidine-loaded poly(lactic acid) microspheres for the treatment of glaucoma. Journal of Controlled Release, 228, 48-57. doi:10.1016/j.jconrel.2016.02.041Appuhamillage, G. A., Reagan, J. C., Khorsandi, S., Davidson, J. R., Voit, W., & Smaldone, R. A. (2017). 3D printed remendable polylactic acid blends with uniform mechanical strength enabled by a dynamic Diels–Alder reaction. Polymer Chemistry, 8(13), 2087-2092. doi:10.1039/c7py00310bZhu, W., Masood, F., O’Brien, J., & Zhang, L. G. (2015). Highly aligned nanocomposite scaffolds by electrospinning and electrospraying for neural tissue regeneration. Nanomedicine: Nanotechnology, Biology and Medicine, 11(3), 693-704. doi:10.1016/j.nano.2014.12.001Gao, S., Guo, W., Chen, M., Yuan, Z., Wang, M., Zhang, Y., … Guo, Q. (2017). Fabrication and characterization of electrospun nanofibers composed of decellularized meniscus extracellular matrix and polycaprolactone for meniscus tissue engineering. Journal of Materials Chemistry B, 5(12), 2273-2285. doi:10.1039/c6tb03299kHu, X., Hu, T., Guan, G., Yu, S., Wu, Y., & Wang, L. (2017). Control of weft yarn or density improves biocompatibility of PET small diameter artificial blood vessels. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 106(3), 954-964. doi:10.1002/jbm.b.33909Recco, M. S., Floriano, A. C., Tada, D. B., Lemes, A. P., Lang, R., & Cristovan, F. H. (2016). Poly(3-hydroxybutyrate-co-valerate)/poly(3-thiophene ethyl acetate) blends as a electroactive biomaterial substrate for tissue engineering application. RSC Advances, 6(30), 25330-25338. doi:10.1039/c5ra26747aRibeiro Lopes, J., Azevedo dos Reis, R., & Almeida, L. E. (2016). Production and characterization of films containing poly(hydroxybutyrate) (PHB) blended with esterified alginate (ALG-e) and poly(ethylene glycol) (PEG). Journal of Applied Polymer Science, 134(1). doi:10.1002/app.44362Wang, Y., Ameer, G. A., Sheppard, B. J., & Langer, R. (2002). A tough biodegradable elastomer. Nature Biotechnology, 20(6), 602-606. doi:10.1038/nbt0602-602Nagata, M., Kiyotsukuri, T., Ibuki, H., Tsutsumi, N., & Sakai, W. (1996). Synthesis and enzymatic degradation of regular network aliphatic polyesters. Reactive and Functional Polymers, 30(1-3), 165-171. doi:10.1016/1381-5148(95)00107-7Radisic, M., Park, H., Chen, F., Salazar-Lazzaro, J. E., Wang, Y., Dennis, R., … Vunjak-Novakovic, G. (2006). Biomimetic Approach to Cardiac Tissue Engineering: Oxygen Carriers and Channeled Scaffolds. Tissue Engineering, 12(8), 2077-2091. doi:10.1089/ten.2006.12.2077Chen, Q.-Z., Bismarck, A., Hansen, U., Junaid, S., Tran, M. Q., Harding, S. E., … Boccaccini, A. R. (2008). Characterisation of a soft elastomer poly(glycerol sebacate) designed to match the mechanical properties of myocardial tissue. Biomaterials, 29(1), 47-57. doi:10.1016/j.biomaterials.2007.09.010Ravichandran, R., Venugopal, J. R., Sundarrajan, S., Mukherjee, S., & Ramakrishna, S. (2011). Poly(Glycerol Sebacate)/Gelatin Core/Shell Fibrous Structure for Regeneration of Myocardial Infarction. Tissue Engineering Part A, 17(9-10), 1363-1373. doi:10.1089/ten.tea.2010.0441Masoumi, N., Annabi, N., Assmann, A., Larson, B. L., Hjortnaes, J., Alemdar, N., … Khademhosseini, A. (2014). Tri-layered elastomeric scaffolds for engineering heart valve leaflets. Biomaterials, 35(27), 7774-7785. doi:10.1016/j.biomaterials.2014.04.039Masoumi, N., Jean, A., Zugates, J. T., Johnson, K. L., & Engelmayr, G. C. (2012). Laser microfabricated poly(glycerol sebacate) scaffolds for heart valve tissue engineering. Journal of Biomedical Materials Research Part A, 101A(1), 104-114. doi:10.1002/jbm.a.34305Motlagh, D., Yang, J., Lui, K. Y., Webb, A. R., & Ameer, G. A. (2006). Hemocompatibility evaluation of poly(glycerol-sebacate) in vitro for vascular tissue engineering. Biomaterials, 27(24), 4315-4324. doi:10.1016/j.biomaterials.2006.04.010Frydrych, M., Román, S., MacNeil, S., & Chen, B. (2015). Biomimetic poly(glycerol sebacate)/poly(l-lactic acid) blend scaffolds for adipose tissue engineering. Acta Biomaterialia, 18, 40-49. doi:10.1016/j.actbio.2015.03.004SUNDBACK, C., SHYU, J., WANG, Y., FAQUIN, W., LANGER, R., VACANTI, J., & HADLOCK, T. (2005). Biocompatibility analysis of poly(glycerol sebacate) as a nerve guide material. Biomaterials, 26(27), 5454-5464. doi:10.1016/j.biomaterials.2005.02.004Deng, Y., Bi, X., Zhou, H., You, Z., Wang, Y., … Fan, X. (2014). Repair of critical-sized bone defects with anti-miR-31-expressing bone marrow stromal stem cells and poly(glycerol sebacate) scaffolds. European Cells and Materials, 27, 13-25. doi:10.22203/ecm.v027a02Zhao, X., Wu, Y., Du, Y., Chen, X., Lei, B., Xue, Y., & Ma, P. X. (2015). A highly bioactive and biodegradable poly(glycerol sebacate)–silica glass hybrid elastomer with tailored mechanical properties for bone tissue regeneration. Journal of Materials Chemistry B, 3(16), 3222-3233. doi:10.1039/c4tb01693aZaky, S. H., Lee, K. W., Gao, J., Jensen, A., Verdelis, K., Wang, Y., … Sfeir, C. (2017). Poly (glycerol sebacate) elastomer supports bone regeneration by its mechanical properties being closer to osteoid tissue rather than to mature bone. Acta Biomaterialia, 54, 95-106. doi:10.1016/j.actbio.2017.01.053Jeong, C. G., & Hollister, S. J. (2010). A comparison of the influence of material on in vitro cartilage tissue engineering with PCL, PGS, and POC 3D scaffold architecture seeded with chondrocytes. Biomaterials, 31(15), 4304-4312. doi:10.1016/j.biomaterials.2010.01.145Kemppainen, J. M., & Hollister, S. J. (2010). Tailoring the mechanical properties of 3D-designed poly(glycerol sebacate) scaffolds for cartilage applications. Journal of Biomedical Materials Research Part A, 94A(1), 9-18. doi:10.1002/jbm.a.32653Sant, S., Hwang, C. M., Lee, S.-H., & Khademhosseini, A. (2011). Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties. Journal of Tissue Engineering and Regenerative Medicine, 5(4), 283-291. doi:10.1002/term.313Gao, J., Crapo, P. M., & Wang, Y. (2006). Macroporous Elastomeric Scaffolds with Extensive Micropores for Soft Tissue Engineering. Tissue Engineering, 12(4), 917-925. doi:10.1089/ten.2006.12.917Gibson, L. J., & Ashby, M. F. (1997). Cellular Solids. doi:10.1017/cbo9781139878326Maliger, R., Halley, P. J., & Cooper-White, J. J. (2012). Poly(glycerol-sebacate) bioelastomers-kinetics of step-growth reactions using Fourier Transform (FT)-Raman spectroscopy. Journal of Applied Polymer Science, 127(5), 3980-3986. doi:10.1002/app.37719Ifkovits, J. L., Padera, R. F., & Burdick, J. A. (2008). Biodegradable and radically polymerized elastomers with enhanced processing capabilities. Biomedical Materials, 3(3), 034104. doi:10.1088/1748-6041/3/3/034104Chen, Q.-Z., Ishii, H., Thouas, G. A., Lyon, A. R., Wright, J. S., Blaker, J. J., … Harding, S. E. (2010). An elastomeric patch derived from poly(glycerol sebacate) for delivery of embryonic stem cells to the heart. Biomaterials, 31(14), 3885-3893. doi:10.1016/j.biomaterials.2010.01.10
Symmetries and conservation laws in the Gunther k-symplectic formalism of field theory
This paper is devoted to studying symmetries of k-symplectic Hamiltonian and
Lagrangian first-order classical field theories. In particular, we define
symmetries and Cartan symmetries and study the problem of associating
conservation laws to these symmetries, stating and proving Noether's theorem in
different situations for the Hamiltonian and Lagrangian cases. We also
characterize equivalent Lagrangians, which lead to an introduction of
Lagrangian gauge symmetries, as well as analyzing their relation with Cartan
symmetries.Comment: 29 page
Hamilton-Jacobi Theory in k-Symplectic Field Theories
In this paper we extend the geometric formalism of Hamilton-Jacobi theory for
Mechanics to the case of classical field theories in the k-symplectic
framework
Analysis of Plasminogen Genetic Variants in Multiple Sclerosis Patients
Dessa Sadovnick, A.; Alcina, Antonio; Fedetz, María; Matesanz, F.; Vilariño-Güell, Carles; Dessa Sadovnick, A. et. al.Multiple sclerosis (MS) is a prevalent neurological disease of complex etiology. Here, we describe the characterization of a multi-incident MS family that nominated a rare missense variant (p.G420D) in plasminogen (PLG) as a putative genetic risk factor for MS. Genotyping of PLG p.G420D (rs139071351) in 2160 MS patients, and 886 controls from Canada, identified 10 additional probands, two sporadic patients and one control with the variant. Segregation in families harboring the rs139071351 variant, identified p.G420D in 26 out of 30 family members diagnosed with MS, 14 unaffected parents, and 12 out of 30 family members not diagnosed with disease. Despite considerably reduced penetrance, linkage analysis supports cosegregation of PLG p.G420D and disease. Genotyping of PLG p.G420D in 14446 patients, and 8797 controls from Canada, France, Spain, Germany, Belgium, and Austria failed to identify significant association with disease (P = 0.117), despite an overall higher prevalence in patients (OR = 1.32; 95% CI = 0.93–1.87). To assess whether additional rare variants have an effect on MS risk, we sequenced PLG in 293 probands, and genotyped all rare variants in cases and controls. This analysis identified nine rare missense variants, and although three of them were exclusively observed in MS patients, segregation does not support pathogenicity. PLG is a plausible biological candidate for MS owing to its involvement in immune system response, blood-brain barrier permeability, and myelin degradation. Moreover, components of its activation cascade have been shown to present increased activity or expression in MS patients compared to controls; further studies are needed to clarify whether PLG is involved in MS susceptibility.We
also thank Généthon, L’Association Française contre les Myopathies
(AFM), la Fondation pour l’Aide à la Recherche sur la Sclérose en
Plaques (ARSEP), and the Biological Resources Centre (BRC) of The
French Multiple Sclerosis Genetics Group (CRB-REFGENSEP). This
research was undertaken thanks to funding from the Canada Research
Chair [950-228408] and Canada Excellence Research Chair programs
[214444], Canadian Institutes of Health Research [MOP-137051],
Vancouver Coastal Health Research Institute, the Milan & Maureen
Ilich Foundation [11-32095000], and the Vancouver Foundation
[ADV14-1597]. Replication studies received funding from the program
“Investissements d’avenir” ANR-10-IAIHU-06. Fondo de Investigación
Sanitaria (FIS)-Instituto de Salud Carlos III (ISCIII)-Fondos
Europeos de Desarrollo Regional (FEDER), Unión Europea [grant numbers
P12/00555, PI13/01527, PI13/01466 and PI13/0879 to F.M., A.A.
and G.I.] and Junta de Andalucía -FEDER [grant number CTS2704
to F.M.]. B.D. is a Clinical Investigator of the Research Foundation
Flanders (FWO-Vlaanderen). A.G. and B.D. are supported by the
Research Fund KU Leuven (OT/11/087 and CREA/14/023) and the
Research Foundation Flanders (G073415N). A.L.T. reports personal
fees from Biogen Idec, Chugai, Medimmune, Teva Innovation, and
EMD Serono, and grants and personal fees from Genzyme Sanofi
and Roche.Peer reviewe
Nonholonomic constraints in -symplectic Classical Field Theories
A -symplectic framework for classical field theories subject to
nonholonomic constraints is presented. If the constrained problem is regular
one can construct a projection operator such that the solutions of the
constrained problem are obtained by projecting the solutions of the free
problem. Symmetries for the nonholonomic system are introduced and we show that
for every such symmetry, there exist a nonholonomic momentum equation. The
proposed formalism permits to introduce in a simple way many tools of
nonholonomic mechanics to nonholonomic field theories.Comment: 27 page
Endothelial dysfunction: a comprehensive appraisal
The endothelium is a thin monocelular layer that covers all the inner surface of the blood vessels, separating the circulating blood from the tissues. It is not an inactive organ, quite the opposite. It works as a receptor-efector organ and responds to each physical or chemical stimulus with the release of the correct substance with which it may maintain vasomotor balance and vascular-tissue homeostasis. It has the property of producing, independently, both agonistic and antagonistic substances that help to keep homeostasis and its function is not only autocrine, but also paracrine and endocrine. In this way it modulates the vascular smooth muscle cells producing relaxation or contraction, and therefore vasodilatation or vasoconstriction. The endothelium regulating homeostasis by controlling the production of prothrombotic and antithrombotic components, and fibrynolitics and antifibrynolitics. Also intervenes in cell proliferation and migration, in leukocyte adhesion and activation and in immunological and inflammatory processes. Cardiovascular risk factors cause oxidative stress that alters the endothelial cells capacity and leads to the so called endothelial "dysfunction" reducing its capacity to maintain homeostasis and leads to the development of pathological inflammatory processes and vascular disease. There are different techniques to evaluate the endothelium functional capacity, that depend on the amount of NO produced and the vasodilatation effect. The percentage of vasodilatation with respect to the basal value represents the endothelial functional capacity. Taking into account that shear stress is one of the most important stimulants for the synthesis and release of NO, the non-invasive technique most often used is the transient flow-modulate "endothelium-dependent" post-ischemic vasodilatation, performed on conductance arteries such as the brachial, radial or femoral arteries. This vasodilatation is compared with the vasodilatation produced by drugs that are NO donors, such as nitroglycerine, called "endothelium independent". The vasodilatation is quantified by measuring the arterial diameter with high resolution ultrasonography. Laser-Doppler techniques are now starting to be used that also consider tissue perfusion. There is so much proof about endothelial dysfunction that it is reasonable to believe that there is diagnostic and prognostic value in its evaluation for the late outcome. There is no doubt that endothelial dysfunction contributes to the initiation and progression of atherosclerotic disease and could be considered an independent vascular risk factor. Although prolonged randomized clinical trials are needed for unequivocal evidence, the data already obtained allows the methods of evaluation of endothelial dysfunction to be considered useful in clinical practice and have overcome the experimental step, being non-invasive increases its value making it use full for follow-up of the progression of the disease and the effects of different treatments
- …