Robust identification from band-limited data

Consider the problem of identifying a scalar bounded-input/bounded-output stable transfer function from pointwise measurements at frequencies within a bandwidth. We propose an algorithm which consists of building a sequence of maps from data to models converging uniformly to the transfer function on the bandwidth when the number of measurements goes to infinity, the noise level to zero, and asymptotically meeting some gauge constraint outside. Error bounds are derived, and the procedure is illustrated by numerical experiment

Optimizing data collection for public health decisions: a data mining approach

Background: Collecting data can be cumbersome and expensive. Lack of relevant, accurate and timely data for research to inform policy may negatively impact public health. The aim of this study was to test if the careful removal of items from two community nutrition surveys guided by a data mining technique called feature selection, can (a) identify a reduced dataset, while (b) not damaging the signal inside that data. Methods: The Nutrition Environment Measures Surveys for stores (NEMS-S) and restaurants (NEMS-R) were completed on 885 retail food outlets in two counties in West Virginia between May and November of 2011. A reduced dataset was identified for each outlet type using feature selection. Coefficients from linear regression modeling were used to weight items in the reduced datasets. Weighted item values were summed with the error term to compute reduced item survey scores. Scores produced by the full survey were compared to the reduced item scores using a Wilcoxon rank-sum test. Results: Feature selection identified 9 store and 16 restaurant survey items as significant predictors of the score produced from the full survey. The linear regression models built from the reduced feature sets had R2 values of 92% and 94% for restaurant and grocery store data, respectively. Conclusions: While there are many potentially important variables in any domain, the most useful set may only be a small subset. The use of feature selection in the initial phase of data collection to identify the most influential variables may be a useful tool to greatly reduce the amount of data needed thereby reducing cost

Readiness to change drinking behaviour among heavy-drinking university students in England

There is growing literature on possible ways of reducing alcohol consumption and alcohol-related harm among university students (Larimer and Cronce, 2002; Siegers and Carey, 2010). However, interventions with this aim might be made more effective by information on students’ readiness to change their drinking behaviour (Carey et al., 2007a), where an assessment of readiness to change might influence the kind of approach that is thought most likely to be successful. For example, it has been found that readiness to change moderated the effects of a brief intervention among heavy-drinking students (either brief motivational intervention or alcohol expectancy challenge) such that high readiness to change made an expectancy challenge relatively more effective in reducing drinking (Capone and Wood, 2009). This study also reported an association between higher readiness to change and greater reductions in alcohol consumption in the overall sample, thus supporting previous findings (Fromme and Corbin, 2004; Carey et al., 2007b). Although high readiness to change may increase the chances of successful brief intervention among heavy-drinking students, it has been found that, even among individuals referred to a university-based alcohol intervention programme, there was limited acknowledgement of a drinking problem or interest in changing behaviour (Caldwell, 2002; Vik et al., 2000). Such research has been conducted mainly in the USA and, with the exception of one study (Hosier, 2001), it is unknown whether a comparable lack of concern about heavy drinking is true of students in England. Moreover, there is limited understanding of the different factors associated with, and predictive of, readiness to change in heavy-drinking students. The aims of this paper are therefore (i) to assess levels of readiness to change among heavy-drinking students at universities in England, (ii) to identify variables predictive of readiness to change among heavy-drinking students and (iii) to generate hypotheses that could be tested in further research

Beyond the ‘Tomlinson Trap’: analysing the effectiveness of section 1 of the Compensation Act 2006

One of the intentions underpinning section 1 of the Compensation Act 2006 was to provide reassurance to individual volunteers, and voluntary organisations, involved in what the provision called ‘desirable activities’ and including sport. The perception was that such volunteers, motivated by an apprehension about their increased vulnerability to negligence liability, and as driven by a fear of a wider societal compensation culture, were engaging excessively in risk-averse behaviour to the detriment of such socially desirable activities. Academic commentary on section 1 of the Compensation Act 2006 has largely regarded the provision as unnecessary and doing little more than restating existing common law practice. This article argues otherwise and, on critically reviewing the emerging jurisprudence, posits the alternative view that section 1, in practice, affords an enhanced level of protection and safeguarding for individuals undertaking functions in connection with a desirable activity. Nonetheless, the occasionally idiosyncratic judicial interpretation given to term ‘desirable activity’, potentially compounded by recent enactment of the Social Action, Responsibility and Heroism Act 2015, remains problematic. Two points of interest will be used to inform this debate. First, an analysis of the then House of Lords’ decision in Tomlinson and its celebrated ‘balancing exercise’ when assessing reasonableness in the context of negligence liability. Second, a fuller analysis of the application of section 1 in the specific context of negligence actions relating to the coaching of sport where it is argued that the, albeit limited, jurisprudence might support the practical utility of a heightened evidential threshold of gross negligence

Development of a yeast model to study the contribution of vacuolar polyphosphate metabolism to lysine polyphosphorylation

A recently discovered protein post-translational modification, lysine polyphosphorylation (K-PPn), consists of the covalent attachment of inorganic polyphosphate (polyP) to lysine residues. The non-enzymatic nature of K-PPn means that the degree of this modification depends on both polyP abundance and the amino acids surrounding the modified lysine. K-PPn was originally discovered in budding yeast (Saccharomyces cerevisiae), in which polyP anabolism and catabolism are well characterized. However, yeast vacuoles accumulate large amounts of polyP, and upon cell lysis, the release of the vacuolar polyP could non-physiologically cause K-PPn of nuclear and cytosolic targets. Moreover, yeast vacuoles possess two very active endopolyphosphatases, Ppn1 and Ppn2, that could have opposing effects on the extent of K-PPn. Here, we characterized the contribution of vacuolar polyP metabolism to K-PPn of two yeast proteins, Top1 (DNA topoisomerase 1) and Nsr1 (nuclear signal recognition 1). We discovered that whereas Top1-targeting K-PPn is only marginally affected by vacuolar polyP metabolism, Nsr1-targeting K-PPn is highly sensitive to the release of polyP and of endopolyphosphatases from the vacuole. Therefore, to better study K-PPn of cytosolic and nuclear targets, we constructed a yeast strain devoid of vacuolar polyP by targeting the exopolyphosphatase Ppx1 to the vacuole and concomitantly depleting the two endopolyphosphatases (ppn1Δppn2Δ, vt-Ppx1). This strain enabled us to study K-PPn of cytosolic and nuclear targets without the interfering effects of cell lysis on vacuole polyP and of endopolyphosphatases. Furthermore, we also define the fundamental nature of the acidic amino acid residues to the K-PPn target domain

Robust identification in the disc algebra from band-limited data

We consider the problem of identifying a scalar BIBO-stable transfer function from a series of experimental pointwise measurements at a set of frequencies lying within the bandwidth. To this end, we propose an algorithm which consists in building a sequence of maps from data to BIBO-stable models which uniformly converges to the seeked transfer function on the bandwidth when the number of measurements goes to infinity and the noise level goes to zero, while asymptotically meeting some gauge constraint outside. Error bounds are derived for this approximation scheme which is also illustrated by numerical experiments

Coherence between text comments and the quantitative ratings in the UK’s National Student Survey

© 2015 UCU Institutions are understandably interested in the profile of their own reputations based upon publicly available data about student experiences. The UK’s National Student Survey (NSS) metrics are integrated into several ‘Good University’ calculations, whereas teaching teams most often use the survey’s text comments to change practices, rather than the metrics directly. There is little information about how messages from the national survey’s text comments relate to the accompanying numerical ratings, partly because text comments are confidential to the institution and unavailable for wide-scale research. We categorised institutional NSS text comments into themes that mirrored those of the original questionnaire. Comparisons were made between frequencies of thematic comments and the national ratings of satisfaction for several subject areas. For the first time, we demonstrate broad agreement between comments about measures of teaching staff and course organisation with the performance of the subject areas (compared to metrics of their national counterparts). These findings are consistent with previous quantitative models predicting the most important factors that most influence overall satisfaction ratings. We intend this study to be a catalyst for other institutions to explore their non-publicly available, textual returns in a similar way. The outcomes of this type of work are pertinent to all countries that use large-scale surveys. However, institutions will need to release findings to a public audience if we are to gain a national/international perspective on this key linkage between publicly available metrics and the associated text comments

Sports coaching and the law of negligence: implications for coaching practice

The ordinary principles of the law of negligence are applicable in the context of sport, including claims brought against volunteer and professional coaches. Adopting the perspective of the coach, this article intends to raise awareness of the emerging intersection between the law of negligence and sports coaching, by utilising an interdisciplinary analysis designed to better safeguard and reassure coaches mindful of legal liability. Detailed scrutiny of two cases concerning alleged negligent coaching, with complementary discussion of some of the ethical dilemmas facing modern coaches, reinforces the legal duty and obligation of all coaches to adopt objectively reasonable and justifiable coaching practices when interacting with athletes. Problematically, since research suggests that some coaching practice may be underpinned by ‘entrenched legitimacy’ and ‘uncritical inertia’, it is argued that coach education and training should place a greater emphasis on developing a coach’s awareness and understanding of the evolving legal context in which they discharge the duty of care incumbent upon them

P145 Safety of colchicine or NSAID prophylaxis when initiating allopurinol for gout: propensity score-matched cohort studies

Abstract Background/Aims Initiating urate-lowering therapy for gout commonly triggers a gout flare and hence co-prescription of colchicine or non-steroidal anti-inflammatory drug (NSAID) prophylaxis is recommended. However, little is known about the incidence of adverse events associated with prophylaxis. We aimed to determine the risk of adverse events severe enough to warrant seeking healthcare associated with colchicine or NSAID prophylaxis when initiating allopurinol for gout. Methods We conducted two matched retrospective cohort studies, using linked data from the Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) datasets. Adults aged ≥18 years with a Read code for gout and a new allopurinol prescription between 1997 and 2016 were identified. We compared those prescribed (1) colchicine or (2) NSAID prophylaxis with those prescribed no prophylaxis, individually matched by age, sex and propensity to receive prophylaxis, to reduce the impact of confounding by indication. Adverse events were identified in CPRD and HES using Read and ICD10 codes respectively. Associations between colchicine or NSAID prophylaxis and the first occurrence of each outcome were investigated using weighted Cox proportional hazards models. CPRD Gold and Aurum datasets were analysed separately and then combined using 2-stage individual patient data meta-analysis. Results 13,945 individuals who initiated allopurinol with colchicine prophylaxis were matched to 13,945 who initiated without prophylaxis (mean age 63.62 years [95%CI 63.54, 63.70]; 78% male). Diarrhoea was the most common adverse event in the colchicine group, followed by nausea/vomiting, myocardial infarction (MI), neuropathy, myalgia, and bone marrow suppression (Table). Diarrhoea, MI, neuropathy, myalgia, and bone marrow suppression were significantly more common with colchicine prophylaxis compared with no prophylaxis. 22,880 individuals who initiated allopurinol with NSAID prophylaxis were matched to 22,880 who initiated without prophylaxis (mean age 63.34 years [95%CI 63.26, 63.42]; 78% male). Angina, acute kidney injury, MI, and peptic ulcer disease were significantly more common with NSAID prophylaxis than without (Table). Conclusion Gastrointestinal, cardiorenal, myoneuropathic, and haematological adverse events were associated with prophylaxis, although absolute event rates were low. This information can inform treatment decisions and choice of colchicine or NSAID for prophylaxis when initiating allopurinol. Disclosure E. Roddy: None. R. Bajpai: None. H. Forrester: None. R. Partington: None. C.D. Mallen: Grants/research support; Keele University School Of Medicine has received funding from BMS to support a non-pharmacological atrial fibrillation screening study. L. Clarson: None. N. Padmanabhan: None. R. Whittle: None. S. Muller: None. </jats:sec

Tracheal Replacement Therapy with a Stem Cell-Seeded Graft: Lessons from Compassionate Use Application of a GMP-Compliant Tissue-Engineered Medicine

Tracheal replacement for the treatment of end-stage airway disease remains an elusive goal. The use of tissue-engineered tracheae in compassionate use cases suggests that such an approach is a viable option. Here, a stem cell-seeded, decellularized tissue-engineered tracheal graft was used on a compassionate basis for a girl with critical tracheal stenosis after conventional reconstructive techniques failed. The graft represents the first cell-seeded tracheal graft manufactured to full good manufacturing practice (GMP) standards. We report important preclinical and clinical data from the case, which ended in the death of the recipient. Early results were encouraging, but an acute event, hypothesized to be an intrathoracic bleed, caused sudden airway obstruction 3 weeks post-transplantation, resulting in her death. We detail the clinical events and identify areas of priority to improve future grafts. In particular, we advocate the use of stents during the first few months post-implantation. The negative outcome of this case highlights the inherent difficulties in clinical translation where preclinical in vivo models cannot replicate complex clinical scenarios that are encountered. The practical difficulties in delivering GMP grafts underscore the need to refine protocols for phase I clinical trials