Developing leaders of change in inner-London sixth form colleges

There is an increasing focus on developing leaders in the further education sector both to improve the experience of students in the sector and to prepare the next generation of leaders. The case study that follows was an investigation of a series of internally run, action learning based leadership development programmes which took place in an inner- London borough in different organisations over a period of years. It was assumed that leadership in sixth form colleges is leadership of academic change to respond to external pressures or to improve teaching and learning practice. Although leadership programmes have to engage with a continually changing neo-liberal, instrumentalist, national educational environment, there is here a further assumption that there is a local dimension to the challenges of leadership in further education and that inner-London with its diversity, social deprivation and cultural richness offers a specific leadership challenge and focus for academic change The research argues that organisations should indeed undertake appropriately designed collaborative action learning programmes, focused on leadership and institutional improvement because they can have a positive impact on the experience of staff and students, make tacit knowledge and understanding explicit and prepare for succession in the sector. These programmes need to be informed by a moral and political vision focused on a broader understanding of the educational needs of students than the current neo-liberal agenda offers. It is also suggested that leadership programmes should be available to all staff not just to middle and senior managers. It is claimed that the ingredients of leadership programmes are successful in a far as they stimulate reflection, make tacit understanding explicit and are taught using active teaching methods which mirror how teachers are expected to engage with their students in the classroom. Coaching is seen as a useful professional development to support this process especially if balanced by a clearly articulated creation of professional, learning communities both within and between organisations. These programmes are more effective if the process is accredited through partnerships with the university sector The ‘virtues’ of leadership it is argued from an Aristotelian perspective, cannot be taught but need to be developed through practice. Action research or research into practice properly understood and carried out is therefore believed to be an effective way to develop understanding of leadership when combined with the right theoretical ingredients. It is hoped that this research has proposed a model for developing leaders of academic change which is of interest not just in inner-London but in the sector in general

Mechanical properties and twin boundary drag in Fe-Pd ferromagnetic shape memory foils-experiments and ab initio modeling

We report on vibrating reed measurements combined with density functional theory-based calculations to assess the elastic and damping properties of Fe-Pd ferromagnetic shape memory alloy splats. While the austenite-martensite phase transformation is generally accompanied by lattice softening, a severe modulus defect and elevated damping behavior are characteristic of the martensitic state. We interpret the latter in terms of twin boundary motion between pinning defects via partial 'twinning' dislocations. Energy dissipation is governed by twin boundary drag, primarily due to lattice imperfections, as concluded from the temperature dependence of damping and related activation enthalpies

Stability borders of feedback control of delayed measured systems

When stabilization of unstable periodic orbits or fixed points by the method given by Ott, Grebogi and Yorke (OGY) has to be based on a measurement delayed by $\tau$ orbit lengths, the performance of unmodified OGY method is expected to decline. For experimental considerations, it is desired to know the range of stability with minimal knowledge of the system. We find that unmodified OGY control fails beyond a maximal Ljapunov number of $\lambda_{max}=1+\frac{1}{\tau}$. In this paper the area of stability is investigated both for OGY control of known fixed points and for difference control of unknown or inaccurately known fixed points. An estimated value of the control gain is given. Finally we outline what extensions have to be considered if one wants to stabilize fixed points with Ljapunov numbers above $\lambda_{max}$.Comment: 5 pages LaTeX using revtex and epsfig (4 figs included). Revised versio

A Geometric Tension Dynamics Model of Epithelial Convergent Extension

Epithelial tissue elongation by convergent extension is a key motif of animal morphogenesis. On a coarse scale, cell motion resembles laminar fluid flow; yet in contrast to a fluid, epithelial cells adhere to each other and maintain the tissue layer under actively generated internal tension. To resolve this apparent paradox, we formulate a model in which tissue flow occurs through adiabatic remodelling of the cellular force balance causing local cell rearrangement. We propose that the gradual shifting of the force balance is caused by positive feedback on myosin-generated cytoskeletal tension. Shifting force balance within a tension network causes active T1s oriented by the global anisotropy of tension. Rigidity of cells against shape changes converts the oriented internal rearrangements into net tissue deformation. Strikingly, we find that the total amount of tissue extension depends on the initial magnitude of anisotropy and on cellular packing order. T1s degrade this order so that tissue flow is self-limiting. We explain these findings by showing that coordination of T1s depends on coherence in local tension configurations, quantified by a certain order parameter in tension space. Our model reproduces the salient tissue- and cell-scale features of germ band elongation during Drosophila gastrulation, in particular the slowdown of tissue flow after approximately twofold extension concomitant with a loss of order in tension configurations. This suggests local cell geometry contains morphogenetic information and yields predictions testable in future experiments. Furthermore, our focus on defining biologically controlled active tension dynamics on the manifold of force-balanced states may provide a general approach to the description of morphogenetic flow.Comment: 44 pages, 19 figure

Disability Pension Rates Among Immigrants in Norway

Immigrants from low-income countries are more likely than ethnic Norwegians to receive disability pensions. In a previous study in Oslo, we showed that occupational position probably accounted for all of this difference. The present article presents a study of the total population, with data on education and age at receipt of pension. Census and social security data for all persons living in Norway from 1992 to 2003 were used to identify new disability pensions to those aged 30–55 years and eligible in 1992, comprising 15.9% females and 11.4% males. Age-adjusted relative risk was 2.03 (95% CI 1.97–2.08) for non-Western males and 1.30 (1.26–1.36) for non-Western females compared with Westerners, and more than three times higher for males from North Africa/the Middle East. Education did not explain any of the risk differences, but when adjusting for age at pension receipt the differences disappeared completely. This is probably due to their being in predominantly unskilled occupations where there is also a low pension age among ethnic Norwegians

Design of a CO2 heat pump drier with dynamic modelling tools

Drying is an energy and time intensive process which thermal energy demand is mostly provided by fossil resources. Especially in the food processing industry it is important to increase the energy efficiency of drying processes in terms of organic products and sustainability. The potential of using a heat pump with R744 (CO2) as a working media to provide the thermal energy was investigated for typical food drying temperature of 50 °C at a relative humidity of 20 %. A dynamic heat pumpassisted dryer model has been developed and validated. The model was created with respect to heat transfer, pressure loss and flow requirements. The simulated results showed that a closed-loop heat pump assisted drying process has the potential to reduce the energy demand by around 80 % compared to conventional open-loop drying processes with fossil resources as energy source. Furthermore, the implementation of a bypass in the air cycle was examined to further enhance the energy efficiency of the system

Effect of nitrogen limitation and soil biophysics on Holocene greening of the Sahara

The so-called Green Sahara (GS), which was a wet and vegetative Sahara region in the early to mid-Holocene, provides useful information on our climate simulation because it is a consequence of complex interaction between biophysical and climatic processes. It is still a challenge to simulate the GS in terms of vegetative extent and precipitation using current climate models. This study attempts to simulate the Green Sahara 8000 years ago by using the state-of-the-art Earth system model CESM that incorporates the nitrogen cycle and the soil–precipitation feedbacks. Our study puts more emphasis on the impact of soil biophysical properties (e.g., bare-soil albedo, porosity, heat capacity, and hydraulic conductivity) and soil nitrogen influenced by soil organic matter on the simulation of the GS. In this coupled simulation, vegetation interacts with changes in soil properties and soil organic matter by phenology, decomposition, and allocation of carbon and nitrogen. With changes in the Earth's orbit and dust in the early to mid-Holocene, the model simulates increased precipitation in North Africa but does not capture the extent of the GS. Our analysis shows that the Holocene greening is simulated better if the amount of soil nitrogen and soil texture is properly modified for the humid and vegetative GS period. Soil biochemical and physical properties increase precipitation and vegetation cover in North Africa through their influence on photosynthesis and surface albedo as well as their consequent enhanced albedo–precipitation and evapotranspiration–precipitation feedbacks. Our findings suggest that future climate simulation needs to consider consequent changes in soil nitrogen and texture with changes in vegetation cover and density for proper climate simulations

OH (1720 MHz) Masers: A Multiwavelength Study of the Interaction between the W51C Supernova Remnant and the W51B Star Forming Region

We present a comprehensive view of the W51B HII region complex and the W51C supernova remnant (SNR) using new radio observations from the VLA, VLBA, MERLIN, JCMT, and CSO along with archival data from Spitzer, ROSAT, ASCA, and Chandra. Our VLA data include the first 400 cm (74 MHz) continuum image of W51 at high resolution (88 arcsec). The 400 cm image shows non-thermal emission surrounding the G49.2-0.3 HII region, and a compact source of non-thermal emission (W51B_NT) coincident with the previously-identified OH (1720 MHz) maser spots, non-thermal 21 and 90 cm emission, and a hard X-ray source. W51B_NT falls within the region of high likelihood for the position of TeV gamma-ray emission. Using the VLBA three OH (1720 MHz) maser spots are detected in the vicinity of W51B_NT with sizes of 60 to 300 AU and Zeeman effect magnetic field strengths of 1.5 to 2.2 mG. The multiwavelength data demonstrate that the northern end of the W51B HII region complex has been partly enveloped by the advancing W51C SNR and this interaction explains the presence of W51B_NT and the OH masers. This interaction also appears in the thermal molecular gas which partially encircles W51B_NT and exhibits narrow pre-shock (DeltaV 5 km/s) and broad post-shock (DeltaV 20 km/s) velocity components. RADEX radiative transfer modeling of these two components yield physical conditions consistent with the passage of a non-dissociative C-type shock. Confirmation of the W51B/W51C interaction provides additional evidence in favor of this region being one of the best candidates for hadronic particle acceleration known thus far.Comment: Accepted to Ap

The Nature of the Nuclear H2O Masers of NGC 1068: Reverberation and Evidence for a Rotating Disk Geometry

We report new (1995) Very Large Array observations and (1984 - 1999) Effelsberg 100m monitoring observations of the 22 GHz H2O maser spectrum of the Seyfert 2 galaxy NGC 1068. The sensitive VLA observations provide a registration of the 22 GHz continuum emission and the location of the maser spots with an accuracy of ~ 5 mas. Within the monitoring data, we find evidence that the nuclear masers vary coherently on time-scales of months to years, much more rapidly than the dynamical time-scale. We argue that the nuclear masers are responding in reverberation to a central power source, presumably the central engine. Between October and November 1997, we detected a simultaneous flare of the blue-shifted and red-shifted satellite maser lines. Reverberation in a rotating disk naturally explains the simultaneous flaring. There is also evidence that near-infrared emission from dust grains associated with the maser disk also responds to the central engine. We present a model in which an X-ray flare results in both the loss of maser signal in 1990 and the peak of the near-infrared light curve in 1994. In support of a rotating disk geometry for the nuclear masers, we find no evidence for centripetal accelerations of the redshifted nuclear masers; the limits are +/- 0.006 km/s/year, implying that the masers are located within 2 degrees of the kinematic line-of-nodes. We also searched for high velocity maser emission like that observed in NGC 4258. In both VLA and Effelsberg spectra, we detect no high velocity lines between +/- 350 km/s to +/- 850 km/s relative to systemic, arguing that masers only lie outside a radius of ~ 0.6 pc (1.9 light years) from the central engine (assuming a distance of 14.4 Mpc).Comment: 62 pages, 19 figure