663 research outputs found

    Periodic minimal surfaces of cubic symmetry

    Get PDF
    A survey of cubic minimal surfaces is presented, based on the concept of fundamental surface patches and their relation to the asymmetric units of the space groups. The software Surface Evolver has been used to test for stability and to produce graphic displays. Particular emphasis is given to those surfaces that can be generated by a finite piece bounded by straight lines. Some new varieties have been found and a systematic nomenclature is introduced, which provides a symbol (a ā€˜geneā€™) for each triply-periodic minimal surface that specifies the surface unambiguously

    Annual Report Readership: A Study of an Agricultural Supply Cooperative

    Get PDF
    Recent corporate collapses have focussed attention on the (un)reliability of financial information. However, although the agricultural sector, which is significant globally, is run primarily using the cooperative form, there is scant research on these users' perception of financial information. Therefore this paper examines members' readership and understanding of the annual reports of a large, fertiliser cooperative. The findings show that there is a lack of readership of the annual report, due to a lack of understanding and a lack of time. A minority of non-readers trust directors to "do a good job". Preparers of information should focus on making reports more user-friendly and evidence suggests that financial information could be released more strategically using other sources of communication, namely other print media and the internet.cooperatives, annual reports, readership, understanding, Agribusiness,

    Effect of catheter ablation on quality of life in patients with atrial fibrillation and its correlation with arrhythmia outcome

    Get PDF
    Objective To assess the effect of catheter ablation on atrial fibrillation (AF) symptoms and quality of life (QoL). Methods Patients with AF scheduled for ablation were recruited. Pulmonary vein isolation (PVI) was performed and complex fractionated atrial electrogram (CFAE)Ā±linear ablation undertaken in patients in AF despite PVI. QoL and AF symptoms were assessed using SF-36 V2 and Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaires before and 3ā€…months after ablation. Change in QoL scores after ablation was correlated with clinical parameters and the extent of ablation. Magnitude of QoL change was compared between AFEQT and SF-36 physical component summary (PCS) and mental component summary (MCS) scores and correlated with arrhythmia outcome. Results 80 patients were studied. Summative and individual health scores for both AFEQT (51.5Ā±22.0 vs 81.3Ā±18.2; p<0.01) and SF-36 (PCS 43.3Ā±10.5 vs 47.9Ā±11.3; p<0.01 and MCS 45.0Ā±11.5 vs 51.5Ā±9.4; p<0.01) improved significantly in patients who maintained sinus rhythm after ablation, but not in those with recurrent AF. Improvement in AFEQT (25.4Ā±19) was significantly greater than change in PCS (6.8Ā±6.4; p<0.01) and MCS (8.5Ā±7.9; p<0.01) scores and correlated more closely with arrhythmia outcome (AFEQT r=0.55; PCS r=0.26; MCS r=0.30). Conclusions Patients who maintained sinus rhythm after ablation had a significant improvement in AF symptoms and QoL; however, no improvement was observed in patients with recurrent AF. QoL change after ablation did not correlate with baseline clinical parameters or ablation strategy. AF specific QoL scales are more responsive to change and correlate better with ablation outcome

    Principal component analysis of atrial fibrillation: Inclusion of posterior ECG leads does not improve correlation with left atrial activity

    Get PDF
    Background Lead V? is routinely analysed due to its large amplitude AF waveform. V? correlates strongly with right atrial activity but only moderately with left atrial activity. Posterior lead V? correlates strongest with left atrial activity. Aims (1) To establish whether surface dominant AF frequency (DAF) calculated using principal component analysis (PCA) of a modified 12-lead ECG (including posterior leads) has a stronger correlation with left atrial activity compared to the standard ECG. (2) To assess the contribution of individual ECG leads to the AF principal component in both ECG configurations. Methods Patients were assigned to modified or standard ECG groups. In the modified ECG, posterior leads V? and V? replaced V? and V?. AF waveform was extracted from one-minute surface ECG recordings using PCA. Surface DAF was correlated with intracardiac DAF from the high right atrium (HRA), coronary sinus (CS) and pulmonary veins (PVs). Results 96 patients were studied. Surface DAF from the modified ECG did not have a stronger correlation with left atrial activity compared to the standard ECG. Both ECG configurations correlated strongly with HRA, CS and right PVs but only moderately with left PVs. V? contributed most to the AF principal component in both ECG configurations

    Aurora-A expressing tumour cells are deficient for homology-directed DNA double strand-break repair and sensitive to PARP inhibition.

    Get PDF
    The protein kinase Aurora-A is a major regulator of the cell cycle that orchestrates mitotic entry and is required for the assembly of a functional mitotic spindle. Overexpression of Aurora-A has been strongly linked with oncogenesis and this has led to considerable efforts at therapeutic targeting of the kinase activity of this protein. However, the exact mechanism by which Aurora-A promotes oncogenesis remains unclear. Here, we show that Aurora-A modulates the repair of DNA double-strand breaks (DSBs). Aurora-A expression inhibits RAD51 recruitment to DNA DSBs, decreases DSB repair by homologous recombination and sensitizes cancer cells to PARP inhibition. This impairment of RAD51 function requires inhibition of CHK1 by Polo-like kinase 1 (PLK1). These results identify a novel function of Aurora-A in modulating the response to DNA DSB that likely contributes to carcinogenesis and suggest a novel therapeutic approach to the treatment of cancers overexpressing this protein

    Sedation for Gastrointestinal Endoscopic Procedures in the Elderly: Getting Safer but Still Not Nearly Safe Enough

    Get PDF
    Previously published UK reports showed that excessively large doses of benzodiazepines and opiates were being commonly used to sedate elderly patients for gastrointestinal (GI) endoscopy. This unsafe practice has lead to avoidable morbidity and mortality. We have taken the opportunity provided by recent reports to examine whether GI endoscopy sedation practice in the elderly has improved in the light of this evidence and the publication of guidelines in which specific recommendations on sedation dosage are given

    Free-living gait characteristics in ageing and Parkinsonā€™s disease: impact of environment and ambulatory bout length

    Get PDF
    Background - Gait is emerging as a powerful diagnostic and prognostic tool, and as a surrogate marker of disease progression for Parkinsonā€™s disease (PD). Accelerometer-based body worn monitors (BWMs) facilitate the measurement of gait in clinical environments. Moreover they have the potential to provide a more accurate reflection of gait in the home during habitual behaviours. Emerging research suggests that measurement of gait using BWMs is feasible but this has not been investigated in depth. The aims of this study were to explore (i) the impact of environment and (ii) ambulatory bout (AB) length on gait characteristics for discriminating between people with PD and age-matched controls. Methods - Fourteen clinically relevant gait characteristics organised in five domains (pace, variability, rhythm, asymmetry, postural control) were quantified using laboratory based and free-living data collected over 7 days using a BWM placed on the lower back in 47 PD participants and 50 controls. Results - Free-living data showed that both groups walked with decreased pace and increased variability, rhythm and asymmetry compared to walking in the laboratory setting. Four of the 14 gait characteristics measured in free-living conditions were significantly different between controls and people with PD compared to two measured in the laboratory. Between group differences depended on bout length and were more apparent during longer ABs. ABsā€‰ā‰¤ā€‰10s did not discriminate between groups. Medium to long ABs highlighted between-group significant differences for pace, rhythm and asymmetry. Longer ABs should therefore be taken into account when evaluating gait characteristics in free-living conditions. Conclusion -This study provides encouraging results to support the use of a single BWM for free-living gait evaluation in people with PD with potential for research and clinical application

    Gait Asymmetry Post-Stroke: Determining Valid and Reliable Methods Using a Single Accelerometer Located on the Trunk

    Get PDF
    Asymmetry is a cardinal symptom of gait post-stroke that is targeted during rehabilitation. Technological developments have allowed accelerometers to be a feasible tool to provide digital gait variables. Many acceleration-derived variables are proposed to measure gait asymmetry. Despite a need for accurate calculation, no consensus exists for what is the most valid and reliable variable. Using an instrumented walkway (GaitRite) as the reference standard, this study compared the validity and reliability of multiple acceleration-derived asymmetry variables. Twenty-five post-stroke participants performed repeated walks over GaitRite whilst wearing a tri-axial accelerometer (Axivity AX3) on their lower back, on two occasions, one week apart. Harmonic ratio, autocorrelation, gait symmetry index, phase plots, acceleration, and jerk root mean square were calculated from the acceleration signals. Testā€“retest reliability was calculated, and concurrent validity was estimated by comparison with GaitRite. The strongest concurrent validity was obtained from step regularity from the vertical signal, which also recorded excellent testā€“retest reliability (Spearmanā€™s rank correlation coefficients (rho) = 0.87 and Intraclass correlation coefficient (ICC21) = 0.98, respectively). Future research should test the responsiveness of this and other step asymmetry variables to quantify change during recovery and the effect of rehabilitative interventions for consideration as digital biomarkers to quantify gait asymmetry

    Dementia care mapping in long-term care settings: a systematic review of the evidence

    Get PDF
    YesThis systematic review identifies and reports the extent and nature of evidence to support the use of Dementia Care Mapping as an intervention in care settings. The review was limited to studies that used Dementia Care Mapping as an intervention and included outcomes involving either care workers and/or people living with dementia. Searches were conducted in PubMed, Web of Knowledge, CINAHL, PsychINFO, EBSCO and Scopus and manually from identified articles reference lists. Studies published up to January 2017 were included. Initial screening of identified papers was based on abstracts read by one author; full-text papers were further evaluated by a second author. The quality of the identified papers was assessed independently by two authors using the Cochrane Risk of Bias Tool. A narrative synthesis of quantitative findings was conducted. We identified 6 papers fulfilling predefined criteria. Studies consist of recent, large scale, good quality trials that had some positive impacts upon care workersā€™ stress and burnout and benefit people with dementia in terms of agitated behaviours, neuropsychiatric symptoms, falls and quality of life. Available research provides preliminary evidence that Dementia Care Mapping may benefit care workers and people living with dementia in care settings. Future research should build on the successful studies to date and use other outcomes to better understand the benefits of this intervention
    • ā€¦
    corecore