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Rasenberg D, Ramaekers M, Jacobs I, Pluyter J, Geurts L, Nederend J, de Hingh I, Bonsing B, Vahrmeijer A, van der Harst E, Dulk MD, van Dam R, Koerkamp BG, Surgery Group AUMC, Riele WT, Reinhard R, Jansen FW, Dankelman J, Mieog S, Luyer M. Computer-aided decision support and 3D modelling in pancreatic cancer surgery. European Journal of Surgical Oncology 2023. [DOI: 10.1016/j.ejso.2022.11.625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Carlier C, Niemeijer K, Mestdagh M, Bauwens M, Vanbrabant P, Geurts L, van Waterschoot T, Kuppens P. In Search of State and Trait Emotion Markers in Mobile-Sensed Language: Field Study. JMIR Ment Health 2022; 9:e31724. [PMID: 35147507 PMCID: PMC8881775 DOI: 10.2196/31724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/21/2021] [Accepted: 10/08/2021] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Emotions and mood are important for overall well-being. Therefore, the search for continuous, effortless emotion prediction methods is an important field of study. Mobile sensing provides a promising tool and can capture one of the most telling signs of emotion: language. OBJECTIVE The aim of this study is to examine the separate and combined predictive value of mobile-sensed language data sources for detecting both momentary emotional experience as well as global individual differences in emotional traits and depression. METHODS In a 2-week experience sampling method study, we collected self-reported emotion ratings and voice recordings 10 times a day, continuous keyboard activity, and trait depression severity. We correlated state and trait emotions and depression and language, distinguishing between speech content (spoken words), speech form (voice acoustics), writing content (written words), and writing form (typing dynamics). We also investigated how well these features predicted state and trait emotions using cross-validation to select features and a hold-out set for validation. RESULTS Overall, the reported emotions and mobile-sensed language demonstrated weak correlations. The most significant correlations were found between speech content and state emotions and between speech form and state emotions, ranging up to 0.25. Speech content provided the best predictions for state emotions. None of the trait emotion-language correlations remained significant after correction. Among the emotions studied, valence and happiness displayed the most significant correlations and the highest predictive performance. CONCLUSIONS Although using mobile-sensed language as an emotion marker shows some promise, correlations and predictive R2 values are low.
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Affiliation(s)
- Chiara Carlier
- Department of Psychology and Educational Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Koen Niemeijer
- Department of Psychology and Educational Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Merijn Mestdagh
- Department of Psychology and Educational Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Michael Bauwens
- Department of Smart Organisations, University College Leuven-Limburg, Heverlee, Belgium
| | - Peter Vanbrabant
- Department of Smart Organisations, University College Leuven-Limburg, Heverlee, Belgium
| | - Luc Geurts
- Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Toon van Waterschoot
- Department of Electrical Engineering, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Peter Kuppens
- Department of Psychology and Educational Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
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Abstract
Wearable activity trackers are routinely applied in physical activity (PA) interventions in late life, but there is little research that focuses on older adults' perspectives on the technology. We conducted a qualitative study with 24 older persons to explore their perspective on wearables and PA. First, we discussed their relationship with PA and wearable trackers during focus groups. Next, nine participants crafted prototypes for wearables during co-design sessions. Through Thematic Analysis, we identified two main themes: (1) PA is personal in terms of preferred activities and reasons for PA, and (2) wearables are an emotional technology, causing negative emotions when resembling medical trackers or pressurizing to perform. We followed upon these results through a survey with 41 participants, which further highlighted individual differences in the perception of wearables. We conclude with questions to guide the design of wearables and reflect on their role to support PA in late life.
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Nida EK, Bekele S, Geurts L, Vanden Abeele V. Acceptance of a Smartphone-Based Visual Field Screening Platform for Glaucoma: Pre-Post Study. JMIR Form Res 2021; 5:e26602. [PMID: 34533462 PMCID: PMC8486992 DOI: 10.2196/26602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/10/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022] Open
Abstract
Background Glaucoma, the silent thief of sight, is a major cause of blindness worldwide. It is a burden for people in low-income countries, specifically countries where glaucoma-induced blindness accounts for 15% of the total incidence of blindness. More than half the people living with glaucoma in low-income countries are unaware of the disease until it progresses to an advanced stage, resulting in permanent visual impairment. Objective This study aims to evaluate the acceptability of the Glaucoma Easy Screener (GES), a low-cost and portable visual field screening platform comprising a smartphone, a stereoscopic virtual reality headset, and a gaming joystick. Methods A mixed methods study that included 24 eye care professionals from 4 hospitals in Southwest Ethiopia was conducted to evaluate the acceptability of GES. A pre-post design was used to collect perspectives before and after using the GES by using questionnaires and semistructured interviews. A Wilcoxon signed-rank test was used to determine the significance of any change in the scores of the questionnaire items (two-tailed, 95% CI; α=.05). The questionnaire and interview questions were guided by the Unified Theory of Acceptance and Use of Technology. Results Positive results were obtained both before and after use, suggesting the acceptance of mobile health solutions for conducting glaucoma screening by using a low-cost headset with a smartphone and a game controller. There was a significant increase (two-tailed, 95% CI; α=.05) in the average scores of 86% (19/22) of postuse questionnaire items compared with those of preuse questionnaire items. Ophthalmic professionals perceived GES as easy to use and as a tool that enabled the conduct of glaucoma screening tests, especially during outreach to rural areas. However, positive evaluations are contingent on the accuracy of the tool. Moreover, ophthalmologists voiced the need to limit the tool to screening only (ie, not for making diagnoses). Conclusions This study supports the feasibility of using a mobile device in combination with a low-cost virtual reality headset and classic controller for glaucoma screening in rural areas. GES has the potential to reduce the burden of irreversible blindness caused by glaucoma. However, further assessment of its sensitivity and specificity is required.
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Affiliation(s)
| | - Sisay Bekele
- Department of Ophthalmology, Institute of Health, Jimma University, Jimma, Ethiopia
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Tang D, Kuppens P, Geurts L, van Waterschoot T. End-to-end speech emotion recognition using a novel context-stacking dilated convolution neural network. EURASIP J Audio Speech Music Process 2021; 2021:18. [PMID: 34721556 PMCID: PMC8550764 DOI: 10.1186/s13636-021-00208-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Amongst the various characteristics of a speech signal, the expression of emotion is one of the characteristics that exhibits the slowest temporal dynamics. Hence, a performant speech emotion recognition (SER) system requires a predictive model that is capable of learning sufficiently long temporal dependencies in the analysed speech signal. Therefore, in this work, we propose a novel end-to-end neural network architecture based on the concept of dilated causal convolution with context stacking. Firstly, the proposed model consists only of parallelisable layers and is hence suitable for parallel processing, while avoiding the inherent lack of parallelisability occurring with recurrent neural network (RNN) layers. Secondly, the design of a dedicated dilated causal convolution block allows the model to have a receptive field as large as the input sequence length, while maintaining a reasonably low computational cost. Thirdly, by introducing a context stacking structure, the proposed model is capable of exploiting long-term temporal dependencies hence providing an alternative to the use of RNN layers. We evaluate the proposed model in SER regression and classification tasks and provide a comparison with a state-of-the-art end-to-end SER model. Experimental results indicate that the proposed model requires only 1/3 of the number of model parameters used in the state-of-the-art model, while also significantly improving SER performance. Further experiments are reported to understand the impact of using various types of input representations (i.e. raw audio samples vs log mel-spectrograms) and to illustrate the benefits of an end-to-end approach over the use of hand-crafted audio features. Moreover, we show that the proposed model can efficiently learn intermediate embeddings preserving speech emotion information.
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Affiliation(s)
- Duowei Tang
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, KU Leuven, Kasteelpark Arenberg 10, Leuven, 3001 Belgium
| | - Peter Kuppens
- Faculty of Psychology and Educational Sciences, KU Leuven, Dekenstraat 2, Leuven, 3000 Belgium
| | - Luc Geurts
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, KU Leuven, Kasteelpark Arenberg 10, Leuven, 3001 Belgium
- e-Media Research Lab, KU Leuven, Andreas Vesaliusstraat 13, Leuven, 3000 Belgium
| | - Toon van Waterschoot
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing, and Data Analytics, KU Leuven, Kasteelpark Arenberg 10, Leuven, 3001 Belgium
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Nida EK, Vandewalle E, Van Keer K, Vanden Abeele V, Geurts L. Clinical validation trial of Glaucoma Easy Screener (GES) as a low‐cost and portable visual field screening tool. Acta Ophthalmol 2019. [DOI: 10.1111/j.1755-3768.2019.5226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
| | - Evelien Vandewalle
- Department of Ophthalmology Neurosciences Laboratory of Ophthalmology Leuven Belgium
| | - Karel Van Keer
- Department of Ophthalmology University Hospitals Leuven Leuven Belgium
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Tang K, Gerling K, Chen W, Geurts L. Information and Communication Systems to Tackle Barriers to Breastfeeding: Systematic Search and Review. J Med Internet Res 2019; 21:e13947. [PMID: 31573903 PMCID: PMC6818436 DOI: 10.2196/13947] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/18/2019] [Accepted: 07/19/2019] [Indexed: 01/19/2023] Open
Abstract
Background Breastfeeding has many benefits for newborns, mothers, and the wider society. The World Health Organization recommends mothers to feed newborns exclusively with breastmilk for the first 6 months after birth, but breastfeeding rates in many countries fail to align with the recommendations because of various barriers. Breastfeeding success is associated with a number of determinants, such as self-efficacy, intention to breastfeed, and attitudes toward breastfeeding. Information and communication technology (ICT) has been leveraged to support breastfeeding by means of improving knowledge or providing practical supports in different maternal stages. Previous reviews have examined and summarized the effectiveness and credibility of interventions; however, no review has been done from a human-computer interaction perspective that is concerned with novel interaction techniques and the perspective of end users. Objective The objective of this review was to provide a comprehensive overview of existing digital interventions that support breastfeeding by investigating systems’ objective, technology design, validation process, and quality attributes, both in terms of clinical parameters as well as usability and user experience. Methods A systematic search was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in the following libraries: PubMed, Science Direct, Association for Computing Machinery Digital Library (ACM Digital Library), and Institute of Electrical and Electronics Engineers Xplore (IEEE Xplore). Results A total of 35 papers discussing 30 interventions were included. The main goals of these interventions were organized into 4 categories: breastfeeding education (n=12), breastfeeding promotion (n=8), communication support (n=6), and daily practical support (n=4). Of the interventions, 13 target mothers in the postnatal period. Most interventions come in forms of client communication systems (n=18), which frequently leverage Web technologies, text message, and mobile apps to provide breastfeeding support. Systems predominantly focus on mothers; validation strategies were rather heterogeneous, with 12 user studies concerning usability and user experience and 18 clinical validation studies focusing on the effects of the interventions on breastfeeding determinants; 5 papers did not report results. Generally, straightforward systems (eg, communication tools or Web-based solutions) seem to be more effective than complex interventions (eg, games). Conclusions Existing information and communication systems offer effective means of improving breastfeeding outcomes, but they do not address all relevant periods in parenthood (eg, the antenatal period) and often do not involve important stakeholders, such as partners. There is an opportunity to leverage more complex technical systems to open up avenues for the broader design of ICT to support breastfeeding; however, considering evaluation outcomes of existing support systems of higher complexity, such systems need to be designed with care.
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Affiliation(s)
- Kymeng Tang
- e-Media Research Lab, KU Leuven, Leuven, Belgium
| | | | - Wei Chen
- Center for Intelligent Medical Electronics, Fudan University, Shanghai, China
| | - Luc Geurts
- e-Media Research Lab, KU Leuven, Leuven, Belgium
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Geuens J, Geurts L, Swinnen TW, Westhovens R, Vanden Abeele V. Mobile Health Features Supporting Self-Management Behavior in Patients With Chronic Arthritis: Mixed-Methods Approach on Patient Preferences. JMIR Mhealth Uhealth 2019; 7:e12535. [PMID: 30907737 PMCID: PMC6452281 DOI: 10.2196/12535] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/21/2018] [Accepted: 01/07/2019] [Indexed: 01/10/2023] Open
Abstract
Background Patients with chronic arthritis (CA) ideally apply self-management behaviors between consultations. This enduring, tedious task of keeping track of disease-related parameters, adhering to medication schemes, and engaging in physical therapy may be supported by using a mobile health (mHealth) app. However, further research is needed to determine which self-management features are valued most by adult patients with CA patients. Objective The aim of this study was to determine the preference of features for an mHealth app to support self-management behavior in patients with CA. In addition, we aimed to explore the motives behind these ratings. Methods A mixed-methods approach was used to gather information from 31 adult patients (14 females), aged 23 to 71 years (mean 51 [SD 12.16]), with CA. Structured interviews were conducted to gather data pertaining to preferences of app features. Interviews were analyzed qualitatively, whereas ratings for each of the 28 features studied were analyzed quantitatively. Results In general, patients with CA favored the use of features pertaining to supporting active and direct disease management, (eg, medication intake and detecting and alarming of bad posture), helping them to keep a close watch on their disease status and inform their health care professional (eg, providing a means to log and report disease-related data) and receiving personalized information (eg, offering tailored information based on the patient’s health data). Patients strongly disliked features that provide a means of social interaction or provide incentivization for disease-related actions (eg, being able to compare yourself with other patients, cooperating toward a common goal, and receiving encouragement from friends and/or family). Driving these evaluations is the finding that every patient with CA hurts in his/her own way, the way the disease unfolds over time and manifests itself in the patient and social environment is different for every patient, and patients with CA are well aware of this. Conclusions We have offered an insight into how patients with CA favor mHealth features for self-management apps. The results of this research can inform the design and development of prospective self-management apps for patients with CA.
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Affiliation(s)
- Jonas Geuens
- e-Media Research Lab, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Luc Geurts
- e-Media Research Lab, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Thijs W Swinnen
- Division of Rheumatology, Universitaire Ziekenhuizen Gasthuisberg, University Hospitals Leuven, Leuven, Belgium.,Department of Development and Regeneration, Skeletal Biology and Engineering Research Center, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Rene Westhovens
- Division of Rheumatology, Universitaire Ziekenhuizen Gasthuisberg, University Hospitals Leuven, Leuven, Belgium.,Department of Development and Regeneration, Skeletal Biology and Engineering Research Center, Katholieke Universiteit Leuven, Leuven, Belgium
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Nida E, Geurts L, Abeele V. Paradoxes in Eye Health Care in Low-Income Countries and Design Strategies for Mobile Health Technology to Overcome them. EAI Endorsed Transactions on Pervasive Health and Technology 2019. [DOI: 10.4108/eai.30-10-2018.161366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Van Hul M, Geurts L, Plovier H, Druart C, Everard A, Ståhlman M, Rhimi M, Chira K, Teissedre PL, Delzenne N, Maguin E, Guilbot A, Brochot A, Gérard P, Bäckhed F, Cani P. Effet d’extraits de cannelle et de marc de raisin riches en polyphénols sur le métabolisme, le microbiote intestinal et la barrière intestinale de la souris. NUTR CLIN METAB 2018. [DOI: 10.1016/j.nupar.2018.09.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Arrogi A, Bogaerts A, Seghers J, Devloo K, Vanden Abeele V, Geurts L, Wauters J, Boen F. Evaluation of stAPP: a smartphone-based intervention to reduce prolonged sitting among Belgian adults. Health Promot Int 2017; 34:16-27. [DOI: 10.1093/heapro/dax046] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Anass Arrogi
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium
| | - An Bogaerts
- Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Jan Seghers
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium
| | - Karlien Devloo
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium
| | | | - Luc Geurts
- e-Media Laboratory, KU Leuven, Leuven, Belgium
| | | | - Filip Boen
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium
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Geuens J, Swinnen TW, Westhovens R, de Vlam K, Geurts L, Vanden Abeele V. A Review of Persuasive Principles in Mobile Apps for Chronic Arthritis Patients: Opportunities for Improvement. JMIR Mhealth Uhealth 2016; 4:e118. [PMID: 27742604 PMCID: PMC5083846 DOI: 10.2196/mhealth.6286] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 08/22/2016] [Accepted: 09/07/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Chronic arthritis (CA), an umbrella term for inflammatory rheumatic and other musculoskeletal diseases, is highly prevalent. Effective disease-modifying antirheumatic drugs for CA are available, with the exception of osteoarthritis, but require a long-term commitment of patients to comply with the medication regimen and management program as well as a tight follow-up by the treating physician and health professionals. Additionally, patients are advised to participate in physical exercise programs. Adherence to exercises and physical activity programs is often very low. Patients would benefit from support to increase medication compliance as well as compliance to the physical exercise programs. To address these shortcomings, health apps for CA patients have been created. These mobile apps assist patients in self-management of overall health measures, health prevention, and disease management. By including persuasive principles designed to reinforce, change, or shape attitudes or behaviors, health apps can transform into support tools that motivate and stimulate users to achieve or keep up with target behavior, also called persuasive systems. However, the extent to which health apps for CA patients consciously and successfully employ such persuasive principles remains unknown. OBJECTIVE The objective of this study was to evaluate the number and type of persuasive principles present in current health apps for CA patients. METHODS A review of apps for arthritis patients was conducted across the three major app stores (Google Play, Apple App Store, and Windows Phone Store). Collected apps were coded according to 37 persuasive principles, based on an altered version of the Persuasive System Design taxonomy of Oinas-Kukkonen and Harjuma and the taxonomy of Behavior Change Techniques of Michie and Abraham. In addition, user ratings, number of installs, and price of the apps were also coded. RESULTS We coded 28 apps. On average, 5.8 out of 37 persuasive principles were used in each app. The most used category of persuasive principles was System Credibility with an average of 2.6 principles. Task Support was the second most used, with an average of 2.3 persuasive principles. Next was Dialogue Support with an average of 0.5 principles. Social Support was last with an average of 0.01 persuasive principles only. CONCLUSIONS Current health apps for CA patients would benefit from adding Social Support techniques (eg, social media, user fora) and extending Dialogue Support techniques (eg, rewards, praise). The addition of automated tracking of health-related parameters (eg, physical activity, step count) could further reduce the effort for CA patients to manage their disease and thus increase Task Support. Finally, apps for health could benefit from a more evidence-based approach, both in developing the app as well as ensuring that content can be verified as scientifically proven, which will result in enhanced System Credibility.
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Perik EVDG, Trevia F, Henriksson A, Geurts L, Ullerup H. Getting a GRIP on work-related stress: design and evaluation of a nature inspired relaxation space. IJART 2016. [DOI: 10.1504/ijart.2016.078612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ullerup H, Geurts L, Henriksson A, Trevia F, Van de Garde Perik E. Getting a GRIP on work-related stress: design and evaluation of a nature inspired relaxation space. IJART 2016. [DOI: 10.1504/ijart.2016.10000207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Geurts L, Neyrinck AM, Delzenne NM, Knauf C, Cani PD. Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics. Benef Microbes 2014; 5:3-17. [PMID: 23886976 DOI: 10.3920/bm2012.0065] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Crosstalk between organs is crucial for controlling numerous homeostatic systems (e.g. energy balance, glucose metabolism and immunity). Several pathological conditions, such as obesity and type 2 diabetes, are characterised by a loss of or excessive inter-organ communication that contributes to the development of disease. Recently, we and others have identified several mechanisms linking the gut microbiota with the development of obesity and associated disorders (e.g. insulin resistance, type 2 diabetes, hepatic steatosis). Among these, we described the concept of metabolic endotoxaemia (increase in plasma lipopolysaccharide levels) as one of the triggering factors leading to the development of metabolic inflammation and insulin resistance. Growing evidence suggests that gut microbes contribute to the onset of low-grade inflammation characterising these metabolic disorders via mechanisms associated with gut barrier dysfunctions. We have demonstrated that enteroendocrine cells (producing glucagon-like peptide-1, peptide YY and glucagon-like peptide-2) and the endocannabinoid system control gut permeability and metabolic endotoxaemia. Recently, we hypothesised that specific metabolic dysregulations occurring at the level of numerous organs (e.g. gut, adipose tissue, muscles, liver and brain) rely from gut microbiota modifications. In this review, we discuss the mechanisms linking gut permeability, adipose tissue metabolism, and glucose homeostasis, and recent findings that show interactions between the gut microbiota, the endocannabinoid system and the apelinergic system. These specific systems are discussed in the context of the gut-to-peripheral organ axis (intestine, adipose tissue and brain) and impacts on metabolic regulation. In the present review, we also briefly describe the impact of a variety of non-digestible nutrients (i.e. inulin-type fructans, arabinoxylans, chitin glucans and polyphenols). Their effects on the composition of the gut microbiota and activity are discussed in the context of obesity and type 2 diabetes.
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Affiliation(s)
- L Geurts
- WELBIO, Walloon Excellence in Life Sciences and BIOtechnology Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Av. E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - A M Neyrinck
- Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Av. E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - N M Delzenne
- Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Av. E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - C Knauf
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Team 3, 31432 Toulouse, France Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier, UPS, CHU Rangueil, 1 Avenue Jean Poulhès, BP 84225, 31432 Toulouse Cedex 4, France
| | - P D Cani
- WELBIO, Walloon Excellence in Life Sciences and BIOtechnology Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Av. E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
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Cani PD, Geurts L, Matamoros S, Plovier H, Duparc T. Glucose metabolism: focus on gut microbiota, the endocannabinoid system and beyond. Diabetes Metab 2014; 40:246-57. [PMID: 24631413 DOI: 10.1016/j.diabet.2014.02.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 02/05/2014] [Accepted: 02/05/2014] [Indexed: 12/25/2022]
Abstract
The gut microbiota is now considered as a key factor in the regulation of numerous metabolic pathways. Growing evidence suggests that cross-talk between gut bacteria and host is achieved through specific metabolites (such as short-chain fatty acids) and molecular patterns of microbial membranes (lipopolysaccharides) that activate host cell receptors (such as toll-like receptors and G-protein-coupled receptors). The endocannabinoid (eCB) system is an important target in the context of obesity, type 2 diabetes (T2D) and inflammation. It has been demonstrated that eCB system activity is involved in the control of glucose and energy metabolism, and can be tuned up or down by specific gut microbes (for example, Akkermansia muciniphila). Numerous studies have also shown that the composition of the gut microbiota differs between obese and/or T2D individuals and those who are lean and non-diabetic. Although some shared taxa are often cited, there is still no clear consensus on the precise microbial composition that triggers metabolic disorders, and causality between specific microbes and the development of such diseases is yet to be proven in humans. Nevertheless, gastric bypass is most likely the most efficient procedure for reducing body weight and treating T2D. Interestingly, several reports have shown that the gut microbiota is profoundly affected by the procedure. It has been suggested that the consistent postoperative increase in certain bacterial groups such as Proteobacteria, Bacteroidetes and Verrucomicrobia (A. muciniphila) may explain its beneficial impact in gnotobiotic mice. Taken together, these data suggest that specific gut microbes modulate important host biological systems that contribute to the control of energy homoeostasis, glucose metabolism and inflammation in obesity and T2D.
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Affiliation(s)
- P D Cani
- Université catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Metabolism and Nutrition research group, Avenue E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium.
| | - L Geurts
- Université catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Metabolism and Nutrition research group, Avenue E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - S Matamoros
- Université catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Metabolism and Nutrition research group, Avenue E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - H Plovier
- Université catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Metabolism and Nutrition research group, Avenue E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
| | - T Duparc
- Université catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Metabolism and Nutrition research group, Avenue E. Mounier, 73 Box B1.73.11, 1200 Brussels, Belgium
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17
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Dhurandhar NV, Geurts L, Atkinson RL, Casteilla L, Clement K, Gerard P, Vijay-Kumar M, Nam JH, Nieuwdorp M, Trovato G, Sørensen TIA, Vidal-Puig A, Cani PD. Harnessing the beneficial properties of adipogenic microbes for improving human health. Obes Rev 2013; 14:721-35. [PMID: 23663746 DOI: 10.1111/obr.12045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/15/2013] [Accepted: 04/16/2013] [Indexed: 12/15/2022]
Abstract
Obesity is associated with numerous metabolic comorbidities. Weight loss is an effective measure for alleviating many of these metabolic abnormalities. However, considering the limited success of most medical weight-management approaches in producing a sustained weight loss, approaches that improve obesity-related metabolic abnormalities independent of weight loss would be extremely attractive and of practical benefit. Metabolically healthy obesity supports the notion that a better metabolic profile is possible despite obesity. Moreover, adequate expansion of adipose tissue appears to confer protection from obesity-induced metabolic comorbidities. To this end, the 10th Stock conference examined new approaches to improve metabolic comorbidities independent of weight loss. In particular, human adenovirus 36 (Ad36) and specific gut microbes were examined for their potential to influence lipid and glucose homeostasis in animals and humans. While these microbes possess some undesirable properties, research has identified attributes of adenovirus Ad36 and gut microbes that may be selectively harnessed to improve metabolic profile without the obligatory weight loss. Furthermore, identifying the host signalling pathways that these microbes recruit to improve the metabolic profile may offer new templates and targets, which may facilitate the development of novel treatment strategies for obesity-related metabolic conditions.
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Affiliation(s)
- N V Dhurandhar
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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18
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Everard A, Belzer C, Geurts L, Ouwerkerk J, Druart C, Bindels L, Guiot Y, Derrien M, Muccioli G, Delzenne N, de Vos WM, Cani P. O80 Akkermansia muciniphila communique avec l’épithélium intestinal pour contrôler le développement de l’obésité et du diabète de type 2. Diabetes & Metabolism 2013. [DOI: 10.1016/s1262-3636(13)71692-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Cani PD, Possemiers S, Van de Wiele T, Guiot Y, Everard A, Rottier O, Geurts L, Naslain D, Neyrinck A, Lambert DM, Muccioli GG, Delzenne NM. Changes in gut microbiota control inflammation in obese mice through a mechanism involving GLP-2-driven improvement of gut permeability. Gut 2009; 58:1091-103. [PMID: 19240062 PMCID: PMC2702831 DOI: 10.1136/gut.2008.165886] [Citation(s) in RCA: 1740] [Impact Index Per Article: 116.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS Obese and diabetic mice display enhanced intestinal permeability and metabolic endotoxaemia that participate in the occurrence of metabolic disorders. Our recent data support the idea that a selective increase of Bifidobacterium spp. reduces the impact of high-fat diet-induced metabolic endotoxaemia and inflammatory disorders. Here, we hypothesised that prebiotic modulation of gut microbiota lowers intestinal permeability, by a mechanism involving glucagon-like peptide-2 (GLP-2) thereby improving inflammation and metabolic disorders during obesity and diabetes. METHODS Study 1: ob/ob mice (Ob-CT) were treated with either prebiotic (Ob-Pre) or non-prebiotic carbohydrates as control (Ob-Cell). Study 2: Ob-CT and Ob-Pre mice were treated with GLP-2 antagonist or saline. Study 3: Ob-CT mice were treated with a GLP-2 agonist or saline. We assessed changes in the gut microbiota, intestinal permeability, gut peptides, intestinal epithelial tight-junction proteins ZO-1 and occludin (qPCR and immunohistochemistry), hepatic and systemic inflammation. RESULTS Prebiotic-treated mice exhibited a lower plasma lipopolysaccharide (LPS) and cytokines, and a decreased hepatic expression of inflammatory and oxidative stress markers. This decreased inflammatory tone was associated with a lower intestinal permeability and improved tight-junction integrity compared to controls. Prebiotic increased the endogenous intestinotrophic proglucagon-derived peptide (GLP-2) production whereas the GLP-2 antagonist abolished most of the prebiotic effects. Finally, pharmacological GLP-2 treatment decreased gut permeability, systemic and hepatic inflammatory phenotype associated with obesity to a similar extent as that observed following prebiotic-induced changes in gut microbiota. CONCLUSION We found that a selective gut microbiota change controls and increases endogenous GLP-2 production, and consequently improves gut barrier functions by a GLP-2-dependent mechanism, contributing to the improvement of gut barrier functions during obesity and diabetes.
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Affiliation(s)
- P D Cani
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
| | - S Possemiers
- Laboratory of Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - T Van de Wiele
- Laboratory of Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Y Guiot
- Department of Pathology, Université catholique de Louvain, Brussels, Belgium
| | - A Everard
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - O Rottier
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - L Geurts
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - D Naslain
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium,Medicinal Chemistry and Radiopharmacy Unit, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - A Neyrinck
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - D M Lambert
- Medicinal Chemistry and Radiopharmacy Unit, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - G G Muccioli
- Laboratory of Chemical and Physico-chemical Analysis of Drugs (CHAM), Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - N M Delzenne
- Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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20
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Abstract
In current cochlear implant systems, the fundamental frequency F0 of a complex sound is encoded by temporal fluctuations in the envelope of the electrical signals presented on the electrodes. In normal hearing, the lower harmonics of a complex sound are resolved, in contrast with a cochlear implant system. In the present study, it is investigated whether "place-coding" of the first harmonic improves the ability of an implantee to discriminate complex sounds with different fundamental frequencies. Therefore, a new filter bank was constructed, for which the first harmonic is always resolved in two adjacent filters, and the balance between both filter outputs is directly related to the frequency of the first harmonic. The new filter bank was compared with a filter bank that is typically used in clinical processors, both with and without the presence of temporal cues in the stimuli. Four users of the LAURA cochlear implant participated in a pitch discrimination task to determine detection thresholds for F0 differences. The results show that these thresholds decrease noticeably for the new filter bank, if no temporal cues are present in the stimuli. If temporal cues are included, the differences between the results for both filter banks become smaller, but a clear advantage is still observed for the new filter bank. This demonstrates the feasibility of using place-coding for the fundamental frequency.
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Affiliation(s)
- Luc Geurts
- Laboratory for Experimental ORL, KULeuven, Kapucijnenvoer 33, B 3000 Leuven, Belgium
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21
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Wouters J, Geurts L, Laneau J, Luts H, Maj JB, Moonen M, Royackers L, Spriet A, Van den Bogaert T, van Wieringen A. Digital hearing aids and future directions for hearing aids. Acta Otorhinolaryngol Belg 2003; 56:357-61. [PMID: 12528252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In recent years many technical evolutions have been applied in hearing aids. In this paper differences between analog, programmable and fully digital hearing aids, the basic and supplementary functions of a hearing aid, and some important issues and future directions for digital hearing aids will be mentioned.
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Affiliation(s)
- J Wouters
- Lab. Exp. ORL/ENT-Dept., K.U. Leuven, Leuven, Belgium.
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22
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Geurts L, Wouters J. Coding of the fundamental frequency in continuous interleaved sampling processors for cochlear implants. J Acoust Soc Am 2001; 109:713-726. [PMID: 11248975 DOI: 10.1121/1.1340650] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this study the perception of the fundamental frequency (F0) of periodic stimuli by cochlear implant users is investigated. A widely used speech processor is the Continuous Interleaved Sampling (CIS) processor, for which the fundamental frequency appears as temporal fluctuations in the envelopes at the output. Three experiments with four users of the LAURA (Registered trade mark of Philips Hearing Implants, now Cochlear Technology Centre Europe) cochlear implant were carried out to examine the influence of the modulation depth of these envelope fluctuations on pitch discrimination. In the first experiment, the subjects were asked to discriminate between two SAM (sinusoidally amplitude modulated) pulse trains on a single electrode channel differing in modulation frequency ( deltaf = 20%). As expected, the results showed a decrease in the performance for smaller modulation depths. Optimal performance was reached for modulation depths between 20% and 99%, depending on subject, electrode channel, and modulation frequency. In the second experiment, the smallest noticeable difference in F0 of synthetic vowels was measured for three algorithms that differed in the obtained modulation depth at the output: the default CIS strategy, the CIS strategy in which the F0 fluctuations in the envelope were removed (FLAT CIS), and a third CIS strategy, which was especially designed to control and increase the depth of these fluctuations (F0 CIS). In general, performance was poorest for the FLAT CIS strategy, where changes in F0 are only apparent as changes of the average amplitude in the channel outputs. This emphasizes the importance of temporal coding of F0 in the speech envelope for pitch perception. No significantly better results were obtained for the F0 CIS strategy compared to the default CIS strategy, although the latter results in envelope modulation depths at which sub-optimal scores were obtained in some cases of the first experiment. This indicates that less modulation is needed if all channels are stimulated with synchronous F0 fluctuations. This hypothesis is confirmed in a third experiment where subjects performed significantly better in a pitch discrimination task with SAM pulse trains, if three channels were stimulated concurrently, as opposed to only one.
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Affiliation(s)
- L Geurts
- Laboratory for Experimental ORL, KULeuven, Belgium.
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Abstract
APEX, an acronym for computer Application for Psycho-Electrical eXperiments, is a user friendly tool used to conduct psychophysical experiments and to investigate new speech coding algorithms with cochlear implant users. Most common psychophysical experiments can be easily programmed and all stimuli can be easily created without any knowledge of computer programing. The pulsatile stimuli are composed off-line using custom-made MATLAB (Registered trademark of The Mathworks, Inc., http://www.mathworks.com) functions and are stored on hard disk or CD ROM. These functions convert either a speech signal into a pulse sequence or generate any sequence of pulses based on the parameters specified by the experimenter. The APEX personal computer (PC) software reads a text file which specifies the experiment and the stimuli, controls the experiment, delivers the stimuli to the subject through a digital signal processor (DSP) board, collects the responses via a computer mouse or a graphics tablet, and writes the results to the same file. At present, the APEX system is implemented for the LAURA (Registered trademark of Philips Hearing Implants) cochlear implant. However, the concept-and many parts of the system-is portable to any other device. Also, psycho-acoustical experiments can be conducted by presenting the stimuli acoustically through a sound card.
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Affiliation(s)
- L Geurts
- Laboratoire Experimental ORL, KULeuven, Belgium.
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24
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Abstract
Five post-lingually deafened users of the LAURA cochlear implant were presented with two trains of biphasic pulses applied concurrently to two widely separated channels. They could all discriminate between stimuli where pulses on the two channels were nearly synchronous (inter-channel delay=0.1 ms) and those where there was a longer delay applied to one channel. All showed an asymmetry, being more sensitive when the longer delay was on either the more basal or, depending on the listener, the more apical channel. For four out of the five listeners this asymmetry could be at least partly attributed to one stimulus, with a 0.1-ms delay in either the apical (three listeners) or basal (one listener) channel, sounding markedly different from all other stimuli used in the experiment. Both the overall sensitivity of listeners and the general pattern of results survived the presentation of maskers on intermediate channels, and did not vary markedly with changes in the polarity of the pulses applied to one channel. Although the results varied substantially across listeners, it is concluded that they demonstrate a genuine sensitivity to the relative timing of stimulation applied to discrete populations of auditory nerve fibers.
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Affiliation(s)
- R P Carlyon
- MRC Cognition and Brain Sciences Unit, 15 Chaucer Rd., Cambridge, UK.
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25
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Geurts L, Wouters J. Enhancing the speech envelope of continuous interleaved sampling processors for cochlear implants. J Acoust Soc Am 1999; 105:2476-2484. [PMID: 10212428 DOI: 10.1121/1.426851] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new method to code the speech envelope in continuous interleaved sampling (CIS) processors for cochlear implants is proposed. In this enhanced envelope, the rapid adaptation seen in the response of auditory nerves to sound stimuli is incorporated. Two strategies, one using the standard envelope (CIS) and one using the enhanced envelope (EECIS), were tested perceptually with six postlingually deafened users of the LAURA cochlear implant. The tests included identification of stop consonants in three different vowel contexts and monosyllabic consonant-vowel-consonant (CVC) words. Significant improvements in correct identification scores were observed for stop consonants in intervocalic /a/ context (p = 0.026): average results varied from 46% correct for CIS to 55% for EECIS. This improvement was mainly due to the better transmission of place of articulation. The differences in identification scores for stop consonants in /i/ and /u/ context were not significant. The identification scores for the medial vowels of the CVC words were significantly higher when the EECIS strategy was used: average results increased from 39% correct to 46% correct (p = 0.018). No significant differences were observed between the results for initial and final consonants of the CVC words. The present results demonstrate that the inclusion of the rapid adaptation in the speech processing for cochlear implants can improve speech intelligibility.
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Affiliation(s)
- L Geurts
- Lab. Exp. ORL, KULeuven, Belgium.
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Wouters J, Geurts L, Peeters S, Vanden Berghe J, van Wieringen A. Developments in speech processing for cochlear implants. Acta Otorhinolaryngol Belg 1998; 52:129-32. [PMID: 9651613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The status of speech processing for cochlear implants is reviewed. Points of interest to enhance further speech intelligibility based on improved signal processing, are discussed.
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Affiliation(s)
- J Wouters
- Lab. Experimental ENT, Leuven, Antwerp, Belgium
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27
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Monfort SL, Harvey E, Geurts L, Padilla L, Simmons HA, Williamson LR, Wildt DE. Urinary 3 alpha,17 beta-androstanediol glucuronide is a measure of androgenic status in Eld's deer stags (Cervus eldi thamin). Biol Reprod 1995; 53:700-6. [PMID: 7578696 DOI: 10.1095/biolreprod53.3.700] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To determine the primary excretory by-products of testosterone (T), 85 microCi [3H]T was administered i.v. to two adult Eld's deer stags. Blood (10 ml) was collected by jugular venipuncture at 0, 5, 10, 15, 30, 45, 60, 90, 120, 150, 180, 240, and 480 min after isotope infusion, and all urine and feces were collected for 96 h after injection. Seventy percent of labeled circulating steroid was conjugated by 30 min postinfusion. The majority (80.4 +/- 3.2%) of T metabolites were excreted into urine, and 95.0 +/- 0.9% of these were conjugated, 95.8 +/- 0.2% being hydrolyzable with glucuronidase. Seven urinary androgen metabolites, including androstanediol (5 alpha-androstan-3 alpha-17 beta-diol and 5 beta-androstan-3 alpha-17 beta-diol), were identified in glucoronidase-hydrolyzed, ether-extracted Eld's deer urine pools after gas chromatography/mass spectrometry. A double-antibody 125I RIA for 5 alpha-androstanediol-3 alpha, 17 beta-diol,17-glucuronide (3 alpha-diol-G) was validated for unprocessed urine. Longitudinal assessments of urine samples collected from 13 stages for 3 yr revealed biological concordance between fluctuations in urinary 3 alpha-diol-G and serum T, as well as seasonal changes in secondary sexual characteristics. Overall correlation between "same-day" matched serum T and urinary 3 alpha-diol-G was 0.58, (n = 6; p < 0.001). Thus, monitoring urinary 3 alpha-diol-G provides a noninvasive, alternative method for characterizing male endocrine interrelationships in an endangered ungulate species.
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Affiliation(s)
- S L Monfort
- National Zoological Park, Conservation and Research Center, Smithsonian Institution, Front Royal, Virginia 22630, USA
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