Learning about learning as systemic practice in the context of environmental decision-making

This paper has been written as the author is beginning a new phase of researching learning, investigating what supports people in their environmental decision making. This process of inquiry has arisen partly as a result of the development and teaching of the UK Open University’s Masters ’ level course Environmental decision making – a systems approach. The implications of approaching an inquiry with a view of ‘learning as systemic practice ’ is considered, drawing on insights into practice, skilled behaviour and learning systems from Lave, Wenger, Schon, Varela, Ison and Russell, among others. The relevance of various action research approaches for learning about learning as systemic practice is discussed. The paper finishes by identifying and exploring three focuses, that seem both challenging and important to the author to take account of as the research progresses. They are the needs for (i) systemic praxis (ii) an awareness of distinctions made by those who participate in the process of inquiry and (iii) using an approach with an epistemological dimension

Method and Apparatus for Powered Descent Guidance

A method and apparatus for landing a spacecraft having thrusters with non-convex constraints is described. The method first computes a solution to a minimum error landing problem for a convexified constraints, then applies that solution to a minimum fuel landing problem for convexified constraints. The result is a solution that is a minimum error and minimum fuel solution that is also a feasible solution to the analogous system with non-convex thruster constraints

List Decoding of Matrix-Product Codes from nested codes: an application to Quasi-Cyclic codes

A list decoding algorithm for matrix-product codes is provided when $C_1,..., C_s$ are nested linear codes and $A$ is a non-singular by columns matrix. We estimate the probability of getting more than one codeword as output when the constituent codes are Reed-Solomon codes. We extend this list decoding algorithm for matrix-product codes with polynomial units, which are quasi-cyclic codes. Furthermore, it allows us to consider unique decoding for matrix-product codes with polynomial units

Gender and educational leadership in England: a comparison of secondary headteachers' views over time

In the context of gender being a barrier to accessing leadership, this paper presents a comparison of the views of men and women head teacher (principals) of secondary schools in England in the 1990s and in 2004. The same survey instrument was used on both occasions. The perceptions of the head teachers show change in some areas and no change in others. Overall, women are more likely to become head teachers and are now less likely to be categorised into pastoral roles, but in some cases women still meet prejudice from governors and others in the wider community. Women head teachers are more likely to have partners and children than in the 1990s, sharing equally or carrying most of the domestic responsibilities, whereas male colleagues are most likely to have partners who take the majority of responsibility in the home. Essentialist stereotypes about women and men as leaders still prevail, although both the women and men head teachers see themselves as adopting a traditionally ‘feminine’ style of leadership. Women head teachers are likely to see some benefits in being a woman in a role stereotypically associated with men. However, there has been an increase in the proportion of women who feel that they have to prove their worth as a leader, and this may be linked with increased levels of accountability in schools

Simulations of Transient Membrane Behavior in Cells Subjected to a High-Intensity Ultrashort Electric Pulse

A molecular dynamics (MD) scheme is combined with a distributed circuit model for a self-consistent analysis of the transient membrane response for cells subjected to an ultrashort (nanosecond) high-intensity (approximately 0.01-V/nm spatially averaged field) voltage pulse. The dynamical, stochastic, many-body aspects are treated at the molecular level by resorting to a course-grained representation of the membrane lipid molecules. Coupling the Smoluchowski equation to the distributed electrical model for current flow provides the time-dependent transmembrane fields for the MD simulations. A good match between the simulation results and available experimental data is obtained. Predictions include pore formation times of about 5-6 ns. It is also shown that the pore formation process would tend to begin from the anodic side of an electrically stressed membrane. Furthermore, the present simulations demonstrate that ions could facilitate pore formation. This could be of practical importance and have direct relevance to the recent observations of calcium release from the endoplasmic reticulum in cells subjected to such ultrashort, high-intensity pulses

Variation for potassium and sodium accumulation in a family from a cross between grapevine rootstocks K 51-40 and 140 Ruggeri

The variation in potassium (K+) and sodium (Na+) accumulation was investigated between 60 hybrids within a family obtained by crossing grapevine rootstocks K 51-40 (Vitis champinii 'Dogridge' × V. riparia 'Gloire', seed parent) with 140 Ruggeri (V. cinerea var. helleri 'Resseguier #2' × V. rupestris'St. George', pollen parent), which are known to result in higher and lower concentrations of K+, respectively, but similar concentrations of Na+, in grape juice and resultant wine from scions grafted to them. The hybrids, their parents and two standard rootstocks, Ramsey (V. champinii 'Ramsey') and 1103 Paulsen (V. cinerea var. helleri 'Resseguier #2' x V. rupestris'St. George') were replicated by clonal propagation and grown under glasshouse conditions either in potting mix, drip-irrigated with a nutrient solution containing 50, 1.7 and 30 mM Cl-, K+ and Na+, respectively, or in aerated nutrient solution containing 25, 1.7 and 15 mM Cl-, K+ and Na+, respectively. In both pot and solution culture trials, there were significant (P < 0.001) differences between parents for mean K+ (but not Na+) concentrations, and between hybrids for mean K+ and Na+ concentrations in laminae. This variation between the hybrids was continuous, indicating multiple rather than single gene control for K+ and Na+ accumulation within the family. Differences among the hybrids for lamina K+ accumulation were not strongly associated with plant vigour. While the ranking of some hybrids for K+ and Na+ accumulation was consistent between the trials, others responded differently, suggesting the environment of the rootzone may affect the K+ and Na+ accumulation phenotype.

The TAMORA algorithm: satellite rainfall estimates over West Africa using multi-spectral SEVIRI data

A multi-spectral rainfall estimation algorithm has been developed for the Sahel region of West Africa with the purpose of producing accumulated rainfall estimates for drought monitoring and food security. Radar data were used to calibrate multi-channel SEVIRI data from MSG, and a probability of rainfall at several different rain-rates was established for each combination of SEVIRI radiances. Radar calibrations from both Europe (the SatPrecip algorithm) and Niger (TAMORA algorithm) were used. 10 day estimates were accumulated from SatPrecip and TAMORA and compared with kriged gauge data and TAMSAT satellite rainfall estimates over West Africa. SatPrecip was found to produce large overestimates for the region, probably because of its non-local calibration. TAMORA was negatively biased for areas of West Africa with relatively high rainfall, but its skill was comparable to TAMSAT for the low-rainfall region climatologically similar to its calibration area around Niamey. These results confirm the high importance of local calibration for satellite-derived rainfall estimates. As TAMORA shows no improvement in skill over TAMSAT for dekadal estimates, the extra cloud-microphysical information provided by multi-spectral data may not be useful in determining rainfall accumulations at a ten day timescale. Work is ongoing to determine whether it shows improved accuracy at shorter timescales