172 research outputs found

    An Experimental Study of Pedestrian Congestions: Influence of Bottleneck Width and Length

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    The placement and dimensioning of exit routes is informed by experimental data and theoretical models. The experimental data is still to a large extent uncertain and contradictory. In this contribution an attempt is made to understand and reconcile these differences with our own experiments.Comment: Conference proceedings for Traffic and Granular Flow 200

    Korrelieren die klinischen, radiologischen und intraoperativen Befunde der Gonarthrose? Eine klinische Untersuchung an 103 Patienten

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    Studienziel: Zielsetzung der vorliegenden Arbeit war es die Ausprägung der diagnostischen Parameter der Gonarthrose (Klinik, Untersuchungsbefunde, radiologische und intraoperative Befunde) von Patienten vor Implantation einer Knietotalendoprothese zu vergleichen und sie somit untereinander in Bezug zu setzen. Methode: In die Studie wurden Patienten, bei denen aufgrund einer primären Gonarthrose eine Versorgung mit einer Oberflächenprothese in unserer Klinik anstand, aufgenommen. Beschwerden wurden anhand des Womac-Scores, dem Knee Subscore (KS) des Knee Society Clinical Rating Systems und einer visuellen Analogskala (VAS) erfasst. Befunde der klinischen Untersuchung wurden dokumentiert. Die radiologische Beurteilung erfolgte anhand standardisierter Röntgenaufnahmen. Gelenkspaltminderung, subchondrale Sklerosierung und Osteophytenbildung sowie die Beinachse wurden dokumentiert und der Kellgren-Score erhoben. Intraoperativ beurteilte ein Facharzt der Orthopädie die Chondromalazie nach Outerbridge. Korrelationsanalysen erfolgten durch den Spearman-Korrelationskoeffizienten (SpK). Ergebnisse: Es wurden 103 Patienten in die Studie aufgenommen (mittleres Alter 68 Jahre, 70 Frauen). Es konnte keine signifikante Assoziation des Womac-Scores und der VAS mit den radiologischen Befunden und der Chondromalazie festgestellt werden (SpK [Womac�Kellgren- Score]: � 0,04; SpK [VAS�Kellgren-Score]: 0,08). Es fanden sich signifikante Korrelationen des KS mit nahezu allen erfassten radiologische Zeichen der Gonarthrose und der Chondromalazie, bedingt durch im KS erfassten Befunde der klinischen Untersuchung (SpK [KS�Kellgren-Score]: � 0,39). Die radiologischen Merkmale korrelierten bis auf das Ausmaß der subchondralen Sklerosierung vollständig mit dem Ausmaß des Knorpeldefekts (SpK [Kellgren-Score�Chondromalazie]: 0,43). Am deutlichsten korrelierte die Osteophytenbildung mit der Chondromalazie: SpK: 0,43. Schlussfolgerung: Für den klinischen Alltag und in klinischen Studien erscheint der Knee Subscore ein probates Mittel zur Erfassung der Arthroseprogredienz. Der Womac-Score dient vor allem zu Erfassung der subjektiven Beschwerden. Wir können die Bedeutung der Osteophyten als das wichtigste radiologische Kriterium der Gonarthrose bestätigen. Der Kellgren-Score erwies sich als zuverlässiges Messinstrument zur Beurteilung einer Gonarthrose

    Microscopic insights into pedestrian motion through a bottleneck, resolving spatial and temporal variations

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    The motion of pedestrians is subject to a wide range of influences and exhibits a rich phenomenology. To enable precise measurement of the density and velocity we use an alternative definition using Voronoi diagrams which exhibits smaller fluctuations than the standard definitions. This method permits examination on scales smaller than the pedestrians. We use this method to investigate the spatial and temporal variation of the observables at bottlenecks. Experiments were performed with 180 test subjects and a wide range of bottleneck parameters. The anomalous flow through short bottlenecks and non-stationary states present with narrow bottlenecks are analysed

    The chemokine CXCL13 in acute neuroborreliosis

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    Objective Recent studies have suggested an important role of the B cell chemoattractant CXCL13 in acute neuroborreliosis (NB). Our aim was to confirm the diagnostic role of CXCL13 and to evaluate its relevance as a therapy response and disease activity marker in NB. Methods CXCL13 was measured in cerebrospinal fluid (CSF) and serum of patients with NB (n = 28), systemic borreliosis (SB, n = 9), Guillaine-Barre syndrome (GBS, n = 11), Bell's palsy (BP, n = 19), other cranial nerve palsies (CNP, n = 5), cephalgia (C, n = 20), bacterial CNS infections (B-CNS-I, n = 16) and viral CNS infections (V-CNS-I, n = 18). For follow-up studies, serial sample pairs were evaluated from 25 patients with NB (n = 56), 11 with B-CNS-I (n = 25) and 14 with V-CNS-I (n = 36). Results CSF-CXCL13 was significantly elevated in NB compared with other neurological diseases (p<0.001). Using receiver operating characteristic analysis, 337 ng/g was determined as a cut-off with a sensitivity of 96.4% and a specificity of 96.9%. Of all the parameters investigated, CSF CXCL13 showed the fastest response to antibiotic therapy, decreasing significantly (p = 0.008) within 1 week. In untreated patients, CSF CXCL13 was elevated in patients with a short duration of disease. Borrelia burgdorferi antibody index showed no significant (p = 0.356) change over follow-up. Conclusions The study confirms the relevance of CXCL13 as a diagnostic biomarker of NB and suggests that CSF CXCL13 in NB is linked to duration of disease and could be a marker of disease activity and response to antibiotic therapy

    From the Inside Out: A Literature Review on Possibilities of Mobile Emotion Measurement and Recognition

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    Information systems are becoming increasingly intelligent and emotion artificial intelligence is an important component for the future. Therefore, the measurement and recognition of emotions is necessary and crucial. This paper presents a state of the art in the research field of mobile emotion measurement and recognition. The aim of this structured literature analysis using the PRISMA statement is to collect and classify the relevant literature and to provide an overview of the current status of mobile emotion recording and its future trends. A total of 59 articles were identified in the relevant literature databases, which can be divided into four main categories of emotion measurement. There was an increase of publications over the years in all four categories, but with a particularly strong increase in the areas of optical and vital-data-based recording. Over time, both the speed as well as the accuracy of the measurement has improved considerably in all four categories

    The rTPJ’s overarching cognitive function in networks for attention and theory of mind

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    Cortical networks underpinning attentional control and mentalizing converge at the right temporoparietal junction (rTPJ). It is debated whether the rTPJ is fractionated in neighboring, but separate functional modules underpinning attentional control and mentalizing, or whether one overarching cognitive mechanism explains the rTPJ's role in both domains. Addressing this question, we combined attentional control and mentalizing in a factorial design within one task. We added a social context condition, in which another individual's mental states became apparently task-relevant, to a spatial cueing paradigm. This allowed for assessing cue validity-and context-dependent functional activity and effective connectivity of the rTPJ within corresponding cortical networks. We found two discriminable rTPJ subregions, an anterior and a posterior one. Yet, we did not observe a sharp functional dissociation between these two, as both regions responded to attention cueing and social context manipulation. The results suggest that the rTPJ is part of both the ventral attention and the ToM network and that its function is defined by context-dependent coupling with the respective network. We argue that the rTPJ as a functional unit underpins an overarching cognitive mechanism in attentional control and mentalizing and discuss how the present results help to further specify this mechanism

    The chemokine CXCL13 is a key regulator of B cell recruitment to the cerebrospinal fluid in acute Lyme neuroborreliosis

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    <p>Abstract</p> <p>Background</p> <p>The chemokine CXCL13 is known to dictate homing and motility of B cells in lymphoid tissue and has been implicated in the formation of ectopic lymphoid tissue in chronic inflammation. Whether it influences B cell trafficking during acute infection, is largely unclear. In previous studies, we showed that (I) CXCL13 levels are markedly increased in the B cell-rich cerebrospinal fluid (CSF) of patients with acute Lyme neuroborreliosis (LNB), and (II) CXCL13 is released by monocytes upon recognition of borrelial outer surface proteins by Toll-like receptor 2. Here, we assessed the role of CXCL13 - in comparison to other chemokines - in the recruitment of B cells to the CSF of patients with acute LNB.</p> <p>Methods</p> <p>Measurement of chemokines was done by ELISA. B cells were isolated from whole blood using magnetic cell separation (MACS). For migration experiments, a modified Boyden chamber assay was used and the migrated B cells were further analysed by FACS. The migration was inhibited either by preincubation of the CSF samples with neutralizing antibodies, heating to 60°C, removal of proteins >3 kDa, or by pre-treatment of the B cells with pertussis toxin. The principal statistical tests used were one-way analysis of variance and Bonferroni test (chemokine measurements) as well as paired Student's t-test (migration experiments).</p> <p>Results</p> <p>Measurements of chemokine levels revealed an increase in three of the four known major B cell chemoattractants CXCL13, CCL19 and CXCL12 in LNB CSF. The CXCL13 CSF:serum ratio, as a measure of the chemotactic gradient, was substantially higher than that of CCL19 and CXCL12. Moreover, the chemotactic activity of LNB CSF was reduced up to 56% after preincubation with a neutralizing CXCL13 antibody, while combined preincubation with antibodies against CXCL13, CCL19, and CXCL12 did not lead to further reduction. Since treatment with pertussis toxin, heating to 60°C, and removal of proteins >3 kDa abrogated the chemotactic activity, further not yet identified chemokines seem to be involved in B cell recruitment to LNB CSF.</p> <p>Conclusion</p> <p>Combined, our study suggests a key role of CXCL13 in B cell migration to sites of infection as shown here for the CSF of LNB patients.</p

    Predictors for rTMS response in chronic tinnitus

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    Background: Repetitive transcranial magnetic stimulation (rTMS) has been studied as a treatment option for chronic tinnitus for almost 10 years now. Although most of these studies have demonstrated beneficial effects, treatment results show high interindividual variability and yet, little is known about predictors for treatment response. Methods: Data from 538 patients with chronic tinnitus were analyzed. Patients received either low-frequency rTMS over the left temporal cortex (n = 345, 1 Hz, 110% motor threshold, 2000 stimuli/day) or combined temporal and frontal stimulation (n = 193, 110% motor threshold, 2000 stimuli at 20 Hz over left dorsolateral prefrontal cortex plus 2000 stimuli at 1 Hz over temporal cortex). Numerous demographic, clinical, and audiological variables as well as different tinnitus characteristics were analyzed as potential predictors for treatment outcome, which was defined as change in the tinnitus questionnaire (TQ) score. Results: Both stimulation protocols resulted in a significant decrease of TQ scores. Effect sizes were small, however. In the group receiving combined treatment, patients with comorbid temporomandibular complaints benefited more from rTMS than patients without those complaints. In addition, patients with higher TQ scores at baseline had more pronounced TQ reductions than patients with low TQ baseline scores. Also, patients who had already improved from screening to baseline benefited less than patients without initial improvement. Conclusions: The results from this large sample demonstrate that rTMS shows only small but clinically significant effects in the treatment of chronic tinnitus. There are no good demographic or clinical predictors for treatment outcome

    Left ventricular support adjustment to aortic valve opening with analysis of exercise capacity

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    Background LVAD speed adjustment according to a functioning aortic valve has hypothetic advantages but could lead to submaximal support. The consequences of an open aortic valve policy on exercise capacity and hemodynamics have not yet been investigated systematically. Methods Ambulatory patients under LVAD support (INCOR®, Berlin Heart, mean support time 465 ± 257 days, average flow 4.0 ± 0.3 L/min) adjusted to maintain a near normal aortic valve function underwent maximal cardiopulmonary exercise testing (CPET) and right heart catheterization (RHC) at rest and during constant work rate exercise (20 Watt). Results Although patients (n = 8, mean age 45 ± 13 years) were in NYHA class 2, maximum work-load and peak oxygen uptake on CPET were markedly reduced with 69 ± 13 Watts (35% predicted) and 12 ± 2 mL/min/kg (38% predicted), respectively. All patients showed a typical cardiac limitation pattern and severe ventilatory inefficiency with a slope of ventilation to carbon dioxide output of 42 ± 12. On RHC, patients showed an exercise-induced increase of mean pulmonary artery pressure (from 16 ± 2.4 to 27 ± 2.8 mmHg, p < 0.001), pulmonary artery wedge pressure (from 9 ± 3.3 to 17 ± 5.3 mmHg, p = 0.01), and cardiac output (from 4.7 ± 0.5 to 6.2 ± 1.0 L/min, p = 0.008) with a corresponding slight increase of pulmonary vascular resistance (from 117 ± 35.4 to 125 ± 35.1 dyn*sec*cm−5, p = 0.58) and a decrease of mixed venous oxygen saturation (from 58 ± 6 to 32 ± 9%, p < 0.001). Conclusion An open aortic valve strategy leads to impaired exercise capacity and hemodynamics, which is not reflected by NYHA-class. Unknown compensatory mechanisms can be suspected. Further studies comparing higher vs. lower support are needed for optimization of LVAD adjustment strategies
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