REFLECTIONS ON THE CHALLENGES OF HEADSHIP

I retired in April 2020 after 17 years as a Headteacher, serving four different schools across two local authorities. One thing that remained constant throughout this period was the privilege I felt being a school leader. I deliberately chose to work in challenging schools serving more deprived communities. I was driven by the belief that a high-quality education has the power to transform the life chances of young people, especially those from disadvantaged backgrounds.In this paper I reflect on my personal experience of government policy during this period and the impact it had on school leaders. In doing so, we will revisit two underpinning themes that featured throughout my headship career. The first was that education became part of the election battleground with each party developing their own ideas and thinking about the direction of education that, in turn, became policy for the successfully elected party. Successive Secretaries of State had their own view of what state education should look like. I have not always been convinced that all policy was based on educational theory and sometimes wonder if it derived from the minister’s own personal experience of education! Sir Kevan Collins describes this as the ‘Complacency of Certainty’ (2021) where ministers speak with authority on education without any substance or research to back it up. The impact this had on school leaders was to experience a see-saw effect as policies swung one way and then the other as governments and ministers changed. The second underpinning theme was the breakdown in trust between the government and the education profession. It is evident that this lack of trust in the system led to the growth of a command-and-control model whereby schools were compelled to follow government policy.To explore these themes, I will focus on three key areas of government policy that were intended to improve standards and reduce education inequality. First the rise of academisation under Tony Blair’s New Labour that accelerated with the Coalition government under David Cameron. Second the government policies designed to give parents far greater choice whilst also creating competition between schools. To this end, we will explore the two system changes that successive governments utilised to drive this culture of choice and competition starting with the high stakes accountability associated with examination results and then finally, reviewing my experience of the Ofsted process

Electrostatic interaction of myristoylated proteins with membranes: simple physics, complicated biology

AbstractCell membrane association by several important peripheral proteins, such as Src, MARCKS, HIV-1 Gag, and K-Ras, requires nonspecific electrostatic interactions between a cluster of basic residues on the protein and acidic phospholipids in the plasma membrane. A simple theoretical model based on the nonlinear Poisson–Boltzmann equation describes well the experimentally measured electrostatic association between such proteins and the cell membrane

Using Gaussian Processes to detect AGN flares

A key feature of active galactic nuclei (AGN) is their variability across all wavelengths. Typically, AGN vary by a few tenths of a magnitude or more over periods lasting from hours to years. By contrast, extreme variability of AGN -- large luminosity changes that are a significant departure from the baseline variability -- are known as AGN flares. These events are rare and their timescales poorly constrained, with most of the literature focusing on individual events. It has been suggested that extreme AGN variability including flares can provide insights into the accretion processes in the disk. With surveys such as the Legacy Survey of Space and Time (LSST) promising millions of transient detections per night in the coming decade, there is a need for fast and efficient classification of AGN flares. The problem with the systematic detection of AGN flares is the requirement to detect them against a stochastically variable baseline; the ability to define a signal as a significant departure from the ever-present variability is a statistical challenge. Recently, Gaussian Processes (GPs) have revolutionised the analysis of time-series data in many areas of astronomical research. They have, however, seen limited uptake within the field of transient detection and classification. Here we investigate the efficacy of Gaussian Processes to detect AGN flares in both simulated and real optical light curves. We show that GP analysis can successfully detect AGN flares with a false-positive rate of less than seven per cent, and we present examples of AGN light curves that show extreme variability.Comment: 14 pages, 25 figures, accepted for publication in MNRA

Dual role for phosphoinositides in regulation of yeast and mammalian phospholipase D enzymes

Phospholipase D (PLD) generates lipid signals that coordinate membrane trafficking with cellular signaling. PLD activity in vitro and in vivo is dependent on phosphoinositides with a vicinal 4,5-phosphate pair. Yeast and mammalian PLDs contain an NH2-terminal pleckstrin homology (PH) domain that has been speculated to specify both subcellular localization and regulation of PLD activity through interaction with phosphatidylinositol 4,5-bisphosphate (PI[4,5]P2). We report that mutation of the PH domains of yeast and mammalian PLD enzymes generates catalytically active PI(4,5)P2-regulated enzymes with impaired biological functions. Disruption of the PH domain of mammalian PLD2 results in relocalization of the protein from the PI(4,5)P2-containing plasma membrane to endosomes. As a result of this mislocalization, mutations within the PH domain render the protein unresponsive to activation in vivo. Furthermore, the integrity of the PH domain is vital for yeast PLD function in both meiosis and secretion. Binding of PLD2 to model membranes is enhanced by acidic phospholipids. Studies with PLD2-derived peptides suggest that this binding involves a previously identified polybasic motif that mediates activation of the enzyme by PI(4,5)P2. By comparison, the PLD2 PH domain binds PI(4,5)P2 with lower affinity but sufficient selectivity to function in concert with the polybasic motif to target the protein to PI(4,5)P2-rich membranes. Phosphoinositides therefore have a dual role in PLD regulation: membrane targeting mediated by the PH domain and stimulation of catalysis mediated by the polybasic motif