937 resultados para Products of Nature Nature


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Husserl reminded us of the imperative to return to the Lebensweldt, or life-world. He was preoccupied with the crisis of Western science which alienated the experiencing self from the world of immediate experience. Immediate experience provides a foundation for what it means to be human. Heidegger, building upon these ideas, foresaw a threat to human nature in the face of ‘technicity’. He argued for a return to a relationship between ‘authentic self’ and nature predicated upon the notion of ‘letting be’ in which humans are open to the mystery of being. Self and nature are not conceived as alienated entities but as aspects of a single entity. In modern times, separation between self and the world is further evidenced by scientific rational modes of being exemplified through consumerism and the incessant use of screen-based technology which dominate human experience. In contrast, extreme sports provide an opportunity for people to return to the life-world by living in relation to the natural world. Engagement in extreme sports enables a return to authenticity as we rediscover self as part of nature.

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Macrophages play a crucial role in the maintenance and resolution of inflammation and express a number of pro- and anti-inflammatory molecules in response to stressors. Among them, the complement receptor 5a (C5aR) plays an integral role in the development of inflammatory disorders. Biliverdin and bilirubin, products of heme catabolism, exert anti-inflammatory effects and inhibit complement activation. Here, we define the effects of biliverdin on C5aR expression in macrophages and the roles of Akt and mammalian target of rapamycin (mTOR) in these responses. Biliverdin administration inhibited lipopolysaccharide (LPS)-induced C5aR expression (without altering basal expression), an effect partially blocked by rapamycin, an inhibitor of mTOR signaling. Biliverdin also reduced LPS-dependent expression of the pro-inflammatory cytokines TNF-alpha and IL-6. Collectively, these data indicate that biliverdin regulates LPS-mediated expression of C5aR via the mTOR pathway, revealing an additional mechanism underlying biliverdin's anti-inflammatory effects.

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The Jericho kimberlite (173.1. ±. 1.3. Ma) is a small (~. 130. ×. 70. m), multi-vent system that preserves products from deep (>. 1. km?) portions of kimberlite vents. Pit mapping, drill core examination, petrographic study, image analysis of olivine crystals (grain size distributions and shape studies), and compositional and mineralogical studies, are used to reconstruct processes from near-surface magma ascent to kimberlite emplacement and alteration. The Jericho kimberlite formed by multiple eruptions through an Archean granodiorite batholith that was overlain by mid-Devonian limestones ~. 1. km in thickness. Kimberlite magma ascended through granodiorite basement by dyke propagation but ascended through limestone, at least in part, by locally brecciating the host rocks. After the first explosive breakthrough to surface, vent deepening and widening occurred by the erosive forces of the waxing phase of the eruption, by gravitationally induced failures as portions of the vent margins slid into the vent and, in the deeper portions of the vent (>. 1. km), by scaling, as thin slabs burst from the walls into the vent. At currently exposed levels, coherent kimberlite (CK) dykes (<. 40. cm thick) are found to the north and south of the vent complex and represent the earliest preserved in-situ products of Jericho magmatism. Timing of CK emplacement on the eastern side of the vent complex is unclear; some thick CK (15-20. m) may have been emplaced after the central vent was formed. Explosive eruptive products are preserved in four partially overlapping vents that are roughly aligned along strike with the coherent kimberlite dyke. The volcaniclastic kimberlite (VK) facies are massive and poorly sorted, with matrix- to clast-supported textures. The VK facies fragmented by dry, volatile-driven processes and were emplaced by eruption column collapse back into the volcanic vents. The first explosive products, poorly preserved because of partial destruction by later eruptions, are found in the central-east vent and were formed by eruption column collapse after the vent was largely cleared of country rock debris. The next active vent was either the north or south vent. Collapse of the eruption column, linked to a vent widening episode, resulted in coeval avalanching of pipe margin walls into the north vent, forming interstratified lenses of country rock-rich boulder breccias in finer-grained volcaniclastic kimberlite. South vent kimberlite has similar characteristics to kimberlite of the north vent and likely formed by similar processes. The final eruptive phase formed olivine-rich and moderately sorted deposits of the central vent. Better sorting is attributed to recycling of kimberlite debris by multiple eruptions through the unconsolidated volcaniclastic pile and associated collapse events. Post-emplacement alteration varies in intensity, but in all cases, has overprinted the primary groundmass and matrix, in CK and VK, respectively. Erosion has since removed all limestone cover.

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Switchgrass was treated by 1% (w/w) H₂SO₄in batch tube reactors at temperatures ranging from 140–220°C for up to 60 minutes. In this study, release patterns of glucose, 5-hydroxymethylfurfural (5-HMF), and levulinic acid from switchgrass cellulose were investigated through a mechanistic kinetic model. The predictions were consistent with the measured products of interest when new parameters reflecting the effects of reaction limitations, such as cellulose crystallinity, acid soluble lignin–glucose complex (ASL–glucose) and humins that cannot be quantitatively analyzed, were included. The new mechanistic kinetic model incorporating these parameters simulated the experimental data with R² above 0.97. Results showed that glucose yield was most sensitive to variations in the parameter regarding the cellulose crystallinity at low temperatures (140–180°C), while the impact of crystallinity on the glucose yield became imperceptible at elevated temperatures (200–220 °C). Parameters related to the undesired products (e.g. ASL–glucose and humins) were the most sensitive factors compared with rate constants and other additional parameters in impacting the levulinic acid yield at elevated temperatures (200–220°C), while their impacts were negligible at 140–180°C. These new findings provide a more rational explanation for the kinetic changes in dilute acid pretreatment performance and suggest that the influences of cellulose crystallinity and undesired products including ASL–glucose and humins play key roles in determining the generation of glucose, 5-HMF and levulinic acid from biomass-derived cellulose.

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India has been acknowledged as a large reservoir of nature's random mutation, an original 'rich' source of knowledge in the context of international genome studies. Human genome knowledge and the possible understanding of the basis of uniqueness of each individual in chemical terms has presented a number of inescapable challenges to our own jurisprudence philosophies and our ethical sensibilities.

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The effect of correlations on the viscosity of a dilute sheared inelastic fluid is analyzed using the ring-kinetic equation for the two-particle correlation function. The leading-order contribution to the stress in an expansion in epsilon=(1-e)(1/2) is calculated, and it is shown that the leading-order viscosity is identical to that obtained from the Green-Kubo formula, provided the stress autocorrelation function in a sheared steady state is used in the Green-Kubo formula. A systemmatic extension of this to higher orders is also formulated, and the higher-order contributions to the stress from the ring-kinetic equation are determined in terms of the terms in the Chapman-Enskog solution for the Boltzmann equation. The series is resummed analytically to obtain a renormalized stress equation. The most dominant contributions to the two-particle correlation function are products of the eigenvectors of the conserved hydrodynamic modes of the two correlated particles. In Part I, it was shown that the long-time tails of the velocity autocorrelation function are not present in a sheared fluid. Using those results, we show that correlations do not cause a divergence in the transport coefficients; the viscosity is not divergent in two dimensions, and the Burnett coefficients are not divergent in three dimensions. The equations for three-particle and higher correlations are analyzed diagrammatically. It is found that the contributions due to the three-particle and higher correlation functions to the renormalized viscosity are smaller than those due to the two-particle distribution function in the limit epsilon -> 0. This implies that the most dominant correlation effects are due to the two-particle correlations.

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Oxygen release accompanying oxidation of vanadyl by diperoxovanadate was suppressed on addition of NADH. The added NADH was rapidly oxidized, oxygen in the medium was consumed, and the reaction terminated on exhaustion of either NADH or vanadyl. The consumption of oxygen and disappearance of NADH needed small concentrations of diperoxovanadate to initiate and increased with increase in the concentration of vanadyl and NADH or decrease of pH. The products of the reaction were found to be NAD(+) from NADH and vanadate oligomers from vanadyl and oxygen. The reaction was insensitive to catalase and was not dependent on H2O2. The reaction was inhibited by superoxide dismutase, cytochrome c, EDTA, Mn2+, histidine, and DMPO, but not by hydroxyl radical scavengers such as ethanol and benzoate, The ESR spectrum of the reaction mixture showed the presence of the 1:2:2:1 quartet signal typical of a DMPO-OH adduct, but this was not modified by ethanol, This oxygen radical species, possibly of (OV)-O-. type derived from diperoxovanadate, is proposed to have a role in the reactions of oxygen release and NADH oxidation

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Lifted turbulent jet diffusion flame is simulated using Conditional Moment Closure (CMC). Specifically, the burner configuration of Cabra et al. [R. Cabra, T. Myhrvold, J.Y. Chen. R.W. Dibble, A.N. Karpetis, R.S. Barlow, Proc. Combust. Inst. 29 (2002) 1881-1887] is chosen to investigate H-2/N-2 jet flame supported by a vitiated coflow of products of lean H-2/air combustion. A 2D, axisymmetric flow-model fully coupled with the scalar fields, is employed. A detailed chemical kinetic scheme is included, and first order CIVIC is applied. Simulations are carried out for different jet velocities and coflow temperatures (T-c) The predicted liftoff generally agrees with experimental data, as well as joint-PDF results. Profiles of mean scalar fluxes in the mixture fraction space, for T-c = 1025 and 1080 K reveal that (1) Inside the flame zone, the chemical term balances the molecular diffusion term, and hence the Structure is of a diffusion flamelet for both cases. (2) In the pre-flame zone, the structure depends on the coflow temperature: for the 1025 K case, the chemical term being small, the advective term balances the axial turbulent diffusion term. However, for the 1080 K case. the chemical term is large and balances the advective term, the axial turbulent diffusion term being small. It is concluded that, lift-off is controlled (a) by turbulent premixed flame propagation for low coflow temperature while (b) by autoignition for high coflow temperature. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

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The details of development of the stiffness matrix for a doubly curved quadrilateral element suited for static and dynamic analysis of laminated anisotropic thin shells of revolution are reported. Expressing the assumed displacement state over the middle surface of the shell as products of one-dimensional first order Hermite polynomials, it is possible to ensure that the displacement state for the assembled set of such elements, is geometrically admissible. Monotonic convergence of total potential energy is therefore possible as the modelling is successively refined. Systematic evaluation of performance of the element is conducted, considering various examples for which analytical or other solutions are available.

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In the eighteenth century, the birth of scientific societies in Europe created a new framework for scientific cooperation. Through a new contextualist study of the contacts between the first scientific societies in Sweden and the most important science academy in Europe at the time, l Académie des Sciences in Paris, this dissertation aims to shed light on the role taken by the Swedish learned men in the new networks. It seeks to show that the academy model was related to a new idea of specialisation in science. In the course of the eighteenth century, it is argued, the study of the northern phenomena and regions offered the Swedes an important field of speciality with regard to their foreign colleagues. Although historical studies have often underlined the economic, practical undertone of eighteenth-century Swedish science, participation in fashionable scientific pursuits had also become an important scene for representation. However, the views prevailing in Europe tied civilisation and learning closely to the sunnier, southern climates, which had lead to the difficulty of portraying Sweden as a learned country. The image of the scientific North, as well as the Swedish strategies to polish the image of the North as a place for science, are analysed as seen from France. While sixteenth-century historians had preferred to put down the effects of the cold and claim a similarity of northern conditions to the others, the scientific exchange between Swedish and French researchers shows a new tendency to underline the difference of the North and its harsh climate. An explanation is sought by analysing how information about northern phenomena was used in France. In the European academies, new empirical methods had lead to a need for direct observations on different phenomena and circumstances. Rather than curiosities or objects for exoticism, the eighteenth-century depictions of the northern periphery tell about an emerging interest in the most extreme, and often most telling, examples of the workings of the invariable laws of nature. Whereas the idea of accumulating knowledge through cooperation was most manifest in joint astronomical projects, the idea of gathering and comparing data from differing places of observation appears also in other fields, from experimental philosophy to natural studies or medicine. The effects of these developments are studied and explained in connection to the Montesquieuan climate theories and the emerging pre-romantic ideas of man and society.

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Nature, science and technology. The image of Finland through popular enlightenment texts 1870-1920 This doctoral thesis looks at how Finnish popular enlightenment texts published between 1870 and 1920 took part in the process of forming a genuine Finnish national identity. The same process was occurring in other Nordic countries at the time and the process in Finland was in many ways influenced by them, particularly Sweden. In Finland the political realities under Russian rule especially during the Russification years, and the fact that its history was considered to be short compared to other European countries, made this nation-building process unique. The undertaking was led by members of the national elite, influential in the cultural, academic as well as political arenas, who were keen to support the foundation of a modern Finnish identity. The political realities and national philosophy of history necessitated a search for elements of identity in nature and the Finnish landscape, which were considered to have special national importance: Finland was very much determined as a political entity on the basis of its geography and nature. Nature was also used as means of taking a cultural or political view in terms of, for example, geographical facts such as the nation s borders or the country s geographical connections to Western Europe. In the building of a proper national identity the concept of nature was not, however, static, but was more or less affected by political and economic progress in society. This meant that nature, or the image of the national landscape, was no longer seen only as a visual image of the national identity, but also as a source of science, technology and a prosperous future. The role of technology in this process was very much connected to the ability to harness natural resources to serve national interests. The major change in this respect had occurred by the early 20th century, when indisputable scientific progress altered the relationship between nature and technology. Concerning technology, the thesis is mainly interested in the large and at the time modern technological manifestations, such as railways, factories and industrial areas in Finland. Despite the fact that the symbiosis between national nature and international but successfully localized technology was in Finnish popular enlightenment literature depicted mostly as a national success story, concerns began to arise already in last years of the 19th century. It was argued that the emerging technology would eventually destroy Finland s natural environment, and therefore the basis of its national identity. The question was not how to preserve nature through natural science, but more how to conserve such natural resources and images that were considered to be the basis of national identity and thus of the national history. National parks, isolated from technology, and distant enough so as to have no economic value, were considered the solution to the problem. Methodologically the thesis belongs to the genre of science and technology studies, and offers new viewpoints with regard to both the study of Finnish popular enlightenment literature and the national development process as a whole.

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Reactions of tetrahalosilanes [SiX4 (X= F, Cl or Br)] and silane (SiH4) with sulphur trioxide (SO3) have been studied under different experimental conditions. Each of the silanes behaves differently in accordance with the bond energy of the Si—X bond. While SiF4 remains unreactive even at 600°C, SiCl4 reacts with SO3 at 500°C giving rise to hexachlorodisiloxane [(SiCl3)2O] as the major product. In contrast SiBr4 and SiH4 react with SO3 at room temperature and below room temperature, respectively, yielding silica as one of the products of reaction. In all cases the SO3 is reduced to sulphur dioxide.

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This work was prompted by the need to be able to identify the invasive mussel species, Perna viridis, in tropical Australian seas using techniques that do not rely solely on morphology. DNA-based molecular methods utilizing a polymerase chain reaction (PCR) approach were developed to distinguish unambiguously between the three species in the genus Perna. Target regions were portions of two mitochondrial genes, cox1 and nad4, and the intergenic spacer between these that occurs in at least two Perna species. Based on interspecific sequence comparisons of the nad4 gene, a conserved primer has been designed that can act as a forward primer in PCRs for any Perna species. Four reverse primers have also been designed, based on nad4 and intergenic spacer sequences, which yield species-specific products of different lengths when paired with the conserved forward primer. A further pair of primers has been designed that will amplify part of the cox1 gene of any Perna species, and possibly other molluscs, as a positive control to demonstrate that the PCR is working.

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Hexafluorodisilane has been prepared by the fluorination of hexachlorodisilane or hexabromodisilane by potassium fluoride in boiling acetonitrile, in yields approximating 45 and 60% respectively. Hexafluorodisilane has been characterised by infrared spectral data, vapour density measurements and analytical data. Both hexafluorodisilane and hexachlorodisilane are found to react with sulfur trioxide when heated to 400°C for 12 h. The products of reaction are silicon tetrafluoride, silica and sulfur dioxide with hexafluorodisilane while hexachlorodisilane in addition gives rise to hexachlorodisiloxane.

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Lumometsän syli, Anni Swanin satusymbolismi 1896-1923 on suomenkielisen satukirjallisuuden poetiikkaa ja 1900-luvun alun modernia naiseutta selvittävä feministiseen tutkimustraditioon liittyvä tutkimus. Sen kohteena ovat lasten- ja nuortenkirjailija Anni Swanin (1875-1958) satukokoelmat vuosilta 1901-1923 ja Uusi Suometar -lehden sadunomaiset novellit vuosilta 1896-1904. Tutkimus tuo uutta tietoa lastenkirjallisuuden osalta 1900-luvun alun modernin ihmisen problematiikasta. Se sisältää naissubjektin kehityskaaren ja sisäisen kasvun kohti naistaiteilijuutta. Yksityiskohtaisen tarkastelun kohteina ovat sadut Veli ja sisar (1917), Ihmekukka (1905), Marjaanan helmikruunu (1912), Aaltojen salaisuus (1901), Jääkukka (1905), Tyttö ja kuolema (1917), Merenkuningatar ja hänen poikansa (1905), Lumolinna (1905) ja Tarina Kultasirkasta (1901). Tutkimuksessa tarkastellaan Swanin satujen poeettista kieltä ja naiseuden tematiikkaa ranskalaisen postmodernin ajan feministisen viitekehyksen valossa. Siinä keskeisiä ovat Julia Kristevan psykoanalyyttispohjaiset näkemykset ja Hélène Cixous´n sekä Luce Irigarayn ajatukset feminiinisestä kirjoituksesta. Sadut kontekstualisoidaan ajankohdan symbolistiseen taidevirtaukseen ja Suomen taiteen kultakauteen. Satuja tulkitaan naiskirjailijan lajina ja erityisenä naisen metaforisen ilmaisun muotona. Satujen feministinen lukutapa purkaa perinteisiä lukemiskonventioita ja merkitsee satutekstin lukemista "toisin". Se avaa varhaista modernia naiseutta ja sille ominaista naisen ilmaisukielen erityisyyttä sekä mykkää ei-kielellistä, melankolian ilmaisua. Tutkimus tuo esiin uudenlaisen naiskirjailijan aistimusvoimaisen kielen. Swanin satusymbolismi on luonnon kauneuden synesteettista ja aistimusvoimaista kerrontaa, jolle on luonteenomaista aistiestetiikka, metaforisuus, metonymisyys ja metamorfoosit. Swan vahvistaa osaltaan naisen sankaruutta, omaa ilmaisukieltä ja ääntä. Tuloksena paljastuu satuperinteeseen verrattuna uudenlaisia tyttöyden, äitiyden, naistaiteilijuuden ja perheen malleja ja niiden representaatioita. Satumallit osoittautuvat aikanaan moderneiksi tyttösankareiksi, osin ambivalenteiksi uudenlaista naiseutta ja suhteessa oloa heijastaviksi ja ovat siten varhaisia feministisen sadun tunnusmerkkejä. Tutkimus selvittää, miten Swan rakentaa omaperäisen satusymboliikan. Satumetsä on luonnonkauniin suomalaismetsän symbolinen mielenmaisema ja samanaikaisesti sadun myyttis-symbolinen topos. Swanin luontokäsitys sisältää luonnonsuojelun ja varhaisen ekokriittisen näkemyksen. Tutkimus osoittaa Swanin satujen kytkeytyvän 1900-luvun alun modernismiin ja Suomen taiteen kultakauteen. Swan on suomenkielisen symbolistisen taidesadun kehittäjä ja feministisen sadun aloittaja.