Steering in computational science: mesoscale modelling and simulation

This paper outlines the benefits of computational steering for high performance computing applications. Lattice-Boltzmann mesoscale fluid simulations of binary and ternary amphiphilic fluids in two and three dimensions are used to illustrate the substantial improvements which computational steering offers in terms of resource efficiency and time to discover new physics. We discuss details of our current steering implementations and describe their future outlook with the advent of computational grids.Comment: 40 pages, 11 figures. Accepted for publication in Contemporary Physic

A short delirium caregiver questionnaire for triage of elderly outpatients with cognitive impairment:a development and test accuracy study

OBJECTIVES: Delirium is often missed in older outpatients. Caregivers can give valuable information that might improve identification rates. The aim of this study was to develop a short and sensitive delirium caregiver questionnaire (DCQ) for triage of elderly outpatients with cognitive impairment by telephone.DESIGN, SETTING, AND PARTICIPANTS: The pilot questionnaire was administered to 112 caregivers of patients who were referred for dementia screening to our clinic for geriatric psychiatry, and the final DCQ to 234 other caregivers.MEASUREMENTS: In phase I (2013-2014), we tested a pilot questionnaire with 17 items. Health professionals who established delirium diagnoses were blinded to the results. We then used the results and other information available at referral to construct the final DCQ with seven items. During phase II (2015-2016), we investigated the test accuracy of the final DCQ in a subsequent cohort. In both phases, the patients received a structured diagnostic workup. Time between referral and first visit was a secondary outcome.RESULTS: The final DCQ consisted of the following items: emergency visit required, sleeping disorder, fluctuating course, hallucinations, suspicious thoughts, previous delirium, and recent discharge from hospital. DCQ results indicated that urgent intake was required in 85 of 234 patients. Sensitivity was 73.5% (95% CI: 58.9-85.1%) and specificity 73.5% (95% CI: 66.5-79.7%). The mean number of days to first visit dropped from 31.6 to 11.2 in delirious patients (p = 0.001).CONCLUSIONS: Triage with the easy-to-use DCQ among patients referred for cognitive screening leads to earlier assessment and higher detection rates of delirium.</p

Sensory qualities of the phantom hand map in the residual forearm of amputees

OBJECTIVE: Most amputees experience referred sensations, known as a phantom hand map, on the residual forearm, where touch on specific areas is perceived as touch on the amputated hand. The aim of this study was to evaluate the sensory qualities of the phantom hand map.METHODS: In 10 traumatic forearm-amputees touch thres-holds and discriminative touch of the phantom hand map were assessed and compared with corresponding areas on the contralateral forearm. The study assessed the localization of touch on the phantom hand map, and how distinct and similar to normal touch the referred feeling was.RESULTS: Similar touch thresholds were seen in the phantom hand map and the control site. Tactile discrimination, requiring both detection of stimulus and interpretation, was significantly better in the phantom hand map.CONCLUSION: This explorative study suggests that the phantom hand map and the superior tactile discrimination seen in the phantom hand map are based on adaptations within the brain. Further studies investigating the neural basis for the phantom hand map are needed

Pollen season is reflected on symptom load for grass and birch pollen-induced allergic rhinitis in different geographic areas—An EAACI Task Force Report

Background: The effectiveness of allergen immunotherapy (AIT) in seasonal allergic rhinitis (AR) depends on the definition of pollen exposure intensity or time period. We recently evaluated pollen and symptom data from Germany to examine the new definitions of the European Academy of Allergy and Clinical Immunology (EAACI) on pollen season and peak pollen period start and end. Now, we aim to confirm the feasibility of these definitions to properly mirror symptom loads for grass and birch pollen-induced allergic rhinitis in other European geographical areas such as Austria, Finland and France, and therefore their suitability for AIT and clinical practice support. Methods: Data from twenty-three pollen monitoring stations from three countries in Europe and for 3 years (2014-2016) were used to investigate the correlation between birch and grass pollen concentrations during the birch and grass pollen season defined via the EAACI criteria, and total nasal symptom and medication scores as reported with the aid of the patient's hay-fever diary (PHD). In addition, we conducted a statistical analysis, together with a graphical investigation, to reveal correlations and dependencies between the studied parameters. Results: The analysis demonstrated that the definitions of pollen season as well as peak pollen period start and end as proposed by the EAACI are correlated to pollen-induced symptom loads reported by PHD users during birch and grass pollen season. A statistically significant correlation (slightly higher for birch) has been found between the Total Nasal Symptom and Medication Score (TNSMS) and the pollen concentration levels. Moreover, the maximum symptom levels occurred mostly within the peak pollen periods (PPP) following the EAACI criteria. Conclusions: Based on our analyses, we confirm the validity of the EAACI definitions on pollen season for both birch and grass and for a variety of geographical locations for the four European countrie

The association between preoperative body composition and aerobic fitness in patients scheduled for colorectal surgery

AIM: Although cardiopulmonary exercise testing (CPET) is considered the gold standard, a preoperative abdominal CT scan might also provide information concerning preoperative aerobic fitness for risk assessment. This study aimed to investigate the association between preoperative CT‐scan‐derived body composition variables and preoperative CPET variables of aerobic fitness in colorectal surgery. METHOD: In this retrospective cohort study, CT images at level L3 were analysed for skeletal muscle mass, skeletal muscle radiation attenuation, visceral adipose tissue (VAT) mass and subcutaneous adipose tissue mass. Regression analyses were performed to investigate the relation between CT‐scan‐derived body composition variables, CPET‐derived aerobic fitness and other preoperative patient‐related variables. Logistic regression analysis was performed to predict a preoperative anaerobic threshold (AT) ≤ 11.1 ml/kg/min as cut‐off for having a high risk for postoperative complications. RESULTS: Data from 78 patients (45 men; mean [SD] age 74.5 [6.4 years]) were analysed. A correlation coefficient of 0.55 was observed between absolute AT and skeletal muscle mass index. Absolute AT (R (2) of 51.1%) was lower in patients with a lower skeletal muscle mass index, together with higher age, lower body mass and higher American Society of Anesthesiologists (ASA) score. Higher ASA score (odds ratio 5.64; P = 0.033) and higher VAT mass (odds ratio 1.02; P = 0.036) were associated with an increased risk of an AT ≤ 11.1 ml/kg/min. CONCLUSION: Body composition variables from the preoperative CT scan were moderately associated with preoperative CPET‐derived aerobic fitness. Higher ASA score and higher VAT mass were associated with an increased risk of an AT ≤ 11.1 ml/kg/min

WLM-1: A Non-Rotating, Gravitationally Unperturbed, Highly Elliptical Extragalactic Globular Cluster

Globular clusters have long been known for presenting (at times) significant deviations from spherical symmetry. While rotation has been the main proposed explanation, other complicating factors such as their constant interaction with the strong gravitational potential of their host galaxy have made it difficult for a consensus to be reached. To address this question we have obtained high-resolution spectra of WLM-1, the lone globular cluster associated with the isolated, low-mass dwarf irregular galaxy WLM. Using archival HST WFPC2 data, we measure the radial ellipticity profile of WLM-1, finding it to be highly elliptical, with a mean value of 0.17 in the region 0.5-5" -- which is comparable to what is found in our Galaxy for the most elliptical globular clusters. There is no evidence of isophote twisting, except for the innermost regions of the cluster (r < 0.5"). To investigate whether the observed flattening can be ascribed to rotation, we have obtained long-slit high-resolution VLT/UVES spectra of this cluster along and perpendicular to the axis of flattening. Using cross-correlation we find that the velocity profile of the cluster is consistent with zero rotation along either axis. Thus neither cluster rotation nor galactic tides can be responsible for the flattened morphology of WLM-1. We argue that the required velocity dispersion anisotropy between the semi-major and semi-minor axes that would be required to account for the observed flattening is relatively small, of order 1 km/s. Even though our errors preclude us from conclusively establishing that such a difference indeed exists, velocity anisotropy remains at present the most plausible explanation for the shape of this cluster.Comment: 11 pages, 10 figures, submitted to the A

Deteriorating health satisfaction among immigrants from Eastern Europe to Germany

BACKGROUND: Migrants from Eastern Europe constitute more than 5% of Germany's population. Since population health in their countries of origin is poor their health status upon arrival may be worse than that of the native-born German population (hypothesis H1). As a minority, they may be socio-economically disadvantaged (H2), and their health status may deteriorate quickly (H3). METHODS: We compared data from 1995 and 2000 for immigrants from Eastern Europe (n = 353) and a random sample of age-matched Germans (n = 2, 824) from the German Socioeconomic Panel. We tested H1-3 using health satisfaction, as a proxy for health status, and socioeconomic indicators. We compared changes over time within groups, and between immigrants and Germans. We assessed effects of socio-economic status and being a migrant on declining health satisfaction in a regression model. RESULTS: In 1995, immigrants under 55 years had a significantly higher health satisfaction than Germans. Above age 54, health satisfaction did not differ. By 2000, immigrants' health satisfaction had declined to German levels. Whereas in 1995 immigrants had a significantly lower SES, differences five years later had declined. In the regression model, immigrant status was much stronger associated with declining health satisfaction than low SES. CONCLUSION: In contrast to H1, younger immigrants had an initial health advantage. Immigrants were initially socio-economically disadvantaged (H2), but their SES improved over time. The decrease in health satisfaction was much steeper in immigrants and this was not associated with differences in SES (H3). Immigrants from Eastern Europe have a high risk of deteriorating health, in spite of socio-economic improvements