2,239 results on '"P. Rupprecht"'
Search Results
202. Brightening of a dark monolayer semiconductor via strong light-matter coupling in a cavity
- Author
-
Hangyong Shan, Ivan Iorsh, Bo Han, Christoph Rupprecht, Heiko Knopf, Falk Eilenberger, Martin Esmann, Kentaro Yumigeta, Kenji Watanabe, Takashi Taniguchi, Sebastian Klembt, Sven Höfling, Sefaattin Tongay, Carlos Antón-Solanas, Ivan A. Shelykh, and Christian Schneider
- Subjects
Science - Abstract
Here, the authors show brightening of dark excitons by strong coupling between cavity photons and high energy, spin-allowed, bright excitons in monolayer WSe2. In this regime, the commonly observed photoluminescence quenching stemming from the fast relaxation to the dark ground state is prevented.
- Published
- 2022
- Full Text
- View/download PDF
203. Elimination of human rabies in Goa, India through an integrated One Health approach
- Author
-
A. D. Gibson, G. Yale, J. Corfmat, M. Appupillai, C. M. Gigante, M. Lopes, U. Betodkar, N. C. Costa, K. A. Fernandes, P. Mathapati, P. M. Suryawanshi, N. Otter, G. Thomas, P. Ohal, I. Airikkala-Otter, F. Lohr, C. E. Rupprecht, A. King, D. Sutton, I. Deuzeman, Y. Li, R. M. Wallace, R. S. Mani, G. Gongal, I. G. Handel, M. Bronsvoort, V. Naik, S. Desai, S. Mazeri, L. Gamble, and R. J. Mellanby
- Subjects
Science - Abstract
Dog vaccination is an effective rabies prevention measure, but widespread vaccination campaigns are challenging in settings like India with large free-roaming dog populations. Here, the authors describe a One Health campaign in Goa state which led to a large reduction of cases in dogs and elimination in humans.
- Published
- 2022
- Full Text
- View/download PDF
204. C1q, a small molecule with high impact on brain development: putative role for aging processes and the occurrence of Alzheimer’s disease
- Author
-
Rupprecht, Christian, Rupprecht, Rainer, and Rammes, Gerhard
- Published
- 2021
- Full Text
- View/download PDF
205. Petrographic, mineralogical, morphological and organic constraints of the Permian shaly-coal in the Tuli Basin of Limpopo-Area Karoo-Aged basin, South Africa: Implication for potential gas generation
- Author
-
George Oluwole Akintola, Francis Amponsah-Dacosta, Steven Rupprecht, and Sphiwe Emmanuel Mhlongo
- Subjects
Shale gas potential ,Condensate gas ,Kerogen ,Back-bulge ,Madzaringwe shale ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
The transition to a low-carbon energy source from coal has become imperative to mitigating the escalating climate change crisis. This study aims to investigate the organic-rich shale core samples of the Limpopo-Area Karoo Basin, retrieved from the borehole at depth 480–580 m. These samples were subjected to petrographic, mineralogical, morphological, and kerogen-type analysis to investigate potentials for shale gas generation. The petrographic analysis reveals maceral group mainly comprised of vitrinite group with some liptinite and inertinite and mineral compositions. The preponderance of pyrite framboids (1.6–12%) indicate redox of FeS2 as a precursor to methane gas generation in anoxic condition. The x-ray diffractometer (XRD) reveals the presence of quartz, albite, microcline, dolomite, pyrite and clay minerals which alluded to the mineral composition indicated by the petrographic analysis. The clay mineral component consists of montmorillonite, illite, chlorite, and mixed layered illite/smectite (I/S) in the Madzaringwe samples. The representative scanning electron microscopy-Energy Dispersive X-ray (SEM-EDX) images of the studied shales depict a combination of organic-matter, groundmass mineral, micro-fracture pore structures reflecting polyframboidal pyrite and carbonate dissolution morphology. The total organic carbon (TOC) contents averaging at 47 wt%, indicating an excellent source rock. The Rock-Eval 6 programmed pyrolysis samples showed S2 value (15.25–16.47 mg HC/g rock) with an average of 15.69 mg HC/g rock and Hydrogen index (HI) (34.0–37.0 mg HC/g TOC) indicating a Type-III Kerogen dominance prone to gas generation. The shale showed Tmax values (464–470 °C) averaging at 467.2 °C, yielding a thermally mature condensate wet-gas. This study reveals that the Permian carbonaceous rock tends to generate gas which can be hosted mainly by the organic matter pore structures, inorganic and micro-fracture pore structures.
- Published
- 2023
- Full Text
- View/download PDF
206. Fostering collective climate action and leadership: Insights from a pilot experiment involving mindfulness and compassion
- Author
-
Lena Ramstetter, Silke Rupprecht, Luis Mundaca, Walter Osika, Cecilia U.D. Stenfors, Johannes Klackl, and Christine Wamsler
- Subjects
Global change ,Interdisciplinary application studies ,Nature conservation ,Psychology ,Science - Abstract
Summary: Recent research suggests that mindfulness, compassion, and self-compassion relate to inner transformative qualities/capacities and intermediary factors that can support increased pro-environmental behavior and attitudes across individual, collective, organizational, and system levels. However, current insights focus on the individual level, are restricted to certain sustainability fields, and wider experimental evidence is scarce and contradictory. Our pilot study addresses this gap and tests the aforementioned proposition in the context of an intervention: an EU Climate Leadership Program for high-level decision-makers. The intervention was found to have significant effects on transformative qualities/capacities, intermediary factors, and pro-environmental behaviors and engagement across all levels. The picture is, however, more complex for pro-environmental attitudes. With due limitations (e.g., small sample size), this preliminary evidence confirms the feasibility and potential of mindfulness- and compassion-based interventions to foster inner-outer transformation for sustainability and climate action. Aspects that should be taken into account in larger confirmatory trials are discussed.
- Published
- 2023
- Full Text
- View/download PDF
207. An improved Nicolai map for super Yang–Mills theory
- Author
-
Olaf Lechtenfeld and Maximilian Rupprecht
- Subjects
Physics ,QC1-999 - Abstract
Adding a topological theta term to the action of N=1 D=4 super Yang–Mills theory modifies its Nicolai map. For the BPS value of the theta angle a chiral version of the map emerges, which allows for a considerable simplification compared to the non-chiral formulation. We exhibit these improvements to all orders in perturbation theory and compute the map to fourth order in the coupling on the Laudau-gauge hypersurface. The second-order contribution vanishes, and antisymmetrizations are more manifest. All checks are verified to third order.
- Published
- 2023
- Full Text
- View/download PDF
208. Modelling modifiable factors associated with the probability of human rabies deaths among self-reported victims of dog bites in Abuja, Nigeria.
- Author
-
Philip P Mshelbwala, Ricardo J Soares Magalhães, J Scott Weese, Nasir O Ahmed, Charles E Rupprecht, and Nicholas J Clark
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Canine-mediated rabies kills tens of thousands of people annually in lesser-developed communities of Asia, Africa, and the Americas, primarily through bites from infected dogs. Multiple rabies outbreaks have been associated with human deaths in Nigeria. However, the lack of quality data on human rabies hinders advocacy and resource allocation for effective prevention and control. We obtained 20 years of dog bite surveillance data across 19 major hospitals in Abuja, incorporating modifiable and environmental covariates. To overcome the challenge of missing information, we used a Bayesian approach with expert-solicited prior information to jointly model missing covariate data and the additive effects of the covariates on the predicted probability of human death after rabies virus exposure. Only 1155 cases of dog bites were recorded throughout the study period, out of which 4.2% (N = 49) died of rabies. The odds for risk of human death were predicted to decrease among individuals who were bitten by owned dogs compared to those bitten by free-roaming dogs. Similarly, there was a predicted decrease in the probability of human death among victims bitten by vaccinated dogs compared to those bitten by unvaccinated dogs. The odds for the risk of human death after bitten individuals received rabies prophylaxis were predicted to decrease compared to no prophylaxis. We demonstrate the practical application of a regularised Bayesian approach to model sparse dog bite surveillance data to uncover risk factors for human rabies, with broader applications in other endemic rabies settings with similar profiles. The low reporting observed in this study underscores the need for community engagement and investment in surveillance to increase data availability. Better data on bite cases will help to estimate the burden of rabies in Nigeria and would be important to plan effective prevention and control of this disease.
- Published
- 2023
- Full Text
- View/download PDF
209. Long-term diazepam treatment enhances microglial spine engulfment and impairs cognitive performance via the mitochondrial 18 kDa translocator protein (TSPO)
- Author
-
Shi, Yuan, Cui, Mochen, Ochs, Katharina, Brendel, Matthias, Strübing, Felix L., Briel, Nils, Eckenweber, Florian, Zou, Chengyu, Banati, Richard B., Liu, Guo-Jun, Middleton, Ryan J., Rupprecht, Rainer, Rudolph, Uwe, Zeilhofer, Hanns Ulrich, Rammes, Gerhard, Herms, Jochen, and Dorostkar, Mario M.
- Published
- 2022
- Full Text
- View/download PDF
210. Rabies in the Tropics
- Author
-
Rupprecht, Charles E., Mani, Reeta S., Mshelbwala, Philip P., Recuenco, Sergio E., and Ward, Michael P.
- Published
- 2022
- Full Text
- View/download PDF
211. Forschungspartizipation von Kindern zwischen Minimalbeteiligung und Entscheidungsmacht: Forschungsethische Herausforderungen und Perspektiven der Forschungssubjekte auf Forschung in Kindertagesstätten
- Author
-
Rupprecht, Beatrice and Lattner, Katrin
- Published
- 2022
- Full Text
- View/download PDF
212. The preference for sugar over sweetener depends on a gut sensor cell
- Author
-
Buchanan, Kelly L., Rupprecht, Laura E., Kaelberer, M. Maya, Sahasrabudhe, Atharva, Klein, Marguerita E., Villalobos, Jorge A., Liu, Winston W., Yang, Annabelle, Gelman, Justin, Park, Seongjun, Anikeeva, Polina, and Bohórquez, Diego V.
- Published
- 2022
- Full Text
- View/download PDF
213. Elimination of human rabies in Goa, India through an integrated One Health approach
- Author
-
Gibson, A. D., Yale, G., Corfmat, J., Appupillai, M., Gigante, C. M., Lopes, M., Betodkar, U., Costa, N. C., Fernandes, K. A., Mathapati, P., Suryawanshi, P. M., Otter, N., Thomas, G., Ohal, P., Airikkala-Otter, I., Lohr, F., Rupprecht, C. E., King, A., Sutton, D., Deuzeman, I., Li, Y., Wallace, R. M., Mani, R. S., Gongal, G., Handel, I. G., Bronsvoort, M., Naik, V., Desai, S., Mazeri, S., Gamble, L., and Mellanby, R. J.
- Published
- 2022
- Full Text
- View/download PDF
214. OF spine classification of osteoporotic thoracolumbar vertebral body fractures by MRI and conventional radiographs only leads to high inter-observer agreement rates-an additional CT adds limited information for the of classification and the OF score
- Author
-
Spiegl, Ulrich J., Behr, Lars, Osterhoff, Georg, Rupprecht, Gunnar, Scheyerer, Max J., and Katscher, Sebastian
- Published
- 2022
- Full Text
- View/download PDF
215. The coupling flow of N $$ \mathcal{N} $$ = 4 super Yang-Mills theory
- Author
-
Maximilian Rupprecht
- Subjects
Extended Supersymmetry ,Supersymmetric Gauge Theory ,Global Symmetries ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We offer a novel perspective on N $$ \mathcal{N} $$ = 4 supersymmetric Yang-Mills (SYM) theory through the framework of the Nicolai map, a transformation of the bosonic fields that allows one to compute quantum correlators in terms of a free, purely bosonic functional measure. Generally, any Nicolai map is obtained through a path-ordered exponential of the so-called coupling flow operator. The latter can be canonically constructed in any gauge using an N $$ \mathcal{N} $$ = 1 off-shell superfield formulation of N $$ \mathcal{N} $$ = 4 SYM, or alternatively through dimensional reduction of the result from N $$ \mathcal{N} $$ = 1 D = 10 SYM, in which case we need to restrict to the Landau gauge. We propose a general theory of the N $$ \mathcal{N} $$ = 4 coupling flow operator, arguing that it exhibits an ambiguity in form of an R-symmetry freedom given by the Lie algebra su $$ \mathfrak{su} $$ (4). This theory incorporates our two construction approaches as special points in su $$ \mathfrak{su} $$ (4) and defines a broad class of Nicolai maps for N $$ \mathcal{N} $$ = 4 SYM.
- Published
- 2022
- Full Text
- View/download PDF
216. On Security Research Towards Future Mobile Network Generations
- Author
-
Rupprecht, David, Dabrowski, Adrian, Holz, Thorsten, Weippl, Edgar, and Pöpper, Christina
- Subjects
Computer Science - Cryptography and Security - Abstract
Over the last decades, numerous security and privacy issues in all three active mobile network generations have been revealed that threaten users as well as network providers. In view of the newest generation (5G) currently under development, we now have the unique opportunity to identify research directions for the next generation based on existing security and privacy issues as well as already proposed defenses. This paper aims to unify security knowledge on mobile phone networks into a comprehensive overview and to derive pressing open research questions. To achieve this systematically, we develop a methodology that categorizes known attacks by their aim, proposed defenses, underlying causes, and root causes. Further, we assess the impact and the efficacy of each attack and defense. We then apply this methodology to existing literature on attacks and defenses in all three network generations. By doing so, we identify ten causes and four root causes of attacks. Mapping the attacks to proposed defenses and suggestions for the 5G specification enables us to uncover open research questions and challenges for the development of next-generation mobile networks. The problems of unsecured pre-authentication traffic and jamming attacks exist across all three mobile generations. They should be addressed in the future, in particular, to wipe out the class of downgrade attacks and, thereby, strengthen the users' privacy. Further advances are needed in the areas of inter-operator protocols as well as secure baseband implementations. Additionally, mitigations against denial-of-service attacks by smart protocol design represent an open research question., Comment: Survey: 198 citations, 25 pages, 4 tables, 3 figures
- Published
- 2017
217. Versehentliche Intoxikation durch Fentanylpflaster
- Author
-
Rupprecht, Holger
- Published
- 2023
- Full Text
- View/download PDF
218. Learning without Prejudice: Avoiding Bias in Webly-Supervised Action Recognition
- Author
-
Rupprecht, Christian, Kapil, Ansh, Liu, Nan, Ballan, Lamberto, and Tombari, Federico
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Webly-supervised learning has recently emerged as an alternative paradigm to traditional supervised learning based on large-scale datasets with manual annotations. The key idea is that models such as CNNs can be learned from the noisy visual data available on the web. In this work we aim to exploit web data for video understanding tasks such as action recognition and detection. One of the main problems in webly-supervised learning is cleaning the noisy labeled data from the web. The state-of-the-art paradigm relies on training a first classifier on noisy data that is then used to clean the remaining dataset. Our key insight is that this procedure biases the second classifier towards samples that the first one understands. Here we train two independent CNNs, a RGB network on web images and video frames and a second network using temporal information from optical flow. We show that training the networks independently is vastly superior to selecting the frames for the flow classifier by using our RGB network. Moreover, we show benefits in enriching the training set with different data sources from heterogeneous public web databases. We demonstrate that our framework outperforms all other webly-supervised methods on two public benchmarks, UCF-101 and Thumos'14., Comment: Submitted to CVIU SI: Computer Vision and the Web
- Published
- 2017
- Full Text
- View/download PDF
219. Emitter-site selective photoelectron circular dichroism of trifluoromethyloxirane
- Author
-
Ilchen, M., Hartmann, G., Rupprecht, P., Artemyev, A. N., Coffee, R. N., Li, Z., Ohldag, H., Ogasawara, H., Osipov, T., Ray, D., Schmidt, Ph., Wolf, T. J. A., Ehresmann, A., Moeller, S., Knie, A., and Demekhin, Ph. V.
- Subjects
Physics - Chemical Physics - Abstract
The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane, C3H3F3O, is studied experimentally and theoretically. Thereby, we investigate the photoelectron circular dichroism (PECD) for nearly-symmetric O 1s and F 1s electronic orbitals, which are localized on different molecular sites. The respective dichroic $\beta_{1}$ and angular distribution $\beta_{2}$ parameters are measured at the photoelectron kinetic energies from 1 to 16 eV by using variably polarized synchrotron radiation and velocity map imaging spectroscopy. The present experimental results are in good agreement with the outcome of ab initio electronic structure calculations. We report a sizable chiral asymmetry $\beta_{1}$ of up to about 9% for the K-shell photoionization of oxygen atom. For the individual fluorine atoms, the present calculations predict asymmetries of similar size. However, being averaged over all fluorine atoms, it drops down to about 2%, as also observed in the present experiment. Our study demonstrates a strong emitter- and site-sensitivity of PECD in the one-photon inner-shell ionization of this chiral molecule.
- Published
- 2017
- Full Text
- View/download PDF
220. Concurrent Segmentation and Localization for Tracking of Surgical Instruments
- Author
-
Laina, Iro, Rieke, Nicola, Rupprecht, Christian, Vizcaíno, Josué Page, Eslami, Abouzar, Tombari, Federico, and Navab, Nassir
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Real-time instrument tracking is a crucial requirement for various computer-assisted interventions. In order to overcome problems such as specular reflections and motion blur, we propose a novel method that takes advantage of the interdependency between localization and segmentation of the surgical tool. In particular, we reformulate the 2D instrument pose estimation as heatmap regression and thereby enable a concurrent, robust and near real-time regression of both tasks via deep learning. As demonstrated by our experimental results, this modeling leads to a significantly improved performance than directly regressing the tool position and allows our method to outperform the state of the art on a Retinal Microsurgery benchmark and the MICCAI EndoVis Challenge 2015., Comment: I. Laina and N. Rieke contributed equally to this work. Accepted to MICCAI 2017
- Published
- 2017
221. Maximal fluctuations of confined actomyosin gels: dynamics of the cell nucleus
- Author
-
Rupprecht, Jean-Francois, Vishen, Amit Singh, Shivashankar, G. V., Rao, Madan, and Prost, Jacques
- Subjects
Physics - Biological Physics ,Condensed Matter - Soft Condensed Matter ,Condensed Matter - Statistical Mechanics - Abstract
We investigate the effect of stress fluctuations on the stochastic dynamics of an inclusion embedded in a viscous gel. We show that, in non-equilibrium systems, stress fluctuations give rise to an effective attraction towards the boundaries of the confining domain, which is reminiscent of an active Casimir effect. We apply this generic result to the dynamics of deformations of the cell nucleus and we demonstrate the appearance of a fluctuation maximum at a critical level of activity, in agreement with recent experiments [E. Makhija, D. S. Jokhun, and G. V. Shivashankar, Proc. Natl. Acad. Sci. U.S.A. 113, E32 (2016)]., Comment: 12 pages, 5 figures
- Published
- 2017
- Full Text
- View/download PDF
222. Soft inclusion in a confined fluctuating active gel
- Author
-
Vishen, Amit Singh, Rupprecht, Jean-Francois, Shivashankar, G. V., Prost, Jacques, and Rao, Madan
- Subjects
Physics - Biological Physics ,Condensed Matter - Soft Condensed Matter ,Condensed Matter - Statistical Mechanics - Abstract
We study stochastic dynamics of a point and extended inclusion within a one dimensional confined active viscoelastic gel. We show that the dynamics of a point inclusion can be described by a Langevin equation with a confining potential and multiplicative noise. Using a systematic adiabatic elimination over the fast variables, we arrive at an overdamped equation with a proper definition of the multiplicative noise. To highlight various features and to appeal to different biological contexts, we treat the inclusion in turn as a rigid extended element, an elastic element and a viscoelastic (Kelvin-Voigt) element. The dynamics for the shape and position of the extended inclusion can be described by coupled Langevin equations. Deriving exact expressions for the corresponding steady state probability distributions, we find that the active noise induces an attraction to the edges of the confining domain. In the presence of a competing centering force, we find that the shape of the probability distribution exhibits a sharp transition upon varying the amplitude of the active noise. Our results could help understanding the positioning and deformability of biological inclusions, eg. organelles in cells, or nucleus and cells within tissues., Comment: 16 pages, 9 figures
- Published
- 2017
- Full Text
- View/download PDF
223. Analyzing and Exploiting NARX Recurrent Neural Networks for Long-Term Dependencies
- Author
-
DiPietro, Robert, Rupprecht, Christian, Navab, Nassir, and Hager, Gregory D.
- Subjects
Computer Science - Neural and Evolutionary Computing - Abstract
Recurrent neural networks (RNNs) have achieved state-of-the-art performance on many diverse tasks, from machine translation to surgical activity recognition, yet training RNNs to capture long-term dependencies remains difficult. To date, the vast majority of successful RNN architectures alleviate this problem using nearly-additive connections between states, as introduced by long short-term memory (LSTM). We take an orthogonal approach and introduce MIST RNNs, a NARX RNN architecture that allows direct connections from the very distant past. We show that MIST RNNs 1) exhibit superior vanishing-gradient properties in comparison to LSTM and previously-proposed NARX RNNs; 2) are far more efficient than previously-proposed NARX RNN architectures, requiring even fewer computations than LSTM; and 3) improve performance substantially over LSTM and Clockwork RNNs on tasks requiring very long-term dependencies.
- Published
- 2017
224. Learning in an Uncertain World: Representing Ambiguity Through Multiple Hypotheses
- Author
-
Rupprecht, Christian, Laina, Iro, DiPietro, Robert, Baust, Maximilian, Tombari, Federico, Navab, Nassir, and Hager, Gregory D.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Many prediction tasks contain uncertainty. In some cases, uncertainty is inherent in the task itself. In future prediction, for example, many distinct outcomes are equally valid. In other cases, uncertainty arises from the way data is labeled. For example, in object detection, many objects of interest often go unlabeled, and in human pose estimation, occluded joints are often labeled with ambiguous values. In this work we focus on a principled approach for handling such scenarios. In particular, we propose a framework for reformulating existing single-prediction models as multiple hypothesis prediction (MHP) models and an associated meta loss and optimization procedure to train them. To demonstrate our approach, we consider four diverse applications: human pose estimation, future prediction, image classification and segmentation. We find that MHP models outperform their single-hypothesis counterparts in all cases, and that MHP models simultaneously expose valuable insights into the variability of predictions., Comment: ICCV 2017
- Published
- 2016
225. Collective Motion of Predictive Swarms
- Author
-
Rupprecht, Nathaniel and Vural, Dervis Can
- Subjects
Nonlinear Sciences - Adaptation and Self-Organizing Systems - Abstract
Theoretical models of populations and swarms typically start with the assumption that the motion of agents is governed by the local stimuli. However, an intelligent agent, with some understanding of the laws that govern its habitat, can anticipate the future, and make predictions to gather resources more efficiently. Here we study a specific model of this kind, where agents aim to maximize their consumption of a diffusing resource, by attempting to predict the future of a resource field and the actions of other agents. Once the agents make a prediction, they are attracted to move towards regions that have, and will have, denser resources. We find that the further the agents attempt to see into the future, the more their attempts at prediction fail, and the less resources they consume. We also study the case where predictive agents compete against non-predictive agents and find the predictors perform better than the non-predictors only when their relative numbers are very small. We conclude that predictivity pays off either when the predictors do not see too far into the future or the number of predictors is small., Comment: 16 pages, 7 figures
- Published
- 2016
- Full Text
- View/download PDF
226. The escape problem for mortal walkers
- Author
-
Grebenkov, D. S. and Rupprecht, J. -F.
- Subjects
Physics - Chemical Physics ,Condensed Matter - Statistical Mechanics - Abstract
We introduce and investigate the escape problem for random walkers that may eventually die, decay, bleach, or lose activity during their diffusion towards an escape or reactive region on the boundary of a confining domain. In the case of a first-order kinetics (i.e., exponentially distributed lifetimes), we study the effect of the associated death rate onto the survival probability, the exit probability, and the mean first passage time. We derive the upper and lower bounds and some approximations for these quantities. We reveal three asymptotic regimes of small, intermediate and large death rates. General estimates and asymptotics are compared to several explicit solutions for simple domains, and to numerical simulations. These results allow one to account for stochastic photobleaching of fluorescent tracers in bio-imaging, degradation of mRNA molecules in genetic translation mechanisms, or high mortality rates of spermatozoa in the fertilization process. This is also a mathematical ground for optimizing storage containers and materials to reduce the risk of leakage of dangerous chemicals or nuclear wastes.
- Published
- 2016
- Full Text
- View/download PDF
227. A Thia-Analogous Indirubin N-Glycoside Disrupts Mitochondrial Function and Causes the Death of Human Melanoma and Cutaneous Squamous Cell Carcinoma Cells
- Author
-
Franziska Wendt, Felix Wittig, Anne Rupprecht, Robert Ramer, Peter Langer, Steffen Emmert, Marcus Frank, and Burkhard Hinz
- Subjects
thia-analogous indirubin N-glycoside ,skin cancer ,melanoma cells ,squamous cell carcinoma cells ,heme oxygenase-1 ,mitochondria ,Cytology ,QH573-671 - Abstract
Skin cancer is the most common malignant disease worldwide and, therefore, also poses a challenge from a pharmacotherapeutic perspective. Derivatives of indirubin are an interesting option in this context. In the present study, the effects of 3-[3′-oxo-benzo[b]thiophen-2′-(Z)-ylidene]-1-(β-d-glucopyranosyl)-oxindole (KD87), a thia-analogous indirubin N-glycoside, on the viability and mitochondrial properties of melanoma (A375) and squamous cell carcinoma cells (A431) of the skin were investigated. In both cell lines, KD87 caused decreased viability, the activation of caspases-3 and -7, and the inhibition of colony formation. At the mitochondrial level, a concentration-dependent decrease in both the basal and ATP-linked oxygen consumption rate and in the reserve capacity of oxidative respiration were registered in the presence of KD87. These changes were accompanied by morphological alterations in the mitochondria, a release of mitochondrial cytochrome c into the cytosol and significant reductions in succinate dehydrogenase complex subunit B (SDHB, subunit of complex II) in A375 and A431 cells and NADH:ubiquinone oxidoreductase subunit B8 (NDUFB8, subunit of complex I) in A375 cells. The effect of KD87 was accompanied by a significant upregulation of the enzyme heme oxygenase-1, whose inhibition led to a partial but significant reduction in the metabolic-activity-reducing effect of KD87. In summary, our data show a mitochondria-targeting effect of KD87 as part of the cytotoxic effect of this compound on skin cancer cells, which should be considered in future studies with this class of compounds.
- Published
- 2023
- Full Text
- View/download PDF
228. Meta-Analysis of European Clinical Trials Characterizing the Healthy-Adult Serum 25-hydroxyvitamin D Response to Vitamin D Supplementation
- Author
-
Manuel Rupprecht, Stefan Wagenpfeil, Jakob Schöpe, Reinhold Vieth, Thomas Vogt, and Jörg Reichrath
- Subjects
vitamin D ,supplementation ,Europe ,vitamin D deficiency ,adults ,healthy ,Nutrition. Foods and food supply ,TX341-641 - Abstract
To obtain reliable data that allow health authorities to re-evaluate recommendations for oral vitamin D uptake, we conducted a meta-analysis to investigate the impact of supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in healthy adults in Europe. Of the publications identified (n = 4005) in our literature search (PUBMED, through 2 January 2022), 49 primary studies (7320 subjects, 73 study arms) were eligible for inclusion in our meta-analysis. The risk of bias was assessed using the Cochrane RoB tool based on seven categories, according to which each study is rated using three grades, and overall was rated as rather low. The median duration of intervention was 136.78 days (range, 1088 days); the mean weighted baseline 25(OH)D concentration and mean age were 33.01 vs. 33.84 nmol/L and 46.8 vs. 44.8 years in the vitamin D and placebo groups, respectively. Using random-effects models, 25(OH)D levels were increased by 36.28 nmol/L (95% CI 31.97–40.59) in the vitamin D group compared to the placebo, with a relative serum increment of 1.77 nmol/L per 2.5 μg of vitamin D daily. Notably, the relative serum 25(OH)D increment was affected by various factors, including the dosage and baseline serum 25(OH)D concentration, decreasing with increasing vitamin D doses and with increasing baseline serum levels. We estimate that supplementation in all healthy adults in Europe with appr. 25 μg of vitamin D (1000 IU) daily would raise serum 25(OH)D levels in 95% of the population to ≥50 nmol/L. Our work provides health authorities with reliable data that can help to re-evaluate recommendations for oral vitamin D supplementation.
- Published
- 2023
- Full Text
- View/download PDF
229. Intraoperative transösophageale Echokardiographie als Notfalldiagnostik bei nichtkardiochirurgischen Patienten
- Author
-
Dumps, C., Umrath, V., Rupprecht, B., Schimpf, J., and Benak, J.
- Published
- 2022
- Full Text
- View/download PDF
230. Reduced microglia activity in patients with long-term immunosuppressive therapy after liver transplantation
- Author
-
Dirks, Meike, Buchert, Ralph, Wirries, Ann-Katrin, Pflugrad, Henning, Grosse, Gerrit M., Petrusch, Carlotta, Schütze, Christian, Wilke, Florian, Mamach, Martin, Hamann, Linda, Langer, Laura B. N., Ding, Xiao-Qi, Barg-Hock, Hannelore, Klempnauer, Jürgen, Wetzel, Christian H., Lukacevic, Mario, Janssen, Eike, Kessler, Mariella, Bengel, Frank M., Geworski, Lilli, Rupprecht, Rainer, Ross, Tobias L., Berding, Georg, and Weissenborn, Karin
- Published
- 2021
- Full Text
- View/download PDF
231. Intraoperative transösophageale Echokardiographie als Monitoring-Verfahren bei nichtkardiochirurgischen Patienten
- Author
-
Umrath, V., Dumps, C., Rupprecht, B., Schimpf, J., and Benak, J.
- Published
- 2021
- Full Text
- View/download PDF
232. Basic Science and Public Policy: Informed Regulation for Nicotine and Tobacco Products
- Author
-
Fowler, Christie D, Gipson, Cassandra D, Kleykamp, Bethea A, Rupprecht, Laura E, Harrell, Paul T, Rees, Vaughan W, Gould, Thomas J, Oliver, Jason, Bagdas, Deniz, Damaj, M Imad, Schmidt, Heath D, Duncan, Alexander, De Biasi, Mariella, and Nicotine and Tobacco, the Basic Science Network of the Society for Research on
- Subjects
Epidemiology ,Public Health ,Health Sciences ,Behavioral and Social Science ,Substance Misuse ,Prevention ,Drug Abuse (NIDA only) ,Tobacco Smoke and Health ,Tobacco ,8.3 Policy ,ethics ,and research governance ,Health and social care services research ,Good Health and Well Being ,Biomedical Research ,Humans ,Nicotine ,Public Policy ,Tobacco Products ,Tobacco Use Disorder ,Basic Science Network (BSN) of the Society for Research on Nicotine and Tobacco ,Clinical Sciences ,Public Health and Health Services ,Marketing ,Public health - Abstract
IntroductionScientific discoveries over the past few decades have provided significant insight into the abuse liability and negative health consequences associated with tobacco and nicotine-containing products. While many of these advances have led to the development of policies and laws that regulate access to and formulations of these products, further research is critical to guide future regulatory efforts, especially as novel nicotine-containing products are introduced and selectively marketed to vulnerable populations.DiscussionIn this narrative review, we provide an overview of the scientific findings that have impacted regulatory policy and discuss considerations for further translation of science into policy decisions. We propose that open, bidirectional communication between scientists and policy makers is essential to develop transformative preventive- and intervention-focused policies and programs to reduce appeal, abuse liability, and toxicity of the products.ConclusionsThrough these types of interactions, collaborative efforts to inform and modify policy have the potential to significantly decrease the use of tobacco and alternative nicotine products and thus enhance health outcomes for individuals.ImplicationsThis work addresses current topics in the nicotine and tobacco research field to emphasize the importance of basic science research and provide examples of how it can be utilized to inform public policy. In addition to relaying current thoughts on the topic from experts in the field, the article encourages continued efforts and communication between basic scientists and policy officials.
- Published
- 2018
233. Self-administered nicotine increases fat metabolism and suppresses weight gain in male rats
- Author
-
Rupprecht, Laura E, Kreisler, Alison D, Spierling, Samantha R, de Guglielmo, Giordano, Kallupi, Marsida, George, Olivier, Donny, Eric C, Zorrilla, Eric P, and Sved, Alan F
- Subjects
Biological Psychology ,Psychology ,Tobacco Smoke and Health ,Nutrition ,Prevention ,Tobacco ,Obesity ,Cancer ,Metabolic and endocrine ,Animals ,Body Weight ,Calorimetry ,Eating ,Feeding Behavior ,Lipid Metabolism ,Male ,Nicotine ,Rats ,Self Administration ,Weight Gain ,Indirect calorimetry ,Energy expenditure ,Respiratory exchange ratio ,Oxymax ,Medical and Health Sciences ,Psychology and Cognitive Sciences ,Psychiatry ,Biological psychology - Abstract
RationaleThe ability of nicotine to suppress body weight is cited as a factor impacting smoking initiation and the failure to quit. Self-administered nicotine in male rats suppresses weight independent of food intake, suggesting that nicotine increases energy expenditure.ObjectiveThe current experiment evaluated the impact of self-administered nicotine on metabolism in rats using indirect calorimetry and body composition analysis.MethodsAdult male rats with ad libitum access to powdered standard rodent chow self-administered intravenous infusions of nicotine (60 μg/kg/infusion or saline control) in daily 1-h sessions in the last hour of the light cycle. Indirect calorimetry measured respiratory exchange ratio (RER), energy expenditure, motor activity, and food and water consumption for 22.5 h between select self-administration sessions.ResultsSelf-administered nicotine suppressed weight gain and reduced the percent of body fat without altering the percent of lean mass, as measured by Echo MRI. Nicotine reduced RER, indicating increased fat utilization; this effect was observed prior to weight suppression. Moreover, nicotine intake did not affect motor activity or energy expenditure. Daily food intake was not altered by nicotine self-administration; however, a trend in suppression of meal size, a transient suppression of water intake, and an increase in meal frequency was observed.ConclusionThese data provide evidence that self-administered nicotine suppresses body weight via increased fat metabolism, independent of significant changes in feeding, activity, or energy expenditure.
- Published
- 2018
234. Spatial coherence of room-temperature monolayer WSe2 exciton-polaritons in a trap
- Author
-
Hangyong Shan, Lukas Lackner, Bo Han, Evgeny Sedov, Christoph Rupprecht, Heiko Knopf, Falk Eilenberger, Johannes Beierlein, Nils Kunte, Martin Esmann, Kentaro Yumigeta, Kenji Watanabe, Takashi Taniguchi, Sebastian Klembt, Sven Höfling, Alexey V. Kavokin, Sefaattin Tongay, Christian Schneider, and Carlos Antón-Solanas
- Subjects
Science - Abstract
Here, the authors show that the interaction between microcavity photons and excitons in an atomically thin WSe2 results in a hybridized regime of strong light-matter coupling. Coherence build-up is accompanied by a threshold-like behaviour of the emitted light intensity, which is a fingerprint of a polariton laser effect.
- Published
- 2021
- Full Text
- View/download PDF
235. Psymberin, a marine-derived natural product, induces cancer cell growth arrest and protein translation inhibition
- Author
-
Divya L. Dayanidhi, Jason A. Somarelli, John B. Mantyh, Gabrielle Rupprecht, Roham Salman Roghani, Sophia Vincoff, Iljin Shin, Yiquan Zhao, So Young Kim, Shannon McCall, Jiyong Hong, and David S. Hsu
- Subjects
patient-derived organoids ,patient-derived models of cancer ,precision medicine ,psymberin ,high-throughput screening ,protein translation ,Medicine (General) ,R5-920 - Abstract
Colorectal cancer (CRC) is the third most prevalent form of cancer in the United States and results in over 50,000 deaths per year. Treatments for metastatic CRC are limited, and therefore there is an unmet clinical need for more effective therapies. In our prior work, we coupled high-throughput chemical screens with patient-derived models of cancer to identify new potential therapeutic targets for CRC. However, this pipeline is limited by (1) the use of cell lines that do not appropriately recapitulate the tumor microenvironment, and (2) the use of patient-derived xenografts (PDXs), which are time-consuming and costly for validation of drug efficacy. To overcome these limitations, we have turned to patient-derived organoids. Organoids are increasingly being accepted as a “standard” preclinical model that recapitulates tumor microenvironment cross-talk in a rapid, cost-effective platform. In the present work, we employed a library of natural products, intermediates, and drug-like compounds for which full synthesis has been demonstrated. Using this compound library, we performed a high-throughput screen on multiple low-passage cancer cell lines to identify potential treatments. The top candidate, psymberin, was further validated, with a focus on CRC cell lines and organoids. Mechanistic and genomics analyses pinpointed protein translation inhibition as a mechanism of action of psymberin. These findings suggest the potential of psymberin as a novel therapy for the treatment of CRC.
- Published
- 2022
- Full Text
- View/download PDF
236. Increased left dorsolateral prefrontal cortex density following escitalopram intake during relearning: a randomized, placebo-controlled trial in healthy humans
- Author
-
Thomas Vanicek, Murray B. Reed, René Seiger, Godber M. Godbersen, Manfred Klöbl, Jakob Unterholzner, Benjamin Spurny-Dworak, Gregor Gryglewski, Patricia Handschuh, Clemens Schmidt, Christoph Kraus, Thomas Stimpfl, Rainer Rupprecht, Siegfried Kasper, and Rupert Lanzenberger
- Subjects
Therapeutics. Pharmacology ,RM1-950 ,Psychiatry ,RC435-571 - Abstract
Background: Serotonergic agents affect brain plasticity and reverse stress-induced dendritic atrophy in key fronto-limbic brain areas associated with learning and memory. Objectives: The aim of this study was to investigate effects of the antidepressant escitalopram on gray matter during relearning in healthy individuals to inform a model for depression and the neurobiological processes of recovery. Design: Randomized double blind placebo control, monocenter study. Methods: In all, 76 (44 females) healthy individuals performed daily an associative learning task with emotional or non-emotional content over a 3-week period. This was followed by a 3-week relearning period (randomly shuffled association within the content group) with concurrent daily selective serotonin reuptake inhibitor (i.e., 10 mg escitalopram) or placebo intake. Results: Via voxel-based morphometry and only in individuals that developed sufficient escitalopram blood levels over the 21-day relearing period, an increased density of the left dorsolateral prefrontal cortex was found. When investigating whether there was an interaction between relearning and drug intervention for all participants, regardless of escitalopram levels, no changes in gray matter were detected with either surfaced-based or voxel-based morphometry analyses. Conclusion: The left dorsolateral prefrontal cortex affects executive function and emotional processing, and is a critical mediator of symptoms and treatment outcomes of depression. In line, the findings suggest that escitalopram facilitates neuroplastic processes in this region if blood levels are sufficient. Contrary to our hypothesis, an effect of escitalopram on brain structure that is dependent of relearning content was not detected. However, this may have been a consequence of the intensity and duration of the interventions. Registration: ClinicalTrials.gov Identifier: NCT02753738; Trial Name: Enhancement of learning associated neural plasticity by Selective Serotonin Reuptake Inhibitors ; URL: https://clinicaltrials.gov/ct2/show/NCT02753738 .
- Published
- 2022
- Full Text
- View/download PDF
237. Improving the continuity and coordination of ambulatory care through feedback and facilitated dialogue—a study protocol for a cluster-randomised trial to evaluate the ACD study (Accountable Care in Germany)
- Author
-
Leonie Sundmacher, Ronja Flemming, Verena Leve, Isabel Geiger, Sebastian Franke, Thomas Czihal, Clemens Krause, Birgitt Wiese, Frank Meyer, Matthias Brittner, Johannes Pollmanns, Johannes Martin, Paul Brandenburg, Annemarie Schultz, Emmanuelle Brua, Udo Schneider, Olga Dortmann, Christoph Rupprecht, Stefan Wilm, and Wiebke Schüttig
- Subjects
Health care ,Networks ,Ambulatory care ,Feedback ,Cluster-randomised trial ,Quality circles ,Medicine (General) ,R5-920 - Abstract
Abstract Background Patients in Germany are free to seek care from any office-based physician and can always ask for multiple opinions on a diagnosis or treatment. The high density of physicians and the freedom to choose among them without referrals have led to a need for better coordination between the multiple health professionals treating any given patient. The objectives of this study are to (1) identify informal networks of physicians who treat the same patient population, (2) provide these physicians with feedback on their network and patients, using routine data and (3) give the physicians the opportunity to meet one another in facilitated network meetings. Methods The Accountable Care Deutschland (ACD) study is a prospective, non-blinded, cluster-randomised trial comprising a process and economic evaluation of informal networks among 12,525 GPs and office-based specialists and their 1.9 million patients. The units of allocation are the informal networks, which will be randomised either to the intervention (feedback and facilitated meetings) or control group (usual care). The informal networks will be generated by identifying connections between office-based physicians using complete datasets from the Regional Associations of Statutory Health Insurance (SHI) Physicians in Hamburg, Schleswig Holstein, North Rhine and Westphalia Lip, as well as data from three large statutory health insurers in Germany. The physicians will (a) receive feedback on selected indicators of their own treatment activity and that of the colleagues in their network and (b) will be invited to voluntary, facilitated network meetings by their Regional Association of SHI physicians. The primary outcome will be ambulatory-care-sensitive hospitalisations at baseline, at the end of the 2-year intervention period, and at six months and at 12 months after the end of the intervention period. Data will be analysed using the intention-to-treat principle. A pilot study preceded the ACD study. Discussion Cochrane reviews show that feedback can improve everyday medical practice by shedding light on previously unknown relationships. Providing physicians with information on how they are connected with their colleagues and what the outcomes are of care delivered within their informal networks can help them make these improvements, as well as strengthen their awareness of possible discontinuities in the care they provide. Trial registration German Clinical Trials Register DRKS00020884 . Registered on 25 March 2020—retrospectively registered.
- Published
- 2021
- Full Text
- View/download PDF
238. Site-specific interrogation of an ionic chiral fragment during photolysis using an X-ray free-electron laser
- Author
-
Markus Ilchen, Philipp Schmidt, Nikolay M. Novikovskiy, Gregor Hartmann, Patrick Rupprecht, Ryan N. Coffee, Arno Ehresmann, Andreas Galler, Nick Hartmann, Wolfram Helml, Zhirong Huang, Ludger Inhester, Alberto A. Lutman, James P. MacArthur, Timothy Maxwell, Michael Meyer, Valerija Music, Heinz-Dieter Nuhn, Timur Osipov, Dipanwita Ray, Thomas J. A. Wolf, Sadia Bari, Peter Walter, Zheng Li, Stefan Moeller, André Knie, and Philipp V. Demekhin
- Subjects
Chemistry ,QD1-999 - Abstract
Ultrashort circularly polarised light pulses from free-electron lasers offer a route for exploring chiral molecules and their dynamics, but remain challenging to harness. Here, X-ray pump-probe experiments enable a site-specific photoelectron circular dichroism measurement on a dissociating chiral molecule.
- Published
- 2021
- Full Text
- View/download PDF
239. Antidepressant effect of repetitive transcranial magnetic stimulation is not impaired by intake of lithium or antiepileptic drugs
- Author
-
Hebel, T., Abdelnaim, M. A., Deppe, M., Kreuzer, P. M., Mohonko, A., Poeppl, T. B., Rupprecht, R., Langguth, B., and Schecklmann, M.
- Published
- 2021
- Full Text
- View/download PDF
240. In situ measurement and closed-loop control for powder supply processes: Retrofittable solution in the context of laser metal deposition
- Author
-
Breese, Philipp Peter, Hauser, Tobias, Regulin, Daniel, Seebauer, Stefan, and Rupprecht, Christian
- Published
- 2021
- Full Text
- View/download PDF
241. Hands-Free Segmentation of Medical Volumes via Binary Inputs
- Author
-
Dubost, Florian, Peter, Loic, Rupprecht, Christian, Gutierrez-Becker, Benjamin, and Navab, Nassir
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
We propose a novel hands-free method to interactively segment 3D medical volumes. In our scenario, a human user progressively segments an organ by answering a series of questions of the form "Is this voxel inside the object to segment?". At each iteration, the chosen question is defined as the one halving a set of candidate segmentations given the answered questions. For a quick and efficient exploration, these segmentations are sampled according to the Metropolis-Hastings algorithm. Our sampling technique relies on a combination of relaxed shape prior, learnt probability map and consistency with previous answers. We demonstrate the potential of our strategy on a prostate segmentation MRI dataset. Through the study of failure cases with synthetic examples, we demonstrate the adaptation potential of our method. We also show that our method outperforms two intuitive baselines: one based on random questions, the other one being the thresholded probability map.
- Published
- 2016
242. An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status
- Author
-
Matter, A., Lopez, B., Antonelli, P., Lehmitz, M., Bettonvil, F., Beckmann, U., Lagarde, S., Jaffe, W., Petrov, R. G., Berio, P., Millour, F., Robbe-Dubois, S., Glindemann, A., Bristow, P., Schoeller, M., Lanz, T., Henning, T., Weigelt, G., Heininger, M., Morel, S., Cruzalebes, P., Meisenheimer, K., Hofferbert, R., Wolf, S., Bresson, Y., Agocs, T., Allouche, F., Augereau, J. -C., Avila, G., Bailet, C., Behrend, J., Van Belle, G., Berger, J. -P., van Boekel, R., Bourget, P., Brast, R., Clausse, J. -M., Connot, C., Conzelmann, R., Csepany, G., Danchi, W. C., Delbo, M., Dominik, C., van Duin, A., Elswijk, E., Fantei, Y., Finger, G., Gabasch, A., Gonté, F., Graser, U., Guitton, F., Guniat, S., De Haan, M., Haguenauer, P., Hanenburg, H., Hofmann, K. -H., Hogerheijde, M., ter Horst, R., Hron, J., Hummel, C., Isderda, J., Ives, D., Jakob, G., Jasko, A., Jolley, P., Kiraly, S., Kragt, J., Kroener, T., Kroes, G., Kuindersma, S., Labadie, L., Laun, W., Leinert, C., Lizon, J. -L., Lucuix, C., Marcotto, A., Martinache, F., Martinot-Lagarde, G., Mauclert, N., Mehrgan, L., Meilland, A., Mellein, M., Menardi, S., Merand, A., Neumann, U., Nussbaum, E., Ottogalli, S., Palsa, R., Panduro, J., Pantin, E., Percheron, I., Duc, T. Phan, Pott, J. -U., Pozna, E., Roelfsema, R., Rupprecht, G., Schertl, D., Schmidt, C., Schuil, M., Spang, A., stegmeier, J., Tromp, N., Vakili, F., Vannier, M., Wagner, K., Venema, L., and Woillez, J.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 um, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution range from R ~ 30 to R ~ 5000. Here, we present one of the main science objectives, the study of protoplanetary disks, that has driven the instrument design and motivated several VLTI upgrades (GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performances. We also discuss the current status of the MATISSE instrument, which is entering its testing phase, and the foreseen schedule for the next two years that will lead to the first light at Paranal., Comment: SPIE Astronomical Telescopes and Instrumentation conference, June 2016, 11 pages, 6 Figures
- Published
- 2016
- Full Text
- View/download PDF
243. Regaining the FORS: making optical ground-based transmission spectroscopy of exoplanets with VLT+FORS2 possible again
- Author
-
Boffin, Henri M. J., Sedaghati, Elyar, Blanchard, Guillaume, Gonzalez, Oscar, Moehler, Sabine, Gibson, Neale, Ancker, Mario van den, Smoker, Jonathan, Anderson, Joseph, Hummel, Christian, Dobrzycka, Danuta, Smette, Alain, and Rupprecht, Gero
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Earth and Planetary Astrophysics ,Astrophysics - Solar and Stellar Astrophysics ,Physics - Instrumentation and Detectors - Abstract
Transmission spectroscopy facilitates the detection of molecules and/or clouds in the atmospheres of exoplanets. Such studies rely heavily on space-based or large ground-based observatories, as one needs to perform time- resolved, high signal-to-noise spectroscopy. The FORS2 instrument at ESO's Very Large Telescope is the obvious choice for performing such studies, and was indeed pioneering the field in 2010. After that, however, it was shown to suffer from systematic errors caused by the Longitudinal Atmospheric Dispersion Corrector (LADC). This was successfully addressed, leading to a renewed interest for this instrument as shown by the number of proposals submitted to perform transmission spectroscopy of exoplanets. We present here the context, the problem and how we solved it, as well as the recent results obtained. We finish by providing tips for an optimum strategy to do transmission spectroscopy with FORS2, in the hope that FORS2 may become the instrument of choice for ground-based transmission spectroscopy of exoplanets., Comment: Paper 9908-85 presented at SPIE 2016
- Published
- 2016
- Full Text
- View/download PDF
244. Deep Active Contours
- Author
-
Rupprecht, Christian, Huaroc, Elizabeth, Baust, Maximilian, and Navab, Nassir
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
We propose a method for interactive boundary extraction which combines a deep, patch-based representation with an active contour framework. We train a class-specific convolutional neural network which predicts a vector pointing from the respective point on the evolving contour towards the closest point on the boundary of the object of interest. These predictions form a vector field which is then used for evolving the contour by the Sobolev active contour framework proposed by Sundaramoorthi et al. The resulting interactive segmentation method is very efficient in terms of required computational resources and can even be trained on comparatively small graphics cards. We evaluate the potential of the proposed method on both medical and non-medical challenge data sets, such as the STACOM data set and the PASCAL VOC 2012 data set.
- Published
- 2016
245. A Taxonomy and Library for Visualizing Learned Features in Convolutional Neural Networks
- Author
-
Grün, Felix, Rupprecht, Christian, Navab, Nassir, and Tombari, Federico
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Over the last decade, Convolutional Neural Networks (CNN) saw a tremendous surge in performance. However, understanding what a network has learned still proves to be a challenging task. To remedy this unsatisfactory situation, a number of groups have recently proposed different methods to visualize the learned models. In this work we suggest a general taxonomy to classify and compare these methods, subdividing the literature into three main categories and providing researchers with a terminology to base their works on. Furthermore, we introduce the FeatureVis library for MatConvNet: an extendable, easy to use open source library for visualizing CNNs. It contains implementations from each of the three main classes of visualization methods and serves as a useful tool for an enhanced understanding of the features learned by intermediate layers, as well as for the analysis of why a network might fail for certain examples.
- Published
- 2016
246. Deeper Depth Prediction with Fully Convolutional Residual Networks
- Author
-
Laina, Iro, Rupprecht, Christian, Belagiannis, Vasileios, Tombari, Federico, and Navab, Nassir
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
This paper addresses the problem of estimating the depth map of a scene given a single RGB image. We propose a fully convolutional architecture, encompassing residual learning, to model the ambiguous mapping between monocular images and depth maps. In order to improve the output resolution, we present a novel way to efficiently learn feature map up-sampling within the network. For optimization, we introduce the reverse Huber loss that is particularly suited for the task at hand and driven by the value distributions commonly present in depth maps. Our model is composed of a single architecture that is trained end-to-end and does not rely on post-processing techniques, such as CRFs or other additional refinement steps. As a result, it runs in real-time on images or videos. In the evaluation, we show that the proposed model contains fewer parameters and requires fewer training data than the current state of the art, while outperforming all approaches on depth estimation. Code and models are publicly available., Comment: Published at IEEE International Conference on 3D Vision (3DV) 2016
- Published
- 2016
247. Optimal search strategies of run-and-tumble walks
- Author
-
Rupprecht, Jean-Francois, Bénichou, Olivier, and Voituriez, Raphael
- Subjects
Condensed Matter - Statistical Mechanics ,Condensed Matter - Soft Condensed Matter ,Physics - Biological Physics - Abstract
The run-and-tumble walk, consisting in randomly reoriented ballistic excursions, models phenomena ranging from gas kinetics to bacteria motility. We evaluate the mean time required for this walk to find a fixed target within a 2D or 3D spherical confinement. We find that the mean search time admits a minimum as a function of the mean run duration for various types of boundary conditions and run duration distributions (exponential, power-law, deterministic). Our result stands in sharp contrast to the pure ballistic motion, which is predicted to be the optimal search strategy in the case of Poisson distributed targets., Comment: 10 pages, 7 figures
- Published
- 2016
- Full Text
- View/download PDF
248. Trade-offs between spatial and temporal resolutions in stochastic super-resolution microscopy techniques
- Author
-
Rupprecht, Jean-Francois, Martinez-Marrades, Ariadna, Changede, Rishita, and Tessier, Gilles
- Subjects
Physics - Biological Physics ,Condensed Matter - Soft Condensed Matter ,Physics - Data Analysis, Statistics and Probability ,Physics - Optics - Abstract
Widefield stochastic microscopy techniques such as PALM or STORM rely on the progressive accumulation of a large number of frames, each containing a scarce number of super-resolved point images. We justify that the redundancy in the localization of detected events imposes a specific limit on the temporal resolution. Based on a theoretical model, we derive analytical predictions for the minimal time required to obtain a reliable image at a given spatial resolution, called image completion time. In contrast to standard assumptions, we find that the image completion time scales logarithmically with the ratio of the image size by the spatial resolution volume. We justify that this non-linear relation is the hallmark of a random coverage problem. We propose a method to estimate the risk that the image reconstruction is not complete, which we apply to an experimental data set. Our results provide a theoretical framework to quantify the pattern detection efficiency and to optimize the trade-off between image coverage and acquisition time, with applications to $1$, $2$ or $3$ dimension structural imaging., Comment: 15 pages, 9 figures
- Published
- 2016
- Full Text
- View/download PDF
249. Learning, playing, and experimenting with critical food futures
- Author
-
Steven R. McGreevy, Christoph D. D. Rupprecht, Norie Tamura, Kazuhiko Ota, Mai Kobayashi, and Maximilian Spiegelberg
- Subjects
food systems ,transformation ,scenarios ,futures literacy ,transdisciplinary ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
Imagining sustainable food futures is key to effectively transforming food systems. Yet even transdisciplinary approaches struggle to open up complex and highly segregated food policy governance for co-production and can fail to critically interrogate assumptions, worldviews, and values. In this Perspective we argue that transdisciplinary processes concerned with sustainable food system transformation need to meaningufully engage with critical food futures, and can do so through the use of soft scenario methods to learn about, play with, and experiment in futures. Specifically, soft scenarios contribute in four ways: 1) questioning widely held assumptions about the future; 2) being inclusive to multiple perspectives and worldviews; 3) fostering receptiveness to unimaginable futures; 4) developing futures literacy. Based on insights from a 5-year transdisciplinary action research project on sustainable food transformation across Asia, we demonstrate how these processes play out in narratives, serious games and interactive art featuring soft scenarios. We conclude by discussing the potential for collaboration between transdisciplinary and futures researchers, especially for transforming food systems.
- Published
- 2022
- Full Text
- View/download PDF
250. Awareness of age-related change in the context of major life events
- Author
-
Fiona S. Rupprecht, Serena Sabatini, Manfred Diehl, Denis Gerstorf, Roman Kaspar, Oliver K. Schilling, and Hans-Werner Wahl
- Subjects
subjective aging ,family events ,health events ,lifespan development ,developmental change ,developmental gains ,Psychiatry ,RC435-571 - Abstract
Although gains and losses are an integral part of human development, the experience of change and readjustment that often comes with major life events may be particularly influential for an individual's subjective aging experience and awareness of age-related change (AARC). Thus, this study focused on the role of life events in the domains of family and health for an individual's awareness of age-related gains and losses. Specifically, we differentiated between the experience of specific life events (e.g., entering a new romantic relationship; hospital stay) and the cumulative experience of multiple life events. Furthermore, we differentiated between life events experienced at an expected time in life and life events experienced relatively early or relatively late compared to established social norms. Data came from the Innovation Sample of the German Socio-Economic Panel (SOEP-IS) and consisted of 1,612 participants aged 16 to 93 years (M = 54.1; SD = 18.2). Life events were assessed annually and retrospectively for the last 2 years. Propensity score matching provided evidence for an association of specific family life events and a higher awareness of age-related gains, as well as specific health life events and a higher awareness of age-related losses. Results furthermore indicated that the cumulative experience of family life events was associated with a higher awareness of age-related gains. Conversely, the cumulative experience of health events was associated with higher awareness of both age-related losses and age-related gains. Moreover, it was not only life events happening at an expected age, but also those happening relatively early and particularly those happening late in life, which were associated with AARC. In summary, life events and the change they may bring seem to be reflected in individuals' awareness of age-related losses and awareness of age-related gains.
- Published
- 2022
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.