Can Control Hierarchies be Developed and Optimised Progressively?

Hierarchical structures are used in robots to achieve effective results in control problems. Hierarchical structures are found in a wide array of applications of AI and robotics, making them a key aspect of control. Even though they hold an integral part in control, such structures are typically produced heuristically, resulting in inconsistent performance. This means that effective control tasks or controllers perform poorly due to the hierarchy being badly defined, limiting what controllers can do. Complex control problems that require adaptive behaviour or autonomy remain challenging for control theorists, with complex problem domains making the heuristic process of producing complex hierarchies harder. It is evident that the heuristic process must have some form of procedure that could be turned into a methodology. By formalising or automating this process, control hierarchies can be produced with consistently effective results without relying on the heuristic production of a control engineer which can easily fail. This thesis proposes an algorithmic approach (inspired by Perceptual Control Theory) known as \ac{DOSA}. \ac{DOSA} produces heirarchies automatically using real world experience and the inputs the system has access to. This thesis shows that DOSA consistently reproduces effective hierarchies that exist in the literature, when billions of possible hierarchies were available. Furthermore, this thesis investigates the value of using hierarchies in general and their benefits in control problems. The computational complexity of hierarchies is compared, showing that while hierarchies do not have a computational advantage, the parameter optimisation procedure is aided greatly by hierarchical parameter optimisation. The thesis then proceeds to study th hierarchical optimisation of parameters and how hierarchies allow this process to be performed more consistently for better results, concluding that hierarchical parameter optimisation produces more consistent controllers that also transfer better to an unseen problem domain. Parameter optimisation is a challenge that also limits otherwise effective controllers and limits the use of larger structures in control. The research described in this thesis formalises the process of generating hierarchical controllers as well as hierarchically optimising them, providing a comprehensive methodology to automate the production of robust controllers for complex problems

Neighbourhood unemployment and other socio-demographic predictors of emergency hospitalisation for infectious intestinal disease in England: A longitudinal ecological study

BACKGROUND:Previous studies have observed that infectious intestinal disease (IID) related hospital admissions are higher in more deprived neighbourhoods. These studies have mainly focused on paediatric populations and are cross-sectional in nature. This study examines recent trends in emergency IID admission rates, and uses longitudinal methods to investigate the effects of unemployment (as a time varying measure of neighbourhood deprivation) and other socio-demographic characteristics on IID admissions for adults and children in England. METHODS:A longitudinal ecological analysis was performed using Hospital Episode Statistics on emergency hospitalisations for IID, collected over the time period 2012-17 across England. Analysis was conducted at the neighbourhood (Lower-layer Super Output Area) level for three age groups (0-14; 15-64; 65+ years). Mixed-effect Poisson regression models were used to assess the relationship between trends in neighbourhood unemployment and emergency IID admission rates, whilst controlling for measures of primary and secondary care access, underlying morbidity and the ethnic composition of each neighbourhood. RESULTS:From 2012-17, declining trends in emergency IID admission rates were observed for children and older adults overall, while rates increased for some sub-groups in the population. Each 1 percentage point increase in unemployment was associated with a 6.3, 2.4 and 4% increase in the rate of IID admissions per year for children [IRR=1.06, 95%CI 1.06-1.07], adults [IRR=1.02, 95%CI 1.02-1.03] and older adults [IRR=1.04, 95%CI 1.036-1.043], respectively. Increases in poor primary care access, the percentage of people from a Pakistani ethnic background, and the prevalence of long-term health problems, in a neighbourhood, were also associated with increases in IID admission rates. CONCLUSIONS:Increasing trends in neighbourhood deprivation, as measured by unemployment, were associated with increases in emergency IID admission rates for children and adults in England, despite controlling for measures of healthcare access, underlying morbidity and ethnicity. Research is needed to improve understanding of the mechanisms that explain these inequalities, so that effective policies can be developed to reduce the higher emergency IID admission rates experienced by more disadvantaged communities

Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions

We describe a measurement of the charge asymmetry of leptons from W boson decays in the rapidity range 0 enu, munu events from 110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The asymmetry data constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry predictions that use parton distribution functions obtained from previously published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur

Social patterning of telephone health-advice for diarrhoea and vomiting: analysis of 24 million telehealth calls in England.

OBJECTIVES:Gastrointestinal (GI) infections are common and most people do not see a physician. There is conflicting evidence of the impact of socioeconomic status (SES) on risk of GI infections. We assessed the relationship between SES and GI calls to two National Health Service (NHS) telephone advice services in England. METHODS:Over 24 million calls to NHS Direct (2010-13) and NHS 111 (2013-15) were extracted from Public Health England (PHE) syndromic surveillance systems. The relationship between SES and GI calls was assessed using generalised linear models (GLM). RESULTS:Adjusting for rurality and age-sex interactions, in NHS Direct, children in disadvantaged areas were at lower risk of GI calls; in NHS 111 there was a higher risk of GI calls in disadvantaged areas for all ages (0-4 years RR 1.27, 95% CI 1.25-1.29; 5-9 years RR 1.43, 95% CI 1.36-1.51; 10-14 years RR 1.36, 95% CI 1.26-1.41; 15-19 years RR 1.59, 95% CI 1.52-1.67; 20-59 years RR 1.50, 95% CI 1.47-1.53, 60 years and over RR 1.12, 95% CI 1.09-1.14). CONCLUSIONS:Disadvantaged areas had higher risk of GI calls in NHS 111. This may relate to differences in exposure or vulnerability to GI infections, or propensity to call about GI infections

Involvement of the Cytokine MIF in the Snail Host Immune Response to the Parasite Schistosoma mansoni

We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions

Species Delimitation in Taxonomically Difficult Fungi: The Case of Hymenogaster

False truffles are ecologically important as mycorrhizal partners of trees and evolutionarily highly interesting as the result of a shift from epigeous mushroom-like to underground fruiting bodies. Since its first description by Vittadini in 1831, inappropriate species concepts in the highly diverse false truffle genus Hymenogaster has led to continued confusion, caused by a large variety of prevailing taxonomical opinions.In this study, we reconsidered the species delimitations in Hymenogaster based on a comprehensive collection of Central European taxa comprising more than 140 fruiting bodies from 20 years of field work. The ITS rDNA sequence dataset was subjected to phylogenetic analysis as well as clustering optimization using OPTSIL software.Among distinct species concepts from the literature used to create reference partitions for clustering optimization, the broadest concept resulted in the highest agreement with the ITS data. Our results indicate a highly variable morphology of H. citrinus and H. griseus, most likely linked to environmental influences on the phenology (maturity, habitat, soil type and growing season). In particular, taxa described in the 19(th) century frequently appear as conspecific. Conversely, H. niveus appears as species complex comprising seven cryptic species with almost identical macro- and micromorphology. H. intermedius and H. huthii are described as novel species, each of which with a distinct morphology intermediate between two species complexes. A revised taxonomy for one of the most taxonomically difficult genera of Basidiomycetes is proposed, including an updated identification key. The (semi-)automated selection among species concepts used here is of importance for the revision of taxonomically problematic organism groups in general

Measurement of the Inclusive Jet Cross Section in pˉp{\bar p p} collisions at s=1.8\sqrt{s}=1.8 TeV

We present results from the measurement of the inclusive jet cross section for jet transverse energies from 40 to 465 GeV in the pseudo-rapidity range $0.1<|\eta|<0.7$. The results are based on 87 $pb^{-1}$ of data collected by the CDF collaboration at the Fermilab Tevatron Collider. The data are consistent with previously published results. The data are also consistent with QCD predictions given the flexibility allowed from current knowledge of the proton parton distributions. We develop a new procedure for ranking the agreement of the parton distributions with data and find that the data are best described by QCD predictions using the parton distribution functions which have a large gluon contribution at high $E_T$ (CTEQ4HJ).Comment: 123 pages, 46 figure