910 resultados para Skeleton clarification
Resumo:
A new steroidal saponin, shatavarin V, (3-O-{[alpha-L-rhamnopyranosy](1-2)][beta-D-glucopyranosyl(1 -> 4)]-beta-D-glucopyranosyl}-(25S)-5 beta-spirostan-3 beta-ol), was isolated from the roots of Asparagus racemosus by RP-HPLC, and its structure determined by 1D and 2D NMR studies. This data permits clarification of the structures reported for several known saponins: asparinins A and B; asparosides A and B; curillin H; curillosides G and H and shavatarins I and IV. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents a novel algorithm for medial surfaces extraction that is based on the density-corrected Hamiltonian analysis of Torsello and Hancock [1]. In order to cope with the exponential growth of the number of voxels, we compute a first coarse discretization of the mesh which is iteratively refined until a desired resolution is achieved. The refinement criterion relies on the analysis of the momentum field, where only the voxels with a suitable value of the divergence are exploded to a lower level of the hierarchy. In order to compensate for the discretization errors incurred at the coarser levels, a dilation procedure is added at the end of each iteration. Finally we design a simple alignment procedure to correct the displacement of the extracted skeleton with respect to the true underlying medial surface. We evaluate the proposed approach with an extensive series of qualitative and quantitative experiments. © 2013 Elsevier Inc. All rights reserved.
Resumo:
A paradigma kifejezést Thomas Kuhn honosította meg a tudományfilozófiában: így nevezte el azt a sajátos szemléletmódot, ahogyan egy kutatási irányzat rátekint vizsgálata tárgyára. Azonos paradigmát használó kutatók hasonló kérdésekre keresik a választ, hasonló módszereket és fogalmakat alkalmaznak. A szerző 1999-ben publikált cikkében vezette be a "rendszerparadigma" kifejezést, amely a társadalomban működő rendszereket helyezi a vizsgálat középpontjába. A tanulmány a posztszocialista átalakulás során szerzett tapasztalatok alapján fejleszti tovább a korábbi cikkben kifejtett elméleti gondolatokat. Az első rész a szocialista és a kapitalista rendszert hasonlítja össze; leírja fő jellemzőiket, majd megállapítja, hogy Észak-Korea és Kuba kivételével az egykori szocialista országokban meghonosodott a kapitalista rendszer. A második rész a politikai-kormányzati formák szerint tipologizálja a kapitalizmus változatait. Három markáns típust különböztet meg: a demokráciát, az autokráciát és a diktatúrát. Huntington a demokratizálás harmadik hullámáról írt. A tanulmány arra a következtetésre jut, hogy ez a hullám elapadt, a 47 posztszocialista ország lakosságának mindössze egytizede él demokráciában, a többiben autokrácia vagy diktatúra uralkodik. A harmadik rész Magyarországra alkalmazza a kialakított fogalmi és elemzési apparátust: itt kapitalizmus van, a politikai-kormányzati forma autokrácia - lényeges közös jellemzők mutathatók ki más kapitalista országokkal, illetve más autokráciákkal. Ez összefér azzal a felismeréssel, hogy egyes - nem alapvető jelentőségű - vonások egyediek, "hungarikumok", különböznek minden más ország tulajdonságaitól. _____ The expression paradigm, introduced into the philosophy of science by Thomas Kuhn for the way a research trend views the subject examined, denotes a case where researchers pursue similar questions by similar methods with similar concepts. The author introduced the expression system paradigm" in a 1999 article centred on the systems operating in society. This paper takes those theoretical ideas further, based on experience in the post-socialist transformation. The first part compares the socialist and capitalist systems and their main features, establishing that all former socialist countries but North Korea and Cuba have embraced the capitalist system. The second adds a typology of the varieties of capitalism by politico-governmental form, marking three types: democracy, autocracy and dictatorship. Huntington writes of a third wave of democratization, which this study concludes has ceased. Democracy reigns in only 10 per cent of the 47 post-socialist countries, autocracy or dictatorship in the others. The third part applies this conceptual and analytical framework to Hungary, where capitalism prevails, with autocracy as its politico-governmental form. It shows strongly similar features to other capitalist countries and other autocracies. This is compatible with recognizing that some features of less than fundamental importance are specific to Hungary and differ from those elsewhere.
Resumo:
Insight into the response of reef corals and other major marine calcifiers to ocean acidification is limited by a lack of knowledge about how seawater pH and carbonate chemistry impact the physiological processes that drive biomineralization. Ocean acidification is proposed to reduce calcification rates in corals by causing declines in internal pH at the calcifying tissue-skeleton interface where biomineralization takes place. Here, we performed an in vivo study on how partial-pressure CO(2)-driven seawater acidification impacts intracellular pH in coral calcifying cells and extracellular pH in the fluid at the tissue-skeleton interface [subcalicoblastic medium (SCM)] in the coral Stylophora pistillata. We also measured calcification in corals grown under the same conditions of seawater acidification by measuring lateral growth of colonies and growth of aragonite crystals under the calcifying tissue. Our findings confirm that seawater acidification decreases pH of the SCM, but this decrease is gradual relative to the surrounding seawater, leading to an increasing pH gradient between the SCM and seawater. Reductions in calcification rate, both at the level of crystals and whole colonies, were only observed in our lowest pH treatment when pH was significantly depressed in the calcifying cells in addition to the SCM. Overall, our findings suggest that reef corals may mitigate the effects of seawater acidification by regulating pH in the SCM, but they also highlight the role of calcifying cell pH homeostasis in determining the response of reef corals to changes in external seawater pH and carbonate chemistry.
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Qualitative Comparative Analysis (QCA) is a method for the systematic analysis of cases. A holistic view of cases and an approach to causality emphasizing complexity are some of its core features. Over the last decades, QCA has found application in many fields of the social sciences. In spite of this, its use in feminist research has been slower, and only recently QCA has been applied to topics related to social care, the political representation of women, and reproductive politics. In spite of the comparative turn in feminist studies, researchers still privilege qualitative methods, in particular case studies, and are often skeptical of quantitative techniques (Spierings 2012). These studies show that the meaning and measurement of many gender concepts differ across countries and that the factors leading to feminist success and failure are context specific. However, case study analyses struggle to systematically account for the ways in which these forces operate in different locations.
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The Dendritic Cell algorithm (DCA) is inspired by recent work in innate immunity. In this paper a formal description of the DCA is given. The DCA is described in detail, and its use as an anomaly detector is illustrated within the context of computer security. A port scan detection task is performed to substantiate the influence of signal selection on the behaviour of the algorithm. Experimental results provide a comparison of differing input signal mappings.
Resumo:
The change in the carbonaceous skeleton of nanoporous carbons during their activation has received limited attention, unlike its counterpart process in the presence of an inert atmosphere. Here we adopt a multi-method approach to elucidate this change in a poly(furfuryl alcohol)-derived carbon activated using cyclic application of oxygen saturation at 250 °C before its removal (with carbon) at 800 °C in argon. The methods used include helium pycnometry, synchrotron-based X-ray diffraction (XRD) and associated radial distribution function (RDF) analysis, transmission electron microscopy (TEM) and, uniquely, electron energy-loss spectroscopy spectrum-imaging (EELS-SI), electron nanodiffraction and fluctuation electron microscopy (FEM). Helium pycnometry indicates the solid skeleton of the carbon densifies during activation from 78% to 93% of graphite. RDF analysis, EELS-SI, and FEM all suggest this densification comes through an in-plane growth of sp2 carbon out to the medium range without commensurate increase in order normal to the plane. This process could be termed ‘graphenization’. The exact way in which this process occurs is not clear, but TEM images of the carbon before and after activation suggest it may come through removal of the more reactive carbon, breaking constraining cross-links and creating space that allows the remaining carbon material to migrate in an annealing-like process.
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We report a multi-wavelength Raman spectroscopy study of the structural changes along the thermal annealing pathway of a poly(furfuryl alcohol) (PFA) derived nanoporous carbon (NPC). The Raman spectra were deconvoluted utilizing G, D, D′, A and TPA bands. The appropriateness of these deconvolutions was confirmed via recovery of the correct dispersive behaviours of these bands. It is proposed that the ID/IG ratio is composed of two parts: one associated with the extent of graphitic crystallites (the Tuinstra–Koenig relationship), and a second related to the inter-defect distance. This model was used to successfully determine the variation of the in-plane size and intra-plane defect density along the annealing pathway. It is proposed that the NPC skeleton evolves along the annealing pathway in two stages: below 1600 °C it was dominated by a reduction of in-plane defects with a minor crystallite growth, and above this temperature growth of the crystallites accelerates as the in-plane defect density approaches zero. A significant amount of transpolyacetylene (TPA)-like structures was found to be remaining even at 2400 °C. These may be responsible for resistance to further graphitization of the PFA-based carbon at higher temperatures.
Resumo:
Cette étude descriptive transversale visait à estimer la proportion de consultations en médecine familiale dans lesquelles sont observées une communication des risques et une clarification des valeurs et des préférences. Au sein de 238 dyades de cliniciens-patients (238 patients et 71 cliniciens), nous avons observé que 63 % (intervalle de confiance [IC] à 95 % : 54 % - 70 %) des consultations comportaient ces deux éléments. Aussi, nous avons observé que six facteurs étaient associés à la présence de ces deux éléments lors de la consultation : 1) les nouvelles options thérapeutiques (rapport de cotes [RC] = 3,54; IC à 95 % : 1,32 - 9,48); 2) les options de traitement (RC = 3,56, IC à 95 % : 1,52 - 8,36); 3) la présence de cinq décisions et plus (RC = 5,00; IC à 95 % : 1,5 - 16,9); 4) report de la décision (RC = 4,92; IC à 95 % : 1,35 - 17,87); 5) la durée de la consultation (RC = 1,03; IC à 95 % : 1,002 - 1,07) et 6) le style de prise de décision collaboratif du clinicien (RC = 8,78; IC à 95% : 1,62 - 47,71). Des interventions ciblant directement les facteurs modifiables sont à considérer en vue d’augmenter la présence de ces deux éléments durant la consultation en médecine familiale.
Resumo:
Housing affordability is gaining increasing prominence in the Australian socioeconomic landscape, despite strong economic growth and prosperity. It is a major consideration for any new development. However, it is multi-dimensional, has many facets, is complex and interwoven. One factor widely held to impact housing affordability is holding costs. Although it is only one contributor, the nature and extent of its impact requires clarification. It is certainly more multifarious than simple calculation of the interest or opportunity cost of land holding. For example, preliminary analysis suggests that even small shifts in the regulatory assessment period can significantly affect housing affordability. Other costs associated with “holding” also impact housing affordability, however these costs cannot always be easily identified. Nevertheless it can be said that ultimately the real impact is felt by those whom can least afford it - new home buyers whom can be relatively easily pushed into the realms of un-affordability.
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Aim: To review the titles, roles and scope of practice of Advanced Practice Nurses internationally.----- Background: There is a worldwide shortage of nurses but there is also an increased demand for nurses with enhanced skills who can manage a more diverse, complex and acutely ill patient population than ever before. As a result, a variety of nurses in advanced practice positions has evolved around the world. The differences in nomenclature have led to confusion over the roles, scope of practice and professional boundaries of nurses in an international context.----- Method: CINAHL, Medline, and the Cochrane database of Systematic Reviews were searched from 1987 to 2008. Information was also obtained through government health and professional organisation websites. All information in the literature regarding current and past status, and nomenclature of advanced practice nursing was considered relevant.----- Findings: There are many names for Advanced Practice Nurses, and although many of these roles are similar in their function, they can often have different titles.----- Conclusion: Advanced Practice Nurses are critical for the future, provide cost-effective care and are highly regarded by patients/clients. They will be a constant and permanent feature of future health care provision. However, clarification regarding their classification and regulation is necessary in some countries.