On well-rounded sublattices of the hexagonal lattice

We produce an explicit parameterization of well-rounded sublattices of the hexagonal lattice in the plane, splitting them into similarity classes. We use this parameterization to study the number, the greatest minimal norm, and the highest signal-to-noise ratio of well-rounded sublattices of the hexagonal lattice of a fixed index. This investigation parallels earlier work by Bernstein, Sloane, and Wright where similar questions were addressed on the space of all sublattices of the hexagonal lattice. Our restriction is motivated by the importance of well-rounded lattices for discrete optimization problems. Finally, we also discuss the existence of a natural combinatorial structure on the set of similarity classes of well-rounded sublattices of the hexagonal lattice, induced by the action of a certain matrix monoid.Comment: 21 pages (minor correction to the proof of Lemma 2.1); to appear in Discrete Mathematic

Monitoring and detection of agitation in dementia: towards real-time and big-data solutions

The changing demographic profile of the population has potentially challenging social, geopolitical, and financial consequences for individuals, families, the wider society, and governments globally. The demographic change will result in a rapidly growing elderly population with healthcare implications which importantly include Alzheimer type conditions (a leading cause of dementia). Dementia requires long term care to manage the negative behavioral symptoms which are primarily exhibited in terms of agitation and aggression as the condition develops. This paper considers the nature of dementia along with the issues and challenges implicit in its management. The Behavioral and Psychological Symptoms of Dementia (BPSD) are introduced with factors (precursors) to the onset of agitation and aggression. Independent living is considered, health monitoring and implementation in context-aware decision-support systems is discussed with consideration of data analytics. Implicit in health monitoring are technical and ethical constraints, we briefly consider these constraints with the ability to generalize to a range of medical conditions. We postulate that health monitoring offers exciting potential opportunities however the challenges lie in the effective realization of independent assisted living while meeting the ethical challenges, achieving this remains an open research question remains.Peer ReviewedPostprint (author's final draft

Atypical antipsychotics in bipolar disorder: systematic review of randomised trials

Background: Atypical antipsychotics are increasingly used for treatment of mental illnesses like schizophrenia and bipolar disorder, and considered to have fewer extrapyramidal effects than older antipsychotics. Methods: We examined efficacy in randomised trials of bipolar disorder where the presenting episode was either depression, or manic/mixed, comparing atypical antipsychotic with placebo or active comparator, examined withdrawals for any cause, or due to lack of efficacy or adverse events, and combined all phases for adverse event analysis. Studies were found through systematic search (PubMed, EMBASE, Cochrane Library), and data combined for analysis where there was clinical homogeneity, with especial reference to trial duration. Results: In five trials (2,206 patients) participants presented with a depressive episode, and in 25 trials (6,174 patients) the presenting episode was manic or mixed. In 8-week studies presenting with depression, quetiapine and olanzapine produced significantly better rates of response and symptomatic remission than placebo, with NNTs of 5-6, but more adverse event withdrawals (NNH 12). With mania or mixed presentation atypical antipsychotics produced significantly better rates of response and symptomatic remission than placebo, with NNTs of about 5 up to six weeks, and 4 at 6-12 weeks, but more adverse event withdrawals (NNH of about 22) in studies of 6-12 weeks. In comparisons with established treatments, atypical antipsychotics had similar efficacy, but significantly fewer adverse event withdrawals (NNT to prevent one withdrawal about 10). In maintenance trials atypical antipsychotics had significantly fewer relapses to depression or mania than placebo or active comparator. In placebo-controlled trials, atypical antipsychotics were associated with higher rates of weight gain of ≥7% (mainly olanzapine trials), somnolence, and extrapyramidal symptoms. In active controlled trials, atypical antipsychotics were associated with lower rates of extrapyramidal symptoms, but had higher rates of weight gain and somnolence. Conclusion: Atypical antipsychotics are effective in treating both phases of bipolar disorder compared with placebo, and as effective as established drug therapies. Atypical antipsychotics produce fewer extrapyramidal symptoms, but weight gain is more common (with olanzapine). There is insufficient data confidently to distinguish between different atypical antipsychotics.© 2007 Derry and Moore; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Citation: Derry, S. & Moore, R. A. (2007). 'Atypical antipsychotics in bipolar disorder: systematic review of randomised trials', BMC Psychiatry, 7:40. [Available at http://www.biomedcentral.com/1471-244X/7/40]

Systematic review and meta-analysis of randomised trials and cohort studies of mycophenolate mofetil in lupus nephritis

Mycophenolate mofetil (MMF) is an immunosuppressant drug being used for induction and maintenance of remission of lupus nephritis in systemic lupus erythematosus. Evidence about its use was sought from full publications and abstracts of randomised trials and cohort studies by using a variety of search strategies. Efficacy and adverse event outcomes were sought. Five randomised trials enrolled patients with World Health Organization (WHO) class III, IV, or V (mostly IV) lupus nephritis, predominantly comparing MMF (1 to 3 g daily) with cyclophosphamide and steroid. Complete response and complete or partial response was significantly more frequent with MMF than with cyclophosphamide, with numbers needed to treat of 8 (95% confidence interval 4.3 to 60) to induce one additional complete or partial response, with wide confidence intervals. Death was reported less frequently with MMF (0.7%, 1 death in 152 patients) than with cyclophosphamide (7.8%, 12 deaths in 154 patients), with a number needed to treat to prevent (NNTp) one death of 14 (8 to 48). Hospital admission was also lower with MMF (1.7% versus 15%; NNTp 7.4 [4.8 to 16]). Serious infections, leucopaenia, amenorrhoea, and hair loss were all significantly less frequent with MMF than with cyclophosphamide, but diarrhoea was significantly more common with MMF. Ten of 18 cohort studies enrolled only patients with lupus nephritis (author-defined or WHO class III to V). Seven of these 10 reported that complete or partial response with MMF (mostly 1 or 2 g daily) with steroid occurred in 121/151 (80%) and that treatment failure or no response occurred in 30/151 (20%). Adverse events were generally similar in cohort studies with and without only patients with lupus nephritis. In all 18 cohorts, gastrointestinal adverse events (diarrhoea, nausea, vomiting) occurred in 30%, infection in 23%, and serious infection in 4.3%. Adverse event discontinuations occurred in 14% and lack of efficacy occurred in 10%. There was a single death with MMF, a mortality rate over the course of 1 year of approximately 0.2%. The results form a basis on which to plan future studies and provide a guide for the use of MMF in lupus nephritis until results of larger studies are available. At least one such study is under way

Deep-water observation of scalloped hammerhead Sphyrna lewini in the western Indian Ocean off Tanzania

A scalloped hammerhead Sphyrna lewini was observed opportunistically from a remotely operated vehicle 1 m off the seabed at 1042 m depth, during hydrocarbon exploration activities in the Ruvuma Basin off Tanzania. The observation, which occurred during night hours, is the deepest accurately recorded for this species and the first deep-water record for the Indian Ocean. The record adds support for the occurrence in deep water during night hours being a widespread and possibly common behaviour in this species, and further expands a small but growing literature that meso- and bathypelagic environments may be of greater importance to elasmobranchs previously considered to be primarily epipelagic

Prevalence of opioid adverse events in chronic non-malignant pain: systematic review of randomised trials of oral opioids

Adverse events of opioids may restrict their use in non-cancer pain. Analysis of the incidence of common adverse events in trials conducted in non-cancer pain has usually been limited to opioids used to treat severe pain according to the WHO three-step ladder. To examine the incidence of common adverse events of opioids in non-cancer pain, a systematic review and meta-analysis of information from randomised trials of all opioids in non-cancer pain was undertaken. Studies used were published randomised trials of oral opioid in non-cancer pain, with placebo or active comparator. Thirty-four trials with 5,546 patients were included with 4,212 patients contributing some information on opioid adverse events. Most opioids used (accounting for 90% of patients) were for treating moderate rather than severe pain. Including trials without a placebo increased the amount of information available by 1.4 times. Because of clinical heterogeneity in condition, opioid, opioid dose, duration, and use of titration, only broad results could be calculated. Use of any oral opioid produced higher rates of adverse events than did placebo. Dry mouth (affecting 25% of patients), nausea (21%), and constipation (15%) were the most common adverse events. A substantial proportion of patients on opioids (22%) withdrew because of adverse events. Because most trials were short, less than four weeks, and because few titrated the dose, these results have limited applicability to longer-term use of opioids in clinical practice. Suggestions for improved studies are made

5D Black Rings and 4D Black Holes

It has recently been shown that the M theory lift of a IIA 4D BPS Calabi-Yau black hole is a 5D BPS black hole spinning at the center of a Taub-NUT-flux geometries, and a certain linear relation between 4D and 5D BPS partition functions was accordingly proposed. In the present work we fortify and enrich this proposal by showing that the M-theory lift of the general 4D multi-black hole geometry are 5D black rings in a Taub-NUT-flux geometry.Comment: 8 pages; version 2, with additional references and explanation

Perceptual adaptation by normally hearing listeners to a simulated "hole" in hearing

Simulations of cochlear implants have demonstrated that the deleterious effects of a frequency misalignment between analysis bands and characteristic frequencies at basally shifted simulated electrode locations are significantly reduced with training. However, a distortion of frequency-to-place mapping may also arise due to a region of dysfunctional neurons that creates a "hole" in the tonotopic representation. This study simulated a 10 mm hole in the mid-frequency region. Noise-band processors were created with six output bands (three apical and three basal to the hole). The spectral information that would have been represented in the hole was either dropped or reassigned to bands on either side. Such reassignment preserves information but warps the place code, which may in itself impair performance. Normally hearing subjects received three hours of training in two reassignment conditions. Speech recognition improved considerably with training. Scores were much lower in a baseline (untrained) condition where information from the hole region was dropped. A second group of subjects trained in this dropped condition did show some improvement; however, scores after training were significantly lower than in the reassignment conditions. These results are consistent with the view that speech processors should present the most informative frequency range irrespective of frequency misalignment. 0 2006 Acoustical Society of America

Systematic reviews do not (yet) represent the ‘gold standard’ of evidence: a position paper

The low quality of included trials, insufficient rigour in review methodology, ignorance of key pain issues, small size, and over-optimistic judgements about the direction and magnitude of treatment effects all devalue systematic reviews, supposedly the ‘gold standard’ of evidence. Available evidence indicates that almost all systematic reviews in the published literature contain fatal flaws likely to make their conclusions incorrect and misleading. Only 3 in every 100 systematic reviews are deemed to have adequate methods and be clinically useful. Examples of research waste and questionable ethical standards abound: most trials have little hope of providing useful results, and systematic review of hopeless trials inspires no confidence. We argue that results of most systematic reviews should be dismissed. Forensically critical systematic reviews are essential tools to improve the quality of trials and should be encouraged and protected