22 research outputs found
Variable remanence acquisition efficiency in sediments containing biogenic and detrital magnetites: Implications for relative paleointensity signal recording
Widespread geological preservation of biogenic magnetite makes it important to assess how such particles contribute to sedimentary paleomagnetic signals. We studied a sediment core from the South China Sea that passes the strict empirical criteria for magnetic "uniformity" used in relative paleointensity studies. Such assessments are based routinely on bulk magnetic parameters that often fail to enable identification of mixed magnetic mineral assemblages. Using techniques that enable component-specific magnetic mineral identification, we find that biogenic and detrital magnetites occur in approximately equal concentrations within the studied sediments. We analyzed normalized remanence signals associated with the two magnetite components to assess whether co-occurring biogenic and detrital magnetites record geomagnetic information in the same way and with the same efficiency. Paleomagnetic directions for the two components have no phase lag, which suggests that the biogenic and detrital magnetites acquired their magnetizations at equivalent times. However, we find that the biogenic magnetite is generally 2-4 times more efficient as the detrital magnetite in contributing to the natural remanent magnetization (NRM) despite their approximately equal magnetic contributions. Variations in the concentration and efficiency of remanence acquisition of the two components suggest that a significant part of the NRM is controlled by nongeomagnetic factors that will affect relative paleointensity recording. We recommend that methods suited to the detection of variable recording efficiency associated with biogenic and detrital magnetites should be used on a routine basis in relative paleointensity studies
Off-line evaluation of indoor positioning systems in different scenarios: the experiences from IPIN 2020 competition
Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1 m for the Smartphone Track and 0.5 m for the Foot-mounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements.Track 3 organizers were supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie Grant 813278 (A-WEAR: A network for dynamic WEarable Applications with pRivacy constraints), MICROCEBUS (MICINN, ref. RTI2018-095168-B-C55, MCIU/AEI/FEDER UE), INSIGNIA (MICINN ref. PTQ2018-009981), and REPNIN+ (MICINN, ref. TEC2017-90808-REDT). We would like to thanks the UJI’s Library managers and employees for their support while collecting the required datasets for Track 3.
Track 5 organizers were supported by JST-OPERA Program, Japan, under Grant JPMJOP1612.
Track 7 organizers were supported by the Bavarian Ministry for Economic Affairs, Infrastructure, Transport and Technology through the Center for Analytics-Data-Applications (ADA-Center) within the framework of “BAYERN DIGITAL II. ”
Team UMinho (Track 3) was supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope under Grant UIDB/00319/2020, and the Ph.D. Fellowship under Grant PD/BD/137401/2018.
Team YAI (Track 3) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 109-2221-E-197-026.
Team Indora (Track 3) was supported in part by the Slovak Grant Agency, Ministry of Education and Academy of Science, Slovakia, under Grant 1/0177/21, and in part by the Slovak Research and Development Agency under Contract APVV-15-0091.
Team TJU (Track 3) was supported in part by the National Natural Science Foundation of China under Grant 61771338 and in part by the Tianjin Research Funding under Grant 18ZXRHSY00190.
Team Next-Newbie Reckoners (Track 3) were supported by the Singapore Government through the Industry Alignment Fund—Industry Collaboration Projects Grant. This research was conducted at Singtel Cognitive and Artificial Intelligence Lab for Enterprises (SCALE@NTU), which is a collaboration between Singapore Telecommunications Limited (Singtel) and Nanyang Technological University (NTU).
Team KawaguchiLab (Track 5) was supported by JSPS KAKENHI under Grant JP17H01762.
Team WHU&AutoNavi (Track 6) was supported by the National Key Research and Development Program of China under Grant 2016YFB0502202.
Team YAI (Tracks 6 and 7) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 110-2634-F-155-001
Noise trauma and systemic application of the selective glucocorticoid receptor modulator compound A
Off-Line Evaluation of Indoor Positioning Systems in Different Scenarios: The Experiences From IPIN 2020 Competition
Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1 m for the Smartphone Track and 0.5 m for the Foot-mounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements.Track 3 organizers were supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie Grant 813278 (A-WEAR: A network for dynamic WEarable Applications with pRivacy constraints), MICROCEBUS (MICINN, ref. RTI2018-095168-B-C55, MCIU/AEI/FEDER UE), INSIGNIA (MICINN ref. PTQ2018-009981), and REPNIN+ (MICINN, ref. TEC2017-90808-REDT). We would like to thanks the UJI’s Library managers and employees for their support while collecting the required datasets for Track 3.
Track 5 organizers were supported by JST-OPERA Program, Japan, under Grant JPMJOP1612.
Track 7 organizers were supported by the Bavarian Ministry for Economic Affairs, Infrastructure, Transport and Technology through the Center for Analytics-Data-Applications (ADA-Center) within the framework of “BAYERN DIGITAL II. ”
Team UMinho (Track 3) was supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope under Grant UIDB/00319/2020, and the Ph.D. Fellowship under Grant PD/BD/137401/2018.
Team YAI (Track 3) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 109-2221-E-197-026.
Team Indora (Track 3) was supported in part by the Slovak Grant Agency, Ministry of Education and Academy of Science, Slovakia, under Grant 1/0177/21, and in part by the Slovak Research and Development Agency under Contract APVV-15-0091.
Team TJU (Track 3) was supported in part by the National Natural Science Foundation of China under Grant 61771338 and in part by the Tianjin Research Funding under Grant 18ZXRHSY00190.
Team Next-Newbie Reckoners (Track 3) were supported by the Singapore Government through the Industry Alignment Fund—Industry Collaboration Projects Grant. This research was conducted at Singtel Cognitive and Artificial Intelligence Lab for Enterprises (SCALE@NTU), which is a collaboration between Singapore Telecommunications Limited (Singtel) and Nanyang Technological University (NTU).
Team KawaguchiLab (Track 5) was supported by JSPS KAKENHI under Grant JP17H01762.
Team WHU&AutoNavi (Track 6) was supported by the National Key Research and Development Program of China under Grant 2016YFB0502202.
Team YAI (Tracks 6 and 7) was supported by the Ministry of Science and Technology (MOST) of Taiwan under Grant MOST 110-2634-F-155-001.Peer reviewe
Effects of Locally Applied Glucocorticoids on the Inner Ear Trauma Caused by Noise and Electrode Insertion in an Animal Model
Die möglichen Uhrsachen für Innenohrerkrankungen sind mannigfaltig. Ein potentieller Auslöser für einen sensorineuralen Hörverlust, der auch dauerhaft sein kann, ist das Lärmtrauma. Die Versorgung mit einem Cochlea-Implantat ist derzeit die effektivste Therapie für die Patienten, die an einer hochgradigen bzw. an Taubheit grenzenden Hörminderung leiden. Durch chirurgische und technische Verbesserungen in den letzten Jahren hat sich die Indikation zur Cochlea-Implantation immer mehr ausgeweitet. Bei Patienten mit erhaltenem Restgehör in den tiefen Frequenzen gibt es die Möglichkeit, nach der Cochlea-Implantat-Operation das Ohr sowohl akustisch als auch elektrische zu stimulieren. In diesem Patienten gut sind mögliche Komplikationen wie akute und chronische Schädigung der Haarzellen und afferenten Hörnervenfasern umso problematischer. Basierend auf zahlreichen wissenschaftlichen Untersuchungen welche gutteils positive Ergebnisse erbrachten, werden Glucocorticoide seit Jahrzehnten als Erst-Linien Therapieder meisten Innenohrerkrankungen, wie zum Beispiel des Hörsturzes, der akuten Lärmschwerhörigkeit, des Morbus Meniere oder auch als otoprotektive Substanz bei der Cochlea-Implantation verwendet.
Bei systemisch angewandten Corticosteroiden können einerseits nur niedrige Perilymph-Konzentrationen erreicht werden und bei langfristiger Applikation drohen Nebenwirkungen. In den letzten Jahren konzentrierte sich die Forschung daher auf den lokalen Einsatz von Substanzen. Im Rahmen dieser Forschungen konnte auch gezeigt werden, dass Dexamethason-geladene thermoreversible Poloxamer-407 Hydrogele einen vielversprechenden Ansatz zur Optimierung der lokalen Corticoid-Therapie darstellen. Durch die intratympanale Injektion gelangt das Hydrogel direkt an die Rundfenstermembran, wodurch über mehrere Tage ein therapeutischer Medikamentenspiegel im Innenohr erreicht werden kann. Weiters kann durch diese Applikations form das Risiko von schwere systemischen Nebenwirkungen reduziert werden. Trotz der vielen beschriebenen Vorteile gibt es bis jetzt nur wenige Daten über die otoprotektiven Wirkungen des Gels.
Im Rahmen dieser Arbeit wurden Dexamethason und Triamcinolon Acetonid, welche beide häufig in der klinischen Routine zur Therapie von verschiedenen Innenohrerkrankungen verwendet werden, in Poloxamer-407 Hydrogelen appliziert, um ihre otoprotektiven Effekte zu vergleichen. Hierfür wurden die Glucocorticoid- geladenden Gele - jeweils in einem Meeschweinchen-Modell - entweder vor der Cochlea Implantation oder nach einem Lärmtrauma appliziert. In den darauffolgenden Wochen wurde das Gehör der Tiere wiederholt getestet und am Ende der Versuche wurden die Felsenbeine zur histologischen Aufarbeitungen und Auswertung entnommen.
Die gewonnenen Daten zeigen, dass die intratympanale Applikation von Dexamethason in einem Poloxamer-407 Hydrogel den durch ein Lärmtrauma oder durch die Insertion einer Cochlea Implantat-Elektrodeverursachten Hörverlust signifikant reduzieren kann. Die Applikation des Dexamethason-Hydrogels einen Tag vor der Cochlea-Implantation, die im Tiermodell einen positiven Effekt auf den Restgehörerhalt in den tiefen Frequenzen hatte, könnte problemlos in der Klinik angewendet werden. Zusätzlich zu den protektiven Effekten im Cochlea-Implantat Modell konnte im Lärmtrauma-Modell eine protektive Wirkung von Dexamethason auf die Spiral ganglion-Zell engezeigt werden. Im Gegensatz dazu konnten für das Triamcinolon-Acetonid Hydrogel im Lärmtrauma Modell keine positven Effekte gezeigt werden.
Zusammenfassend zeigen die durchgeführten Arbeiten, dass die lokale Applikation eines 6% Dexamethason-Hydrogels das Innenohr vor einem Lärm-und auch vor einem Elektrodeninsertionstrauma schützen kann. Diese Ergebnisse bilden sowohl eine gute Basis für weitere mögliche experimentelle Anwendungen von Glucocorticoid- gelandenen Hydrogelen, als auch für translationelle Studien im klinischen Bereich.Potential causes for inner ear disorders are diverse. Among them, overstimulation of the inner ear in form of noise is one of the major reasons for permanent hearing loss, and therefore affects millions of people in the world. As cochlear implantation is well established as the most effective therapy for patients suffering from severe to profound hearing loss, indications for this treatment modality have been continuously expanded. In cochlear implant candidates with residual low frequency hearing, insertion of the electrode into the inner ear can however impair acoustic hearing acutely and chronically. Based on abundant studies which indicated protective effects, glucocorticoids currently serve as first line therapy in multiple inner ear disorders including noise-induced hearing loss, sudden sensorineural hearing loss, Meniere's disease as well as during cochlear implantation when residual hearing protection is attempted. Because the systemic application of glucocorticoids is limited due to the relatively low perilymph drug concentrations and potential side effects after long-term administration, topical drug application is of particular clinical interest and is therefore extensively been researched. A couple of years ago, a glucocorticoid-loaded thermoreversible poloxamer 407 hydrogel emerged as a promising approach to improve local drug delivery. This hydrogel can be easily applied via a single intratympanic injection and maintains drug concentrations in the inner ear above clinically relevant levels for a long time. Furthermore, it reduces the risk for side effects. However, studies addressing the otoprotective effects of such glucocorticoids-loaded hydrogels are rare.
Based on this background, this thesis aimed to improve the inner ear therapy by using local drug-loaded hydrogels. Therefore, dexamethasone and triamcinolone acetonide, which are widely used in clinics for inner ear disorders, were formulated into poloxamer 407 hydrogels for intratympanic injection in animal models. Two series of studies were performed during this thesis, one investigating such hydrogels in a model for hearing loss caused by noise exposure and the other evaluating protective effects in the setting of cochlear implant electrode insertion. In these series dexamethasone loaded hydrogels were applied after noise exposure or prior to surgery. Hearing threshold shifts were analyzed at different points in time and a histological workup of the ears was performed in the course of the generation of this thesis.
We found a significantly reduced hearing loss after local application of 6% dexamethasone-loaded hydrogel in noise-induced inner ear trauma as well as in inner ear trauma induced by electrode insertion. The achieved hearing preservation effect in the low frequencies by pre-operative application of 6% dexamethasone-loaded hydrogel is of particular importance for speech perception after cochlear implantation for electric acoustic stimulation. Additionally, 6% dexamethasone-loaded hydrogel exhibited promising results with respect to spiral ganglion cell protection in the noise-induced hearing loss model. According to our data and in contrast to dexamethasone, neither concentration of triamcinolone acetonide-hydrogel showed otoprotective effects following noise exposure.
In summary, local application of 6% dexamethasone-loaded thermoreversible hydrogel protected inner ear function after noise-induced inner ear trauma and improved hearing preservation during cochlear implantation. Studies from this thesis demonstrated the versatility of glucocorticoid-loaded hydrogels in the treatment of inner ear disorders and shed light on future possibilities for translation into clinical studies.Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersArbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprüftMedizinische Universität Wien, Diss., 2019(VLID)445776
Study on chip formation in grinding nickel-based single-crystal superalloy DD5
According to the significant anisotropy of nickel-based single-crystal superalloy, a three-dimensional single abrasive grinding model based on the Hill model was developed. In this work, the change in the actual grinding thickness (ag) of the abrasive is taken into account in establishing the model. In addition, a combination of theoretical research and experimental research is used. The surface morphology and chip morphology of DD5 were first studied. Then, the evolution of chip morphology and the change in grinding force were investigated. Finally, the influence of grinding speed (vs) on chip morphology and chip segmentation frequency (fc) was studied. The research shows that serrated chips can easily occur when machining DD5 within the range of grinding parameters. The grinding force increased steadily and was accompanied by inevitable periodic fluctuations corresponding to serrated chips. As the grinding speed increased, the abrasive could enter the cutting stage more quickly, and its critical chip thickness (acr) eventually decreased from 0.225 ÎĽm to 0.158 ÎĽm. The percentage of the cutting phase increased from 85% to 89.5%. However, the critical scratch thickness was not significantly influenced by the change in grinding speed. The grinding speed and thickness substantially influence the morphology and segmentation frequency of DD5 chips. Specifically, as the grinding speed continues to increase, the DD5 chip morphology changes from a densely stacked unit nodal shape with serrated subsections to a continuous type of serrated shape and finally develops into a strip-shaped chip. At different grinding speeds, the chip segmentation frequency of DD5 decreases with increasing grinding depth
Analysis and Forecasting of Wetness-Dryness Encountering of a Multi-Water System Based on a Vine Copula Function-Bayesian Network
The analysis and forecasting of wetness-dryness encountering is the basis of joint operation of a multi-water system, which is important for water management of intake areas of water transfer projects. On the basis of a vine copula function-Bayesian network, this study developed an analysis and forecasting of a wetness-dryness encountering model. The model consists of two modules: firstly, the joint distribution among multi-inflows is established based on the vine copula function, and the obtained historical laws of wetness-dryness encountering; then, a Bayesian network is established in order to forecast wetness-dryness encountering in the future, using the forecasting information of some water systems. The model was applied to the water receiving areas inside Jiangsu Province of the South-to-North Water Transfer East Route Project in China. The results revealed the following: (1) Compared with conventional copulas, the probability values of wetness-dryness encountering obtained by the vine copula function were closer to the observed values. (2) The wetness-dryness encountering in 2017–2019 was forecasted, and the results were consistent with reality. These results demonstrate that the proposed model improves the accuracy of the obtained historical laws of wetness-dryness encountering, and that it can forecast wetness-dryness encountering in the future
Variable remanence acquisition efficiency in sediments containing biogenic and detrital magnetites: Implications for relative paleointensity signal recording
Sensitivity of Sediment Magnetic Records to Climate Change during Holocene for the Northern South China Sea
Sensitivity of Sediment Magnetic Records to Climate Change during Holocene for the Northern South China Sea
Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: (1) Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; (2) χARM/SIRM was more sensitive to detrital magnetite particles and SIRM/χ was more effective to bioge χARM/SIRM and SIRM/χ are corresponding to precipitation and temperature, respectively; (3) the Holocene Megathermal in the study area was identified as 7.5–3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1–3.9 cal. ka BP; (4) The 8 ka cold event was characterized as cold and dry during 8.55–8.25 cal. ka BP; (5) During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka B