14,612 research outputs found
A summary report on system effectiveness and optimization study
Report treats optimization and effectiveness separately. Report illustrates example of dynamic programming solution to system optimization. Computer algorithm has been developed to solve effectiveness problem and is included in report
Bringing adult learning principles to university–policy engagement training involving students and policy professionals
Within the knowledge exchange literature, there is growing recognition of the role that students have in contributing to knowledge exchange through university-based programmes. To add to this growing, but embryonic, knowledge base, this paper brings together reflections of policy engagement facilitators delivering an optional, online policy training course at UCL (University College London) and the University of Manchester, UK. Known as the Policy Boot Camp, it involved fifty policy professionals, from the civil service, think tanks, local government and the third sector, and three hundred students from undergraduate and master’s degree courses. We reflect on how we drew on the principles of andragogy to create our knowledge exchange programme, so that it was problem-focused, student-led, and interactive and collaborative in nature. We discuss if an intervention such as this can be a route to support more collaborative and fluid policymaking processes. Although our conclusions from this small-scale programme are tentative, we sketch out directions for future research that could contribute to evidencing the potential benefits of courses such as this
Nitrate and phosphate availability and distribution have different effects on root system architecture of Arabidopsis
Plant root systems can respond to nutrient availability and distribution by changing the three-dimensional deployment of their roots: their root system architecture (RSA). We have compared RSA in homogeneous and heterogeneous nitrate and phosphate supply in Arabidopsis. Changes in nitrate and phosphate availability were found to have contrasting effects on primary root length and lateral root density, but similar effects on lateral root length. Relative to shoot dry weight (DW), primary root length decreased with increasing nitrate availability, while it increased with increasing phosphate supply. Lateral root density remained constant across a range of nitrate supplies, but decreased with increasing phosphate supply. In contrast, lateral root elongation was suppressed both by high nitrate and high phosphate supplies. Local supplies of high nitrate or phosphate in a patch also had different effects. Primary root growth was not affected by a high nitrate patch, but growth through a high phosphate patch reduced primary root growth after the root left the patch. A high nitrate patch induced an increase in lateral root density in the patch, whereas lateral root density was unaffected by a high phosphate patch. However, both phosphate- and nitrate-rich patches induced lateral root elongation in the patch and suppressed it outside the patch. This co-ordinated response of lateral roots also occurs in soil-grown plants exposed to a nutrient-rich patch. The auxin-resistant mutants axr1, axr4 and aux1 all showed the wild-type lateral root elongation responses to a nitrate-rich patch, suggesting that auxin is not required for this response
[Introduction to] Property-Owning Democracy: Rawls and Beyond
Property-Owning Democracy: Rawls and Beyond features a collection of original essays that represent the first extended treatment of political philosopher John Rawls\u27 idea of a property-owning democracy.
- Offers new and essential insights into Rawls\u27s idea of property-owning democracy
- Addresses the proposed political and economic institutions and policies which Rawls\u27s theory would require
- Considers radical alternatives to existing forms of capitalism
- Provides a major contribution to debates among progressive policymakers and activists about the programmatic direction progressive politics should take in the near futurehttps://scholarship.richmond.edu/bookshelf/1032/thumbnail.jp
Phosphate availability regulates root system architecture in Arabidopsis
Plant root systems are highly plastic in their development and can adapt their architecture in response to the prevailing environmental conditions. One important parameter is the availability of phosphate, which is highly immobile in soil such that the arrangement of roots within the soil will profoundly affect the ability of the plant to acquire this essential nutrient. Consistent with this, the availability of phosphate was found to have a marked effect on the root system architecture of Arabidopsis. Low phosphate availability favored lateral root growth over primary root growth, through increased lateral root density and length, and reduced primary root growth mediated by reduced cell elongation. The ability of the root system to respond to phosphate availability was found to be independent of sucrose supply and auxin signaling. In contrast, shoot phosphate status was found to influence the root system architecture response to phosphate availability
Effect of wetting layers on the strain and electronic structure of InAs self-assembled quantum dots
The effect of wetting layers on the strain and electronic structure of InAs
self-assembled quantum dots grown on GaAs is investigated with an atomistic
valence-force-field model and an empirical tight-binding model. By comparing a
dot with and without a wetting layer, we find that the inclusion of the wetting
layer weakens the strain inside the dot by only 1% relative change, while it
reduces the energy gap between a confined electron and hole level by as much as
10%. The small change in the strain distribution indicates that strain relaxes
only little through the thin wetting layer. The large reduction of the energy
gap is attributed to the increase of the confining-potential width rather than
the change of the potential height. First-order perturbation calculations or,
alternatively, the addition of an InAs disk below the quantum dot confirm this
conclusion. The effect of the wetting layer on the wave function is
qualitatively different for the weakly confined electron state and the strongly
confined hole state. The electron wave function shifts from the buffer to the
wetting layer, while the hole shifts from the dot to the wetting layer.Comment: 14 pages, 3 figures, and 3 table
Saline aquifer CO2 storage : a demonstration project at the Sleipner Field : Work Area 5 (Geophysics) : gravity modelling of the CO2 bubble
A principal aim of the SACS project is to monitor the injected CO2 by geophysical
methods and to develop a robust and repeatable monitoring and verification
methodology for future CO2 sequestration operations. This report evaluates the
applicability of microgravity surveys as a means of monitoring the future subsurface
distribution and migration of the Sleipner CO2 bubble.
Time-lapse seismic data acquired in 1999, after 2.3 MT of CO2 injection, show an
exceptionally clear image of the CO2 bubble, characterised by very high reflection
amplitudes. The outer envelope of the amplitude anomaly roughly defines an elliptical
cylindrical ‘bubble envelope’, ~ 225 m high, with a major axis of ~ 1500 m oriented
NNE and a minor axis of ~ 600 m.
Gravity modelling was based on a number of scenarios. Two ‘in situ’ scenarios
assume that the CO2 is entirely contained within the bubble envelope. The 1999 and
2001 in situ models assume respectively that 2.3 MT and 4MT of CO2 are contained
within the envelope. Two migration scenarios are also modelled. The first assumes
that 2.3MT of CO2 migrate vertically upwards into the overlying caprock succession
to between depths of 375 and 600 m. The second migration model looks further ahead
to the situation where 3 x 107 m3 (~ 10.5 – 21.0 MT depending on the density) of CO2
have been injected, and migrate laterally beneath the caprock at the top of the
reservoir.
Results depend strongly on the assumed density of the injected CO2 at reservoir
conditions, which is subject to significant uncertainty. Only one, poorly-constrained,
reservoir temperature measurement of 37 ° C is available. A density-depth profile
based on this suggests that the density of CO2 in the reservoir is ~ 700 kgm-3.
However the possibility of significantly lower densities cannot be discounted and
modelling also includes a lower density case of 350 kgm-3.
The 1999 and 2001 in situ cases produce anomalies which would be barely detectable
if the higher density of CO2 is assumed. With the lower density however anomalies
should be readily detectable with a modern seabed gravimeter. The vertical migration
scenario indicates that large-scale vertical migration into the caprock, to depths where
densities would be unequivocally lower, would be readily detected. The lateral
migration scenario, whereby a single thin layer of CO2 migrates beneath the top
reservoir seal, produces small anomalies which may be locally detectable but with
insufficient resolution to enable effective migration mapping. However if lateral
migration is via several layers, beneath intra-reservoir shales, then anomalies should
be more usefully measurable.
Obtaining time-lapse gravimeter readings directly above the bubble would appear to
offer the best chance of obtaining useful information. Coupled with geometric
information provided by the time-lapse seismic data, the gravity should be able to
discriminate between the low and high CO2 density scenarios. This would provide
important constraints on future reservoir modelling and also the volume estimates
based on the seismic velocity pushdown effect. Related to this, gravity data would
offer the potential to provide independent verification of the amount of CO2 sequestered. In addition gravimetric surveys above the bubble could provide an
effective ‘early warning’ of major caprock breaching
Co-ordination and public administration in a global economy — A Hungarian point of view
The purpose of social co-ordination mechanisms is to co-ordinate the activities of individuals and organisations specialised in the distribution of work. The paper reviews five basic types of mechanisms: market, bureaucratic, ethical, aggressive and co-operative co-ordination. Today’s world operates on the basis of a duality: international cooperation is based on nation states, in which the public administrations work according to bureaucratic coordination. However, the increasingly globalised market responds to the logic of market coordination. The article argues that in terms of understanding the working of public administration, the various coordination mechanisms are of crucial importance, especially where various mechanisms meet, such as the relationship between nation states and multinational corporations
Re: Bhatti et al.: Microcystic macular edema in optic nerve glioma (Ophthalmology. 2020;127:930)
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