131 research outputs found

    Bone Mineral Quality

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    El papel del desarrollo sostenible en el atractivo del turismo urbano

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    This paper investigates the role of sustainable development in city tourism attractiveness. A tripartite theoretical model of tourism attractiveness was tested to verify the relevance of the economic, environmental, social and cultural aspects of urban sustainable development. The comparative analysis of Québec City and Bordeaux was based on visitors’ perceptions established through a questionnaire survey conducted with 499 tourists in summer 2014. This analysis produced three main findings. First, four levels of city tourism attractiveness were revealed (context, belt, complementary attractions and nucleus) and variables related to the urban living environment stood out in importance. Second, visitors recognized four sustainable development dimensions, and proved most sensitive to cultural aspects, followed by environmental concerns. Third, the correlations between tourism attractiveness and sustainable development were stronger within the broader spheres of attractiveness. The study reveals that sustainability notions are most strongly internalized by tourists when tangibly reflected in the public space. By offering visitors new perspectives on urban living, sustainable development brings smart solutions to perpetuate the urban tourism industry while improving quality of life for residents.Este artículo investiga el papel del desarrollo sostenible en el atractivo del turismo urbano. Se probó un modelo teórico tripartito de atractivo turístico para verificar la relevancia de los aspectos económicos, ambientales, sociales y culturales del desarrollo urbano sostenible. El análisis comparativo de la ciudad de Québec y Burdeos se basó en las percepciones de los visitantes establecidas a través de una encuesta realizada con 499 turistas en el verano de 2014. Este análisis arrojó tres conclusiones principales. Primero, se manifestaron cuatro niveles de atractivo para la ciudad (contexto, cinturón, atracciones complementarias y núcleos) y destacaron las variables relacionadas con el entorno urbano. En segundo lugar, los visitantes reconocieron cuatro dimensiones de desarrollo sostenible y demostraron ser más sensibles a los aspectos culturales, seguidos de las preocupaciones ambientales. En tercer lugar, las correlaciones entre el atractivo turístico y el desarrollo sostenible eran más fuertes dentro de las esferas más amplias del atractivo turístico. El estudio revela que las nociones de sostenibilidad están más fuertemente internalizadas por los turistas cuando se reflejan de manera tangible en el espacio público. Ofreciendo a los visitantes nuevas perspectivas sobre la vida urbana, el desarrollo sostenible brinda soluciones inteligentes para perpetuar la industria del turismo urbano al tiempo que mejora la calidad de vida de los residentes

    How Urban Sustainable Development Can Improve Tourism Attractiveness

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    This paper investigates the role of sustainable development in city tourism attractiveness. A tripartite theoretical model of tourism attractiveness was tested to verify the relevance of the economic, environmental, social and cultural aspects of urban sustainable development. The comparative analysis of Québec City and Bordeaux was based on visitors’ perceptions established through a questionnaire survey conducted with 499 tourists in summer 2014. This analysis produced three main findings. First, four levels of city tourism attractiveness were revealed (context, belt, complementary attractions and nucleus) and variables related to the urban living environment stood out in importance. Second, visitors recognized four sustainable development dimensions, and proved most sensitive to cultural aspects, followed by environmental concerns. Third, the correlations between tourism attractiveness and sustainable development were stronger within the broader spheres of attractiveness. The study reveals that sustainability notions are most strongly internalized by tourists when tangibly reflected in the public space. By offering visitors new perspectives on urban living, sustainable development brings smart solutions to perpetuate the urban tourism industry while improving quality of life for residents

    Natural Health Products, Modulation of Immune Function and Prevention of Chronic Diseases

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    The immune system is increasingly found to be involved in the development of several chronic illnesses, for which allopathic medicine has provided limited tools for treatment and especially prevention. In that context, it appears worthwhile to target the immune system in order to modulate the risk of certain chronic illnesses. Meanwhile, natural health products (NHPs) are generating renewed interest, particularly in the prevention and treatment of several chronic diseases. Over 20 scientists from fields related to immune function and NHPs were thus convened to establish the state of knowledge on these subjects and to explore future research directions. This review summarizes the result of discussions held during the symposium. It thus seeks to be thought provoking rather than to comprehensively cover such broad areas of research. Notably, a brief overview of the immune system is presented, including potentially useful targets and strategies to keep it in an equilibrated state, in order to prevent certain disorders. The pertinence and limitations of targeting the immune system to prevent chronic diseases is also discussed. The paper then discusses the usefulness and limitations of current experimental tools available to study the immune modulating effects of NHPs. Finally, a concise review of some of the most studied NHPs showing promising immunomodulatory activity is given, and avenues for future research are described

    Validation of a novel microradiography device for characterization of bone mineralization

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    International audienceIn order to simplify bone mineralization measurements, a system using radiographic films has been updated with a digital detector. The objective of this paper was to validate this new device. Technologies and physical phenomena involved in both systems (radiographic films and digital detector) are different. The methodology used to compare the two systems was based on image quality and assessed on two main parameters: contrast to noise ratio and spatial resolution. Results showed that the contrast to noise ratio was similar between the two systems, provided that acquisition parameters were optimized. With regard to spatial resolution, a magnification factor of at least 4 or more was required to achieve the same resolution as films. A final validation was also shown on a real image of a bone sample. The results showed that both systems have similar image quality performances, and the system using digital detector has several advantages (easier to use than films, no consumables and faster acquisition time)

    Respective roles of organic and mineral components of human cortical bone matrix in micromechanical behavior: An instrumented indentation study

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    International audienceBone is a multiscale composite material made of both a type I collagen matrix and a poorly crystalline apatite mineral phase. Due to remodeling activity, cortical bone is made of Bone Structural Units (BSUs) called osteons. Since osteon represents a fundamental level of structural hierarchy, it is important to investigate the relationship between mechanical behavior and tissue composition at this scale for a better understanding of the mechanisms of bone fragility. The aim of this study is to analyze the links between ultrastructural properties and the mechanical behavior of bone tissue at the scale of osteon. Iliac bone biopsies were taken from untreated postmenopausal osteoporotic women, embedded, sectioned and microradiographed to assess the degree of mineralization of bone (DMB). On each section, BSUs of known DMB were indented with relatively high load (∼500 mN) to determine local elastic modulus (E), contact hardness (Hc) and true hardness(H) of several bone lamellae. Crystallinity and collagen maturity were measured by Fourier Transform InfraRed Microspectroscopy (FTIRM) on the same BSUs. Inter-relationships between mechanical properties and ultrastructural components were analyzed using multiple regression analysis. This study showed that elastic deformation was only explained by DMB whereas plastic deformation was more correlated with collagen maturity. Contact hardness, reflecting both elastic and plastic behaviors, was correlated with both DMB and collagen maturity. Norelationship was found between crystallinity and mechanical properties at the osteon level

    L'Estuaire, vol. 25 (1)

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    Éditorial -- Sainte-Luce: refuge d'un incorruptible -- Le "Vocabulaire micmac" de Joseph Hamel. L'histoire d'une cueillette de données linguistiques. Partie 2: qui est Joseph Hamel? -- La famille Desrosiers dans la région de Rimouski au XVIIIe siècle. Partie 1: implantation dans la seigneurie de Rimouski -- Les trésors du grenier -- L'année des Français -- Un grand marin gaspésien. Le capitaine Paul M. Fournier -- Matane dans les relations de voyage de Champlain: un 375e anniversaire -- La naissance d'une petite paroisse au coeur de La Mitis: le cas de Sainte-Flavie -- Nouvelles brèves -- Des livres à lire

    Trachyte phase relations and implication for magma storage conditions in the Chaîne des Puys (French Massif Central).

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    International audiencePetrological data have been acquired on the natural trachytes from the Chaîne des Puys, French Massif Central, and on experimental products from phase equilibria in order to (i) constrain the storage conditions of the trachytic magmas that lead to explosive eruptions (dome destructions as block-and-ash flows or pumice-and-ash flows) and (ii) provide phase relationships and chemical compositions for differentiated alkaline liquids in intraplate continental context. Phase assemblages, proportions, and compositions have been determined on six trachytes with SiO2 contents varying from 62 to 69 wt % and alkali contents of 10.5-12.0 wt %. The samples contain up to 30 % of phenocrysts, mainly consisting of feldspar (15-17 %; plagioclase and/or alkali-feldspar), biotite (2-6 %; except in the SiO2-poorest sample), Fe-Ti oxides (1-3 %) ± amphibole (< 5 %), ± clinopyroxene (~1 %). All samples have apatite and zircon as minor phases and titanite has been found in one sample. Pristine glasses (melt inclusions or residual glasses) in pumice from explosive events are trachytic to rhyolitic (65-73 wt % SiO2 and 10.5-13.0 wt % alkali). H2O dissolved in melt inclusions and the biotite+alkali feldspar+magnetite hygrobarometer both suggest pre-eruptive H2O contents up to 8 wt %. These are so far the highest H2O contents ever reported for alkaline liquids in an intraplate continental context. Melt inclusions also contain ~3400 ppm chlorine, ~700 ppm fluorine, and ~300 ppm sulphur. Crystallisation experiments of the six trachytes have been performed between 200 and 400 MPa, 700 and 900°C, H2O saturation, and oxygen fugacity of NNO +1. The comparison between the natural and experimental phase assemblage, proportion, and composition suggests magma storage conditions at a pressure of 300-350 MPa (~10-12 km deep), melt H2O content ~8 wt % (close to saturation), an oxygen fugacity close to NNO~0.5, and temperatures increasing from 700 to 825°C with decreasing bulk SiO2 of the trachyte. The high H2O contents of the trachytes show that wet conditions may prevail during the differentiation of continental alkaline series. Regardless of the size of the magma reservoir assumed to have fed the trachyte eruptions, calculation of the thermal relaxation timescales indicates that the tapped reservoir(s) are likely to be still partially molten nowadays. The four northernmost edifices may correspond to a single large reservoir with a lateral extension of up to 10 km, which could be possibly reactivated in weeks to months if intercepted by new rising basalt batches

    Mineral maturity and crystallinity index are distinct characteristics of bone mineral

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    The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis

    Bone sialoprotein plays a functional role in bone formation and osteoclastogenesis.

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    International audienceBone sialoprotein (BSP) and osteopontin (OPN) are both highly expressed in bone, but their functional specificities are unknown. OPN knockout ((-/-)) mice do not lose bone in a model of hindlimb disuse (tail suspension), showing the importance of OPN in bone remodeling. We report that BSP(-/-) mice are viable and breed normally, but their weight and size are lower than wild-type (WT) mice. Bone is undermineralized in fetuses and young adults, but not in older (>/=12 mo) BSP(-/-) mice. At 4 mo, BSP(-/-) mice display thinner cortical bones than WT, but greater trabecular bone volume with very low bone formation rate, which indicates reduced resorption, as confirmed by lower osteoclast surfaces. Although the frequency of total colonies and committed osteoblast colonies is the same, fewer mineralized colonies expressing decreased levels of osteoblast markers form in BSP(-/-) versus WT bone marrow stromal cultures. BSP(-/-) hematopoietic progenitors form fewer osteoclasts, but their resorptive activity on dentin is normal. Tail-suspended BSP(-/-) mice lose bone in hindlimbs, as expected. In conclusion, BSP deficiency impairs bone growth and mineralization, concomitant with dramatically reduced bone formation. It does not, however, prevent the bone loss resulting from loss of mechanical stimulation, a phenotype that is clearly different from OPN(-/-) mice
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