The synthesis of high coercivity cobalt-in-carbon nanotube hybrid structures and their optical limiting properties

Magnetic heterostructures with carbon nanotubes having multiple functionalities are fascinating materials which can be manipulated by means of an external magnetic field. In this paper we report our investigations on the synthesis and optical limiting properties of pristine cobalt nanotubes and high coercivity cobalt-in-carbon nanotubes (a new nanosystem where carbon nanotubes are filled with cobalt nanotubes). A general mobility assisted growth mechanism for the formation of one-dimensional nanostructures inside nanopores is verified in the case of carbon nanotubes. The open-aperture z-scan technique is employed for the optical limiting measurements in which nanosecond laser pulses at 532 nm have been used for optical excitation. Compared to the benchmark pristine carbon nanotubes these materials show an enhanced nonlinear optical absorption, and the nonlinear optical parameters calculated from the data show that these materials are efficient optical limiters. To the best of our knowledge this is the first report where the optical limiting properties of metal nanotubes are compared to those of carbon nanotubes

Nitrogen fertilizer and seed rate effects on Hagberg failing number of hybrid wheats and their parents are associated with alpha-amylase activity, grain cavity size and dormancy

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha(-1)) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with a-amylase activity. Phadebas grain blotting suggested two populations of grains with different types of a-amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm a-amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for a-amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero-nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post-harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase. (c) 2004 Society of Chemical Industry.

Hybrid proton and electron transport in peptide fibrils

Protons and electrons are being exploited in different natural charge transfer processes. Both types of charge carriers could be, therefore, responsible for charge transport in biomimetic self-assembled peptide nanostructures. The relative contribution of each type of charge carrier is studied in the present work for fi brils self-assembled from amyloid- β derived peptide molecules, in which two non-natural thiophene-based amino acids are included. It is shown that under low humidity conditions both electrons and protons contribute to the conduction, with current ratio of 1:2 respectively, while at higher relative humidity proton transport dominates the conductance. This hybrid conduction behavior leads to a bimodal exponential dependence of the conductance on the relative humidity. Furthermore, in both cases the conductance is shown to be affected by the peptide folding state under the entire relative humidity range. This unique hybrid conductivity behavior makes self-assembled peptide nanostructures powerful building blocks for the construction of electric devices that could use either or both types of charge carriers for their function.

Supramolecular Approach to Gold Nanoparticle/Triruthenium Cluster Hybrid Materials and Interfaces

A systematic and comprehensive study of the interaction of citrate-stabilized gold nanoparticles with triruthenium cluster complexes of general formula [Ru(3)(CH(3)COO)(6)(L)](+) [L = 4-cyanopyridine (4-CNpy), 4,4`-bipyridine (4,4`-bpy) or 4,4`-bis(pyridyl)ethylene (bpe)] has been carried out. The cluster-nanoparticle interaction in solution and the construction of thin films of the hybrid materials were investigated in detail by electronic and surface plasmon resonance (SPR) spectroscopy, Raman scattering spectroscopy and scanning electron microscopy (SEM). Citrate-stabilized gold nanoparticles readily interacted with [Ru(3)O(CH(3)COO)(6)(L)(3)](+) complexes to generate functionalized nanoparticles that tend to aggregate according to rates and extents that depend on the bond strength defined by the characteristics of the cluster L ligands following the sequence bpe > 4,4`-bpy >> 4-CNpy. The formation of compact thin films of hybrid AuNP/[Ru(3)O(CH(3)COO)(6)(L)(3)](+) derivatives with L = bpe and 4,4`-bpy indicated that the stability/lability of AuNP-cluster bonds as well as their solubility are important parameters that influence the film contruction process. Fluorine-doped tin oxide electrodes modified with thin films of these nanomaterials exhibited similar electrocatalytic activity but much higher sensitivity than a conventional gold electrode in the oxidation of nitrite ion to nitrate depending on the bridging cluster complex, demonstrating the high potential for the development of amperometric sensors.

The hybrid stranger and intercultural hermeneutics

The category of the stranger has experienced a renaissance in contemporary social theory. Within this burgeoning literature, a new conceptualisation has emerged known as the 'in-between stranger' or the 'hybrid of modernity'. The formulation of this stranger has raised epistemological concerns. Not only can the hybrid expose the misunderstanding between Self and Other or between two life-worlds, it is able to transcend the self/other dichotomy. The unresolved hermeneutic problem -the meeting with strangers -results in uncertainty, in particular uncertainty about how to read and respond to unfamiliar social situations. What is interesting is not the fact that misunderstanding occurs between the host and the stranger, but that the stranger's physical nearness and social distance fosters an interpretative view of the world that is not accessible to either the host (Self) or parent group (Other). The position of hybrid strangers purportedly encourages a critical and 'objective' stance that transcends conventional and 'situated' knowledge. The discourse on 'the stranger', beginning with Simmel, has constructed the hybrid stranger as disinterested third party. This in-between, third position allows hybrid strangers to see things more clearly and/or differently than those occupying opposing positions or cultural perspectives. In this paper I critically examine the nature of this third type of consciousness and its association with the idea of the intercultural.

Claiming the (n)either/(n)or of 'third space': (re)presenting hybrid identity and the embodiment of mixed race

As a multiracial artist, I am interested in how people of mixed race have been represented in popular culture and how mixed race image-makers can redress popular representation and facilitate a movement beyond the dichotomy, which seeks to reduce us to the sum of our parts. In the footsteps of Evelyn Alsultany I advocate the creation of a new cartography—a space that is inclusive and beyond existing notions of race. To this end I embarked on a project of exploration of the representation of multiracial identity, drawing from Homi K. Bhabha’s notion of Third Space.

The hybrid self and the ambivalence of boundaries

The paper outlines the main features of the contemporary discourse on hybrid subjectivity, a discourse which is internally differentiated along 'organic', 'intentional', and critical social theory lines. It then examines how these discourses can be applied to our understanding of hybrid cultures and identities. The article focuses on two central claims underlying the intentional approach: one, that cultural boundaries are theoretically and empirically problematic; and secondly, that a hybrid position provides the potential for an enlightened and critical world-view. In response, two contentions are articulated that will provide a more nuanced understanding of the hybrid self. Drawing on the work of Simmel and Park, the paper, in contrast to the intentional account, highlights the ambivalence of boundaries; secondly, a critical investigation of the enlightened hybrid consciousness is offered which suggests that this new form of consciousness underplays the role of prejudice and ambivalence. As a result of these discussions, the article demonstrates that the discourse on hybrid identity raises key theoretical issues either ignored or insufficiently addressed by existing scholarship.

The hybrid stranger and cosmopolitan self

The paper critically identifies and examines the affinities between the category of the stranger & the cosmopolitan attitude/disposition that underlies recent theories of cosmopolitanism. I argue that the cosmopolitan attitude can be located within the sociological discourse of the stranger. Thus one needs to reconceptualise the cosmopolitan self in terms of the cosmopolitan stranger.

This new subject develops a more perceptive, broader and keener insight of the social world that is not available than those confined to a universalistic or particularistic perspective. The final part of the paper challenges this assertion through a critical assessment of the socalled in-between position occupied by the cosmopolitan stranger.

A cloud of smug over outdoor education : South Park, hybrid cars and environmental morality

In an episode of South Park titled ‘Hey, People, You’ve Gotta Drive Hybrids Already’, Stan convinces townsfolk to buy hybrid cars. This reduces the rate of smog but creates a toxic cloud of ‘smug’. In this paper, I use this parody of eco-correctness to interrogate some of Outdoor Education’s environmental aims. Michel Foucault’s later work on the self, morality and governmentality is used to analyse the production of the [neo- iberal] ‘environmentally responsible citizen’. The possibilities and problems of contemporary citizenship discourse are explored in relation to findings from a longitudinal study of students undertaking a tertiary outdoor and environmental education course.

Hybrid partnerships and social technology at the BoP: a case study

A crescente expectativa dos vários stakeholders, bem como as diferentes partes interessadas nas áreas de atuação de várias empresas, recentemente tem levado diversas corporações a se envolverem em iniciativas que visam o desenvolvimento social e a erradicação da pobreza. Porém, apesar das inúmeras tentativas, resultados convincentes ainda não foram produzidos, mantendo a separação entre os indivíduos que vivem na base da pirâmide económica e aqueles pertencentes às camadas mais elevadas quase inalterada. Consequentemente alguns estudiosos criticaram a falta de contextualização das práticas de gestão existentes, atribuindo o mesmo à forte influência das ideologias ocidentais, que impedem que as iniciativas sociais se adaptem às necessidades dos diferentes contextos geopolíticos. Por meio da análise de um conjunto de iniciativas sociais da Coca-Cola Brasil ("Projetos Coletivo") implementadas em várias comunidades brasileiras, o presente estudo mostra como Coca-Cola Brasil tentou produzir, em colaboração com os ONG locais, um tipo de "tecnologia social" universal, que poderia ser facilmente adaptada a diferentes contextos, acelerando o processo de implementação das iniciativas sociais e ampliando o seu impacto.

Construction of a river buffalo (Bubalus bubalis) whole-genome radiation hybrid panel and preliminary RH mapping of chromosomes 3 and 10

The buffalo (Bubalus bubalis) not only is a useful source of milk, it also provides meat and works as a natural source of labor and biogas. To establish a project for buffalo genome mapping a 5,000-rad whole genome radiation hybrid panel was constructed for river buffalo and used to build preliminary RH maps from two chromosomes (BBU 3 and BBU10). The preliminary maps contain 66 markers, including coding genes, cattle ESTs and microsatellite loci. The RH maps presented here are the starting point for mapping additional loci, in particular, genes and expressed sequence tags that will allow detailed comparative maps between buffalo, cattle and other species to be constructed. A large quantity of DNA has been prepared from the cell lines forming the RH panel reported here and will be made publicly available to the international community both for the study of chromosome evolution and for the improvement of traits important to the role of buffalo in animal agriculture.

Construction of a river buffalo (Bubalus bubalis) whole-genome radiation hybrid panel and preliminary RH mapping of chromosomes 3 and 10

The buffalo (Bubalus bubalis) is a source of milk and meat, and also serves as a draft animal. In this study, a 5000-rad whole-genome radiation hybrid (RH) panel for river buffalo was constructed and used to build preliminary RH maps for BBU3 and BBU10 chromosomes. The preliminary maps contain 66 markers, including coding genes, cattle expressed sequence tags (ESTs) and microsatellite loci. The RH maps presented here are the starting point for mapping additional loci that will allow detailed comparative maps between buffalo, cattle and other species whose genomes may be mapped in the future. A large quantity of DNA has been prepared from the cell lines forming the river buffalo RH panel and will be made publicly available to the international community both for the study of chromosome evolution and for the improvement of traits important to the role of buffalo in animal agriculture.

Cryopreservation of Dendrobium hybrid seeds and protocorms as affected by phloroglucinol and Supercool X1000

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)