917 resultados para Koch fractal elements
Resumo:
The idea of buildings in harmony with nature can be traced back to ancient times. The increasing concerns on sustainability oriented buildings have added new challenges in building architectural design and called for new design responses. Sustainable design integrates and balances the human geometries and the natural ones. As the language of nature, it is, therefore, natural to assume that fractal geometry could play a role in developing new forms of aesthetics and sustainable architectural design. This paper gives a brief description of fractal geometry theory and presents its current status and recent developments through illustrative review of some fractal case studies in architecture design, which provides a bridge between fractal geometry and architecture design.
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This essay contends that the constitutive elements of well-being are plural, partly objective, and separable. The essay argues that these elements are pleasure, friendship, significant achievement, important knowledge, and autonomy, but not either the appreciation of beauty or the living of a morally good life. The essay goes on to attack the view that elements of well-being must be combined in order for well-being to be enhanced. The final section argues against the view that, because anything important to say about well-being could be reduced to assertions about these separable elements, the concept of well-being or personal good is ultimately unimportant.
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This article focuses on one particular factor that is of crucial importance to all self-defence actions. It is a factor that is almost always present in the application and appraisal of the right, but one that is not always explicitly engaged with: time. There are various ratione temporis elements underpinning the lawful exercise of the right of self-defence, and questions related to the timing of both an attack being responded to in self-defence and the response itself are notably controversial. The self-defence timeline is therefore charted, and the key legal debates encountered along its trajectory are identified. In particular, there is a focus on three temporal ‘stages’ of the right of self-defence: (i) the much-debated question of preventative forms of self-defence (the ‘before’); (ii) the timeliness of a state's defensive action, or what is sometimes called the need for the response to be ‘immediate’ (the ‘during’); and (iii) the duration of self-defence actions, including the crucial issue of when they must end (the ‘after’). The aim of this article is not to break new substantive ground with regard to these ‘stages’ as such, but is, rather, to draw together the temporal strands of self-defence in a more focused manner than is often the case in the literature.
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The solvothermal synthesis and characterisation of [C6H16N2][GaS2]2 (1), [C6H16N2][Ga2Se3(Se2)] (2), and mixed-metal phases with composition [C6H16N2][Ga2–xInxSe3(Se2)] (0 < x < 2)(3–5), is described. These materials have been characterised by single-crystal and powder X-ray diffraction, thermogravimetric analysis and UV/Vis diffuse reflectance spectroscopy. The materials contain one-dimensional anionic chains. In 1, these chains consist of edge-linked GaS4 tetrahedra, whilst in 2–5, the chains contain perselenide (Se2)2– units and comprise alternating four-membered [M2Se2] and five-membered [M2Se3] rings (where M = Ga, In). Compounds 3–5 represent the first examples of ternary mixed-metal [M2Se3(Se2)]2– chains.
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This study investigates the effects of temperature and pressure on inactivation of myrosinase extracted from black, brown and yellow mustard seeds. Brown mustard had higher myrosinase activity (2.75 un/mL) than black (1.50 un/mL) and yellow mustard (0.63 un/mL). The extent of enzyme inactivation increased with pressure (600-800 MPa) and temperature (30-70 °C) for all the mustard seeds. However, at combinations of lower pressures (200-400 MPa) and high temperatures (60-80 °C), there was less inactivation. For example, application of 300 MPa and 70 °C for 10 minutes retained 20%, 80% and 65% activity in yellow, black and brown mustard, respectively, whereas the corresponding activity retentions when applying only heat (70 °C, 10min) were 0%, 59% and 35%. Thus, application of moderate pressures (200-400 MPa) can potentially be used to retain myrosinase activity needed for subsequent glucosinolate hydrolysis.
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Trace element measurements in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 aerosol were performed with 2 h time resolution at kerbside, urban background and rural sites during the ClearfLo winter 2012 campaign in London. The environment-dependent variability of emissions was characterized using the Multilinear Engine implementation of the positive matrix factorization model, conducted on data sets comprising all three sites but segregated by size. Combining the sites enabled separation of sources with high temporal covariance but significant spatial variability. Separation of sizes improved source resolution by preventing sources occurring in only a single size fraction from having too small a contribution for the model to resolve. Anchor profiles were retrieved internally by analysing data subsets, and these profiles were used in the analyses of the complete data sets of all sites for enhanced source apportionment. A total of nine different factors were resolved (notable elements in brackets): in PM10–2.5, brake wear (Cu, Zr, Sb, Ba), other traffic-related (Fe), resuspended dust (Si, Ca), sea/road salt (Cl), aged sea salt (Na, Mg) and industrial (Cr, Ni); in PM2.5–1.0, brake wear, other traffic-related, resuspended dust, sea/road salt, aged sea salt and S-rich (S); and in PM1.0–0.3, traffic-related (Fe, Cu, Zr, Sb, Ba), resuspended dust, sea/road salt, aged sea salt, reacted Cl (Cl), S-rich and solid fuel (K, Pb). Human activities enhance the kerb-to-rural concentration gradients of coarse aged sea salt, typically considered to have a natural source, by 1.7–2.2. These site-dependent concentration differences reflect the effect of local resuspension processes in London. The anthropogenically influenced factors traffic (brake wear and other traffic-related processes), dust and sea/road salt provide further kerb-to-rural concentration enhancements by direct source emissions by a factor of 3.5–12.7. The traffic and dust factors are mainly emitted in PM10–2.5 and show strong diurnal variations with concentrations up to 4 times higher during rush hour than during night-time. Regionally influenced S-rich and solid fuel factors, occurring primarily in PM1.0–0.3, have negligible resuspension influences, and concentrations are similar throughout the day and across the regions.
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Ambient concentrations of trace elements with 2 h time resolution were measured in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3–6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6–3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10–2.5 mass fraction, roughly twice that of the PM1.0–0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4–5.4 for SW, 1.7–2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10–2.5 sea salt (factor of up to 2), which may be influenced by traffic-induced resuspension of sea and/or road salt. Heavy-duty vehicles appeared to have a larger effect than passenger vehicles on the concentrations of all elements influenced by resuspension (including sea salt) and wearing processes. Trace element concentrations in London were influenced by both local and regional sources, with coarse and intermediate fractions dominated by traffic-induced resuspension and wearing processes and fine particles influenced by regional transport.
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1. Understanding the behaviour and ecology of large carnivores is becoming increasingly important as the list of endangered species grows, with felids such as Panthera leo in some locations heading dangerously close to extinction in the wild. In order to have more reliable and effective tools to understand animal behaviour, movement and diet, we need to develop novel, integrated approaches and effective techniques to capture a detailed profile of animal foraging and movement patterns. 2. Ecological studies have shown considerable interest in using stable isotope methods, both to investigate the nature of animal feeding habits, and to map their geographical location. However, recent work has suggested that stable isotope analyses of felid fur and bone is very complex and does not correlate directly with the isotopic composition of precipitation (and hence geographical location). 3. We present new data that suggest these previous findings may be atypical, and demonstrate that isotope analyses of Felidae are suitable for both evaluating dietary inputs and establishing geo-location as they have strong environmental referents to both food and water. These data provide new evidence of an important methodology that can be applied to the family Felidae for future research in ecology, conservation, wildlife forensics and archaeological science.
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The abundance of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of a star`s age. The space UV region (lambda < 3000 angstrom) presents a large number of lines of the heavy elements, and in the case of some elements, such as Bi, Pt, Au, detectable lines are not available elsewhere. The extreme ""r-process star"" CS 31082-001 ([Fe/H] = -2.9) was observed in the space UV to determine abundances of the heaviest stable elements, using STIS on board Hubble Space Telescope.
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This paper deals with the morphological features of the tracheary elements of the vegetative organs in four Portulaca species (Portulaca hirsutissima Camb., P. halimoides L., P. wedermannii Poelln. and P. mucronata Link.) occurring in Southeast and Northeast Brazil. The vessel elements are small (< 25 mu m) and with simple perforation plate. The pattern of wall thickening varied from bordered pitting (in roots) to scalariform and helicoidal (stem and leaves). Statistical methods show variation in vessel-element diameter in different vegetative organs; wider elements were observed in roots. Tracheids occurring in leaves of P. hirsutissima and P. wedermannii, have morphological features that are similar to terminal tracheids or tracheoid idiolasts frequently associated with xerophytes. The paedomorphic features (juvenlism) observed here may be related, in part, to aspects of water transport and storage as described in Cactaceae.
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Type XVIII collagen is a component of basement membranes, and expressed prominently in the eye, blood vessels, liver, and the central nervous system. Homozygous mutations in COL18A1 lead to Knobloch Syndrome, characterized by ocular defects and occipital encephalocele. However, relatively little has been described on the role of type XVIII collagen in development, and nothing is known about the regulation of its tissue-specific expression pattern. We have used zebrafish transgenesis to identify and characterize cis-regulatory sequences controlling expression of the human gene. Candidate enhancers were selected from non-coding sequence associated with COL18A1 based on sequence conservation among mammals. Although these displayed no overt conservation with orthologous zebrafish sequences, four regions nonetheless acted as tissue-specific transcriptional enhancers in the zebrafish embryo, and together recapitulated the major aspects of col18a1 expression. Additional post-hoc computational analysis on positive enhancer sequences revealed alignments between mammalian and teleost sequences, which we hypothesize predict the corresponding zebrafish enhancers; for one of these, we demonstrate functional overlap with the orthologous human enhancer sequence. Our results provide important insight into the biological function and regulation of COL18A1, and point to additional sequences that may contribute to complex diseases involving COL18A1. More generally, we show that combining functional data with targeted analyses for phylogenetic conservation can reveal conserved cis-regulatory elements in the large number of cases where computational alignment alone falls short. (C) 2009 Elsevier Inc. All rights reserved.
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We describe Kochiana new genus to accommodate a small Brazilian theraphosine species described originally as Mygale brunnipes by Koch (1842), resulting in Kochiana brunnipes new combination. Recently, specimens were rediscovered in northeastern Brazilian Atlantic rainforest. A preliminary cladistic analysis using equal weights parsimony and implied weights, was carried out to examine its phylogenetic placement. Kochiana new genus was monophyletic in all trees regardless of weighting scheme or concavity used. There is preliminary evidence for Kochiana new genus monophyly and weak evidence for its placement as sister group of Plesiopelma. Kochiana new genus can be characterized by the presence of a hornshaped spermatheca in females and males with a palpal bulb having prolateral accessory keels and a well developed medial crest on the embolus apex.
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Avicularia diversipes (C. L. Koch 1842) known previously only from its original description is redescribed along with Avicularia sooretama sp. nov. and Avicularia gamba sp. nov. The three species are endemic to Brazilian Atlantic rainforest. With other Avicularia species, they share a procurved anterior eye row, slender embolus and medially folded spermathecae, whereas they have unusual characters, such as a very long and spiraled embolus (A. diversipes) and spermathecae with multilobular apex (A. sooretama sp. nov.). Furthermore, the three species lack a tibial apophysis in males and share a distinctive color pattern ontogeny that is not known in any other Avicularia species. The conservation status of the three species is discussed, especially with respect to endemism, illegal trafficking and habitat destruction. The creation of protected areas in southern State of Bahia, Brazil, is recommended, as well as the inclusion of these species in IUCN and CITES lists. Appendices with figures and species information are presented to facilitate correct specimen identification by custom officers, in order to limit illegal traffic.
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Two mariner-like elements, Ramar1 and Ramar2, are described in the genome of Rhynchosciara americana, whose nucleotide consensus sequences were derived from multiple defective copies containing deletions, frame shifts and stop codons. Ramar1 contains several conserved amino acid blocks which were identified, including a specific D,D(34)D signature motif. Ramar2 is a defective mariner-like element, which contains a deletion overlapping in most of the internal region of the transposase ORF while its extremities remain intact. Predicted transposase sequences demonstrated that Ramar1 and Ramar2 phylogenetically present high identity to mariner-like elements of mauritiana subfamily. Southern blot analysis indicated that Ramar1 is widely represented in the genome of Rhynchosciara americana. In situ hybridizations showed Ramar1 localized in several chromosome regions, mainly in pericentromeric heterochromatin and their boundaries, while Ramar2 appeared as a single band in chromosome A.