M. Bach

ALICE HLT High Speed Tracking on GPU

The on-line event reconstruction in ALICE is performed by the High Level Trigger, which should process up to 2000 events per second in proton-proton collisions and up to 300 central events per second in heavy-ion collisions, corresponding to an input data stream of 30 GB/s. In order to fulfill the time requirements, a fast on-line tracker has been developed. The algorithm combines a Cellular Automaton method being used for a fast pattern recognition and the Kalman Filter method for fitting of found trajectories and for the final track selection. The tracker was adapted to run on Graphics Processing Units (GPU) using the NVIDIA Compute Unified Device Architecture (CUDA) framework. The implementation of the algorithm had to be adjusted at many points to allow for an efficient usage of the graphics cards. In particular, achieving a good overall workload for many processor cores, efficient transfer to and from the GPU, as well as optimized utilization of the different memories the GPU offers turned out to be critical. To cope with these problems a dynamic scheduler was introduced, which redistributes the workload among the processor cores. Additionally a pipeline was implemented so that the tracking on the GPU, the initialization and the output processed by the CPU, as well as the DMA transfer can overlap. The GPU tracking algorithm significantly outperforms the CPU version for large events while it entirely maintains its efficiency.

Rollator use and functional outcome of geriatric rehabilitation

In a quasi-experimental pre- and postdesign, we examined the effect of rollator use on functional rehabilitation outcome in geriatric patients.From a sample of 458 geriatric inpatients, we matched 30 subjects who were not using assistive devices in their everyday lives but received a wheeled walker at the time of hospital admission (first-time user group) according to their admission scores on three motor performance tests (Timed Up-and-Go, Five-Times-Sit-to-Stand, and Performance-Oriented Mobility Assessment -Balance) with 30 patients who were actively using rollators as their primary walking aid for at least 3 months (long-term user group) and 30 control subjects without walking-aid assistance. Measurements were repeated after the inpatient rehabilitation regimen.The Kruskal-Wallis test did not reveal significant group differences in rehabilitation progress. Controls and device users, regardless of walking-aid experience, demonstrated nearly comparable mobility, strength, and balance improvements. More than half of each cohort (controls, n = 22; first-time, n = 17; long-term, n = 18) achieved functional gains in all three motor tests.The study showed that rollator assistance does not interfere with rehabilitation outcome and, to some extent, legitimates the prescription of assistive devices to improve confidence and restore or maintain motor ability at the highest possible level.

An etiologic profile of anemia in 405 geriatric patients.

Background. Anemia is a common condition in the elderly and a significant risk factor for increased morbidity and mortality, reducing not only functional capacity and mobility but also quality of life. Currently, few data are available regarding anemia in hospitalized geriatric patients. Our retrospective study investigated epidemiology and causes of anemia in 405 hospitalized geriatric patients. Methods. Data analysis was performed using laboratory parameters determined during routine hospital admission procedures (hemoglobin, ferritin, transferrin saturation, C-reactive protein, vitamin B12, folic acid, and creatinine) in addition to medical history and demographics. Results. Anemia affected approximately two-thirds of subjects. Of 386 patients with recorded hemoglobin values, 66.3% were anemic according to WHO criteria, mostly (85.1%) in a mild form. Anemia was primarily due to iron deficiency (65%), frequently due to underlying chronic infection (62.1%), or of mixed etiology involving a combination of chronic disease and iron deficiency, with absolute iron deficiency playing a comparatively minor role. Conclusion. Greater awareness of anemia in the elderly is warranted due to its high prevalence and negative effect on outcomes, hospitalization duration, and mortality. Geriatric patients should be routinely screened for anemia and etiological causes of anemia individually assessed to allow timely initiation of appropriate therapy.

Efficacy and Safety of Intravenous Ferric Carboxymaltose in Geriatric Inpatients at a German Tertiary University Teaching Hospital: A Retrospective Observational Cohort Study of Clinical Practice

Current iron supplementation practice in geriatric patients is erratic and lacks evidence-based recommendations. Despite potential benefits in this population, intravenous iron supplementation is often withheld due to concerns regarding pharmacy expense, perceived safety issues, and doubts regarding efficacy in elderly patients. This retrospective, observational cohort study aimed to evaluate the safety and efficacy of intravenous ferric carboxymaltose (FCM, Ferinject) in patients aged >75 years with iron deficiency anaemia (IDA). Within a twelve-month data extraction period, the charts of 405 hospitalised patients aged 65–101 years were retrospectively analysed for IDA, defined according to WHO criteria for anaemia (haemoglobin: <13.0 g/dL (m)/<12.0 g/dL (f)) in conjunction with transferrin saturation <20%. Of 128 IDA patients screened, 51 (39.8%) received intravenous iron. 38 patient charts were analysed. Mean cumulative dose of intravenous FCM was 784.4 ± 271.7 mg iron (1–3 infusions). 18 patients (47%) fulfilled treatment response criteria (≥1.0 g/dL increase in haemoglobin between baseline and hospital discharge). AEs were mild/moderate, most commonly transient increases of liver enzymes (n = 5/13.2%). AE incidence was comparable with that observed in patients <75 years. No serious AEs were observed. Ferric carboxymaltose was well tolerated and effective for correction of Hb levels and iron stores in this cohort of IDA patients aged over 75 years.

Slip resistance of non-slip socks – An accelerometer-based approach

The present study investigated the relative slip resistance of commercially available non-slip socks during gait. Twenty-four healthy subjects (29.3±10.4 years) participated in the study. Each subject completed 4 different test conditions (barefoot, non-slip socks, conventional socks, backless slippers) in a randomized, balanced order. The slip resistance was estimated by measuring the heel deceleration time using a heel-mounted accelerometer. Repeated measures ANOVA and post hoc paired-sample t-test with Bonferroni correction were used for statistical analysis. Compared to barefoot walking absolute deceleration times [ms] were significantly increased when wearing conventional socks or slippers. No significant differences were observed between the barefoot and non-slip socks conditions. The present study shows that non-slip socks improved slip-resistance during gait when compared to conventional socks and slippers. Future investigations should verify the present findings in hospital populations prone to slip-related falls.

Lattice-CSC: Optimizing and Building an Efficient Supercomputer for Lattice-QCD and to Achieve First Place in Green500

In the last decades, supercomputers have become a necessity in science and industry. Huge data centers consume enormous amounts of electricity and we are at a point where newer, faster computers must no longer drain more power than their predecessors. The fact that user demand for compute capabilities has not declined in any way has led to studies of the feasibility of exaflop systems. Heterogeneous clusters with highly-efficient accelerators such as GPUs are one approach to higher efficiency. We present the new L-CSC cluster, a commodity hardware compute cluster dedicated to Lattice QCD simulations at the GSI research facility. L-CSC features a multi-GPU design with four FirePro S9150 GPUs per node providing 320 GB/s memory bandwidth and 2.6 TFLOPS peak performance each. The high bandwidth makes it ideally suited for memory-bound LQCD computations while the multi-GPU design ensures superior power efficiency. The November 2014 Green500 list awarded L-CSC the most power-efficient supercomputer in the world with 5270 MFLOPS/W in the Linpack benchmark. This paper presents optimizations to our Linpack implementation HPL-GPU and other power efficiency improvements which helped L-CSC reach this benchmark. It describes our approach for an accurate Green500 power measurement and unveils some problems with the current measurement methodology. Finally, it gives an overview of the Lattice QCD application on L-CSC.

Twisted-Mass Lattice QCD using OpenCL

Graphics Processing Units (GPUs) are by now an established tool for Lattice QCD applications. I present an update on our OpenCL based code for Lattice QCD with twisted-mass fermions. On current generation AMD GPUs we now reach over 100GFLOPS in double-precision / D and 70GFLOPS in our double-precision inverter. For the hybrid Monte-Carlo (HMC) we improve energy-efficiency by a factor of four over a plain CPU system. We also found one 4-GPU node to provide about 12 times the throughput of a pure CPU system of comparable cost.

Inclusive photon production at forward rapidities in proton–proton collisions at √s = 0.9, 2.76 and 7 TeV - eScholarship

The multiplicity and pseudorapidity distributions of inclusive photons have been measured at forward rapidities (2.3 < η < 3.9) in proton–proton collisions at three center-of-mass energies, √ s = 0.9, 2.76 and 7 TeV using the ALICE detector. It is observed that the increase in the average photon multiplicity as a function of beam energy is compatible with both a logarithmic and a power-law dependence. The relative increase in average photon multiplicity produced in inelastic pp collisions at 2.76 and 7 TeV center-of-mass energies with respect to 0.9 TeV are 37.2 ± 0.3 % (stat) ± 8.8 % (sys) and 61.2 ± 0.3 % (stat) ± 7.6 % (sys), respectively. The photon multiplicity distributions for all center-of-mass energies are well described by negative binomial distributions. The multiplicity distributions are also presented in terms of KNO variables. The results are compared to model predictions, which are found in general to underestimate the data at large photon multiplicities, in particular at the highest center-of-mass energy. Limiting fragmentation behavior of photons has been explored with the data, but is not observed in the measured pseudorapidity range.

Wirksamkeit und Verträglichkeit einer intravenösen Eisentherapie bei geriatrischen Patienten mit Anämie

ZusammenfassungHintergrund:Anämie hat im höheren Lebensalter eine hohe Prävalenz und kommt als Eisenmangelanämie mit absolutem Eisenmangel, als Anämie chronischer Erkrankungen mit funktionellem Eisenmangel oder als unerklärbare Anämie vor. Bei funktionellem Eisenmangel ist Hepcidin erhöht, wodurch die enterale Eisenresorption vermindert wird. Eine intravenöse Eisengabe kann dieses Problem beheben. Die Datenlage dazu ist bei geriatrischen Patienten dünn. In drei nicht-interventionellen Studien wurden Wirksamkeit und Verträglichkeit einer intravenösen Eisengabe (Eisencarboxymaltose, Ferinject®) an drei Patientengruppen mit funktionellem Eisenmangel unterschiedlicher Genese (Tumorerkrankungen, chronische Nierenerkrankungen [CKD] und chronisch entzündliche Darmerkrankungen [CED]) untersucht.Patienten, Methode:Subanalyse der Studiendaten im geriatrischen Kollektiv von 264 Patienten im Alter von 70–90 Jahren (76,9 ± 5,2 Jahre); durchschnittlich wurden 1200 mg Eisen (746 mg bis 1575 mg) pro Patient infundiert.Ergebnisse:Signifikanter Anstieg von Hämoglobin (p < 0,001), Serum-Ferritin (p > 0,001) und Transferrinsättigung (p < 0,05) in der Gruppe der nephrologischen Patienten; bei den gastroenterologischen Patienten signifikanter Anstieg nur bei Hämoglobin (p < 0,05) und Transferrinsättigung (p < 0,05), jedoch nicht bei Ferritin. In der Gruppe der onkologischen Patienten kam es sowohl bei Hämoglobin als auch bei Ferritin zu einem hoch signifikanten Anstieg (p < 0,0001) und bei der Transferrinsättigung zu einem signifikanten Anstieg (p = 0,02). Müdigkeit, Konzentrationsschwäche und Dyspnoe-Symptomatik verbesserten sich in der CKD- und CED-Gruppe. Es traten keine schwerwiegenden Nebenwirkungen auf.Schlussfolgerung:Zusammenfassend lässt sich daraus schließen, dass der Einsatz von Eisencarboxymaltose auch bei geriatrischen Patienten mit funktionellem Eisenmangel gut verträglich und effektiv erfolgen kann.AbstractBackground:Anemia in the elderly is a common clinical finding. Prevalence in hospitalized geriatric patients approximates up to 40% presenting as iron deficiency anemia associated with absolute iron deficiency, anemia of chronic disease associated with functional iron deficiency or unexplained anemia. In patients with functional iron deficiency oral iron substitution is ineffective due to elevated hepcidin levels, such as in renal anemia. In these patients intravenous iron substitution represents a cornerstone. However, data among geriatric patients are limited. We conducted three non-interventional studies collecting data with respect to efficacy and tolerance of ferric carboxymaltose (ferinject®) in three patient groups (cancer, chronic kidney disease [CKD], chronic inflammatory bowel disease [CIBD]) with anemia and functional iron deficiency. The present sub-analysis describes the results among the geriatric patients (age > 70 years) observed in all three observational studies.Patients, Methods:264 patients were analyzed (mean age of 76.9 years [70–90 years; SD ± 5.2 years]). Patients received an average amount of 1200 mg ferric carboxymaltose (746–1575 mg).Results:Hemoglobin levels (p < 0.001), serum ferritin (p < 0.001) and transferrin saturation (p < 0.05) rose significantly in CKD patients; in CIBD patients hemoglobin and transferrin saturation rose significantly (p < 0.05) while the rise of ferritin failed to be significant. In oncologic patients the rise of hemoglobin and ferritin levels was of high statistic significance (p < 0.001) and transferrin saturation also rose significantly (p = 0.02) Fatigue, mental capacities as well as dyspnea improved among CKD- and CIBD-groups. No severe adverse reactions occurred.Conclusions:Administration of ferric carboxymaltose in geriatric patients is well tolerated and offers an effective treatment option for the treatment of functional iron deficiency.

O2: A novel combined online and offline computing system for the ALICE Experiment after 2018

ALICE (A Large Ion Collider Experiment) is a detector dedicated to the studies with heavy ion collisions exploring the physics of strongly interacting nuclear matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). After the second long shutdown of the LHC, the ALICE Experiment will be upgraded to make high precision measurements of rare probes at low pT, which cannot be selected with a trigger, and therefore require a very large sample of events recorded on tape. The online computing system will be completely redesigned to address the major challenge of sampling the full 50 kHz Pb-Pb interaction rate increasing the present limit by a factor of 100. This upgrade will also include the continuous un-triggered read-out of two detectors: ITS (Inner Tracking System) and TPC (Time Projection Chamber)) producing a sustained throughput of 1 TB/s. This unprecedented data rate will be reduced by adopting an entirely new strategy where calibration and reconstruction are performed online, and only the reconstruction results are stored while the raw data are discarded. This system, already demonstrated in production on the TPC data since 2011, will be optimized for the online usage of reconstruction algorithms. This implies much tighter coupling between online and offline computing systems. An R&D program has been set up to meet this huge challenge. The object of this paper is to present this program and its first results.