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1. Arm muscle area is correlated to handgrip strength in postmenopausal women

Author

Ludwig R. Álvarez-Córdova, Reyes Artacho, Peter Chedraui, Cecilia Arteaga-Pazmiño, Melissa Sánchez-Briones, and María D. Ruiz-López

Subjects
Handgrip strength, postmenopause, anthropometry, arm muscle area, manual dynamometry, aging, Gynecology and obstetrics, RG1-991, Diseases of the endocrine glands. Clinical endocrinology, RC648-665
Abstract

Objective To analyze the correlation between arm muscle area and handgrip strength among postmenopausal community dwelling low-income women in order to provide an easy anthropometric indicator to assess muscle mass quantity and quality.Methods This was a cross-sectional study involving postmenopausal women (n = 171) from three urban-marginal communities of Guayaquil, Ecuador. Corrected arm muscle area was calculated using the Frisancho formula. Dynapenia was defined as HGS < 16 kg. Spearman’s correlation coefficient was calculated at a 5% significance level to test the correlation between corrected arm muscle area and handgrip strength.Results Median (interquartile range: IQR) age of the sample was 72.0 years (17.0). The median of corrected arm muscle area was 34.8 cm2 (20.7). The overall prevalence of dynapenia was 57.9% (n = 99). There was a significant decreasing trend with age regarding all anthropometric characteristics and handgrip strength, as well as a higher prevalence of dynapenia with age. For the whole sample, a statistically significant positive correlation was found between corrected arm muscle area and handgrip strength [r = 0.267; p

Published
2024
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2. Reliable identification of protein-protein interactions by crosslinking mass spectrometry

Author

Swantje Lenz, Ludwig R. Sinn, Francis J. O’Reilly, Lutz Fischer, Fritz Wegner, and Juri Rappsilber

Subjects
Science
Abstract

Cross-linking mass spectrometry (MS) can identify protein-protein interaction (PPI) networks but assessing the reliability of these data remains challenging. To address this issue, the authors develop and validate a method to determine the false-discovery rate of PPIs identified by cross-linking MS.

Published
2021
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3. Retention time prediction using neural networks increases identifications in crosslinking mass spectrometry

Author

Sven H. Giese, Ludwig R. Sinn, Fritz Wegner, and Juri Rappsilber

Subjects
Science
Abstract

Predicting chromatographic retention times (RTs) has proven beneficial in proteomics but has not yet been achieved for crosslinked peptides. Here, the authors develop an RT prediction tool for crosslinked peptides and leverage predicted RTs to increase identifications in crosslinking mass spectrometry studies.

Published
2021
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4. Nanoparticle-based hyperthermia distinctly impacts production of ROS, expression of Ki-67, TOP2A, and TPX2, and induction of apoptosis in pancreatic cancer

Author

Ludwig R, Teran FJ, Teichgraeber U, and Hilger I

Subjects
iron oxide nanoparticles, magnetic hyperthermia, heat dose, nanomedicine, proliferation marker, Medicine (General), R5-920
Abstract

Robert Ludwig,1 Francisco J Teran,2,3 Ulf Teichgraeber,1 Ingrid Hilger1 1Department of Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Jena University Hospital – Friedrich Schiller University Jena, Jena, Germany; 2iMdea-Nanociencia, Campus Universitario de Cantoblanco, 3Nanobiotecnología (iMdea-Nanociencia), Unidad Asociada al Centro Nacional de Biotecnología (CSIC), Madrid, Spain Abstract: So far, the therapeutic outcome of hyperthermia has shown heterogeneous responses depending on how thermal stress is applied. We studied whether extrinsic heating (EH, hot air) and intrinsic heating (magnetic heating [MH] mediated by nanoparticles) induce distinct effects on pancreatic cancer cells (PANC-1 and BxPC-3 cells). The impact of MH (100 µg magnetic nanoparticles [MNP]/mL; H=23.9 kA/m; f=410 kHz) was always superior to that of EH. The thermal effects were confirmed by the following observations: 1) decreased number of vital cells, 2) altered expression of pro-caspases, and 3) production of reactive oxygen species, and 4) altered mRNA expression of Ki-67, TOP2A, and TPX2. The MH treatment of tumor xenografts significantly (P≤0.05) reduced tumor volumes. This means that different therapeutic outcomes of hyperthermia are related to the different responses cells exert to thermal stress. In particular, intratumoral MH is a valuable tool for the treatment of pancreatic cancers. Keywords: iron oxide nanoparticles, magnetic hyperthermia, heat dose, nanomedicine, proliferation marker

Published
2017

10. Hydrogen Bonding in Ionic Liquids Probed by Linear and Nonlinear Vibrational Spectroscopy

Author

Roth, C., Chatzipapadopoulos, S., Kerlé, D., Friedriszik, F., Lütgens, M., Lochbrunner, S., Kühn, O., and Ludwig, R.

Subjects
Physics - Chemical Physics
Abstract

Three imidazolium-based ionic liquids of the type [Cnmim][NTf2] with varying alkyl chain lengths (n = 1, 2 and 8) at the 1 position of the imidazolium ring were studied applying IR, linear Raman, and multiplex CARS spectroscopy. The focus has been on the CH-stretching region of the imidazolium ring, which is supposed to carry information about a possible hydrogen bonding network in the ionic liquid. The measurements are compared to calculations of the corresponding anharmonic vibrational spectra for a cluster of [C2mim][NTf2] consisting of four ion pairs. The results support the hypothesis of weak hydrogen bonding involving the C(4)-H and C(5)-H groups and somewhat stronger hydrogen bonds of the C(2)-H groups., Comment: revised manuscript, accepted for publication in New J. Phys

Published
2012
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16. Oxonium ion scanning mass spectrometry for large-scale plasma glycoproteomics

Author

White, Matthew E H, Sinn, Ludwig R; https://orcid.org/0000-0003-4692-0681, Jones, D Marc, de Folter, Joost; https://orcid.org/0000-0001-9704-2925, Aulakh, Simran Kaur, Wang, Ziyue, Flynn, Helen R; https://orcid.org/0000-0001-7002-9130, Krüger, Lynn, Tober-Lau, Pinkus, Demichev, Vadim, Kurth, Florian; https://orcid.org/0000-0002-3807-473X, Mülleder, Michael; https://orcid.org/0000-0001-9792-3861, Blanchard, Véronique, Messner, Christoph B, Ralser, Markus; https://orcid.org/0000-0001-9535-7413, White, Matthew E H, Sinn, Ludwig R; https://orcid.org/0000-0003-4692-0681, Jones, D Marc, de Folter, Joost; https://orcid.org/0000-0001-9704-2925, Aulakh, Simran Kaur, Wang, Ziyue, Flynn, Helen R; https://orcid.org/0000-0001-7002-9130, Krüger, Lynn, Tober-Lau, Pinkus, Demichev, Vadim, Kurth, Florian; https://orcid.org/0000-0002-3807-473X, Mülleder, Michael; https://orcid.org/0000-0001-9792-3861, Blanchard, Véronique, Messner, Christoph B, and Ralser, Markus; https://orcid.org/0000-0001-9535-7413

Abstract

Protein glycosylation, a complex and heterogeneous post-translational modification that is frequently dysregulated in disease, has been difficult to analyse at scale. Here we report a data-independent acquisition technique for the large-scale mass-spectrometric quantification of glycopeptides in plasma samples. The technique, which we named ‘OxoScan-MS’, identifies oxonium ions as glycopeptide fragments and exploits a sliding-quadrupole dimension to generate comprehensive and untargeted oxonium ion maps of precursor masses assigned to fragment ions from non-enriched plasma samples. By applying OxoScan-MS to quantify 1,002 glycopeptide features in the plasma glycoproteomes from patients with COVID-19 and healthy controls, we found that severe COVID-19 induces differential glycosylation in IgA, haptoglobin, transferrin and other disease-relevant plasma glycoproteins. OxoScan-MS may allow for the quantitative mapping of glycoproteomes at the scale of hundreds to thousands of samples.

Published
2023

21. Morphology and Hemodynamics of Cerebral Arteries and Aneurysms in a Pair of Monozygotic Twins

Author

Hang Yi, Zifeng Yang, Luke C Bramlage, and Ludwig R Bryan

Subjects
biomedical_chemical_engineering
Abstract

The contribution of genetic and environmental factors to the pathophysiology of cerebral aneurysms in monozygotic twins is under-reported and presents ambiguous arguments. The morphology and hemodynamics of neurovascular arteries in a pair of monozygotic twins (MTs) were investigated to reveal the underlying mechanisms. Four arterial models were reconstructed for the twin A-right brain and left brain, twin B-left brain, and B-left brain without anterior cerebral arteries based on preclinical scanned information. Subsequently, the dimensions, configurations and outlined curves of the three-perspective geometries were compared between the MTs. Adopting an in-vitro validated numerical cerebral aneurysm model, hemodynamic patterns were investigated and compared in the MT models, respectively. Morphological comparisons of the MTs show the size and shape of cerebral arteries exist significant differences, despite of the expected genetic similarities. These differences can be attributed to variations during embryological development and external environmental influences. Qualitatively and generally, numerical results indicate the MTs have some hemodynamic similarities (e.g., time-averaged pressure (TAP) distributions (~13400 Pa), and oscillatory shear index (0~0.49), but present significant differences in specific local arteries due to morphological variances. Specifically, the difference in the volumetric blood flow rate in corresponding arteries between the MTs is from 16% (smallest) in anterior choroidal artery (AChA) to 221% (largest) in the ophthalmic artery (OphA), varying with specific compared arteries. Also, the registered hemodynamic indicators, such as the maximum time-averaged wall shear stress (TWSS) (53.6 Pa vs. 37.8 Pa), and different local OSI distributions were observed between the MTs. The findings revealed that morphological variations in MTs could be generated by embryological and environmental factors, thus assuming they share the identical morphology in cardiovascular and neurovascular systems may lead to significant misevaluations in hemodynamics quantifications and further lesions.

Published
2023

22. An event-based typology of hydrological droughts in Bavaria: Type definition, uncertainties and future probability changes at decadal scales

Author

Böhnisch, A., Sasse, A., Wood, R., and Ludwig, R.

Abstract

Southern Germany was subject to considerably adverse effects on water supply during recent hot and dry (compound) summers like 2022, 2018 or 2015. They included, but were not limited to drinking water scarcity, transport shortages, forest damages, and crop yield failures. Major rivers experienced extreme low flows which in parts caused or aggravated these effects.In order to categorize these (hydrological) drought events, we investigate the occurrence and extremeness of alike events in observational data and hydrological simulations in 98 southern German, Austrian and Swiss river catchments under current and climate change conditions. Low flow events correspond to days below a variable percentile threshold with respect to 1991-2020. Recently observed events serve as analogue for event type definition. Event type (e.g., 2018-type) specific characteristics include volume deficit, event duration, and spatial coverage. With this, we also address limitations and uncertainties related to event type definition. Since we aim at robustly quantifying these event types, their characteristics and implications, the sample size of observational records alone is insufficient. Therefore, we employ a large single model initial condition ensemble of a regional climate model (the Canadian Regional Climate Model, version 5; CRCM5-LE) to produce 50 instances of hydrological simulations (1960-2099) in the Water balance Simulation Model (WaSiM).This allows to also investigate currently extremely unlikely or newly emerging events. We further use the comprehensive sample of typified events in the ensemble to assess preceding meteorological and hydrological conditions to create a basis of potential drought predictors on catchment scale., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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23. Retrieval of freeze/thaw-cycles using remote sensing data with deep learning approach in western Nunavik (Québec, Canada)

Author

Chen, Y., Li, S., Wang, L., Mittermeier, M., Bernier, M., and Ludwig, R.

Abstract

As an important component in the terrestrial cryosphere, the soil freeze-thaw (FT) cycle plays a determinant role in climatic, hydrological, ecological, and biogeochemical processes in permafrost landscapes. The FT-state can be monitored exactly with in-situ field measurements, which is costly and limited to single chosen sites. Remote sensing data provides the possibility of collecting information over a large area repeatedly. To explore a more effective way to monitor the FT states in the terrestrial cryosphere, we used microwave and optic remote sensing data and introduced the Deep Learning approach to simulate the soil FT state. MLP and CNN networks were trained and tested with, respectively, over 35000 and about 54000 randomly selected data samples over the entire western part of Nunavik, Canada. The data were labeled following chosen FT reference periods in a year. The trained CNN networks generally performed better than MLP networks and reached model accuracies of around 95%. Different feature combinations and FT references were tested and discussed. The model performance is further validated with a ground truth data set and an extended conceptual ground truth data set. These two sets are built independently of the training and testing sets based on in-situ data from 30 measurement stations from all seasons in a year and reached the accuracies of 87.27% and 94.70, respectively., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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24. The deepest geoid low on Earth and its possible relation to the instability of the West Antarctic Ice Sheet

Author

Steinberger, B., Grasnick, M., and Ludwig, R.

Abstract

The deepest geoid low globally w.r.t. hydrostatic equilibrium is in the Ross Sea area. Nearby in West Antarctica is a residual topography high. Both are in a region with thin lithosphere, where a mantle plume has been suggested. Hence upper mantle viscosity could be regionally reduced, allowing for faster rebound than elsewhere upon melting of the West Antarctic Ice Sheet, one of the global climate system's tipping elements. To study possible causes of the geoid low / topography high combination, we compute the effects of disk-shaped density anomalies. With -1% density anomaly, geoid low and topography high can be explained with disk radius ~10° and depth range ~150-650km. Alternatively, there may be two separate disks somewhat laterally displaced, one just below the lithosphere and mainly causing a dynamic topography high and one below the transition zone causing the geoid low. In order to test the feasibility of such density models, we perform computations of a plume that enters at the base of a cartesian box corresponding to a region in the upper mantle, as well as some whole-mantle plume models, with ASPECT. However, these plume models have typically a narrow conduit and the plume tends to only become wider as it spreads beneath the lithosphere, typically shallower than ~300km, hence they would tend to rather under-predict the amplitude of the geoid compared to dynamic topography. We discuss how to possibly overcome the discrepancy between what is required to explain geoid and dynamic topography, and the outcome of numerical forward models., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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30. Leveraging parameter dependencies in high-field asymmetric waveform ion-mobility spectrometry and size exclusion chromatography for proteome-wide cross-linking mass spectrometry

Author

Ludwig R. Sinn, Sven H. Giese, Marchel Stuiver, and Juri Rappsilber

Subjects
543 Analytische Chemie, gel, Proteome, nucleic acid structure, proteome, peptides and proteins, Mass Spectrometry, Analytical Chemistry, methods, ion mobility spectrometry, Ion Mobility Spectrometry, 572 Biochemie, Chromatography, Gel, liquid chromatography, chromatography, precursors, liquid, Chromatography, Liquid, mass spectrometry
Abstract

Ion-mobility spectrometry shows great promise to tackle analytically challenging research questions by adding another separation dimension to liquid chromatography-mass spectrometry. The understanding of how analyte properties influence ion mobility has increased through recent studies, but no clear rationale for the design of customized experimental settings has emerged. Here, we leverage machine learning to deepen our understanding of field asymmetric waveform ion-mobility spectrometry for the analysis of cross-linked peptides. Knowing that predominantly m/z and then the size and charge state of an analyte influence the separation, we found ideal compensation voltages correlating with the size exclusion chromatography fraction number. The effect of this relationship on the analytical depth can be substantial as exploiting it allowed us to almost double unique residue pair detections in a proteome-wide cross-linking experiment. Other applications involving liquid- and gas-phase separation may also benefit from considering such parameter dependencies.

Published
2022

32. Comparison of the effects of cold water immersion and percussive massage on the recovery after exhausting eccentric exercise: A three-armed randomized controlled trial

Author

Lars Heinke, Sasha Javanmardi, Ludwig Rappelt, Andreas Konrad, Robert Schleip, Axel J. Knicker, Jürgen Freiwald, and Christian Baumgart

Subjects
performance recovery, cold water immersion, percussive massage, fatigue, eccentric exercise, counter movement jumps, Physiology, QP1-981
Abstract

IntroductionAthletic training requires both challenging stimuli for adaptation and sufficient recovery for improved performance. While cold water immersion (CWI) is already a popular recovery method, handheld percussive massage (PM) devices have also gained popularity in recent years. This study aims to assess the effects of CWI and PM on performance recovery after strenuous eccentric exercises compared to a passive rest (PR) control condition.MethodsThirty-four healthy physically active participants (9 females, 25 males) were randomly divided into three groups: CWI (n = 11), PM (n = 11), and passive rest (PR) (n = 12). They underwent an exhausting eccentric exercise protocol and different measurements at six time points (baseline, POST1, POST2, POST24, POST48, and POST72) over the time course of 72 h. These included subjective assessments of muscle soreness and perceived stiffness as well as measures of skin temperature, leg volume, creatine kinase activity, and three different jump tests. The eccentric exercise protocol consisted of 15 min downhill running (slope: 12%, speed: 10 km/h) and 3 sets of successive depth jumps (dropping height: 0.5 m) until individual exhaustion. After POST1 measurements, participants received 12 min of either CWI (11 ± 0.5°C), PM (40 Hz) or PR (supine posture).ResultsNo significant group effects were found for the number of depth jumps performed during the exhaustion protocol. All jump tests displayed a significant group × time interaction effect. Post-hoc analysis indicated significant lower jump heights in ΔPOST2 between CWI and both PM and PR. No other significant group effects were observed at any time point. No significant group × time interaction effects were noted for CK, leg volume, and soreness. The perceived stiffness showed a significant group × time interaction effect. Post-hoc analysis revealed a significant decrease in stiffness for PM compared to PR at ΔPOST2.ConclusionNeither CWI nor PM showed any significant improvement in performance recovery over the 72-h period following strenuous eccentric exercise compared to PR. CWI showed an immediate performance decline which may be attributed to a cold-related reduction in motor nerve conduction velocity.

Published
2024
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35. Post-activation performance enhancement (PAPE) protocols do not further increase jumping performance beyond warm-up effects: findings from three acute randomized crossover trials

Author

Ludwig Rappelt, Steffen Held, Tim Wiedenmann, Florian Micke, and Lars Donath

Subjects
PAP, counter-movement-jump, potentiation, resistance training, maximal voluntary contraction, muscle, Physiology, QP1-981
Abstract

Introduction: Post-activation performance enhancement (PAPE) cannot be clearly distinguished from and may be explained in large by warm-up effects. To disentangle PAPE from a systemic warm-up effect, we conducted three randomized crossover trials (RCT).Methods: Each RCT consisted of a familiarization/one-repetition-maximum (1RM) assessment session followed by two interventional sessions (random order). In Study I, 18 participants (age: 26 ± 4 years; height: 1.84 ± 0.06 m; mass: 83.7 ± 8.7 kg; Squat-1RM: 146 ± 19 kg) performed either a 3-s isometric squat at 130%1RM or a 6-s isometric squat at 65%1RM. In Study II, 28 participants (11 female; age: 23 ± 3 years; height: 1.77 ± 0.08 m; mass: 76.5 ± 10.4 kg; Squat-1RM: 109 ± 38 kg) completed either Squat (3 × 3 repetitions, 85%1RM) or local electromyostimulation of the quadriceps muscle (85% of individual pain threshold). In Study III, 20 participants (6 female, age: 25.0 ± 3.5 years, mass: 78.5 ± 15.8 kg, height: 1.75 ± 0.08 m; SQ-1RM: 114 ± 33 kg, chest-press-1RM: 74 ± 29 kg) performed either squats or chest press (4 repetitions, 80%1RM). Counter-Movement-Jump height (CMJ) was assessed after a general (PRE) and/or muscle-specific warm-up (POST_WU) and for up to 11 min after the PAPE protocols. To identify possible differences in CMJ between the experimental conditions, mixed-design ANOVA models were used for each study individually, with condition and time modelled as fixed effects, while participants were included as a random effect blocking factor. The level of statistical significance was set at α = 5%.Results: In studies I and II, significant effects for time (p < 0.05, ωp2 = 0.06 and p < 0.001, ωp2 = 0.43) were found with the highest CMJ compared to all other time points at PRE (≤8.2 ± 4.6%, standardized mean difference: ≤0.39), regardless of condition. In study III, no significant effects were observed.Discussion: Thus, PAPE protocols do not further improve jumping performance compared to a general and muscle-specific traditional warm-up. Prior to tasks requiring explosive strength, general and sport-specific warm-up strategies should be used.

Published
2024
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36. Concurrent validity of countermovement and squat jump height assessed with a contact mat and force platform in professional soccer players

Author

Ludwig Ruf, Stefan Altmann, Katharina Müller, Anja Rehborn, Fabian Schindler, Alexander Woll, and Sascha Härtel

Subjects
adults, vertical jumping, football, testing, accuracy, Sports, GV557-1198.995
Abstract

PurposeThe aim of this study was to assess the concurrent validity of a contact mat against force plates to measure jump height in countermovement jump (CMJ) and squat jump (SJ) in professional soccer players.Methods23 male professional soccer players performed the CMJ and SJ, which were concurrently recorded using a portable contact mat (SmartJump) and a portable dual force plate system (ForceDecks). Equivalence testing between both systems (contact mat vs. force plate) and the two methods (impulse-momentum vs. flight-time and flight-time vs. flight-time) was performed compared to equivalence bounds of ±1.1 cm for the CMJ and ±1.6 cm for the SJ. Additionally, 95% Limits of Agreement (LoA) and intraclass correlation coefficients (ICC) were computed.ResultsMean differences for the impulse-momentum vs. flight-time comparison for CMJ [3.2 cm, 95% CI (2.3–4.1)] and SJ [2.7 cm, (1.8–3.6)] were non-equivalent between both systems. LoA were larger than the equivalence bunds for CMJ and SJ, while ICCs were good [CMJ, 0.89, (0.76–0.95)] and excellent [SJ, 0.91, (0.79–0.96)]. As for the flight-time vs. flight-time comparison, mean differences were non-equivalent for the CMJ [1.0 cm (0.8 to 1.2 cm)] and equivalent for the SJ [0.9 cm (0.7–1.1 cm)]. LoA were narrower than the equivalence bounds for CMJ and SJ, while ICCs were excellent [CMJ, 0.995, 95% CI (0.989–0.998); SJ, 0.997, 95% CI (0.993–0.997)].ConclusionOur findings indicate that the SmartJump contact mat cannot be used interchangeably with the ForceDecks force platform to measure jump height for the CMJ and SJ.

Published
2024
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37. Handcycling with concurrent lower body low-frequency electromyostimulation significantly increases acute oxygen uptake in elite wheelchair basketball players: an acute crossover trial

Author

Ludwig Rappelt, Steffen Held, Florian Micke, Tim Wiedenmann, Jan-Philip Deutsch, Heinz Kleinöder, and Lars Donath

Subjects
Cardiorespiratory fitness, EMS, Electrical muscle stimulation, Endurance, SCI, Spinal cord injury, Therapeutics. Pharmacology, RM1-950
Abstract

Objective: Wheelchair basketball (WCB) demands high-intensity training due to its intermittent nature. However, acute oxygen uptake (V˙O2) in handcycling is restricted. Combining handcycling with low-frequency electromyostimulation (LF-EMS) may enhance V˙O2 in elite WBC athletes. Design: Randomized crossover trail. Subjects: Twelve German national team WCB players (age: 25.6 [5.6] years, height: 1.75 [0.16] m, mass: 74.0 [21.7] kg, classification: 2.92 [1.26]). Method: Participants underwent 2×5 min of handcycling (60 rpm, ¾ bodyweight resistance in watts) (HANDCYCLE) and 2×5 min of handcycling with concurrent LF-EMS (EMS_HANDCYCLE). LF-EMS (4Hz, 350µs, continuous stimulation) targeted gluteal, quadriceps, and calf muscles, adjusted to individual pain thresholds (buttocks: 69.5 [22.3] mA, thighs: 66.8 [20.0] mA, calves: 68.9 [31.5] mA). Results: Significant mode-dependent differences between HANDCYCLE and EMS_HANDCYCLE were found in V˙O2 (17.60 [3.57] vs 19.23 [4.37] ml min-1 kg-1, p = 0.001) and oxygen pulse (16.69 [4.51] vs 18.41 [5.17] ml, p = 0.002). ΔLactate was significantly lower in HANDCYCLE (0.04 [0.28] vs 0.31 [0.26] mmol l-1). Although perceived effort did not differ (p = 0.293), discomfort was rated lower in HANDCYCLE (1.44 [1.28] vs 3.94 [2.14], p = 0.002). Conclusion: LF-EMS applied to the lower extremities increases oxygen demand during submaximal handcycling. Thus, longitudinal application of LF-EMS should be investigated as a potential training stimulus to improve aerobic capacity in wheelchair athletes.

Published
2024
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38. Early sedation with dexmedetomidine in ventilated critically ill patients and heterogeneity of treatment effect in the SPICE III randomised controlled trial.

Author

Abidin H.Z., Hassan M.H., Omar S.C., Shukeri W.F.W., Brealey D., Bercades G., Blackburn E., Macallum N., Macklin A., Ryu J.H., Tam K., Smyth D., Arif A., Bassford C., Morgan C., Swann C., Ward G., Wild L., Bone A., Elderkin T., Green D., Sach D., Salerno T., Simpson N., Brohi F., Clark M., Williams L., Brooks J., Cocks E., Cole J., Curtin J., Davies R., Hill H., Morgan M., Palmer N., Whitton C., Wise M., Baskaran P., Hasan M.S., Tham L.Y., Cruz R.S., Dinsdale D., Edney S., Firkin C., FitzJohn F., Hill G., Hunt A., Hurford S., Jones G., Judd H., Latimer-Bell C., Lawrence C., Lesona E., Navarra L., Robertson Y., Smellie H., Vucago A.M., Young P., Dawson H., Griffith D.M., Paterson R., Clark P., Kong J., Ho J., Nayyar V., Skelly C., Shehabi Y., Serpa Neto A., Howe B.D., Arabi Y.M., Bass F.E., Kadiman S.B., McArthur C.J., Reade M.C., Seppelt I.M., Wise M.P., Mashonganyika C., McKee H., Tonks A., Donnelly A., Hemmings N., O'Kane S., Blakemore A., Butler M., Cowdrey K., Dalton J., Gilder E., Long S., McCarthy L., McGuinness S., Parke R., Chen Y., McArthur C., McConnochie R., Newby L., Bellomo R., Eastwood G., Peck L., Young H., Boschert C., Edington J., Fletcher J., Nand K., Raza A., Sara T., Bennett-Britton J., Bewley J., Bodenham V., Cole L., Driver K., Grimmer L., Howie L., Searles C., Sweet K., Webster D., van Berkel A., Connor H., Dennett J., van Der Graaff M., Henderson S., Mehrtens J., Miller K., Minto E., Morris A., Noble S., Parker K., Hart N., Shepherd K., Vij S., Dickson S., Elloway E., Ferguson C., Jackson R., MacNaughton P., Marner M., Squire R., Waddy S., Wafer P., Welbourne J., Ashcroft P., Chambler D., Dukes S., Harris A., Horton S., Sharpe S., Williams P., Williams S., Bailey M., Blazquez E., France D., Hutchison R., Comadira G., Gough M., Tallott M., Bastick M., Cameron R., Donovan S., Gaur A., Gregory R., Naumoff J., Turner E., White M., Au K.F.J., Fratzia J., Treloar S., Lim C.H., Maseeda Y., Tan A.P., Tang C.L., Yong C.Y., Akaltan M., Berger S., Blaser D., Fazlija L., Jong M.L., Lensch M., Ludwig R., Merz T., Nettelbeck K., Roth M., Schafer M., Takala J., Wehr A., Zacharias D., Amran R., Ashraf H.N., Azmi N., Basri N., Burhanuddin H., Hadinata Y., Hamdan A., Kadiman S., Rashid A.I.Y.M., Sabran I.N., Sulaiman S., Zabidi I.N., Al-Dawood A., Aljuaid M., Al Anizi H., Al Saeedi A., Arabi Y., Dbsawy M., Deeb A., Hegazy M., Magdi I., Corcoran E., Finney C., Dumlao L.A., Bassam R., Hassan M.A., Naseem N., Al-Kurdi M.H., Al-Harthy A.M., Bernard S., Sebafundi L., Serban C., Lim S.K., Mazidah N., Saidin N., Sjamsuddin N., Tan I.T.A., Zabidi N., Brain M., Mineall S., Kanhere M., Soar N., Kadir N.A., Abdullah N.H., Awang R., Emperan Z., Husin N.S., Ismail N.I., Ismail S.Z., Khadzali F.N.A.M., Norddin M.F., Aguila J., Bold C., Clatworthy B., Dias A., Hogan C., Kazemi A., Lai V., Song R., Williams A., Bhatia D., Bulfin L., Elliot S., Galt P., Lavrans K., Ritchie P., Wang A., Gresham R., Lowrey J., Masters K., Palejs P., Seppelt I., Symonds F., Weisbrodt L., Whitehead C., Babio-Galan M., Calder V., Clement I., Harrison A., McCullagh I., Scott C., Bevan R., Caniba S., Hacking D., Maher L., Azzolini M.L., Beccaria P., Colombo S., Landoni G., Leggieri C., Luca C., Mamo D., Moizo E., Monti G., Mucci M., Zangrillo A., Albania M., Arora S., Shi Y., Abudayah A., Almekhlafi G., Al Amodi E., Al Samarrai S., Badawi M., Caba R.C., Elffaki O., Mandourah Y., Valerio J., Joyce C., Meyer J., Saylor E., Venkatesh B., Venz E., Walsham J., Wetzig K., Clarey E., Harris C., Hopkins P., Noble H., Thompson L., Williams T., Khoo T.M., Liew J.E.S., Sakthi A.N., Zulkurnain A., Bamford A., Bergin C., Carrera R., Cooper L., Despy L., Ellis K., Harkett S., Mee L., Reeves E., Snelson C., Spruce E., Cooper G., Hodgson R., Pearson D., Rosbergen M., Ali M.N., Bahar N.I., Ismail A., Ismail W.N.W., Samat N.M., Piah N.S.M., Rahman R.A., Duroux M., Ratcliffe M., Warhurst T., Buehner U., Williams E., Jacques N., Keating L., Macgill S., Tamang K.L., Tolan N., Walden A., Bower R., Cranshaw J., Molloy K., Pitts S., Butler J., Dunlop R., Fourie C., Jarrett P., Lassig-Smith M., Livermore A., O'Donoghue S., Reade M., Starr T., Stuart J., Campbell L., Phillips M., Stephens D., Thomas J., Cooper D., McAllister R., Andrew G., Barclay L., Hope D., Wojcik G., McCulloch C., Ascough L., Paisley C., Patrick-Heselton J., Shaw D., Waugh V., Williams K., Welters I., Barge D., Jordan A., MacIsaac C., Rechnitzer T., Bass F., Gatward J., Hammond N., Janin P., O'Connor A., Stedman W., Yarad E., Razak N.A., Dzulkipli N., Jong S.L., Asen K., Voon W.L., Liew S., Ball J., Barnes V., Dalton C., Farnell-Ward S., Farrah H., Maher K., Mellinghoff J., Ryan C., Shirley P., Conlon L., Glover A., Martin-Loeches I., O'Toole E., Ewan J., Ferrier J., Litton E., Webb S.A., Berry W., Alonso U.B., Bociek A., Campos S., Jawara S., Hanks F., Kelly A., Lei K., McKenzie C., Ostermann M., Wan R., Al-Soufi S., Leow S., McCann K., Reynolds C., Brickell K., Fahey C., Hays L., Hyde N., Nichol A., Ryan D., Brailsford J., Buckley A., Forbes L., Maguire T., Moore J., Murray L., Ghosh A., Park M., Said S., Smith J., Visser A., Ali S., Abidin H.Z., Hassan M.H., Omar S.C., Shukeri W.F.W., Brealey D., Bercades G., Blackburn E., Macallum N., Macklin A., Ryu J.H., Tam K., Smyth D., Arif A., Bassford C., Morgan C., Swann C., Ward G., Wild L., Bone A., Elderkin T., Green D., Sach D., Salerno T., Simpson N., Brohi F., Clark M., Williams L., Brooks J., Cocks E., Cole J., Curtin J., Davies R., Hill H., Morgan M., Palmer N., Whitton C., Wise M., Baskaran P., Hasan M.S., Tham L.Y., Cruz R.S., Dinsdale D., Edney S., Firkin C., FitzJohn F., Hill G., Hunt A., Hurford S., Jones G., Judd H., Latimer-Bell C., Lawrence C., Lesona E., Navarra L., Robertson Y., Smellie H., Vucago A.M., Young P., Dawson H., Griffith D.M., Paterson R., Clark P., Kong J., Ho J., Nayyar V., Skelly C., Shehabi Y., Serpa Neto A., Howe B.D., Arabi Y.M., Bass F.E., Kadiman S.B., McArthur C.J., Reade M.C., Seppelt I.M., Wise M.P., Mashonganyika C., McKee H., Tonks A., Donnelly A., Hemmings N., O'Kane S., Blakemore A., Butler M., Cowdrey K., Dalton J., Gilder E., Long S., McCarthy L., McGuinness S., Parke R., Chen Y., McArthur C., McConnochie R., Newby L., Bellomo R., Eastwood G., Peck L., Young H., Boschert C., Edington J., Fletcher J., Nand K., Raza A., Sara T., Bennett-Britton J., Bewley J., Bodenham V., Cole L., Driver K., Grimmer L., Howie L., Searles C., Sweet K., Webster D., van Berkel A., Connor H., Dennett J., van Der Graaff M., Henderson S., Mehrtens J., Miller K., Minto E., Morris A., Noble S., Parker K., Hart N., Shepherd K., Vij S., Dickson S., Elloway E., Ferguson C., Jackson R., MacNaughton P., Marner M., Squire R., Waddy S., Wafer P., Welbourne J., Ashcroft P., Chambler D., Dukes S., Harris A., Horton S., Sharpe S., Williams P., Williams S., Bailey M., Blazquez E., France D., Hutchison R., Comadira G., Gough M., Tallott M., Bastick M., Cameron R., Donovan S., Gaur A., Gregory R., Naumoff J., Turner E., White M., Au K.F.J., Fratzia J., Treloar S., Lim C.H., Maseeda Y., Tan A.P., Tang C.L., Yong C.Y., Akaltan M., Berger S., Blaser D., Fazlija L., Jong M.L., Lensch M., Ludwig R., Merz T., Nettelbeck K., Roth M., Schafer M., Takala J., Wehr A., Zacharias D., Amran R., Ashraf H.N., Azmi N., Basri N., Burhanuddin H., Hadinata Y., Hamdan A., Kadiman S., Rashid A.I.Y.M., Sabran I.N., Sulaiman S., Zabidi I.N., Al-Dawood A., Aljuaid M., Al Anizi H., Al Saeedi A., Arabi Y., Dbsawy M., Deeb A., Hegazy M., Magdi I., Corcoran E., Finney C., Dumlao L.A., Bassam R., Hassan M.A., Naseem N., Al-Kurdi M.H., Al-Harthy A.M., Bernard S., Sebafundi L., Serban C., Lim S.K., Mazidah N., Saidin N., Sjamsuddin N., Tan I.T.A., Zabidi N., Brain M., Mineall S., Kanhere M., Soar N., Kadir N.A., Abdullah N.H., Awang R., Emperan Z., Husin N.S., Ismail N.I., Ismail S.Z., Khadzali F.N.A.M., Norddin M.F., Aguila J., Bold C., Clatworthy B., Dias A., Hogan C., Kazemi A., Lai V., Song R., Williams A., Bhatia D., Bulfin L., Elliot S., Galt P., Lavrans K., Ritchie P., Wang A., Gresham R., Lowrey J., Masters K., Palejs P., Seppelt I., Symonds F., Weisbrodt L., Whitehead C., Babio-Galan M., Calder V., Clement I., Harrison A., McCullagh I., Scott C., Bevan R., Caniba S., Hacking D., Maher L., Azzolini M.L., Beccaria P., Colombo S., Landoni G., Leggieri C., Luca C., Mamo D., Moizo E., Monti G., Mucci M., Zangrillo A., Albania M., Arora S., Shi Y., Abudayah A., Almekhlafi G., Al Amodi E., Al Samarrai S., Badawi M., Caba R.C., Elffaki O., Mandourah Y., Valerio J., Joyce C., Meyer J., Saylor E., Venkatesh B., Venz E., Walsham J., Wetzig K., Clarey E., Harris C., Hopkins P., Noble H., Thompson L., Williams T., Khoo T.M., Liew J.E.S., Sakthi A.N., Zulkurnain A., Bamford A., Bergin C., Carrera R., Cooper L., Despy L., Ellis K., Harkett S., Mee L., Reeves E., Snelson C., Spruce E., Cooper G., Hodgson R., Pearson D., Rosbergen M., Ali M.N., Bahar N.I., Ismail A., Ismail W.N.W., Samat N.M., Piah N.S.M., Rahman R.A., Duroux M., Ratcliffe M., Warhurst T., Buehner U., Williams E., Jacques N., Keating L., Macgill S., Tamang K.L., Tolan N., Walden A., Bower R., Cranshaw J., Molloy K., Pitts S., Butler J., Dunlop R., Fourie C., Jarrett P., Lassig-Smith M., Livermore A., O'Donoghue S., Reade M., Starr T., Stuart J., Campbell L., Phillips M., Stephens D., Thomas J., Cooper D., McAllister R., Andrew G., Barclay L., Hope D., Wojcik G., McCulloch C., Ascough L., Paisley C., Patrick-Heselton J., Shaw D., Waugh V., Williams K., Welters I., Barge D., Jordan A., MacIsaac C., Rechnitzer T., Bass F., Gatward J., Hammond N., Janin P., O'Connor A., Stedman W., Yarad E., Razak N.A., Dzulkipli N., Jong S.L., Asen K., Voon W.L., Liew S., Ball J., Barnes V., Dalton C., Farnell-Ward S., Farrah H., Maher K., Mellinghoff J., Ryan C., Shirley P., Conlon L., Glover A., Martin-Loeches I., O'Toole E., Ewan J., Ferrier J., Litton E., Webb S.A., Berry W., Alonso U.B., Bociek A., Campos S., Jawara S., Hanks F., Kelly A., Lei K., McKenzie C., Ostermann M., Wan R., Al-Soufi S., Leow S., McCann K., Reynolds C., Brickell K., Fahey C., Hays L., Hyde N., Nichol A., Ryan D., Brailsford J., Buckley A., Forbes L., Maguire T., Moore J., Murray L., Ghosh A., Park M., Said S., Smith J., Visser A., and Ali S.

Abstract

Purpose: To quantify potential heterogeneity of treatment effect (HTE), of early sedation with dexmedetomidine (DEX) compared with usual care, and identify patients who have a high probability of lower or higher 90-day mortality according to age, and other identified clusters. Method(s): Bayesian analysis of 3904 critically ill adult patients expected to receive invasive ventilation > 24 h and enrolled in a multinational randomized controlled trial comparing early DEX with usual care sedation. Result(s): HTE was assessed according to age and clusters (based on 12 baseline characteristics) using a Bayesian hierarchical models. DEX was associated with lower 90-day mortality compared to usual care in patients > 65 years (odds ratio [OR], 0.83 [95% credible interval [CrI] 0.68-1.00], with 97.7% probability of reduced mortality across broad categories of illness severity. Conversely, the probability of increased mortality in patients = 65 years was 98.5% (OR 1.26 [95% CrI 1.02-1.56]. Two clusters were identified: cluster 1 (976 patients) mostly operative, and cluster 2 (2346 patients), predominantly non-operative. There was a greater probability of benefit with DEX in cluster 1 (OR 0.86 [95% CrI 0.65-1.14]) across broad categories of age, with 86.4% probability that DEX is more beneficial in cluster 1 than cluster 2. Conclusion(s): In critically ill mechanically ventilated patients, early sedation with dexmedetomidine exhibited a high probability of reduced 90-day mortality in older patients regardless of operative or non-operative cluster status. Conversely, a high probability of increased 90-day mortality was observed in younger patients of non-operative status. Further studies are needed to confirm these findings.Copyright © 2021, Crown.

Published
2021

40. The European Climate Research Alliance (ECRA): Collaboration from bottom-up

Author

Hoke W., Swierczynski T., Braesicke P., Lochte K., Shaffrey L., Drews M., Gregow H., Ludwig R., Nilsen J. E. O., Palazzi E., Sannino G., Smedsrud L. H., Hoke, W., Swierczynski, T., Braesicke, P., Lochte, K., Shaffrey, L., Drews, M., Gregow, H., Ludwig, R., Nilsen, J. E. O., Palazzi, E., Sannino, G., and Smedsrud, L. H.

Abstract

The European Climate Research Alliance (ECRA) is an association of leading European research institutions in the field of climate research (http://www.ecra-climate.eu/, last access: 6 December 2018). ECRA is a bottom-up initiative and helps to facilitate the development of climate change research, combining the capacities of national research institutions, and inducing closer ties between existing national research initiatives, projects and infrastructures. ECRA works as an open platform to bring together climate researchers, providing excellent scientific expertise for policy makers and of societal relevance. The ECRA Board consists of representatives of ECRA partners and decides on governance, scientific priorities, and organisational matters. Currently organized into four Collaborative Programmes, climate scientists share their knowledge, experience and expertise to identify the most important research requirements for the future, thus developing a foresight approach. The CPs cover the topics: (1) Arctic variability and change, (2) Sea level changes and coastal impacts, (3) Changes in the hydrological cycle and (4) High impact events. The CP activities are planned in workshops and participation is open to all interested scientists from the relevant research fields. In particular, young researchers are actively encouraged to join the network. Each CP develops its joint research priorities for shaping European research into the future. Because scientific themes are interconnected, the four Collaborative Programmes interact with each other, e.g.Through the organization of common workshops or joint applications. In addition, the Collaborative Programme leads attend the Board meetings. The different formats of ECRA meetings range from scientific workshops to briefing events and side events at conferences to involve different groups of interests. This facilitates the interaction of scientists, various stakeholder groups and politicians. A biennial open ECRA General Assembly that is organised in Brussels represents an umbrella event and acts as a platform for discussion and contact with stakeholders. This event is an excellent opportunity to jointly discuss research priorities of high societal relevance. 2019

Published
2019

41. Valoración geriátrica integral en una comunidad marginal de Ecuador

Author

Álvarez Córdova,Ludwig R, Artacho,Reyes, Arteaga,Cecilia, Fonseca Pérez,Diana, Sierra Nieto,Víctor H, and Ruiz-López,María Dolores

Subjects
Adulto mayor, Evaluación geriátrica integral, Atención primaria
Abstract

Resumen Antecedentes: los adultos mayores presentan enfermedades que pueden repercutir en sus parámetros funcionales, psicológicos y sociales. La Valoración Geriátrica integral (VGI) se utiliza como herramienta de evaluación de estos parámetros a través del uso de instrumentos validados, sencillos y de fácil aplicación. Objetivo: determinar el estado de salud de los adultos mayores en un área urbano-marginal de Guayaquil (Ecuador) mediante la VGI, como primer paso para poder establecer un plan de cuidados coordinado en las áreas estudiadas. Material y métodos: estudio transversal de 196 sujetos mayores de 65 años que acuden a un centro de salud comunitario de atención primaria en Guayaquil y a los que se les ha realizado una VGI. Resultados: los participantes tenían una edad media de 70,9 ± 7,1 años. Variables demográficas: el 73 % eran afroecuatorianos, el 69 % tenían instrucción básica y el 57 % no realizaban ninguna actividad física. Evaluación clínica: el 47,4 % presentaban dificultad de visión, el 52 % riesgo nutricional y el 6 % desnutrición. Valoración social: el 13 % tenían deterioro social severo; el 40 % presentaban algún deterioro cognitivo y el 8,2 % tenían depresión; el 46,9 % eran funcionalmente dependientes y el 16,8 % presentaban dinapenia. Conclusiones: la VGI permite identificar los principales problemas de salud de esta población, por lo que se considera una herramienta práctica y fácil de aplicar en los centros de atención primaria de las poblaciones urbano-marginales, como primer paso para mejorar el estado de salud de esta población mayor que en los últimos años está creciendo de forma importante en los países en vías de desarrollo tales como Ecuador.

Published
2020

42. Perfil antropométrico y composición corporal en Futbolistas de élite ecuatorianos según su posición de juego

Author

Quiroz Brunes, Jestin A., Poveda Loor, Carlos L., Cabañas Armesilla, María D., Álvarez Córdova, Ludwig R., Quiroz Brunes, Jestin A., Poveda Loor, Carlos L., Cabañas Armesilla, María D., and Álvarez Córdova, Ludwig R.

Abstract

Background: Kinanthropometry is essential for the quantitative assessment of the body composition (BC) and nutritional status of athletes. Objective: To describe the anthropometric characteristics, the BC and the specific somatotype of professional soccer players.Method: Anthropometric variables were analyzed in male professional soccer players from a first division team of the Ecuadorian soccer league, evaluating the somatotype, BC, fat mass (FM) and fat free mass (FFM) according to playing position. Results: Mean height, weight, age and body mass index (BMI) of all players was 179 ± 5.1 cm, 78 ± 7.1 kg, 25.0 ± 5 years and 24.9 ± 2.2 Kg/m2, respectively; with the midfielders being older and the goalkeepers and forwards being taller. The average body fat percentage (BF%) was 13.1 ± 3.3%, with this value being higher in goalkeepers and lower in defensemen. Mean FFM (%) was 45.2 ±1.7%, FM 9.8 ± 2.9 Kg and FFM 66 ± 5.8 Kg. The somatotype of the soccer players (n=30) was endomorphic (1.8 ± 0.5), mesomorphic (5.4 ± 0.9) and ectomorphic (1.8 ± 0.8). There were significant differences between goalkeepers compared to defenders and forwards in terms of endomorphic somatotype. However, all players regardless of their playing position presented a meso-balanced somatotype. Conclusion: According to the playing position soccer players presented a meso-balanced somatotype; with a BC according to what has been published in the literature regarding this sport., Antecedente: La cineantropometría es imprescindible para la valora-ción cuantitativa de la composición corporal (CC) y estado nutricional de los deportistas.Objetivo: Describir las características antropométricas, la CC y el somatotipo específico de futbolistas profesionales.Método: Se analizaron las variables antropométricas de 30 futbo-listas profesionales masculinos de un equipo de primera división de la liga ecuatoriana de fútbol, evaluándose el somatotipo, CC, masa grasa (MG) y masa libre de grasa (MLG) según posición de juego. Resultados: La media de talla, peso, edad, e índice de masa corporal (IMC) de todos los participantes fue: 179.0 ± 5.3 cm, 78.4 ± 7.0 Kg, 25.0 ± 5 años, 24.9 ± 2.2 Kg/m2, respectivamente; siendo de mayor edad los centrocampistas y de mayor talla los porteros y delanteros. La media de porcentaje de grasa corporal (% GC) fue de 13.1 ± 3.3%, siendo mayor en los porteros y menor en los defensas. El promedio de MLG (%) fue 45.2 ± 1.7%, de MG 9.8 ± 2.9 Kg y MLG 66.0 ± 5.8 Kg. El somatotipo de los futbolistas (n=30) fue endomorfio (1.8 ±0.5), mesomorfio (5.4 ± 0.9) y ectomorfio (1.8 ± 0.8). Existieron diferencias significativas entre porteros en comparación con defensas y delan-teros en cuanto al somatotipo endomorfio. Sin embargo, todos los jugadores independientemente de la posición de juego presentaron un somatotipo meso-balanceado. Conclusión: Según su posición de juego los futbolistas presentaron un somatotipo meso-balanceado; con una CC acorde a lo publicado en la literatura en cuanto a este deporte.

Published
2020

43. Managing future risks and building socio-ecological resilience

Author

Cramer, Wolfgang, Guiot, Joel, Marini, Katarzyna, Vafeidis, AT, Abdulla, AA, Bondeau, A, Brotons, Ll, Ludwig, R, Portman, M, Reimann, L, Vousdoukas, M, Xoplaki, E, Aroua, N, Behr, L, Dottori, F, Garrabou, J, Giannakopoulos, C, Rohat, G, Symeonakis, Elias, Cramer, Wolfgang, Guiot, Joel, Marini, Katarzyna, Vafeidis, AT, Abdulla, AA, Bondeau, A, Brotons, Ll, Ludwig, R, Portman, M, Reimann, L, Vousdoukas, M, Xoplaki, E, Aroua, N, Behr, L, Dottori, F, Garrabou, J, Giannakopoulos, C, Rohat, G, and Symeonakis, Elias

Abstract

The Mediterranean Basin is experiencing major changes in environmental conditions, which can introduce new challenges to the resilience of its natural and human systems. This situation is combined with rapid and spatially diverse socio-economic development in the region, mainly in terms of demographic trends and settlement patterns, thus leading to higher exposure to environmental hazards. Furthermore, new risks are expected to emerge from interactions between drivers and impacts across sectors, thus increasing the vulnerability of natural systems and human populations.

Published
2020

44. The role of computational methods for automating and improving clinical target volume definition

Author

Unkelbach, J., Bortfeld, T., Cardenas, C. E., Gregoire, V., Hager, W., Heijmen, B., Jeraj, R., Korreman, S. S., Ludwig, R., Pouymayou, B., Shusharina, N., Söderberg, J., Toma-Dasu, I., (0000-0001-9550-9050) Troost, E. G. C., Osorio, E. V., Unkelbach, J., Bortfeld, T., Cardenas, C. E., Gregoire, V., Hager, W., Heijmen, B., Jeraj, R., Korreman, S. S., Ludwig, R., Pouymayou, B., Shusharina, N., Söderberg, J., Toma-Dasu, I., (0000-0001-9550-9050) Troost, E. G. C., and Osorio, E. V.

Abstract

Treatment planning in radiotherapy distinguishes three target volume concepts: the gross tumor volume (GTV), the clinical target volume (CTV), and the planning target volume (PTV). Over time, GTV definition and PTV margins have improved through the development of novel imaging techniques and better image guidance, respectively. CTV definition is sometimes considered the weakest element in the planning process. CTV definition is particularly complex since the extension of microscopic disease cannot be seen using currently available in-vivo imaging techniques. Instead, CTV definition has to incorporate knowledge of the patterns of tumor progression. While CTV delineation has largely been considered the domain of radiation oncologists, this paper, arising from a 2019 ESTRO Physics research workshop, discusses the contributions that medical physics and computer science can make by developing computational methods to support CTV definition. First, we overview the role of image segmentation algorithms, which may in part automate CTV delineation through segmentation of lymph node stations or normal tissues representing anatomical boundaries of microscopic tumor progression. The recent success of deep convolutional neural networks has also enabled learning entire CTV delineations from examples. Second, we discuss the use of mathematical models of tumor progression for CTV definition, using as example the application of glioma growth models to facilitate GTV-to-CTV expansion for glioblastoma that is consistent with neuroanatomy. We further consider statistical machine learning models to quantify lymphatic metastatic progression of tumors, which may eventually improve elective CTV definition. Lastly, we discuss approaches to incorporate uncertainty in CTV definition into treatment plan optimization as well as general limitations of the CTV concept in the case of infiltrating tumors without natural boundaries.

Published
2020

45. Residing near allergenic trees can increase risk of allergies later in life: LISA Leipzig study

Author

Markevych, I., Ludwig, R., Baumbach, C., Standl, M., Heinrich, J., Herberth, Gunda, de Hoogh, K., Pritsch, K., Weikl, F., Markevych, I., Ludwig, R., Baumbach, C., Standl, M., Heinrich, J., Herberth, Gunda, de Hoogh, K., Pritsch, K., and Weikl, F.

Abstract

BackgroundWe investigated whether residing in places with higher greenness, more trees and more allergenic trees early in life increases the risk of allergic outcomes, and whether these associations differ depending on the concentration of air pollutants.MethodsThe analytic sample included 631 children from the German birth cohort LISA Leipzig. Asthma and allergic rhinitis, sensitization to aeroallergens and food allergens, as well as confounders, were collected prospectively up to 15 years. Greenness was assessed by Normalized Difference Vegetation Index (NDVI). A tree registry was used to derive information on trees, which were classified into allergenic and non-allergenic. Annual average concentrations of nitrogen dioxide (NO2) and ozone were also used. Geographic exposures were assigned to home addresses at birth. Longitudinal associations were analysed using generalized estimating equations.ResultsMedium and high numbers (tertiles) of trees and allergenic trees in a 500 m buffer around birth addresses were associated with increased odds of allergic rhinitis up to 15 years regardless of NDVI. These exposures were also related to higher odds of sensitization to aeroallergens. Associations with asthma and sensitization to food allergens were less consistent. Effect estimates for allergic rhinitis were stronger in the high tertile of NO2 compared to the low tertile, while an opposite tendency was observed for ozone.ConclusionWe observed that early life residence in places with many trees, and allergenic trees specifically, may increase the prevalence of allergic rhinitis later in life. This association and its modification by air pollution should be pursued in further studies.

Published
2020

48. MoM volume integral equation solution for an isolated metal-dielectric resonator with the edge-based basis functions

Author

Kulkarni, S., Uy, S., Lemdiasov, R., Ludwig, R., and Makarov, S.

Subjects
Antennas (Electronics) -- Research, Resonators -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

The objective of the present study is to show that the method of volume integral used in conjunction with the zeroth-order edge-based basis functions (de Carvalho and de Souza Mendes 1999) gives an accurate and stable solution for a metal-dielectric resonator, when the number of the basis functions remains relatively small. Special attention is paid to the resonator in the form of a thin dielectric layer backed by two metal sheets. The metal surface is described in terms of the Rao--Wilton--Glisson (RWG) basis functions. Index Terms--Edge basis functions, method of moments (MoM), resonators, volume integral equation.

Published
2005

49. Comparison of two sets of low-order basis functions for tetrahedral VIE modeling

Author

Kulkarni, S., Lemdiasov, R., Ludwig, R., and Makarov, S.

Subjects
Antennas (Electronics) -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

A convergence study is made for the two types of low-order basis functions for the volume integral equation. Both functions impose the continuity of the normal component of the electric flux through the faces. The one basis function is that of Schaubert, Wilton, and Glisson and is face-based. Another basis function was first introduced by de Carvalho and de Souza Mendes and is edge-based. The exact number of unknowns for the edge-based functions is determined in this study. The study demonstrates a better performance of the edge-based basis functions compared to the face-based bases. First, the edge-based basis functions have nearly the same of a faster convergence rate for equal tetrahedral meshes. They also show a high numerical stability. Second, for the same tetrahedral mesh, the number of unknowns for the edge-based functions is considerably smaller. The ratio of unknowns (edge-based versus face-based) ranges from 0.6 for rough plate meshes to approximately 0.5 for large volumetric meshes. Third, the edge-based functions are piecewise constant and are easily implemented into the method of moments. Their disadvantage is a preliminary condition 'operation,' which implies the elimination of the nullspace of the basis set. Index Terms--Edge basis functions, method of moments (MoM), scattering, volume integral equation.

Published
2004

Catalog

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