1,173 results on '"Sandmann, P"'
Search Results
2. Environmental performance of an autonomous laser weeding robot—a case study
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Krupanek, Janusz, de Santos, Pablo Gonzales, Emmi, Luis, Wollweber, Merve, Sandmann, Hendrik, Scholle, Karsten, Di Minh Tran, Duc, Schouteten, Joachim Jietse, and Andreasen, Christian
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- 2024
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3. Acoustic Sensing after 50 km of Transmission Fibre using Coherent Optical Subassembly
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Azendorf, Florian, Sandmann, André, Reimer, Wolfgang, and Eiselt, Michael
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Electrical Engineering and Systems Science - Signal Processing ,Physics - Optics - Abstract
A coherent optical subassembly (COSA) is evaluated for coherent-correlation optical time domain reflectometry (CC-OTDR) based fibre sensing. Even though the COSA was originally designed for digital communication applications, acoustic signals with frequencies up to 360 Hz can be detected after 50 km of transmission., Comment: This work has received funding from the Horizon Europe Framework Programme under grant agreement No 101093015 (SoFiN Project) and was partially funded by the German Federal Ministry of Education and Research in the framework of the RUBIN project Quantifisens (Project ID 03RU1U071D)
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- 2023
4. Acoustic Sensing with Correlation and Coherent Detection using an Integrated Coherent Transceiver
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Sandmann, André, Azendorf, Florian, Alnairat, Saif, and Eiselt, Michael
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Physics - Instrumentation and Detectors - Abstract
Fiber optic sensing is becoming an important means to physically secure today's network infrastructure. However, a network-wide deployment of the monitors will require cost reduction of the interrogator system, which can only be achieved by highly integrated system components. In this contribution, we report on the use of an in-house designed single-chip coherent transceiver for acoustic fiber sensing. The transceiver on the basis of silicon photonics contains a high-speed dual-polarization IQ-modulator as well as a coherent receiver with balanced photodiodes and trans-impedance amplifiers, as defined by the OIF integrated coherent transmit-receive optical sub assembly (IC-TROSA) implementation agreement. The laser, used for transmission and as local oscillator, is provided external to the photonic integrated circuit and can be chosen according to the line-width requirements of the sensing system. The acoustic sensing demonstration is using a correlation-based optical time domain reflectometry with coherent detection. This method is able to detect, besides the amplitude information, the phase of the back-scattered signal, which has a significantly higher sensitivity to environmental effects on the fiber, like temperature and strain. As a proof of concept, sensing of an acoustic signal after a fiber span of 20 km is demonstrated by evaluating the obtained phase information, providing information on external dynamic events up to a frequency of 1.75 kHz., Comment: This work has received funding from the Horizon Europe Framework Programme under grant agreement No 101093015 (SoFiN Project)
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- 2023
5. Monitoring of Optical Networks Using Correlation-Aided Time-Domain Reflectometry with Direct and Coherent Detection
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Eiselt, Michael H., Azendorf, Florian, Sandmann, Andre, Spinty, Florian, and Lawin, Mirko
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Electrical Engineering and Systems Science - Signal Processing ,Physics - Optics - Abstract
We report on methods to monitor the transmission path in optical networks using a correlation-based OTDR technique with direct and coherent detection. A high probing symbol rate can provide picosecond-accuracy of the fiber propagation delay, while a sensitive phase detection with a high repetition rate allows the monitoring of dynamic effects in the vicinity of the fiber. We discuss various approaches to evaluate the measured traces and show the results of a few monitoring applications., Comment: Invited paper to OECC 2023, Shanghai, July 2-6, 2023
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- 2023
6. Simultaneous Temperature and Acoustic Sensing with Coherent Correlation OTDR
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Sandmann, André, Azendorf, Florian, and Eiselt, Michael
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Electrical Engineering and Systems Science - Signal Processing ,Physics - Instrumentation and Detectors - Abstract
Superimposed temperature variations and dynamic strain applied through a 400 Hz acoustic signal on a 195 m single-mode fiber section are successfully measured using a coherent correlation optical time domain reflectometry as an interrogator., Comment: This work was partially funded by the German Federal Ministry of Education and Research in the framework of the RUBIN project Quantifisens (Project ID 03RU1U071D)
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- 2023
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7. Systematic analysis of ChatGPT, Google search and Llama 2 for clinical decision support tasks
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Sandmann, Sarah, Riepenhausen, Sarah, Plagwitz, Lucas, and Varghese, Julian
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- 2024
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8. Predicting subnational incidence of COVID-19 cases and deaths in EU countries
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Robert, Alexis, Chapman, Lloyd A. C., Grah, Rok, Niehus, Rene, Sandmann, Frank, Prasse, Bastian, Funk, Sebastian, and Kucharski, Adam J.
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- 2024
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9. Functional traits in soil-living oribatid mites unveil trophic reorganization in belowground communities by introduced tree species
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Jing-Zhong Lu, Christian Bluhm, Estela Foltran, Carmen Alicia Rivera Pérez, Christian Ammer, Tancredi Caruso, Jonas Glatthorn, Norbert Lamersdorf, Andrea Polle, Dorothee Sandmann, Ina Schaefer, Andreas Schuldt, Mark Maraun, and Stefan Scheu
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Soil biodiversity ,Functional diversity ,Ecosystem functions ,Douglas fir ,Acari ,Community assembly ,Science - Abstract
Biodiversity loss and its potential threat on ecosystem functions call for a critical evaluation of human impacts on forest ecosystems. Management practices based on stand diversification offer a possible solution to biodiversity loss due to monoculture plantations, and these practices often involve planting introduced tree species. Although introduced non-native tree species may provide high economic returns, they may also form novel ecosystems and threaten local biodiversity, but this has been little studied. Here, we combined a taxonomic and trait-based approach and investigated communities of oribatid mites (Oribatida, Acari) across forest types of both native and introduced tree species in Northern Germany. Both trophic and life-history traits of oribatid mites were evaluated using native European beech (Fagus sylvatica) as reference, compared to native Norway spruce (Picea abies), introduced Douglas fir (Pseudotsuga menziesii) and beech-conifer mixtures. The abundance and diversity of oribatid mites were generally similar among monocultures of European beech, Norway spruce and Douglas fir. By contrast, species and trait compositions of oribatid mite communities were shifted to include more primary decomposers and more surface-living oribatid mites in Douglas fir, resulting in a trophic reorganization with less predators than in European beech forests. These results suggest that oribatid mites maintain a similar level of trait diversity regardless of forest type, but the changes in trophic guild composition and vertical distribution indicate greater availability of litter-based resources in Douglas fir than in European beech forests. The similar abundance and diversity of oribatid mite communities in Douglas fir mixed stands as in native European beech forests points to mixed forests as a promising management option for future forestry. Overall, our trait-based analyses provided insights into the changes of soil biota composition, revealing the impact of introduced tree species on the structure and functions of soil animal communities.
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- 2024
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10. Distributed Sensing of Single Mode Fibers with Correlation Techniques
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Azendorf, Florian, Sandmann, André, Eiselt, Michael, and Schmauss, Bernhard
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Physics - Instrumentation and Detectors ,Physics - Optics - Abstract
In this paper, we report on the development progress of correlation-based optical time domain reflectometry (OTDR). Substituting the direct detection receiver with a coherent receiver enables to extract the phase and polarization information of the reflected signal. Furthermore, due to the mixing of a weak probe signal with a strong local oscillator the sensitivity of the receiver improved. This improvement was demonstrated by analyzing the reflection from an angled physical contact (APC) connector. To further quantify the improvements, we compare the direct detection correlation OTDR (C-OTDR) with the coherent detection correlation OTDR (CC-OTDR) with respect to the spatial and amplitude resolution., Comment: This work was partly funded by the German Federal Ministry of Education and Research (FKZ16KIS1279K) in the framework of the CELTIC-NEXT project AI-NET-Protect (Project ID C2019/3-4)
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- 2022
11. A virtual reality-based method for examining audiovisual prosody perception
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Meister, Hartmut, Winter, Isa Samira, Waeachtler, Moritz, Sandmann, Pascale, and Abdellatif, Khaled
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Computer Science - Computation and Language - Abstract
Prosody plays a vital role in verbal communication. Acoustic cues of prosody have been examined extensively. However, prosodic characteristics are not only perceived auditorily, but also visually based on head and facial movements. The purpose of this report is to present a method for examining audiovisual prosody using virtual reality. We show that animations based on a virtual human provide motion cues similar to those obtained from video recordings of a real talker. The use of virtual reality opens up new avenues for examining multimodal effects of verbal communication. We discuss the method in the framework of examining prosody perception in cochlear implant listeners.
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- 2022
12. Systematic analysis of ChatGPT, Google search and Llama 2 for clinical decision support tasks
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Sarah Sandmann, Sarah Riepenhausen, Lucas Plagwitz, and Julian Varghese
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Science - Abstract
Abstract It is likely that individuals are turning to Large Language Models (LLMs) to seek health advice, much like searching for diagnoses on Google. We evaluate clinical accuracy of GPT-3·5 and GPT-4 for suggesting initial diagnosis, examination steps and treatment of 110 medical cases across diverse clinical disciplines. Moreover, two model configurations of the Llama 2 open source LLMs are assessed in a sub-study. For benchmarking the diagnostic task, we conduct a naïve Google search for comparison. Overall, GPT-4 performed best with superior performances over GPT-3·5 considering diagnosis and examination and superior performance over Google for diagnosis. Except for treatment, better performance on frequent vs rare diseases is evident for all three approaches. The sub-study indicates slightly lower performances for Llama models. In conclusion, the commercial LLMs show growing potential for medical question answering in two successive major releases. However, some weaknesses underscore the need for robust and regulated AI models in health care. Open source LLMs can be a viable option to address specific needs regarding data privacy and transparency of training.
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- 2024
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13. Predicting subnational incidence of COVID-19 cases and deaths in EU countries
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Alexis Robert, Lloyd A. C. Chapman, Rok Grah, Rene Niehus, Frank Sandmann, Bastian Prasse, Sebastian Funk, and Adam J. Kucharski
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Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Recurring COVID-19 waves highlight the need for tools able to quantify transmission risk, and identify geographical areas at risk of outbreaks. Local outbreak risk depends on complex immunity patterns resulting from previous infections, vaccination, waning and immune escape, alongside other factors (population density, social contact patterns). Immunity patterns are spatially and demographically heterogeneous, and are challenging to capture in country-level forecast models. Methods We used a spatiotemporal regression model to forecast subnational case and death counts and applied it to three EU countries as test cases: France, Czechia, and Italy. Cases in local regions arise from importations or local transmission. Our model produces age-stratified forecasts given age-stratified data, and links reported case counts to routinely collected covariates (e.g. test number, vaccine coverage). We assessed the predictive performance of our model up to four weeks ahead using proper scoring rules and compared it to the European COVID-19 Forecast Hub ensemble model. Using simulations, we evaluated the impact of variations in transmission on the forecasts. We developed an open-source RShiny App to visualise the forecasts and scenarios. Results At a national level, the median relative difference between our median weekly case forecasts and the data up to four weeks ahead was 25% (IQR: 12–50%) over the prediction period. The accuracy decreased as the forecast horizon increased (on average 24% increase in the median ranked probability score per added week), while the accuracy of death forecasts was more stable. Beyond two weeks, the model generated a narrow range of likely transmission dynamics. The median national case forecasts showed similar accuracy to forecasts from the European COVID-19 Forecast Hub ensemble model, but the prediction interval was narrower in our model. Generating forecasts under alternative transmission scenarios was therefore key to capturing the range of possible short-term transmission dynamics. Discussion Our model captures changes in local COVID-19 outbreak dynamics, and enables quantification of short-term transmission risk at a subnational level. The outputs of the model improve our ability to identify areas where outbreaks are most likely, and are available to a wide range of public health professionals through the Shiny App we developed.
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- 2024
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14. Optical fiber for remote sensing with high spatial resolution
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Eiselt, Michael, Azendorf, Florian, and Sandmann, Andre
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Physics - Optics ,Electrical Engineering and Systems Science - Signal Processing - Abstract
The use of optical fiber as sensor as well as transmission medium for sensing data is discussed, enabling the use of optically active sensors without power supply at distances of tens of kilometers. Depending on the interrogation system, a spatial resolution of less than a millimeter can be achieved. The basic sensing principle is optical time-domain reflectometry (OTDR) with direct detection or coherent detection of the Rayleigh back-scattered or Fresnel reflected signal. Spatial resolution is improved by a cross-correlation between the transmitted sequence and the received signals.
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- 2022
15. Novel App knock-in mouse model shows key features of amyloid pathology and reveals profound metabolic dysregulation of microglia
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Xia, Dan, Lianoglou, Steve, Sandmann, Thomas, Calvert, Meredith, Suh, Jung H, Thomsen, Elliot, Dugas, Jason, Pizzo, Michelle E, DeVos, Sarah L, Earr, Timothy K, Lin, Chia-Ching, Davis, Sonnet, Ha, Connie, Leung, Amy Wing-Sze, Nguyen, Hoang, Chau, Roni, Yulyaningsih, Ernie, Lopez, Isabel, Solanoy, Hilda, Masoud, Shababa T, Liang, Chun-chi, Lin, Karin, Astarita, Giuseppe, Khoury, Nathalie, Zuchero, Joy Yu, Thorne, Robert G, Shen, Kevin, Miller, Stephanie, Palop, Jorge J, Garceau, Dylan, Sasner, Michael, Whitesell, Jennifer D, Harris, Julie A, Hummel, Selina, Gnörich, Johannes, Wind, Karin, Kunze, Lea, Zatcepin, Artem, Brendel, Matthias, Willem, Michael, Haass, Christian, Barnett, Daniel, Zimmer, Till S, Orr, Anna G, Scearce-Levie, Kimberly, Lewcock, Joseph W, Di Paolo, Gilbert, and Sanchez, Pascal E
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Neurosciences ,Aging ,Acquired Cognitive Impairment ,Alzheimer's Disease ,Biotechnology ,Genetics ,Neurodegenerative ,Brain Disorders ,Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD) ,Dementia ,Aetiology ,2.1 Biological and endogenous factors ,Neurological ,Alzheimer Disease ,Amyloid beta-Peptides ,Amyloid beta-Protein Precursor ,Amyloidosis ,Animals ,Brain ,Disease Models ,Animal ,Mice ,Mice ,Transgenic ,Microglia ,Plaque ,Amyloid ,Receptors ,GABA ,Neuritic plaques ,Vascular amyloid ,Neurodegeneration ,Astrogliosis ,Phagocytic microglia ,Lipid dyshomeostasis ,Clinical Sciences ,Neurology & Neurosurgery - Abstract
BackgroundGenetic mutations underlying familial Alzheimer's disease (AD) were identified decades ago, but the field is still in search of transformative therapies for patients. While mouse models based on overexpression of mutated transgenes have yielded key insights in mechanisms of disease, those models are subject to artifacts, including random genetic integration of the transgene, ectopic expression and non-physiological protein levels. The genetic engineering of novel mouse models using knock-in approaches addresses some of those limitations. With mounting evidence of the role played by microglia in AD, high-dimensional approaches to phenotype microglia in those models are critical to refine our understanding of the immune response in the brain.MethodsWe engineered a novel App knock-in mouse model (AppSAA) using homologous recombination to introduce three disease-causing coding mutations (Swedish, Arctic and Austrian) to the mouse App gene. Amyloid-β pathology, neurodegeneration, glial responses, brain metabolism and behavioral phenotypes were characterized in heterozygous and homozygous AppSAA mice at different ages in brain and/ or biofluids. Wild type littermate mice were used as experimental controls. We used in situ imaging technologies to define the whole-brain distribution of amyloid plaques and compare it to other AD mouse models and human brain pathology. To further explore the microglial response to AD relevant pathology, we isolated microglia with fibrillar Aβ content from the brain and performed transcriptomics and metabolomics analyses and in vivo brain imaging to measure energy metabolism and microglial response. Finally, we also characterized the mice in various behavioral assays.ResultsLeveraging multi-omics approaches, we discovered profound alteration of diverse lipids and metabolites as well as an exacerbated disease-associated transcriptomic response in microglia with high intracellular Aβ content. The AppSAA knock-in mouse model recapitulates key pathological features of AD such as a progressive accumulation of parenchymal amyloid plaques and vascular amyloid deposits, altered astroglial and microglial responses and elevation of CSF markers of neurodegeneration. Those observations were associated with increased TSPO and FDG-PET brain signals and a hyperactivity phenotype as the animals aged.DiscussionOur findings demonstrate that fibrillar Aβ in microglia is associated with lipid dyshomeostasis consistent with lysosomal dysfunction and foam cell phenotypes as well as profound immuno-metabolic perturbations, opening new avenues to further investigate metabolic pathways at play in microglia responding to AD-relevant pathogenesis. The in-depth characterization of pathological hallmarks of AD in this novel and open-access mouse model should serve as a resource for the scientific community to investigate disease-relevant biology.
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- 2022
16. Characterising information gains and losses when collecting multiple epidemic model outputs
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Katharine Sherratt, Ajitesh Srivastava, Kylie Ainslie, David E. Singh, Aymar Cublier, Maria Cristina Marinescu, Jesus Carretero, Alberto Cascajo Garcia, Nicolas Franco, Lander Willem, Steven Abrams, Christel Faes, Philippe Beutels, Niel Hens, Sebastian Müller, Billy Charlton, Ricardo Ewert, Sydney Paltra, Christian Rakow, Jakob Rehmann, Tim Conrad, Christof Schütte, Kai Nagel, Sam Abbott, Rok Grah, Rene Niehus, Bastian Prasse, Frank Sandmann, and Sebastian Funk
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Information ,Scenarios ,Uncertainty ,Aggregation ,Modelling ,Infectious and parasitic diseases ,RC109-216 - Abstract
Background: Collaborative comparisons and combinations of epidemic models are used as policy-relevant evidence during epidemic outbreaks. In the process of collecting multiple model projections, such collaborations may gain or lose relevant information. Typically, modellers contribute a probabilistic summary at each time-step. We compared this to directly collecting simulated trajectories. We aimed to explore information on key epidemic quantities; ensemble uncertainty; and performance against data, investigating potential to continuously gain information from a single cross-sectional collection of model results. Methods: We compared projections from the European COVID-19 Scenario Modelling Hub. Five teams modelled incidence in Belgium, the Netherlands, and Spain. We compared July 2022 projections by incidence, peaks, and cumulative totals. We created a probabilistic ensemble drawn from all trajectories, and compared to ensembles from a median across each model’s quantiles, or a linear opinion pool. We measured the predictive accuracy of individual trajectories against observations, using this in a weighted ensemble. We repeated this sequentially against increasing weeks of observed data. We evaluated these ensembles to reflect performance with varying observed data. Results: By collecting modelled trajectories, we showed policy-relevant epidemic characteristics. Trajectories contained a right-skewed distribution well represented by an ensemble of trajectories or a linear opinion pool, but not models’ quantile intervals. Ensembles weighted by performance typically retained the range of plausible incidence over time, and in some cases narrowed this by excluding some epidemic shapes. Conclusions: We observed several information gains from collecting modelled trajectories rather than quantile distributions, including potential for continuously updated information from a single model collection. The value of information gains and losses may vary with each collaborative effort’s aims, depending on the needs of projection users. Understanding the differing information potential of methods to collect model projections can support the accuracy, sustainability, and communication of collaborative infectious disease modelling efforts.
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- 2024
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17. Exploration of a Pathway from Leadership Development to Institutionalization of Community Engagement
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Murrah-Hanson, A. Laurie and Sandmann, Lorilee R.
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The institutionalization of community engagement is a lengthy, complex process to which higher education change agents have turned their attention over the past few decades. This study examined the experiences of participants in leadership workshops designed specifically to develop the capacities of campus and community leaders to facilitate this work. Using Conner's (2006) curve of commitment, this research highlighted factors contributing to and deterring community engagement, and explored the role of leadership development in the institutionalization of community engagement. Findings revealed five critical issues related to this work: administrative support, faculty buy-in, positionality/power dynamics, resources, and embeddedness--with administrative support and leadership serving as a linchpin. In addition to the need for effective leadership development as a pathway to supporting this multifaceted organizational change, the results also underscored the need for a model of shared leadership to guide the purpose, planning, and persistence necessary for institutional change.
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- 2021
18. Protein familiarity is a fundamental but rarely operationalized concept in the safety assessment of genetically modified crops: example of phosphomannose isomerase (PMI)
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Carlson, Anne B., Mathesius, Carey A., Gunderson, Tim A., Hession, Aideen, Bruyere, Reba, Mirsky, Henry P., Zhang, John, Sandmann, Mat, Fallers, Melissa N., and Herman, Rod A.
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- 2023
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19. GEFAAR: a generic framework for the analysis of antimicrobial resistance providing statistics and cluster analyses
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Sandmann, Sarah, Schaumburg, Frieder, and Varghese, Julian
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- 2023
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20. Seasonality of acute kidney injury phenotypes in England: an unsupervised machine learning classification study of electronic health records
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Bolt, Hikaru, Suffel, Anne, Matthewman, Julian, Sandmann, Frank, Tomlinson, Laurie, and Eggo, Rosalind
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- 2023
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21. Mitochondrial DNA mutations in Medulloblastoma
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Funke, Viktoria L. E., Sandmann, Sarah, Melcher, Viktoria, Seggewiss, Jochen, Horvath, Judit, Jäger, Natalie, Kool, Marcel, Jones, David T. W., Pfister, Stefan M., Milde, Till, Rutkowski, Stefan, Mynarek, Martin, Varghese, Julian, Sträter, Ronald, Rust, Stephan, Seelhöfer, Anja, Reunert, Janine, Fiedler, Barbara, Schüller, Ulrich, Marquardt, Thorsten, and Kerl, Kornelius
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- 2023
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22. OGRE: calculate, visualize, and analyze overlap between genomic input regions and public annotations
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Berres, Sven, Gromoll, Jörg, Wöste, Marius, Sandmann, Sarah, and Laurentino, Sandra
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- 2023
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23. The influence of COVID-19 risk perception and vaccination status on the number of social contacts across Europe: insights from the CoMix study
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Wambua, James, Loedy, Neilshan, Jarvis, Christopher I., Wong, Kerry L. M., Faes, Christel, Grah, Rok, Prasse, Bastian, Sandmann, Frank, Niehus, Rene, Johnson, Helen, Edmunds, W.John, Beutels, Philippe, Hens, Niel, and Coletti, Pietro
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- 2023
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24. What are economic costs and when should they be used in health economic studies?
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Turner, Hugo C., Sandmann, Frank G., Downey, Laura E., Orangi, Stacey, Teerawattananon, Yot, Vassall, Anna, and Jit, Mark
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- 2023
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25. Correction: Network analysis of polymicrobial chronic wound infections in Masanga, Sierra Leone
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Sandmann, Sarah, Nunes, Jonathan Vas, Grobusch, Martin P., Sesay, Maxwell, Kriegel, Martin A., Varghese, Julian, and Schaumburg, Frieder
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- 2023
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26. Network analysis of polymicrobial chronic wound infections in Masanga, Sierra Leone
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Sandmann, Sarah, Nunes, Jonathan Vas, Grobusch, Martin P., Sesay, Maxwell, Kriegel, Martin A., Varghese, Julian, and Schaumburg, Frieder
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- 2023
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27. GEFAAR: a generic framework for the analysis of antimicrobial resistance providing statistics and cluster analyses
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Sarah Sandmann, Frieder Schaumburg, and Julian Varghese
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Medicine ,Science - Abstract
Abstract Easy access to antimicrobial resistance data and meaningful visualization is essential to guide the empirical antimicrobial treatment and to promote the rational use of antimicrobial agents. Currently available solutions are commonly externally hosted, centralized systems. However, there is a need for close monitoring by local analysis tools. To fill this gap, we developed GEFAAR—a generic framework for the analysis of antimicrobial resistance data. Following the example of the German Robert Koch Institute (RKI), an interactive web-application is provided to determine basic pathogen and resistance statistics. In addition to the RKI’s externally maintained database, our application provides a generic framework to import tabular data and to analyze them safely in a local environment. Moreover, our application offers an intuitive web-based user interface to visualize resistance trend analysis as well as advanced cluster analyses on species- or clinic/unit level to generate alerts of potential transmission events.
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- 2023
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28. Seasonality of acute kidney injury phenotypes in England: an unsupervised machine learning classification study of electronic health records
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Hikaru Bolt, Anne Suffel, Julian Matthewman, Frank Sandmann, Laurie Tomlinson, and Rosalind Eggo
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Acute kidney injury ,Seasonality ,Phenotypes ,Clustering ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background Acute Kidney Injury (AKI) is a multifactorial condition which presents a substantial burden to healthcare systems. There is limited evidence on whether it is seasonal. We sought to investigate the seasonality of AKI hospitalisations in England and use unsupervised machine learning to explore clustering of underlying comorbidities, to gain insights for future intervention. Methods We used Hospital Episodes Statistics linked to the Clinical Practice Research Datalink to describe the overall incidence of AKI admissions between 2015 and 2019 weekly by demographic and admission characteristics. We carried out dimension reduction on 850 diagnosis codes using multiple correspondence analysis and applied k-means clustering to classify patients. We phenotype each group based on the dominant characteristics and describe the seasonality of AKI admissions by these different phenotypes. Results Between 2015 and 2019, weekly AKI admissions peaked in winter, with additional summer peaks related to periods of extreme heat. Winter seasonality was more evident in those diagnosed with AKI on admission. From the cluster classification we describe six phenotypes of people admitted to hospital with AKI. Among these, seasonality of AKI admissions was observed among people who we described as having a multimorbid phenotype, established risk factor phenotype, and general AKI phenotype. Conclusion We demonstrate winter seasonality of AKI admissions in England, particularly among those with AKI diagnosed on admission, suggestive of community triggers. Differences in seasonality between phenotypes suggests some groups may be more likely to develop AKI as a result of these factors. This may be driven by underlying comorbidity profiles or reflect differences in uptake of seasonal interventions such as vaccines.
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- 2023
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29. PyVertical: A Vertical Federated Learning Framework for Multi-headed SplitNN
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Romanini, Daniele, Hall, Adam James, Papadopoulos, Pavlos, Titcombe, Tom, Ismail, Abbas, Cebere, Tudor, Sandmann, Robert, Roehm, Robin, and Hoeh, Michael A.
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Computer Science - Machine Learning ,Computer Science - Cryptography and Security ,Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
We introduce PyVertical, a framework supporting vertical federated learning using split neural networks. The proposed framework allows a data scientist to train neural networks on data features vertically partitioned across multiple owners while keeping raw data on an owner's device. To link entities shared across different datasets' partitions, we use Private Set Intersection on IDs associated with data points. To demonstrate the validity of the proposed framework, we present the training of a simple dual-headed split neural network for a MNIST classification task, with data samples vertically distributed across two data owners and a data scientist., Comment: ICLR 2021 Workshop on Distributed and Private Machine Learning (DPML 2021)
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- 2021
30. Shear Transfer in Concrete Joints with Non-Metallic Reinforcement
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Lore Zierul, Enrico Baumgärtel, David Sandmann, and Steffen Marx
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shear transfer ,joints ,carbon fiber-reinforced polymers (CFRPs) ,glass fiber-reinforced polymers (GFRPs) ,non-metallic reinforcement ,carbon reinforced concrete ,Building construction ,TH1-9745 - Abstract
The use of non-metallic reinforcement can significantly reduce the carbon footprint of the construction sector. Mixed structures made out of steel and non-metallic reinforcement should be avoided due to the risk of galvanic corrosion. So far, researchers have been focusing on the load-bearing behavior in the longitudinal direction of the fibers. In this study, the behavior of the fibers in the non-metallic reinforcements is analyzed perpendicular to the fiber orientation. Therefore, a uniaxial shear test on a single bar (uniaxial shear test), as well as a series of push-off tests with reinforcements embedded in the concrete, was carried out. For both experiments, bars made of carbon fiber-reinforced polymers (CFRPs) and glass fiber-reinforced polymers (GFRPs) were investigated. In order to analyze the influence of non-metallic reinforcement in the joint, specimens without reinforcement have been tested as well. Also, the joint roughness and reinforcement ratio of the concrete joint was varied in the tests. The determined transverse shear strengths for the single bar exceed the values of the producer. For the push-off test, high standard deviations occurred, making it difficult to draw firm conclusions. Nevertheless, it is shown that increasing the amount of reinforcement leads to higher ultimate forces. The presented study emphasizes the necessity of further studies of the shear transfer in concrete joints.
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- 2024
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31. Graph Repair and its Application to Meta-Modeling
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Sandmann, Christian
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Computer Science - Software Engineering - Abstract
Model repair is an essential topic in model-driven engineering. We present typed graph-repair programs for specific conditions; application to any typed graph yields a typed graph satisfying the condition. A model graph based on the Eclipse Modeling Framework (EMF), short EMF-model graph, is a typed graph satisfying some structural EMF-constraints. Application of the results to the EMF-world yields model-repair programs for EMFk constraints, a first-order variant of EMF constraints; application to any typed graph yields an EMFk model graph. From these results, we derive results for EMF model repair., Comment: In Proceedings GCM 2020, arXiv:2012.01181
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- 2020
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32. Asymmetric Private Set Intersection with Applications to Contact Tracing and Private Vertical Federated Machine Learning
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Angelou, Nick, Benaissa, Ayoub, Cebere, Bogdan, Clark, William, Hall, Adam James, Hoeh, Michael A., Liu, Daniel, Papadopoulos, Pavlos, Roehm, Robin, Sandmann, Robert, Schoppmann, Phillipp, and Titcombe, Tom
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Computer Science - Cryptography and Security ,Computer Science - Machine Learning - Abstract
We present a multi-language, cross-platform, open-source library for asymmetric private set intersection (PSI) and PSI-Cardinality (PSI-C). Our protocol combines traditional DDH-based PSI and PSI-C protocols with compression based on Bloom filters that helps reduce communication in the asymmetric setting. Currently, our library supports C++, C, Go, WebAssembly, JavaScript, Python, and Rust, and runs on both traditional hardware (x86) and browser targets. We further apply our library to two use cases: (i) a privacy-preserving contact tracing protocol that is compatible with existing approaches, but improves their privacy guarantees, and (ii) privacy-preserving machine learning on vertically partitioned data., Comment: NeurIPS 2020 Workshop on Privacy Preserving Machine Learning (PPML 2020)
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- 2020
33. Mitochondrial DNA mutations in Medulloblastoma
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Viktoria L. E. Funke, Sarah Sandmann, Viktoria Melcher, Jochen Seggewiss, Judit Horvath, Natalie Jäger, Marcel Kool, David T. W. Jones, Stefan M. Pfister, Till Milde, Stefan Rutkowski, Martin Mynarek, Julian Varghese, Ronald Sträter, Stephan Rust, Anja Seelhöfer, Janine Reunert, Barbara Fiedler, Ulrich Schüller, Thorsten Marquardt, and Kornelius Kerl
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Medulloblastoma ,DNA, Mitochondrial ,Mitochondrial diseases ,DNA mutational analysis ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract To date, several studies on genomic events underlying medulloblastoma (MB) biology have expanded our understanding of this tumour entity and led to its division into four groups—WNT, SHH, group 3 (G3) and group 4 (G4). However, there is little information about the relevance of pathogenic mitochondrial DNA (mtDNA) mutations and their consequences across these. In this report, we describe the case of a female patient with MB and a mitochondriopathy, followed by a study of mtDNA variants in MB groups. After being diagnosed with G4 MB, the index patient was treated in line with the HIT 2000 protocol with no indications of relapse after five years. Long-term side effects of treatment were complemented by additional neurological symptoms and elevated lactate levels ten years later, resulting in suspected mitochondrial disease. This was confirmed by identifying a mutation in the MT-TS1 gene which appeared homoplasmic in patient tissue and heteroplasmic in the patient’s mother. Motivated by this case, we explored mtDNA mutations across 444 patients from ICGC and HIT cohorts. While there was no statistically significant enrichment of mutations in one MB group, both cohorts encompassed a small group of patients harbouring potentially deleterious mtDNA variants. The case presented here highlights the possible similarities between sequelae caused by MB treatment and neurological symptoms of mitochondrial dysfunction, which may apply to patients across all MB groups. In the context of the current advances in characterising and interpreting mtDNA aberrations, recognising affected patients could enhance our future knowledge regarding the mutations’ impact on carcinogenesis and cancer treatment.
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- 2023
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34. OGRE: calculate, visualize, and analyze overlap between genomic input regions and public annotations
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Sven Berres, Jörg Gromoll, Marius Wöste, Sarah Sandmann, and Sandra Laurentino
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Annotation ,Genomic association ,Genomic regions ,Omics ,Overlap ,Regulatory elements ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Modern genome sequencing leads to an ever-growing collection of genomic annotations. Combining these elements with a set of input regions (e.g. genes) would yield new insights in genomic associations, such as those involved in gene regulation. The required data are scattered across different databases making a manual approach tiresome, unpractical, and prone to error. Semi-automatic approaches require programming skills in data parsing, processing, overlap calculation, and visualization, which most biomedical researchers lack. Our aim was to develop an automated tool providing all necessary algorithms, benefiting both bioinformaticians and researchers without bioinformatic training. Results We developed overlapping annotated genomic regions (OGRE) as a comprehensive tool to associate and visualize input regions with genomic annotations. It does so by parsing regions of interest, mining publicly available annotations, and calculating possible overlaps between them. The user can thus identify location, type, and number of associated regulatory elements. Results are presented as easy to understand visualizations and result tables. We applied OGRE to recent studies and could show high reproducibility and potential new insights. To demonstrate OGRE’s performance in terms of running time and output, we have conducted a benchmark and compared its features with similar tools. Conclusions OGRE’s functions and built-in annotations can be applied as a downstream overlap association step, which is compatible with most genomic sequencing outputs, and can thus enrich pre-existing analyses pipelines. Compared to similar tools, OGRE shows competitive performance, offers additional features, and has been successfully applied to two recent studies. Overall, OGRE addresses the lack of tools for automatic analysis, local genomic overlap calculation, and visualization by providing an easy to use, end-to-end solution for both biologists and computational scientists.
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- 2023
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35. The influence of COVID-19 risk perception and vaccination status on the number of social contacts across Europe: insights from the CoMix study
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James Wambua, Neilshan Loedy, Christopher I. Jarvis, Kerry L. M. Wong, Christel Faes, Rok Grah, Bastian Prasse, Frank Sandmann, Rene Niehus, Helen Johnson, W.John Edmunds, Philippe Beutels, Niel Hens, and Pietro Coletti
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Risk Perceptions ,SARS-CoV-2 ,COVID-19 ,Contact data ,Social contact behaviour ,Vaccination ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background The SARS-CoV-2 transmission dynamics have been greatly modulated by human contact behaviour. To curb the spread of the virus, global efforts focused on implementing both Non-Pharmaceutical Interventions (NPIs) and pharmaceutical interventions such as vaccination. This study was conducted to explore the influence of COVID-19 vaccination status and risk perceptions related to SARS-CoV-2 on the number of social contacts of individuals in 16 European countries. Methods We used data from longitudinal surveys conducted in the 16 European countries to measure social contact behaviour in the course of the pandemic. The data consisted of representative panels of participants in terms of gender, age and region of residence in each country. The surveys were conducted in several rounds between December 2020 and September 2021 and comprised of 29,292 participants providing a total of 111,103 completed surveys. We employed a multilevel generalized linear mixed effects model to explore the influence of risk perceptions and COVID-19 vaccination status on the number of social contacts of individuals. Results The results indicated that perceived severity played a significant role in social contact behaviour during the pandemic after controlling for other variables (p-value < 0.001). More specifically, participants who had low or neutral levels of perceived severity reported 1.25 (95% Confidence intervals (CI) 1.13 - 1.37) and 1.10 (95% CI 1.00 - 1.21) times more contacts compared to those who perceived COVID-19 to be a serious illness, respectively. Additionally, vaccination status was also a significant predictor of contacts (p-value < 0.001), with vaccinated individuals reporting 1.31 (95% CI 1.23 - 1.39) times higher number of contacts than the non-vaccinated. Furthermore, individual-level factors played a more substantial role in influencing contact behaviour than country-level factors. Conclusion Our multi-country study yields significant insights on the importance of risk perceptions and vaccination in behavioral changes during a pandemic emergency. The apparent increase in social contact behaviour following vaccination would require urgent intervention in the event of emergence of an immune escaping variant.
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- 2023
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36. Group-specific cellular metabolism in Medulloblastoma
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Viktoria L. E. Funke, Carolin Walter, Viktoria Melcher, Lanying Wei, Sarah Sandmann, Marc Hotfilder, Julian Varghese, Natalie Jäger, Marcel Kool, David T. W. Jones, Stefan M. Pfister, Till Milde, Martin Mynarek, Stefan Rutkowski, Jochen Seggewiss, Daniela Jeising, Flavia W. de Faria, Thorsten Marquardt, Thomas K. Albert, Ulrich Schüller, and Kornelius Kerl
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Medulloblastoma ,Metabolism ,Inositol phosphates ,Nucleotides ,RNA-Seq ,Medicine - Abstract
Abstract Background Cancer metabolism influences multiple aspects of tumorigenesis and causes diversity across malignancies. Although comprehensive research has extended our knowledge of molecular subgroups in medulloblastoma (MB), discrete analysis of metabolic heterogeneity is currently lacking. This study seeks to improve our understanding of metabolic phenotypes in MB and their impact on patients’ outcomes. Methods Data from four independent MB cohorts encompassing 1,288 patients were analysed. We explored metabolic characteristics of 902 patients (ICGC and MAGIC cohorts) on bulk RNA level. Moreover, data from 491 patients (ICGC cohort) were searched for DNA alterations in genes regulating cell metabolism. To determine the role of intratumoral metabolic differences, we examined single-cell RNA-sequencing (scRNA-seq) data from 34 additional patients. Findings on metabolic heterogeneity were correlated to clinical data. Results Established MB groups exhibit substantial differences in metabolic gene expression. By employing unsupervised analyses, we identified three clusters of group 3 and 4 samples with distinct metabolic features in ICGC and MAGIC cohorts. Analysis of scRNA-seq data confirmed our results of intertumoral heterogeneity underlying the according differences in metabolic gene expression. On DNA level, we discovered clear associations between altered regulatory genes involved in MB development and lipid metabolism. Additionally, we determined the prognostic value of metabolic gene expression in MB and showed that expression of genes involved in metabolism of inositol phosphates and nucleotides correlates with patient survival. Conclusion Our research underlines the biological and clinical relevance of metabolic alterations in MB. Thus, distinct metabolic signatures presented here might be the first step towards future metabolism-targeted therapeutic options. Graphical Abstract
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- 2023
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37. What are economic costs and when should they be used in health economic studies?
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Hugo C. Turner, Frank G. Sandmann, Laura E. Downey, Stacey Orangi, Yot Teerawattananon, Anna Vassall, and Mark Jit
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Economic costs ,Opportunity costs ,Decision making ,Definition ,Rationale ,Health economics ,Medicine (General) ,R5-920 - Abstract
Abstract Economic analyses of healthcare interventions are an important consideration in evidence-based policymaking. A key component of such analyses is the costs of interventions, for which most are familiar with using budgets and expenditures. However, economic theory states that the true value of a good/service is the value of the next best alternative forgone as a result of using the resource and therefore observed prices or charges do not necessarily reflect the true economic value of resources. To address this, economic costs are a fundamental concept within (health) economics. Crucially, they are intended to reflect the resources’ opportunity costs (the forgone opportunity to use those resources for another purpose) and they are based on the value of the resource's next-best alternative use that has been forgone. This is a broader conceptualization of a resource’s value than its financial cost and recognizes that resources can have a value that may not be fully captured by their market price and that by using a resource it makes it unavailable for productive use elsewhere. Importantly, economic costs are preferred over financial costs for any health economic analyses aimed at informing decisions regarding the optimum allocation of the limited/competing resources available for healthcare (such as health economic evaluations), and they are also important when considering the replicability and sustainability of healthcare interventions. However, despite this, economic costs and the reasons why they are used is an area that can be misunderstood by professionals without an economic background. In this paper, we outline to a broader audience the principles behind economic costs and when and why they should be used within health economic analyses. We highlight that the difference between financial and economic costs and what adjustments are needed within cost calculations will be influenced by the context of the study, the perspective, and the objective.
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- 2023
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38. Rule-based Graph Repair
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Sandmann, Christian and Habel, Annegret
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Computer Science - Software Engineering - Abstract
Model repair is an essential topic in model-driven engineering. Since models are suitably formalized as graph-like structures, we consider the problem of rule-based graph repair: Given a rule set and a graph constraint, try to construct a graph program based on the given set of rules, such that the application to any graph yields a graph satisfying the graph constraint. We show the existence of repair programs for specific constraints, and show the existence of rule-based repair programs for specific constraints compatible with the rule set., Comment: In Proceedings GCM 2019, arXiv:1912.08966
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- 2019
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39. Network analysis of polymicrobial chronic wound infections in Masanga, Sierra Leone
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Sarah Sandmann, Jonathan Vas Nunes, Martin P. Grobusch, Maxwell Sesay, Martin A. Kriegel, Julian Varghese, and Frieder Schaumburg
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Microbiome ,Wound infection ,Africa ,Community networks ,Staphylococcus aureus, Pseudomonas aeruginosa ,Panton-Valentine leukocidin ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Chronic wounds are frequently colonized or infected with multiple bacterial or fungal species, which can both promote or inhibit each other. Network analyses are helpful to understand the interplay of these species in polymicrobial infections. Our aim was to analyse the network of bacterial and fungal species in chronic wounds. Methods Swabs (n = 163) from chronic wound infections (Masanga, Sierra Leone, 2019–2020) were screened for bacterial and fungal species using non-selective agars. Some of these wounds were suspected but not confirmed Buruli ulcer. Species identification was done with MALDI-TOF mass spectrometry. Network analysis was performed to investigate co-occurrence of different species within one patient. All species with n ≥ 10 isolates were taken into account. Results Of the 163 patients, 156 had a positive wound culture (median of three different species per patient; range 1–7). Pseudomonas aeruginosa (n = 75) was the dominating species with frequent co-detections of Klebsiella pneumoniae (21 cases; OR = 1.36, 95%CI: 0.63–2.96, p = 0.47), Staphylococcus aureus (14 cases; OR = 1.06, 95%CI: 0.44–2.55, p = 1) and Proteus mirabilis (13 cases; OR = 0.84, 95%CI: 0.35–1.99, p = 0.69). Conclusion The culturome of chronic wounds in Sierra Leonean patients is highly diverse and characterized by the co-occurrence of P. aeruginosa, K. pneumoniae and S. aureus.
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- 2023
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40. At the Intersection of Housing, Energy, and Mobility Poverty: Trapped in Social Exclusion
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Katrin Großmann, Helene Oettel, and Leona Sandmann
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affordable housing ,energy poverty ,mobility poverty ,social exclusion ,cost burden ,Technology - Abstract
The individual debates on housing poverty, energy poverty, and mobility poverty for the most part overlook the interwoven nature of all three cost burdens, especially for low-income households. This study examines how the three cost factors interact on a household level, the consequences for those affected by cost burdens, and how they cope and negotiate their expenses. Our research comprises two sets of semi-structured interviews, one before and one during the energy crisis, to gain insight into household experiences and constraints. We found that the freedom to choose where and how to live largely determines how households heat their homes and organize their mobility. The housing crisis together with housing market mechanisms appears to be the main driver of this cost trap; and from here, a complex interplay of causal factors unfolds. Location, often conceived of in terms of an urban–rural divide, seems to be of secondary importance. The intersection of cost burdens results in stress, anxiety, and social exclusion, further limiting the capacity for coping.
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- 2024
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41. Kinetics and Value of Hepatitis B Core-Related Antigen in Patients with Chronic Hepatitis B Virus Infection during Antiviral Treatment
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Lisa Sandmann, Birgit Bremer, Valerie Ohlendorf, Jerzy Jaroszewicz, Heiner Wedemeyer, Markus Cornberg, and Benjamin Maasoumy
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HBV ,HBcrAg ,NA ,predictive value ,HBsAg-loss ,HBeAg seroconversion ,Microbiology ,QR1-502 - Abstract
Background: The hepatitis B core-related antigen (HBcrAg) correlates with HBV DNA in patients with chronic HBV infection without antiviral treatment. Its utility in monitoring patients during and after the cessation of nucleos(t)ide analog (NA) treatment is unknown. Methods: The levels of HBcrAg were longitudinally determined in two cohorts of chronic HBV-infected patients with (A) newly started NA treatment or (B) after NA cessation during a median follow up (FU) of 60 months or 48 weeks, respectively. The correlation of HBcrAg and HBV DNA and the predictive value for HBeAg seroconversion and HBsAg loss were evaluated. Results: Fifty-six patients with newly-started NA treatment and 22 patients with NA cessation were identified. HBcrAg and HBV DNA strongly correlated before NA treatment (r = 0.77, p < 0.0001) and at virological relapse (0.66, p = 0.0063). At the individual level, the discrepant kinetics of HBcrAg and HBV DNA became evident. During NA treatment, 33% (6/18) and 9% (5/56) of patients showed HBeAg seroconversion or HBsAg loss/HBsAg < 100 IU/mL, respectively. Low levels of HBcrAg were associated with these endpoints. Conclusion: HBcrAg levels before antiviral treatment help to identify patients with chances of HBsAg loss or HBeAg seroconversion. However, its utility in replacing quantitative HBV DNA to evaluate treatment efficacy or virological relapse off-treatment is limited.
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- 2024
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42. Cost of the COVID-19 pandemic versus the cost-effectiveness of mitigation strategies in EU/UK/OECD: a systematic review
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Esteve Fernández, Frank Sandmann, Anastasia Pharris, Katerina Nikitara, Constantine Vardavas, Jo Leonardi-Bee, Konstantinos Zisis, Konstantinos Athanasakis, Revati Phalkey, Jonathan E Suk, Charlotte Deogan, Ioanna Lagou, Valia Marou, Katerina Aslanoglou, Orla Condell, and Favelle Lamb
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Medicine - Abstract
Objectives The economic burden of COVID-19 pandemic is substantial, with both direct and indirect costs playing a significant role.Design A systematic literature review was conducted to estimate the cost of the COVID-19 pandemic and the cost-effectiveness of pharmaceutical or non-pharmaceutical interventions. All cost data were adjusted to the 2021 Euro, and interventions compared with null.Data sources Ovid MEDLINE and EMBASE were searched from January 2020 through 22 April 2021.Eligibility criteria Studies regarding COVID-19 outbreak or public health preparedness measures or interventions with outcome measures related to the direct and indirect costs for disease and preparedness and/or response in countries of the European Union (EU), the European Economic Area (EEA), the UK and the Organisation for Economic Co-operation and Development (OECD) of all relevant epidemiological designs which estimate cost within the selected time frame were considered eligible.Data extraction and synthesis Studies were searched, screened and coded independently by two reviewers with high measure of inter-rater agreement. Data were extracted to a predefined data extraction sheet. The risk of bias was assessed using the Consensus on Health Economic Criteria checklist.Results We included data from 41 economic studies. Ten studies evaluated the cost of the COVID-19 pandemic, while 31 assessed the cost-benefit of public health surveillance, preparedness and response measures. Overall, the economic burden of the COVID-19 pandemic was found to be substantial. Community screening, bed provision policies, investing in personal-protective-equipment and vaccination strategies were cost-effective. Physical distancing measures were associated with health benefits; however, their cost-effectiveness was dependent on the duration, compliance and the phase of the epidemic in which it was implemented.Conclusions COVID-19 pandemic is associated with substantial short-term and long-term economic costs to healthcare systems, payers and societies, while interventions including testing and screening policies, vaccination and physical distancing policies were identified as those presenting cost-effective options to deal with the pandemic, dependent on population vaccination and the Re at the stage of the pandemic.
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- 2023
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43. Hepatitis D virus infection: Pathophysiology, epidemiology and treatment. Report from the first international delta cure meeting 2022Key points
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Pietro Lampertico, Elisabetta Degasperi, Lisa Sandmann, Heiner Wedemeyer, Cihan Yurdaydin, Dominique Roulot, Fabien Zoulim, Florin Alexandru Caruntu, Helenie Kefalakes, Julie Lucifora, Kosh Agarwal, Laurent Castera, Maria Buti, Mario Rizzetto, Markus Cornberg, Maura Dandri, Maurizia Brunetto, Nancy Reau, Robert Gish, Saeed Hamid, Soo Aleman, Stephan Urban, Tarik Asselah, Thomas Berg, and Victor de Lédinghen
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Chronic hepatitis Delta ,HDV ,HDV RNA ,cirrhosis ,Entry Inhibitor ,Bulevirtide ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Summary: Chronic infection with hepatitis delta virus (HDV) affects between 12-20 million people worldwide and represents the most severe form of viral hepatitis, leading to accelerated liver disease progression, cirrhosis and its complications, such as end-stage-liver disease and hepatocellular carcinoma. From the discovery of HDV in 1977 by Prof. Mario Rizzetto, knowledge on the HDV life cycle and mechanisms of viral spread has expanded. However, little is still known about the natural history of the disease, host-viral interactions, and the role of the immune system in HDV persistence. Diagnosis of HDV is still challenging due to a lack of standardised assays, while accurate viral load quantification is needed to assess response and endpoints of antiviral treatment. Until recently, interferon has represented the only treatment option in patients with chronic hepatitis delta; however, it is associated with low efficacy and a high burden of side effects. The discovery of the entry inhibitor bulevirtide has represented a breakthrough in HDV treatment, by demonstrating high rates of viral suppression in phase II and III trials, results which have been confirmed in real-world settings and in patients with compensated advanced liver disease. In the meantime, other compounds (i.e. lonafarnib, new anti-hepatitis B virus drugs) are under development to provide alternative or combined strategies for HDV cure. The first international Delta Cure meeting was organised in Milan in October 2022 with the aim of sharing and disseminating the latest data; this review summarises key takeaway messages from state-of-the-art lectures and research data on HDV.
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- 2023
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44. Pharyngeal Communities and Antimicrobial Resistance in Pangolins in Gabon
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Johanna P. Wiethoff, Sarah Sandmann, Tom Theiler, Chimene Nze Nkogue, Etienne-François Akomo-Okoue, Julian Varghese, Andrea Kreidenweiss, Alexander Mellmann, Bertrand Lell, Ayôla A. Adegnika, Jana Held, and Frieder Schaumburg
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Africa ,ESBL ,pangolin ,antimicrobial resistance ,microbiome ,Microbiology ,QR1-502 - Abstract
ABSTRACT Wildlife can be a reservoir and source of zoonotic pathogens for humans. For instance, pangolins were considered one of the potential animal reservoirs of SARS-CoV-2. The aim of this study was to assess the prevalence of antimicrobial-resistant species (e.g., extended-spectrum β-lactamase [ESBL]-producing Enterobacterales) and Staphylococcus aureus-related complex and to describe the bacterial community in wild Gabonese pangolins. The pharyngeal colonization of pangolins sold in Gabon (n = 89, 2021 to 2022) was analyzed using culture media selective for ESBL-producing Enterobacterales, S. aureus-related complex, Gram-positive bacteria and nonfermenters. Phylogenetic analyses of ESBL-producing Enterobacterales was done using core-genome multilocus sequence typing (cgMLST) and compared with publicly available genomes. Patterns of cooccurring species were detected by network analysis. Of the 439 bacterial isolates, the majority of species belonged to the genus Pseudomonas (n = 170), followed by Stenotrophomonas (n = 113) and Achromobacter (n = 37). Three Klebsiella pneumoniae isolates and one Escherichia coli isolate were ESBL-producers, which clustered with human isolates from Nigeria (MLST sequence type 1788 [ST1788]) and Gabon (ST38), respectively. Network analysis revealed a frequent cooccurrence of Stenotrophomonas maltophilia with Pseudomonas putida and Pseudomonas aeruginosa. In conclusion, pangolins can be colonized with human-related ESBL-producing K. pneumoniae and E. coli. Unlike in other African wildlife, S. aureus-related complex was not detected in pangolins. IMPORTANCE There is an ongoing debate if pangolins are a relevant reservoir for viruses such as SARS-CoV-2. Here, we wanted to know if African pangolins are colonized with bacteria that are relevant for human health. A wildlife reservoir of antimicrobial resistance would be of medical relevance in regions were consumption of so-called bushmeat is common. In 89 pangolins, we found three ESBL-producing Klebsiella pneumoniae strains and one ESBL-producing Escherichia coli strains, which were closely related to isolates from humans in Africa. This points toward either a transmission between pangolins and humans or a common source from which both humans and pangolins became colonized.
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- 2023
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45. Approximate Numerical Integration of the Chemical Master Equation for Stochastic Reaction Networks
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Mikeev, Linar and Sandmann, Werner
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Quantitative Biology - Molecular Networks ,Mathematics - Numerical Analysis ,Quantitative Biology - Biomolecules - Abstract
Numerical solution of the chemical master equation for stochastic reaction networks typically suffers from the state space explosion problem due to the curse of dimensionality and from stiffness due to multiple time scales. The dimension of the state space equals the number of molecular species involved in the reaction network and the size of the system of differential equations equals the number of states in the corresponding continuous-time Markov chain, which is usually enormously huge and often even infinite. Thus, efficient numerical solution approaches must be able to handle huge, possibly infinite and stiff systems of differential equations efficiently. We present an approximate numerical integration approach that combines a dynamical state space truncation procedure with efficient numerical integration schemes for systems of ordinary differential equations including adaptive step size selection based on local error estimates. The efficiency and accuracy is demonstrated by numerical examples.
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- 2019
46. Politisierung oder Aufklärung? Analysen der Akteur:innen- und Aussagenstruktur in medialen Diskursen über gesundheitliche Risikophänomene und die Rolle wissenschaftlicher Expert:innen
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Melanie Leidecker-Sandmann and Markus Lehmkuhl
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Communication. Mass media ,P87-96 - Abstract
Die Covid-19-Pandemie war und ist ein in der (medialen) Öffentlichkeit überaus präsentes und vieldiskutiertes Thema. Nach Habermas stellt ein normativer Anspruch an öffentliche Diskurse dar, dass sich prinzipiell alle gesellschaftlichen Gruppen an ihnen beteiligen können. Dies gilt insbesondere dann, wenn politische Handlungsentscheidungen bezüglich gesellschaftlich relevanter Fragen und Probleme getroffen werden müssen. Wir fragen, welche gesellschaftlichen Akteur:innengruppen zu welchen Anteilen in den medialen, öffentlichen Corona-Diskurs eingebunden wurden und mit welcher Art von Aussagen sie in den Artikeln zu Wort kamen. Diese Fragen beantworten wir jeweils im Vergleich zu sechs anderen medial-öffentlichen Gesundheitsdebatten mittels quantitativer Inhaltsanalysen der Medienberichterstattung. Ein besonderer Fokus der Analyse liegt auf wissenschaftlichen Akteur:innen, die gemäß des Weberschen Prinzips der Werturteilsfreiheit der Wissenschaft idealerweise in der Rolle sachlicher ‚Aufklärer:innen‘ in den Diskurs eingebunden werden sollten, jedoch keine politischen Handlungsempfehlungen aussprechen sollten. Unsere Analyse zeigt einige Spezifika das Corona-Diskurses im Vergleich zu den anderen Gesundheitsdebatten. Er präsentierte sich im Jahr 2020 als relativ stark vermachteter Diskurs, in dem insbesondere Akteur:innen der politischen Exekutive sowie Par tialinteressenvertreter:innen stark präsent waren. Vertreter:innen von Kollektivgüterinteressen spielten hingegen so gut wie keine Rolle, wissenschaftliche Akteur:innen zumindest keine dominierende. Verhältnismäßig stark gekoppelt ist das Vorkommen wissenschaftlicher Akteur:innen innerhalb der Corona-Artikel mit Akteur:innen aus der Politik. Dies deutet darauf, dass die politische Exekutive in der Corona-Krise stark auf wissenschaftliche Expertise angewiesen war. Substantiierende Aussagen dominieren die Aussagenstruktur in der Covid-19-Berichterstattung deutlich. Wissenschaftliche Expert:innen äußerten in der Corona-Debatte moderat häufiger politische Handlungsempfehlungen als in den Vergleichsdebatten.
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- 2022
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47. Machine learning in the detection and management of atrial fibrillation
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Wegner, Felix K., Plagwitz, Lucas, Doldi, Florian, Ellermann, Christian, Willy, Kevin, Wolfes, Julian, Sandmann, Sarah, Varghese, Julian, and Eckardt, Lars
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- 2022
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48. Generation of stable homozygous transformants of diploid yeasts such as Xanthophyllomyces dendrorhous
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Sandmann, Gerhard
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- 2022
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49. Irrationality and Indecision
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Sandmann, Jan-Paul
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- 2023
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50. Side-of-Implantation Effect on Functional Asymmetry in the Auditory Cortex of Single-Sided Deaf Cochlear-Implant Users
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Weglage, Anna, Müller, Verena, Layer, Natalie, Abdel-Latif, Khaled H. A., Lang-Roth, Ruth, Walger, Martin, and Sandmann, Pascale
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- 2022
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