Quantifying simulator discrepancy in discrete-time dynamical simulators

When making predictions with complex simulators it can be important to quantify the various sources of uncertainty. Errors in the structural specification of the simulator, for example due to missing processes or incorrect mathematical specification, can be a major source of uncertainty, but are often ignored. We introduce a methodology for inferring the discrepancy between the simulator and the system in discrete-time dynamical simulators. We assume a structural form for the discrepancy function, and show how to infer the maximum likelihood parameter estimates using a particle filter embedded within a Monte Carlo expectation maximization (MCEM) algorithm. We illustrate the method on a conceptual rainfall runoff simulator (logSPM) used to model the Abercrombie catchment in Australia. We assess the simulator and discrepancy model on the basis of their predictive performance using proper scoring rules

Third City: Changing roles of performers and tools within electroacoustic improvisation

Ensemble improvisation can lead to different roles being taken by the performers as a result of, for example, performer temperament, the sound sources being used, and any pre-determined structures used. As an example of how these roles can be described, Walduck’s taxonomy results in the categories of solo, background, heckle, punctuation, counterpart, contrapart and block (1997, Role-taking in free improvisation and collaborative composition). Whilst in some cases the roles are established and maintained throughout a piece, in other cases they might suddenly switch or fluidly shift. Third City is an electroacoustic improvisation duo that uses loosely pre-determined structures applied to predetermined sound sources. For the most part, instrumental sound sources are triggered by Jon Aveyard with the resulting sound being sampled, processed and played back by Dan Wilkinson. The resulting pieces can be described as Cubist in the way that phrases are presented both unmediated and transformed, both in real time and in delay. This presentation offers examples of pieces from the Third City set to demonstrate the changing relationships between the performers; the way in which different sound sources facilitate these relationships; and the way in which musical parameters are managed within these relationships

Third City project

The subject of this collaboration between Dr. Jon Aveyard and Dan Wilkinson is the relationship between acoustic and digital musical instruments (DMIs) using live sampling in improvisation. This practice-based research took place in Preston, 2016-2018, leading to multiple performances, record releases, conference presentations and journal publication. The research is framed by a consideration of the affordances and limitations offered by acoustic and digital instruments as identified through literature review, particularly Magnusson and Hurtado Mendieta (2007). The Third City research argues that using different acoustic instruments and different audio paths to link the acoustic instrument and DMI leads to different improvisational roles being adopted by the performers, and that some of the perceived limitations of DMIs can be mitigated against through the use of live sampling. Furthermore, an acoustic-digital hybrid instrument was developed with which samples, when selected on the DMI, were only triggered when sounds from the acoustic instrument surpassed a given intensity meaning performer co-operation could lead to timbrally different but rhythmically synchronised musical events, acoustic and digital together. The research identified additional ways in which this hybridisation could overcome perceived limits of DMIs and that the hybrid made far more apparent in the performance the performers’ use of co-operation and blocking (i.e. a chosen absence of co-operation by one performer). The significance of the research, therefore, is in engaging with the implications of using acoustic and digital instruments linked by live sampling in improvisational performance practice, and in the development of an acoustic-digital hybrid whose need for performer co-operation to trigger samples adds to the perceivable performer dynamic

SUMOylation of FOXP1 regulates transcriptional repression via CtBP1 to drive dendritic morphogenesis

AbstractForkhead Box P (FOXP) transcriptional repressors play a major role in brain development and their dysfunction leads to human cognitive disorders. However, little is known about how the activity of these proteins is regulated. Here, we show that FOXP1 SUMOylation at lysine 670 is required for recruiting the co-repressor CtBP1 and transcriptional repression. FOXP1 SUMOylation is tightly controlled by neuronal activity, in which synapse to nucleus signalling, mediated via NMDAR and L-type calcium channels, results in rapid FOXP1 deSUMOylation. Knockdown of FOXP1 in cultured cortical neurons stunts dendritic outgrowth and this phenotype cannot be rescued by replacement with a non-SUMOylatable FOXP1-K670R mutant, indicating that SUMOylation of FOXP1 is essential for regulation of proper neuronal morphogenesis. These results suggest that activity-dependent SUMOylation of FOXP1 may be an important mediator of early cortical development and neuronal network formation in the brain.</jats:p

Improving household air quality: The neglected cultural dimension

Household air pollution is now recognized as the single largest environmental health risk factor worldwide contributing to the global burden of disease, with the World Health Organization (WHO) estimating that close to 4million people per year die prematurely as a result(1,2).This form of pollution is widespread in resource-poor countries mainly due to the use of biomass fuels, derived from crop residues, animal dung, wood or charcoal, as a source of household energy. It has been linked with an increased frequency of lower respiratory infection, cataract, ischemic stroke, hemorrhagic stroke, hypertension, ischemic heart disease and chronic obstructive pulmonary disease, as well as tracheal, bronchial and lung cancer (2). Vulnerable groups, such as the rural poor or women and children, appear to be disproportionately affected, the former as they are forced by economic circumstances to use more polluting fuel sources and the latter as a consequence of carrying out common domestic tasks such as cooking. The substantial disease burden and its propensity to affect vulnerable populations have led to its identification as a major target for intervention to improve global health and it is specifically mentioned in the current Sustainable Development Goals (Goal 3 –which recommends implementation of the WHO indoor air quality guidelines on household fuel combustion)

G254: USU student payload flown on STS-64 in September, 1994

G254 is the culmination of USU Get Away Special (GAS) students' efforts to get back into space. After a hiatus of a decade, the USU GAS program flew its sixth canister on STS-64 in September 1994. Like its predecessor payloads, this one contained a diverse set of experiments, six in all. Each experiment has its own lessons learned, which hopefully can be passed on to the next generation of GAS students. This presentation will give a balanced view of the successes and failures of G254. Emphasis will be placed on describing the stumbling blocks and the many lessons learned that come from experience rather than academic training. G254 has once again taken a team of about fifteen USU students, plus about one hundred fourth and fifth graders, and given them an immeasurable education

What is a galaxy? How Cold is Cold Dark Matter? Recent progress in Near Field Cosmology

There has been a vast recent improvement in photometric and kinematic data for star clusters, Ultra Compact dwarfs, galactic nuclei, and local dSph galaxies, with Subaru contributing substantially to the photometric studies in particular. These data show that there is a bimodal distribution in half-light radii, with stable star clusters always being smaller than 35pc, while stable galaxies are always larger than 120pc. We extend the previously known observational relationships and interpret them in terms of a more fundamental pair of intrinsic properties of dark matter itself: dark matter forms cored mass distributions, with a core scale length of greater than about 100pc, and always has a maximum central mass density with a narrow range. The dark matter in dSph galaxies appears to be clustered such that there is a mean volume mass density within the stellar distribution which has the very low value of about 0.1$M_{\odot}$ pc$^{-3}$. None of the dSphs displays kinematics which require the presence of an inner cusp, while in two dSphs there is evidence that the density profile is shallow (cored) in the inner regions. The maximum central dark matter density derived is model dependent, but is likely to have a mean value (averaged over a volume of radius 10pc) of about 0.1$M_{\odot}$ pc$^{-3}$, which is 5GeV/c$^2$cm$^{-3}$). Galaxies are embedded in dark matter halos with these properties; smaller systems containing dark matter are not observed.Comment: proceedings of The 1st Subaru International Conference, "Panoramic Views of Galaxy Formation and Evolution" (Hayama, Japan, 11-16 Dec 2007) ASP Conf se