1,178 research outputs found
Effect of cation size variance on spin and orbital order in Eu(LaY)VO
We have investigated the -ion ( = rare earth or Y) size variance effect
on spin/orbital order in Eu(LaY)VO. The
size variance disturbs one-dimensional orbital correlation in -type
spin/-type orbital ordered states and suppresses this spin/orbital order. In
contrast, it stabilizes the other spin/orbital order. The results of neutron
and resonant X-ray scattering denote that in the other ordered phase, the
spin/orbital patterns are -type/-type, respectively.Comment: 4 pages, 4 figures, accepted to Rapid Communication in Physical
Review
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Hydroxylated texaphyrins
A method of using texaphyrins as radiosensitizers. Advantageous properties of texaphyrins for use as a radiosensitizer include i) a low redox potential which allows radiation induced solvated electrons to flow to texaphyrin rather than neutralizing hydroxyl radicals, allowing the hydroxyl radicals to cause cellular damage, ii) a relatively stable texaphyrin radical which, nevertheless, reacts readily to covalently modify neighboring molecules causing further cellular damage, and iii) intrinsic biolocalization and indifference to the presence of O.sub.2 which allow texaphyrin to be particularly effective for treating the hypoxic areas of solid tumors. Sensitizer enhancement ratios of 1.62 and 2.2 were achieved at 20 .mu.M and 80 .mu.M gadolinium-texaphyrin, respectively, with a mouse leukemia cell line. Methods of treatment for an individual having a tumor include the use of a texaphyrin as a radiosensitizer and as an agent for photodynamic tumor therapy, or the use of a texaphyrin for internal and for external ionizing radiation. New water soluble hydroxy-substituted texaphyrins are described.Board of Regents, University of Texas Syste
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Method of magnetic resonance image enhancement
Texaphyrins are provided for use as radiation sensitizers. Advantageous properties of texaphyrins for use as a radiation sensitizer include: i) a low redox potential which allows radiation-induced hydrated electrons to flow to texaphyrin rather than neutralizing hydroxyl radicals, allowing hydroxyl radicals to cause cellular damage, ii) a relatively stable texaphyrin radical that reacts readily to covalently modify neighboring molecules causing further cellular damage, iii) intrinsic biolocalization, and iv) indifference to the presence or absence of O.sub.2. These properties allow texaphyrins to be particularly effective for treating the hypoxic areas of solid neoplasms. Methods of treatment for an individual having a neoplasm or atheroma include the use of a texaphyrin as a radiation sensitizer and as an agent for photodynamic tumor therapy, or the use of a texaphyrin for internal and for external ionizing radiation. Novel texaphyrins are provided.Board of Regents, University of Texas Syste
Learning through ICTS in the environmental justice movement: case studies from Scotland
The data for this article derives from research funded by an ESRC grant:
award number RES-000-22-2301.Historically, social purpose adult education was linked with progressive struggles for social justice, equality and democracy, and its contribution waxed and waned depending on the vibrancy and demands of wider social forces in society. However, these forces have altered considerably over the past century. This is not the only important difference in today's context. Information and communication technologies (ICTs) are having an impact
on the nature of social and political conflicts by creating new sites of struggle and new means of participation in social action. They also have a potential impact on the process of individual and social learning in movement activities. If social purpose adult education is to reassert itself as a resource for progressive social movements, it will have to reconnect with these struggles and adopt new ways of allying itself to their cause. In this
paper we draw upon ongoing research into the environmental justice movement in Scotland, which focuses on the contribution of ICTs to learning and participation.div_MCaPAAgents for Environmental Justice and Scandrett, E (2003) Voices from the
Grassroots, Edinburgh: Friends of the Earth Scotland.
Agyeman, J., Bullard, R and Evans, B (2003) Just Sustainabilities:
Development in an Unequal World, Cambridge, MA: MIT Press.
Bayne, S (2006) 'Temptation, trash and trust: the authorship and authority of
digital texts', E-Learning 3 (1) 16-26.
Blumer, M (1995) 'Social movements', in Lyman S (ed) Social Movements:
Critiques, Concepts, Case-Studies, London: MacMillan Press.
Brunsting, S and Postmes, T (2002) 'Social movement participation in the
digital age: predicting offline and online collective action', Small Group
Research, 33 (5) 525-554.
Colley, H., Hodkinson, P and Malcolm, J (2002) Non-formal learning:
mapping the conceptual terrain. A Consultation Report, Leeds: University of
Leeds Lifelong Learning Institute. Also available in the informal education
archives: http://www.infed.org/archives/e-texts/colley_informal_learning.htm.
Cook, J and Smith, M (2004) 'Beyond formal learning: informal community
elearning', Computers and Education, CAL03 Special Issue, 43 (1-2), 35-47.
Dunion, K (2003) Troublemakers: The Struggle for Environmental Justice in
Scotland, Edinburgh: Edinburgh University Press.
Elsdon, K with Reynolds, J and Stewart, S (1995) Voluntary Organisations:
Citizenship, Learning and Change, Leicester: NIACE.
Eyerman, R and Jamison, A (1991) Social Movements: A Cognitive
Approach, Bristol: Polity Press.
Foley, G (1999) Learning in Action, London: Zed Books/NIACE.
Hall, B., Turray, T., Chow, W., Dragne, C and Parks, E (2005) Final Report
- Social Movement Learning, Canada: Canadian Council for Learning.
Lave, J and Wenger, E (1991) Situated Learning: Legitimate Peripheral
Participation, Cambridge: Cambridge University Press.
Sawchuk, P., Gawron, Z and Taylor, J (2002) 'E-learning and union
mobilization', Journal of Distance Education, 17 (3) 80-96.
Selwyn, N., Gorard, S and Furlong, J (2006) 'Adults' use of computers and
the Internet for self-education', Studies in the Education of Adults, 38 (2)
Autumn 141-159.
Selwyn, N. (2003) 'Apart from technology: understanding people's non-use
of information and communication technologies in everyday life', Technology
in Society. 25 (1): 99-116.
Scandrett, E O'Leary, T and Martinez, T (2005) 'Learning environmental
justice through dialogue' in Proceedings of PASCAL Conference, Making
Knowledge Work, Leicester: NIACE.
Virilio, P. (2005) The Information Bomb. London: Verso Books.
Wildermeersch, D and Jansen, T (1997) 'Strengths and limitations of social
learning as a key concept for adult and continuing education in reflexive
modernity', in Armstrong, P., Miller, N and Zukas, M (eds) Crossing Borders,
Breaking Boundaries, 27th Annual SCUTREA Conference Proceedings,
London: Birkbeck College.unpub567unpu
Regional differences in the preferred e-vector orientation of honeybee ocellar photoreceptors
In addition to compound eyes, honeybees (Apis mellifera) possess three single lens eyes called ocelli located on the top of the head. Ocelli are involved in head-attitude control and in some insects have been shown to provide celestial compass information. Anatomical and early electrophysiological studies have suggested that UV and blue-green photoreceptors in ocelli are polarization sensitive. However, their retinal distribution and receptor characteristics have not been documented. Here, we used intracellular electrophysiology to determine the relationship between the spectral and polarization sensitivity of photoreceptors and their position within the visual field of the ocelli. We first determined a photoreceptor’s spectral response through a series of monochromatic flashes (340 - 600 nm). We found UV and Green receptors, with peak sensitivities at 360 nm and 500 nm respectively. We subsequently measured polarization sensitivity at the photoreceptor’s peak sensitivity wavelength by rotating a polarizer with monochromatic flashes. Polarization sensitivity (PS) values were significantly higher in UV receptors (3.8±1.5, N=61) than Green receptors (2.1±0.6, N=60). Interestingly, most receptors with receptive fields below 35° elevation were sensitive to vertically polarized light while the receptors with visual fields above 35° were sensitive to a wide range of polarization angles. These results agree well with anatomical measurements showing differences in rhabdom orientations between dorsal and ventral retinae. We discuss the functional significance of the distribution of polarization sensitivities across the visual field of ocelli by highlighting the information the ocelli are able to extract from the bee’s visual environment.This study was supported by a Japan Society for the Promotion of Science (JSPS)
Postdoctoral Fellowship for Research Abroad to Y.O. and an Australian Research
Council grant (FT110100528) to J.M.H
Validation of the High Performance Conduction-Cooled Prototype LTS Pulse Coil for UPS-SMES
A conduction-cooled low temperature superconducting (LTS) pulse coil has been developed as a key technology for UPS-SMES. We have been developing a 1 MW, 1 s UPS-SMES for a protection from a momentary voltage drop and an instant power failure. A conduction-cooled LTS pulse coil has excellent characteristics, which are adequate for a short-time uninterruptible power supply (UPS). The LTS coil has better cost performance over the HTS coil at present and the conduction cooling has higher reliability and easier operation than the conventional cooling schemes such as pool boiling with liquid helium or forced flow of supercritical helium. To demonstrate the high performances of the LTS pulse coil, we have fabricated a prototype coil with stored energy of 100 kJ and have conducted cooling and excitation tests. The successful performance test results including current shut-off test with a time constant of 1.3 s and repeated excitation of a triangular waveform with high ramp rate are reporte
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