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Playing with AVATAR
No full textModern first-order resolution and superposition theorem provers use saturation algorithms to search for a refutation in clauses derivable from the input clauses. On hard problems, this search space often grows rapidly and performance degrades especially fast when long and heavy clauses are generated. One approach that has proved successful in taming the search space is splitting where clauses are split into components with disjoint variables and the components are asserted in turn. This reduces the length and weight of clauses in the search space at the cost of keeping track of splitting decisions.This paper considers the new AVATAR (Advanced Vampire Architecture for Theories And Resolution) approach to splitting which places a SAT (or SMT) solver at the centre of the theorem prover and uses it to direct the exploration of the search space. Using such an approach also allows the propositional part of the search space to be dealt with outside of the first-order prover.AVATAR has proved very successful, especially for problems coming from applications such as program verification and program analysis as these commonly contain clauses suitable for splitting. However, AVATAR is still a new idea and there is much left to understand. This paper presents an in-depth exploration of this new architecture, introducing new, highly experimental, options that allow us to vary the operation and interaction of the various components. It then extensively evaluates these new options, using the TPTP library, to gain an insight into which of these options are essential and how AVATAR can be optimally applied
An examination of the SEP candidate analogical inference rule within pure inductive logic
No full textWithin the framework of (Unary) Pure Inductive Logic we investigate four possible formulations of a probabilistic principle of analogy based on a template considered by Paul Bartha in the Stanford Encyclopedia of Philosophy [1] and give some characterizations of the probability functions which satisfy them. In addition we investigate an alternative interpretation of analogical support, also considered by Bartha, based not on the enhancement of probability but on the creation of possibility
Structural aspects of metal-organic framework-based energy materials research at Diamond
No full textLarge-scale central facilities such as Diamond Light Source fulfil an increasingly pivotal role in many large-scale scientific research programmes. We illustrate these developments by reference to energy-centred projects at the University of Nottingham, the progress of which depends crucially on access to these facilities. Continuing access to beamtime has now become a major priority for those who direct such programmes
Unified framework for spectral efficiency analysis of AF relay system
No full textThis paper presents new framework for spectral efficiency expression, that include unified interference analysis for two-hop fixed-gain amplify-and-forward relay systems. Utilizing Jensen inequality, the novel spectral efficiency expression enable us to accurately model various interference distributions at the relay and at the destination, together with the effect of noise, in a single unified equation. The framework enable tractable analytical interference analyses, that either based on the non-random interferers location or based on the random distribution of interferers distributed according to Poisson point process; by using moment generating function of the interferers. This method simplify the analysis of AF relay system in upcoming cellular systems and in heterogeneous communication systems. Simulations and analytical results are provided
Evaluation of the efficacy of a Kv3 ion channel modulator in the acute ketamine-challenge model of psychosis using pharmacological challenge functional MRI.
No full textPoster Ref: P2-F-026 Theme: F: Nervous System Disorders Evaluation of the efficacy of a Kv3 ion channel modulator in the acute ketamine-challenge model of psychosis using pharmacological challenge functional MRI. Samaneh Maysami⁽¹⁾, Shane McKie⁽²⁾, Giuseppe Alvaro⁽³⁾, Charles Large⁽⁴⁾ and Steve Williams⁽¹⁾ ¹Centre for Imaging Science, University of Manchester, ²Neuroscience and Psychiatry Unit, University of Manchester, ³Autifony SRL, 37135, Verona Italy, ⁴Autifony Therapeutics Ltd, Imperial Incubator, Imperial College London Introduction: Schizophrenia presents with both cognitive and so cial symptoms which can progress to functional deterioration and psychosis. The pathology of schizophrenia includes dysfunction of cortical networks with contribution from parvalbumin-positive (PV+) interneurons. Recently, brain Kv3 potassium channel mRNA & protein expression was found to be significantly reduced in untreated patients (1). Kv3 channels are primarily expressed by PV+ interneurons, thus reduced expression might contribute to their dysfunction and pharmacological modulation of the channels might be a means to treat disease. Here we examine the ability of AUT9, a novel selective modulator of Kv3.1 and Kv3.2 ion channels to prevent the characteristic alterations in brain function induced by low dose ketamine in rat. Methods: We used an EPI sequence (TE/TR:15/3000ms) to acquire pharmacological-challenge fMRI (phMRI) images exploiting blood oxygenation level dependent (BOLD) contrast in a ketamine model of acute psychosis in male Sprague Dawley rats. Anaesthesia was induced with isofluorane (1.5%), maintained with α-chloralose (30-50mg/kg) and baseline scans were collected for ≥10min. Following an injection of AUT9 (60mg/kg, ip) or vehicle, animals were scanned for an additional 30min. They then received ketamine (30mg/kg, sc) and BOLD imaging was continued for 30min. All animals were monitored for vital signs (body temperature, respiratory rate, blood gasses, pH & glucose). phMRI scans were analysed using SPM8. Results: Ketamine significantly changed BOLD signal in the prefrontal and parietal cortices, striatum, hippocampus and para-hippocampal regions as described previously (2). Pre-administration of AUT9 significantly reduced the ketamine mediated BOLD changes in cortices and striatum. AUT9 did not cause changes in BOLD signal on its own when compared to vehicle. Conclusion: Using BOLD phMRI and an acute model of psychosis, we have shown that modulation of Kv3 channels might be a useful novel approach for the treatment of schizophrenia. (1)-Yanagi, M., et al. Mol Psychiatry 19, 573 (2014) (2)-Hodkinson, D.J., et al. Br J Med Med Res 2, 373 (2012)
Improving oral hygiene for patients.
No full textSystematic reviews and patient safety initiatives recommend that oral hygiene should be part of routine patient care. However, evidence suggests it is often neglected in hospitals and care homes. Research recommends encouraging beliefs that support oral hygiene, and teaching nurses appropriate skills, as necessary prerequisites to implementing best practice in hospital wards. This article describes a pilot study of an educational workshop on oral hygiene. Results from the pilot study suggest that this workshop is a feasible intervention for a service-wide trial. The literature suggests that other interventions are required to complement this approach if nurses are to make oral hygiene a priority in daily patient care
Cognitive-behavioural features of progressive supranuclear palsy syndrome overlap with frontotemporal dementia.
No full textCognitive impairment is common in patients with the neurodegenerative tauopathy progressive supranuclear palsy (PSP). Although a pattern of 'subcortical' cognitive impairment is considered prototypical in PSP, pathological and clinical observations suggest an overlap with frontotemporal dementia (FTD). Our objective was to evaluate behavioural and cognitive symptoms in a retrospective study of patients with PSP syndrome (PSPS) and their relationship to features seen in behavioural variant FTD. We reviewed the records of 62 patients (29 male, 33 female, median age 65.5 years) evaluated at a tertiary cognitive clinic who met NINDS-SPSP criteria for probable or possible PSP, and collected clinical details of their presenting history, cognitive and behavioural features. We also evaluated the proportion of patients fulfilling FTD Consensus criteria. Cognitive and behavioural symptoms were a predominant presenting feature in 58 % of patients evaluated. Cognitive slowing, executive impairments, and inefficient memory recall, consistent with 'subcortical' impairment, were identified in the majority of patients. Twenty patients (32 %) fulfilled cognitive and behavioural criteria for possible FTD at initial assessment, whereas behavioural changes not meeting formal diagnostic criteria were present in a greater proportion of the patients. Our findings support the existence of a spectrum of cognitive-behavioural features in PSPS, with significant clinical overlap with behavioural variant FTD. Cognitive and behavioural profiling should be an integral part of the assessment of patients with PSPS
