86 resultados para Machiavelli, Niccolo 1469-1527


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Cosmopolitanism as the existential condition of humanity refers to the view that human beings are both transcendent and social. This is argued through another pair of concepts, commonality and difference. If humans are moral, it is because they recognise each other as sharing a basic ontology. But this morality is expressed in the sort of regard that separates ‘me’ from ‘you’. Two aspects of difference are elaborated: foreignness feared as alien but also found in oneself, and alterity as irreducibly other. How can these differences keep us both individual and social?

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A wireless relay network with one source, one relay and one destination is considered, where nodes communicate via N orthogonal channels. We develop optimal power allocation strategies at both the source and relay for maximizing the overall source-destination capacity under individual power constraints at the source and relay. Some properties of the optimal solution are studied. © 2012 IEEE.

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P>In order to gain insights into the transport and distribution of arsenic (As) in intact rice (Oryza sativa) plants and its unloading into the rice grain, we investigated the spatial distribution of As and the temporal variation of As concentration in whole rice plants at different growth stages. To the best of our knowledge, this is the first time that such a study has been performed.

Inductively coupled plasma mass spectroscopy (ICP-MS) and high-performance liquid chromatography (HPLC)-ICP-MS were used to analyze total As concentration and speciation. Moreover, synchrotron-based X-ray fluorescence (SXRF) was used to investigate in situ As distribution in the leaf, internode, node and grain.

Total As concentrations of vegetative tissues increased during the 2 wk after flowering. The concentration of dimethylarsinic acid (DMA) in the caryopsis decreased progressively with its development, whereas inorganic As concentration remained stable. The ratios of As content between neighboring leaves or between neighboring internodes were c. 0.6. SXRF revealed As accumulation in the center of the caryopsis during its early development and then in the ovular vascular trace.

These results indicate that there are different controls on the unloading of inorganic As and DMA; the latter accumulated mainly in the caryopsis before flowering, whereas inorganic As was mainly transported into the caryopsis during grain filling. Moreover, nodes appeared to serve as a check-point in As distribution in rice shoots.

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Duckweeds are a common macrophyte in paddy and aquatic environments. Here, we investigated arsenic (As) accumulation, speciation and tolerance of the rootless duckweed Wolffia globosa and its potential for As phytofiltration.

When grown with 1 mu M arsenate, W. globosa accumulated two to 10 times more As than four other duckweed or Azolla species tested. W. globosa was able to accumulate > 1000 mg As kg(-1) in frond dry weight (DW), and tolerate up to 400 mg As kg-1 DW. At the low concentration range, uptake rate was similar for arsenate and arsenite, but at the high concentration range, arsenite was taken up at a faster rate.

Arsenite was the predominant As species (c. 90% of the total extractable As) in both arsenate-and arsenite-exposed duckweed. W. globosa was more resistant to external arsenate than arsenite, but showed a similar degree of tolerance internally. W. globosa decreased arsenate in solution rapidly, but also effluxed arsenite.

Wolffia globosa is a strong As accumulator and an interesting model plant to study As uptake and metabolism because of the lack of a root-to-frond translocation

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The fate of missing persons is a central issue in post-conflict societies facing truth recovery and human rights dilemmas. Despite widespread public sympathy towards relatives, societies emerging from conflict often defer the recovery of missing for decades. More paradoxically, in post-1974 Cyprus, the official authorities delayed unilateral exhumations of victims buried within cemeteries in their own jurisdiction. Analysis of official post-1974 discourse reveals a Greek-Cypriot consensus to emphasise the issue as one of Turkish aggression, thus downplaying in-group responsibilities and the legacy of intra-communal violence. We compare the experience of Cyprus with other post-conflict societies such as Spain, Northern Ireland, and Mozambique and explore the linkages between institutions and beliefs about transitional justice. We argue that elite consensus initiates and facilitates the transition to democracy but often leads to the institutionalization of groups opposing truth recovery even for in-group members.

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BackgroundChildren with autism spectrum disorder are increasingly educated in mainstream classrooms in the United Kingdom (Wilkinson & Twist, Autism and Educational Assessment: UK Policy and Practice. NFER, Slough, 2010), and some employers are now specifically seeking out staff on the autism spectrum. Does that mean that we are living in an inclusive society' [United Nations Department of Economic and Social Affairs (UNDESA), Creating an Inclusive Society: Practical Strategies to Promote Social Integration 2008], in the sense that inequalities are reduced and full economic, social and cultural participation is advanced for individuals with autism?

MethodsA general population survey was conducted to assess how close we, as a society, are to an inclusive society for individuals with autism in Northern Ireland. Public attitudes were examined to (i) visibility and social interaction, (ii) aetiology, needs and interventions, and (iii) rights and resources.

ResultsA stratified, representative sample of 1204 adults took part in the survey; of these, 989 were aware of autism and their attitudes and behavioural projections reflected a mix of acceptance and denunciation. The level of confusion with regard to interventions reflected the general uncertainty within UK policy regarding meeting the needs of individuals on the autism spectrum (International Journal of Disability, Development and Education 61, 134, 2014a).

ConclusionTherefore, it seems that inclusion is working to an extent, but more clarity is needed with regard to adequate education, intervention and support for individuals with autism.

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The growing popularity of English national insignia in international football tournaments has been widely interpreted as evidence of the emergence of a renewed English national consciousness. However, little empirical research has considered how people in England actually understand football support in relation to national identity. Interview data collected around the time of the Euro 2000 and the 2002 World Cup tournaments fail to substantiate the presumption that support for the England football team maps onto claims to patriotic sentiment in any straightforward way. People with far-right political affiliations did generally use national football support to symbolise a general pride in English national identity. However, other people either claimed not to support the England national team precisely because of its associations with nationalism, or else bracketed the domain of football support from more general connotations of English patriotism.

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Laccase-mediator systems have numerous potential uses for green oxidations, but their practical use may be limited because the reactive, oxidised mediators deactivate the enzyme. TEMPO, 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl caused almost complete deactivation of laccase from Trametes versicolor within 24-140 h. By contrast, 18% activity was retained after 188 h in controls without mediator, and 15% in the presence of ABTS. A biphasic reaction system was developed to protect the laccase, by partitioning the mediator into water-immiscible ionic liquids. In the presence of [C mim][AOT], laccase retained 54, 35, 35 and 41% activity after 188 h in the presence of 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl and ABTS, respectively, whilst 30% activity was retained in the presence of [N][Sac] and TEMPO. The protection against deactivation by the mediators correlated strongly with the distribution coefficients of the mediators between ionic liquids and water. © 2014 The Royal Society of Chemistry.

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Pseudomonas aeruginosa genotyping relies mainly upon DNA fingerprinting methods, which can be subjective, expensive and time-consuming. The detection of at least three different clonal P. aeruginosa strains in patients attending two cystic fibrosis (CF) centres in a single Australian city prompted the design of a non-gel-based PCR method to enable clinical microbiology laboratories to readily identify these clonal strains. We designed a detection method utilizing heat-denatured P. aeruginosa isolates and a ten-single-nucleotide polymorphism (SNP) profile. Strain differences were detected by SYBR Green-based real-time PCR and high-resolution melting curve analysis (HRM10SNP assay). Overall, 106 P. aeruginosa sputum isolates collected from 74 patients with CF, as well as five reference strains, were analysed with the HRM10SNP assay, and the results were compared with those obtained by pulsed-field gel electrophoresis (PFGE). The HRM10SNP assay accurately identified all 45 isolates as members of one of the three major clonal strains characterized by PFGE in two Brisbane CF centres (Australian epidemic strain-1, Australian epidemic strain-2 and P42) from 61 other P. aeruginosa strains from Australian CF patients and two representative overseas epidemic strain isolates. The HRM10SNP method is simple, is relatively inexpensive and can be completed in <3 h. In our setting, it could be made easily available for clinical microbiology laboratories to screen for local P. aeruginosa strains and to guide infection control policies. Further studies are needed to determine whether the HRM10SNP assay can also be modified to detect additional clonal strains that are prevalent in other CF centres.

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Polycyclic aromatic hydrocarbons (PAHs) are an important class of persistent organic pollutants (POPs) in the environment and accumulate in forest soils. These soils are often dominated by ectomycorrhizal (EcM) roots, but little is known about how EcM fungi degrade PAHs, or the overall effect of field colonized EcM roots on the fate of PAHs. The ability of eight EcM fungi to degrade PAHs in liquid culture spiked with 14C labelled PAHs was investigated. Microcosms were used to determine the impact of naturally colonized mycorrhizal pine seedlings on PAH mineralization and volatilization. Only two EcM fungi (Thelephora terrestris and Laccaria laccata) degraded at least one PAH and none were able to mineralize the PAHs in pure culture. Where degradation occurred, the compounds were only mono-oxygenated. EcM pine seedlings did not alter naphthalene mineralization or volatilization but retarded fluorene mineralization by 35% compared with unplanted, ectomycorrhizosphere soil inoculated, microcosms. The EcM fungi possessed limited PAH degrading abilities, which may explain why EcM dominated microcosms retarded fluorene mineralization. This observation is considered in relation to the 'Gadgil-effect', where retarded litter decomposition has been observed in the presence of EcM roots. © New Phytologist (2004).

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The genetics of arsenic tolerance in plants has not been extensively studied and no arsenic tolerance gene has been genetically mapped. Screening 20 diverse genotypes of rice for reduced root growth in 13.3 μM arsenate identified marked differences in tolerance. The most sensitive variety, Dawn, is known to be highly susceptible to straighthead, a condition linked to arsenic contamination of soil. Screening 108 recombinant inbred lines of the Bala x Azucena mapping population revealed the presence of a major gene, AsTol, which mapped between markers RZ516 and RG213 on chromosome 6. This gene is a good target for further characterisation. It should prove valuable for investigations into the physiological and molecular mechanism behind arsenic tolerance in plants and may lead to strategies aimed at breeding for arsenic contaminated regions. © New Phytologist (2004).

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The development of proteoid roots under phosphorus deficiency by white lupin (Lupinus albus) may result in increased arsenate uptake, as arsenate is a phosphate analogue. This, together with its high biomass production, rapid growth and ability to survive in soils with low phosphate and nitrogen contents, low pH and high metal contents make them an interesting species to investigate with respect to revegetation, and possibly also for long-term phytoremediation, of arsenic contaminated soils. Kinetic parameters for arsenate uptake for P-deficient and P-sufficient plants, as well as for proteoid and nonproteoid roots were obtained. Down-regulation of arsenate uptake by phosphate, as well as phosphate/arsenate competition for P-deficient and P-sufficient plants was studied. Arsenate uptake was reduced by phosphate, but small differences were found between P-deficient and P-sufficient plants. Arsenate uptake by proteoid roots was higher than for nonproteoid roots of P-deficient plants, with higher Vmax and similar Km values. Down-regulation of the high affinity phosphate/arsenate uptake system by phosphate does take place but seems to be slower than in other plants. This study suggests that the low sensitivity of the phosphate/arsenate uptake system to regulation by phosphate may be related to the adaptations of white lupin to low P available environments. Such adaptation are absent in plants unable to develop proteoid roots.

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Here the mechanism of arsenite transport into paddy rice (Oryza sativa) roots, uptake of which is described by Michaelis-Menten kinetics, is reported. A recent study on yeast (Saccharomyces cerevisiae) showed that undissociated arsenite (its pKa is 9.2) was transported across the plasma membrane via a glycerol transporting channel. To investigate whether the same mechanism of transport was involved for rice, competitive studies with glycerol, which is transported into cells via aquaporins, were performed. Glycerol competed with arsenite for transport in a dose-dependent manner, indicating that arsenite and glycerol uptake mechanisms were the same. Arsenate transport was unaffected by glycerol, confirming that arsenate and arsenite are taken up into cells by different mechanisms. Antimonite, an arsenite analogue that is transported into S. cerevisiae cells by aquaporins, also competed with arsenite transport in a dose-dependent manner, providing further evidence that arsenite is transported into rice roots via glycerol transporting channels. Mercury (Hg2+) inhibited both arsenite and arsenate uptake, suggesting that inhibition of influx was due to general cellular stress rather than the specific action of Hg2+ on aquaporins. Arsenite uptake by pea (Pisum sativum) and wheat (Triticum aestivum) was also described by Michaelis-Menten kinetics.

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A range of fern species (45) and their allies, Equisetum (5) and Selaginella (2) species and Psilotum nudum were screened for their ability to hyperaccumulate arsenic, to develop a phylogenetic understanding of this phenomenon. A number of varieties (5) of a known arsenic hyperaccumulator Pteris cretica were additionally included in this study. This study is the first to report members of the Pteris genus that do not hyperaccumulate arsenic, Pteris straminea and tremula. A phylogenetic basis for arsenic accumulation in ferns was investigated. Some orders can accumulate more arsenic than others. Although members of the Equisetales and Blechnales did not hyperaccumulate arsenic, they still accumulated relatively high levels in their fronds, approaching 100 mg kg-1 when grown on a soil dosed with 100 mg kg-1 arsenic. Arsenic hyperaccumulation was identified as a phenomenon at the extreme range of fern arsenic accumulation. Ferns that exhibit arsenic hyperaccumulation arrived relatively late in terms of fern evolution, as this character is not exhibited by primitive ferns or their allies.