162 results on '"Simons, S."'
Search Results
2. Chern-Simons S-Brane Solutions in M-theory and Accelerating Cosmologies
- Author
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Deger, Nihat Sadik, Kaya, Ali, Deger, Nihat Sadik, and Kaya, Ali
- Abstract
We construct an intersecting S-brane solution of 11-dimensional supergravity for which the contribution of the Chern-Simons term to the field equations is non-zero. After studying some of its properties, we consider three different compactifications (each with 3 separate subcases) of this system to 4-dimensions. Two of these give accelerating cosmologies, however their expansion factors are of order unity. We also find two static versions of this configuration and its dimensional reduction to type IIA theory., Comment: 18 pages, v3: a new static solution and references added, v4: references added, to appear in JHEP
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- 2009
- Full Text
- View/download PDF
3. Global mortality and readmission rates following COPD exacerbation-related hospitalisation: a meta-analysis of 65 945 individual patients
- Author
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Waeijen-Smit, K, Crutsen, M, Keene, S, Miravitlles, M, Crisafulli, E, Torres, A, Mueller, C, Schuetz, P, Ringbæk, T, Fabbian, F, Mekov, E, Harries, T, Lun, C, Ergan, B, Esteban, C, Quintana Lopez, J, López-Campos, J, Chang, C, Hancox, R, Shafuddin, E, Ellis, H, Janson, C, Ulrik, C, Gudmundsson, G, Epstein, D, Dominguez, J, Lacoma, A, Osadnik, C, Alia, I, Spannella, F, Karakurt, Z, Mehravaran, H, Utens, C, de Kruif, M, San Ko, F, Trethewey, S, Turner, A, Bumbacea, D, Murphy, P, Vermeersch, K, Zilberman-Itskovich, S, Steer, J, Echevarria, C, Bourke, S, Lane, N, de Batlle, J, Sprooten, R, Russell, R, Faverio, P, Cross, J, Prins, H, Spruit, M, Simons, S, Houben-Wilke, S, Franssen, F, Waeijen-Smit K., Crutsen M., Keene S., Miravitlles M., Crisafulli E., Torres A., Mueller C., Schuetz P., Ringbæk T. J., Fabbian F., Mekov E., Harries T. H., Lun C. T., Ergan B., Esteban C., Quintana Lopez J. M., López-Campos J. L., Chang C. L., Hancox R. J., Shafuddin E., Ellis H., Janson C., Ulrik C. S., Gudmundsson G., Epstein D., Dominguez J., Lacoma A., Osadnik C., Alia I., Spannella F., Karakurt Z., Mehravaran H., Utens C., de Kruif M. D., San Ko F. W., Trethewey S. P., Turner A. M., Bumbacea D., Murphy P. B., Vermeersch K., Zilberman-Itskovich S., Steer J., Echevarria C., Bourke S. C., Lane N., de Batlle J., Sprooten R. T. M., Russell R., Faverio P., Cross J. L., Prins H. J., Spruit M. A., Simons S. O., Houben-Wilke S., Franssen F. M. E., Waeijen-Smit, K, Crutsen, M, Keene, S, Miravitlles, M, Crisafulli, E, Torres, A, Mueller, C, Schuetz, P, Ringbæk, T, Fabbian, F, Mekov, E, Harries, T, Lun, C, Ergan, B, Esteban, C, Quintana Lopez, J, López-Campos, J, Chang, C, Hancox, R, Shafuddin, E, Ellis, H, Janson, C, Ulrik, C, Gudmundsson, G, Epstein, D, Dominguez, J, Lacoma, A, Osadnik, C, Alia, I, Spannella, F, Karakurt, Z, Mehravaran, H, Utens, C, de Kruif, M, San Ko, F, Trethewey, S, Turner, A, Bumbacea, D, Murphy, P, Vermeersch, K, Zilberman-Itskovich, S, Steer, J, Echevarria, C, Bourke, S, Lane, N, de Batlle, J, Sprooten, R, Russell, R, Faverio, P, Cross, J, Prins, H, Spruit, M, Simons, S, Houben-Wilke, S, Franssen, F, Waeijen-Smit K., Crutsen M., Keene S., Miravitlles M., Crisafulli E., Torres A., Mueller C., Schuetz P., Ringbæk T. J., Fabbian F., Mekov E., Harries T. H., Lun C. T., Ergan B., Esteban C., Quintana Lopez J. M., López-Campos J. L., Chang C. L., Hancox R. J., Shafuddin E., Ellis H., Janson C., Ulrik C. S., Gudmundsson G., Epstein D., Dominguez J., Lacoma A., Osadnik C., Alia I., Spannella F., Karakurt Z., Mehravaran H., Utens C., de Kruif M. D., San Ko F. W., Trethewey S. P., Turner A. M., Bumbacea D., Murphy P. B., Vermeersch K., Zilberman-Itskovich S., Steer J., Echevarria C., Bourke S. C., Lane N., de Batlle J., Sprooten R. T. M., Russell R., Faverio P., Cross J. L., Prins H. J., Spruit M. A., Simons S. O., Houben-Wilke S., and Franssen F. M. E.
- Abstract
Background Exacerbations of COPD (ECOPD) have a major impact on patients and healthcare systems across the world. Precise estimates of the global burden of ECOPD on mortality and hospital readmission are needed to inform policy makers and aid preventive strategies to mitigate this burden. The aims of the present study were to explore global in-hospital mortality, post-discharge mortality and hospital readmission rates after ECOPD-related hospitalisation using an individual patient data meta-analysis (IPDMA) design. Methods A systematic review was performed identifying studies that reported in-hospital mortality, postdischarge mortality and hospital readmission rates following ECOPD-related hospitalisation. Data analyses were conducted using a one-stage random-effects meta-analysis model. This study was conducted and reported in accordance with the PRISMA-IPD statement. Results Data of 65 945 individual patients with COPD were analysed. The pooled in-hospital mortality rate was 6.2%, pooled 30-, 90- and 365-day post-discharge mortality rates were 1.8%, 5.5% and 10.9%, respectively, and pooled 30-, 90- and 365-day hospital readmission rates were 7.1%, 12.6% and 32.1%, respectively, with noticeable variability between studies and countries. Strongest predictors of mortality and hospital readmission included noninvasive mechanical ventilation and a history of two or more ECOPD-related hospitalisations < 12 months prior to the index event. Conclusions This IPDMA stresses the poor outcomes and high heterogeneity of ECOPD-related hospitalisation across the world. Whilst global standardisation of the management and follow-up of ECOPD-related hospitalisation should be at the heart of future implementation research, policy makers should focus on reimbursing evidence-based therapies that decrease (recurrent) ECOPD.
- Published
- 2024
4. Development of a Web-Based Oxygenation Dashboard for Preterm Neonates:A Quality Improvement Initiative
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Poppe, J. A., Smorenburg, R. S., Goos, T. G., Taal, H. R., Reiss, I. K.M., Simons, S. H.P., Poppe, J. A., Smorenburg, R. S., Goos, T. G., Taal, H. R., Reiss, I. K.M., and Simons, S. H.P.
- Abstract
Background: Preterm neonates are extensively monitored to require strict oxygen target attainment for optimal outcomes. In daily practice, detailed oxygenation data are hardly used and crucial patterns may be missed due to the snapshot presentations and subjective observations. This study aimed to develop a web-based dashboard with both detailed and summarized oxygenation data in real-time and to test its feasibility to support clinical decision making. Methods: Data from pulse oximeters and ventilators were synchronized and stored to enable real-time and retrospective trend visualizations in a web-based viewer. The dashboard was designed based on interviews with clinicians. A preliminary version was evaluated during daily clinical rounds. The routine evaluation of the respiratory condition of neonates (gestational age < 32 weeks) with respiratory support at the NICU was compared to an assessment with the assistance of the dashboard. Results: The web-based dashboard included data on the oxygen saturation (SpO2), fraction of inspired oxygen (FiO2), SpO2/FiO2 ratio, and area < 80% and > 95% SpO2 curve during time intervals that could be varied. The distribution of SpO2 values was visualized as histograms. In 65% of the patient evaluations (n = 86) the level of hypoxia was assessed differently with the use of the dashboard. In 75% of the patients the dashboard was judged to provide added value for the clinicians in supporting clinical decisions. Conclusions: A web-based customized oxygenation dashboard for preterm neonates at the NICU was developed and found feasible during evaluation. More clear and objective information was found supportive for clinicians during the daily rounds in tailoring treatment strategies.
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- 2024
5. Development of a Web-Based Oxygenation Dashboard for Preterm Neonates: A Quality Improvement Initiative
- Author
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Poppe, J. A. (author), Smorenburg, R. S. (author), Goos, T.G. (author), Taal, H. R. (author), Reiss, I. K.M. (author), Simons, S. H.P. (author), Poppe, J. A. (author), Smorenburg, R. S. (author), Goos, T.G. (author), Taal, H. R. (author), Reiss, I. K.M. (author), and Simons, S. H.P. (author)
- Abstract
Background: Preterm neonates are extensively monitored to require strict oxygen target attainment for optimal outcomes. In daily practice, detailed oxygenation data are hardly used and crucial patterns may be missed due to the snapshot presentations and subjective observations. This study aimed to develop a web-based dashboard with both detailed and summarized oxygenation data in real-time and to test its feasibility to support clinical decision making. Methods: Data from pulse oximeters and ventilators were synchronized and stored to enable real-time and retrospective trend visualizations in a web-based viewer. The dashboard was designed based on interviews with clinicians. A preliminary version was evaluated during daily clinical rounds. The routine evaluation of the respiratory condition of neonates (gestational age < 32 weeks) with respiratory support at the NICU was compared to an assessment with the assistance of the dashboard. Results: The web-based dashboard included data on the oxygen saturation (SpO2), fraction of inspired oxygen (FiO2), SpO2/FiO2 ratio, and area < 80% and > 95% SpO2 curve during time intervals that could be varied. The distribution of SpO2 values was visualized as histograms. In 65% of the patient evaluations (n = 86) the level of hypoxia was assessed differently with the use of the dashboard. In 75% of the patients the dashboard was judged to provide added value for the clinicians in supporting clinical decisions. Conclusions: A web-based customized oxygenation dashboard for preterm neonates at the NICU was developed and found feasible during evaluation. More clear and objective information was found supportive for clinicians during the daily rounds in tailoring treatment strategies., Medical Instruments & Bio-Inspired Technology
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- 2024
- Full Text
- View/download PDF
6. Quantification of stress exposure in very preterm infants: Development of the NeO-stress score
- Author
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Brain, Child Health, MS Neonatologie, Meesters, N. J., van den Bosch, G. E., van het Hof, L. J., Benders, M. J.N.L., Tataranno, M. L., Reiss, I. K.M., van Kaam, A., Haverman, L., Simons, S. H.P., van Dijk, M., Brain, Child Health, MS Neonatologie, Meesters, N. J., van den Bosch, G. E., van het Hof, L. J., Benders, M. J.N.L., Tataranno, M. L., Reiss, I. K.M., van Kaam, A., Haverman, L., Simons, S. H.P., and van Dijk, M.
- Published
- 2023
7. Population Pharmacokinetics and Dosing Optimization of Ceftazidime in Term Asphyxiated Neonates during Controlled Therapeutic Hypothermia.
- Author
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Veer, Marlotte A.A. van der, Haan, T.R. de, Franken, L.G., Hodiamont, C.J., Groenendaal, F., Dijk, P.H., Boode, W.P. de, Simons, S., Dijkman, K.P., Straaten, H.L. van, Rijken, M., Cools, F., Nuytemans, D.H., Kaam, A.H. van, Bijleveld, Y.A., Mathôt, R.A.A., Veer, Marlotte A.A. van der, Haan, T.R. de, Franken, L.G., Hodiamont, C.J., Groenendaal, F., Dijk, P.H., Boode, W.P. de, Simons, S., Dijkman, K.P., Straaten, H.L. van, Rijken, M., Cools, F., Nuytemans, D.H., Kaam, A.H. van, Bijleveld, Y.A., and Mathôt, R.A.A.
- Abstract
Item does not contain fulltext, Ceftazidime is an antibiotic commonly used to treat bacterial infections in term neonates undergoing controlled therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy after perinatal asphyxia. We aimed to describe the population pharmacokinetics (PK) of ceftazidime in asphyxiated neonates during hypothermia, rewarming, and normothermia and propose a population-based rational dosing regimen with optimal PK/pharmacodynamic (PD) target attainment. Data were collected in the PharmaCool prospective observational multicenter study. A population PK model was constructed, and the probability of target attainment (PTA) was assessed during all phases of controlled TH using targets of 100% of the time that the concentration in the blood exceeds the MIC (T(>MIC)) (for efficacy purposes and 100% T(>4×MIC) and 100% T(>5×MIC) to prevent resistance). A total of 35 patients with 338 ceftazidime concentrations were included. An allometrically scaled one-compartment model with postnatal age and body temperature as covariates on clearance was constructed. For a typical patient receiving the current dose of 100 mg/kg of body weight/day in 2 doses and assuming a worst-case MIC of 8 mg/L for Pseudomonas aeruginosa, the PTA was 99.7% for 100% T(>MIC) during hypothermia (33.7°C; postnatal age [PNA] of 2 days). The PTA decreased to 87.7% for 100% T(>MIC) during normothermia (36.7°C; PNA of 5 days). Therefore, a dosing regimen of 100 mg/kg/day in 2 doses during hypothermia and rewarming and 150 mg/kg/day in 3 doses during the following normothermic phase is advised. Higher-dosing regimens (150 mg/kg/day in 3 doses during hypothermia and 200 mg/kg/day in 4 doses during normothermia) could be considered when achievements of 100% T(>4×MIC) and 100% T(>5×MIC) are desired.
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- 2023
8. Optimisation of fluconazole therapy for the treatment of invasive candidiasis in preterm infants
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Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., Brüggemann, R.J.M., Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., and Brüggemann, R.J.M.
- Abstract
Item does not contain fulltext, INTRODUCTION: Fluconazole is an important antifungal in the prevention and treatment of invasive Candida infections in neonates, even though its use in preterm infants is still off-label. Here, we performed a population pharmacokinetic study on fluconazole in preterm neonates in order to optimise dosing through the identified predictive patient characteristics. METHODS: Fluconazole concentrations obtained from preterm infants from two studies were pooled and analysed using NONMEM V.7.3. The developed model was used to evaluate current dosing practice. A therapeutic dosing strategy aiming to reach a minimum target exposure of 400 and 200 mg×hour/L per 24 hours for fluconazole-susceptible C. albicans meningitis and other systemic infections, respectively, was developed. RESULTS: In 41 preterm neonates with median (range) gestational age 25.3 (24.0-35.1) weeks and median postnatal age (PNA) at treatment initiation 1.4 (0.2-32.5) days, 146 plasma samples were collected. A one-compartment model described the data best, with an estimated clearance of 0.0147 L/hour for a typical infant of 0.87 kg with a serum creatinine concentration of 60 µmol/L and volume of distribution of 0.844 L. Clearance was found to increase with 16% per 100 g increase in actual body weight, and to decrease with 12% per 10 µmol/L increase in creatinine concentration once PNA was above 1 week. Dose adjustments based on serum creatinine and daily dosing are required for therapeutic target attainment. CONCLUSION: In preterm neonates, fluconazole clearance is best predicted by actual body weight and serum creatinine concentration. Therefore, fluconazole dosing should not only be based on body weight but also on creatinine concentration to achieve optimal exposure in all infants. ETHICS STATEMENT: The Erasmus MC ethics review board approved the protocol of the DINO Study (MEC-2014-067) and the Radboud UMC ethics review board waived the need for informed consent for cohort 2 (CMO-2021-8302). Written info
- Published
- 2022
9. Optimisation of fluconazole therapy for the treatment of invasive candidiasis in preterm infants
- Author
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Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., Brüggemann, R.J.M., Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., and Brüggemann, R.J.M.
- Abstract
Item does not contain fulltext, INTRODUCTION: Fluconazole is an important antifungal in the prevention and treatment of invasive Candida infections in neonates, even though its use in preterm infants is still off-label. Here, we performed a population pharmacokinetic study on fluconazole in preterm neonates in order to optimise dosing through the identified predictive patient characteristics. METHODS: Fluconazole concentrations obtained from preterm infants from two studies were pooled and analysed using NONMEM V.7.3. The developed model was used to evaluate current dosing practice. A therapeutic dosing strategy aiming to reach a minimum target exposure of 400 and 200 mg×hour/L per 24 hours for fluconazole-susceptible C. albicans meningitis and other systemic infections, respectively, was developed. RESULTS: In 41 preterm neonates with median (range) gestational age 25.3 (24.0-35.1) weeks and median postnatal age (PNA) at treatment initiation 1.4 (0.2-32.5) days, 146 plasma samples were collected. A one-compartment model described the data best, with an estimated clearance of 0.0147 L/hour for a typical infant of 0.87 kg with a serum creatinine concentration of 60 µmol/L and volume of distribution of 0.844 L. Clearance was found to increase with 16% per 100 g increase in actual body weight, and to decrease with 12% per 10 µmol/L increase in creatinine concentration once PNA was above 1 week. Dose adjustments based on serum creatinine and daily dosing are required for therapeutic target attainment. CONCLUSION: In preterm neonates, fluconazole clearance is best predicted by actual body weight and serum creatinine concentration. Therefore, fluconazole dosing should not only be based on body weight but also on creatinine concentration to achieve optimal exposure in all infants. ETHICS STATEMENT: The Erasmus MC ethics review board approved the protocol of the DINO Study (MEC-2014-067) and the Radboud UMC ethics review board waived the need for informed consent for cohort 2 (CMO-2021-8302). Written info
- Published
- 2022
10. Editorial: Sedation and analgesia challenges in critically ill neonates and children
- Author
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Amigoni, A., Simons, S., Hoog, M. de, Wildt, S.N. de, Karam, O., Amigoni, A., Simons, S., Hoog, M. de, Wildt, S.N. de, and Karam, O.
- Abstract
Contains fulltext : 287651.pdf (Publisher’s version ) (Open Access)
- Published
- 2022
11. Optimisation of fluconazole therapy for the treatment of invasive candidiasis in preterm infants
- Author
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Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., Brüggemann, R.J.M., Engbers, A.G.J., Flint, R.B., Voeller, S., Reiss, I., Liem, K.D., Alffenaar, J.C., Tibboel, D., Simons, S., Knibbe, C.A.J., and Brüggemann, R.J.M.
- Abstract
Item does not contain fulltext, INTRODUCTION: Fluconazole is an important antifungal in the prevention and treatment of invasive Candida infections in neonates, even though its use in preterm infants is still off-label. Here, we performed a population pharmacokinetic study on fluconazole in preterm neonates in order to optimise dosing through the identified predictive patient characteristics. METHODS: Fluconazole concentrations obtained from preterm infants from two studies were pooled and analysed using NONMEM V.7.3. The developed model was used to evaluate current dosing practice. A therapeutic dosing strategy aiming to reach a minimum target exposure of 400 and 200 mg×hour/L per 24 hours for fluconazole-susceptible C. albicans meningitis and other systemic infections, respectively, was developed. RESULTS: In 41 preterm neonates with median (range) gestational age 25.3 (24.0-35.1) weeks and median postnatal age (PNA) at treatment initiation 1.4 (0.2-32.5) days, 146 plasma samples were collected. A one-compartment model described the data best, with an estimated clearance of 0.0147 L/hour for a typical infant of 0.87 kg with a serum creatinine concentration of 60 µmol/L and volume of distribution of 0.844 L. Clearance was found to increase with 16% per 100 g increase in actual body weight, and to decrease with 12% per 10 µmol/L increase in creatinine concentration once PNA was above 1 week. Dose adjustments based on serum creatinine and daily dosing are required for therapeutic target attainment. CONCLUSION: In preterm neonates, fluconazole clearance is best predicted by actual body weight and serum creatinine concentration. Therefore, fluconazole dosing should not only be based on body weight but also on creatinine concentration to achieve optimal exposure in all infants. ETHICS STATEMENT: The Erasmus MC ethics review board approved the protocol of the DINO Study (MEC-2014-067) and the Radboud UMC ethics review board waived the need for informed consent for cohort 2 (CMO-2021-8302). Written info
- Published
- 2022
12. Editorial: Sedation and analgesia challenges in critically ill neonates and children
- Author
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Amigoni, A., Simons, S., Hoog, M. de, Wildt, S.N. de, Karam, O., Amigoni, A., Simons, S., Hoog, M. de, Wildt, S.N. de, and Karam, O.
- Abstract
Contains fulltext : 287651.pdf (Publisher’s version ) (Open Access)
- Published
- 2022
13. Sousveillance & Black Lives Matter Een nieuwe machtsverdeling door panoptische, synoptische en omnioptische sousveillance op politiegeweld in de VS
- Author
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Simons, S., Mul, E. de (Thesis Advisor), Simons, S., and Mul, E. de (Thesis Advisor)
- Published
- 2021
14. Sousveillance & Black Lives Matter Een nieuwe machtsverdeling door panoptische, synoptische en omnioptische sousveillance op politiegeweld in de VS
- Author
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Simons, S., Mul, E. de (Thesis Advisor), Simons, S., and Mul, E. de (Thesis Advisor)
- Published
- 2021
15. Profiling of Patients with COPD for Adequate Referral to Exercise-Based Care: The Dutch Model
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Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., Simons, S., Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., and Simons, S.
- Abstract
Contains fulltext : 225497.pdf (Publisher’s version ) (Open Access), A loss of physical functioning (i.e., a low physical capacity and/or a low physical activity) is a common feature in patients with chronic obstructive pulmonary disease (COPD). To date, the primary care physiotherapy and specialized pulmonary rehabilitation are clearly underused, and limited to patients with a moderate to very severe degree of airflow limitation (GOLD stage 2 or higher). However, improved referral rates are a necessity to lower the burden for patients with COPD and for society. Therefore, a multidisciplinary group of healthcare professionals and scientists proposes a new model for referral of patients with COPD to the right type of exercise-based care, irrespective of the degree of airflow limitation. Indeed, disease instability (recent hospitalization, yes/no), the burden of disease (no/low, mild/moderate or high), physical capacity (low or preserved) and physical activity (low or preserved) need to be used to allocate patients to one of the six distinct patient profiles. Patients with profile 1 or 2 will not be referred for physiotherapy; patients with profiles 3-5 will be referred for primary care physiotherapy; and patients with profile 6 will be referred for screening for specialized pulmonary rehabilitation. The proposed Dutch model has the intention to get the right patient with COPD allocated to the right type of exercise-based care and at the right moment.
- Published
- 2020
16. Profiling of Patients with COPD for Adequate Referral to Exercise-Based Care: The Dutch Model
- Author
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Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., Simons, S., Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., and Simons, S.
- Abstract
Contains fulltext : 225497.pdf (Publisher’s version ) (Open Access), A loss of physical functioning (i.e., a low physical capacity and/or a low physical activity) is a common feature in patients with chronic obstructive pulmonary disease (COPD). To date, the primary care physiotherapy and specialized pulmonary rehabilitation are clearly underused, and limited to patients with a moderate to very severe degree of airflow limitation (GOLD stage 2 or higher). However, improved referral rates are a necessity to lower the burden for patients with COPD and for society. Therefore, a multidisciplinary group of healthcare professionals and scientists proposes a new model for referral of patients with COPD to the right type of exercise-based care, irrespective of the degree of airflow limitation. Indeed, disease instability (recent hospitalization, yes/no), the burden of disease (no/low, mild/moderate or high), physical capacity (low or preserved) and physical activity (low or preserved) need to be used to allocate patients to one of the six distinct patient profiles. Patients with profile 1 or 2 will not be referred for physiotherapy; patients with profiles 3-5 will be referred for primary care physiotherapy; and patients with profile 6 will be referred for screening for specialized pulmonary rehabilitation. The proposed Dutch model has the intention to get the right patient with COPD allocated to the right type of exercise-based care and at the right moment.
- Published
- 2020
17. Profiling of Patients with COPD for Adequate Referral to Exercise-Based Care: The Dutch Model
- Author
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Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., Simons, S., Spruit, Martijn A., Hul, A.J. van 't, Vreeken, H.L., Beekman, E., Post, M.H.T., Meerhoff, G.A., Valk, A.L. Van der, Zagers, C., Sillen, M.J., Vooijs, M., Custers, J, Muris, J., Langer, D., Donkers, J., Bregman, M., Tissink, L., Bergkamp, E., Wempe, J., Houben-Wilke, S., Augustin, I.M., Vaate, E. Bij de, Franssen, F.F.J., Ranst, D. van, Vaart, H. van der, Antons, J.C., Doormaal, M. Van, Koolen, E.H., Wees, P.J. van der, Snippenburg, R. Van, Janssen, D.J., and Simons, S.
- Abstract
Contains fulltext : 225497.pdf (Publisher’s version ) (Open Access), A loss of physical functioning (i.e., a low physical capacity and/or a low physical activity) is a common feature in patients with chronic obstructive pulmonary disease (COPD). To date, the primary care physiotherapy and specialized pulmonary rehabilitation are clearly underused, and limited to patients with a moderate to very severe degree of airflow limitation (GOLD stage 2 or higher). However, improved referral rates are a necessity to lower the burden for patients with COPD and for society. Therefore, a multidisciplinary group of healthcare professionals and scientists proposes a new model for referral of patients with COPD to the right type of exercise-based care, irrespective of the degree of airflow limitation. Indeed, disease instability (recent hospitalization, yes/no), the burden of disease (no/low, mild/moderate or high), physical capacity (low or preserved) and physical activity (low or preserved) need to be used to allocate patients to one of the six distinct patient profiles. Patients with profile 1 or 2 will not be referred for physiotherapy; patients with profiles 3-5 will be referred for primary care physiotherapy; and patients with profile 6 will be referred for screening for specialized pulmonary rehabilitation. The proposed Dutch model has the intention to get the right patient with COPD allocated to the right type of exercise-based care and at the right moment.
- Published
- 2020
18. Neonatal sepsis: need for consensus definition, collaboration and core outcomes
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MS Neonatologie, Child Health, Infection & Immunity, Molloy, Eleanor J, Wynn, J L, Bliss, J, Koenig, J M, Keij, Fleur M., McGovern, M, Simons, S H P, van den Hoogen, A, Boode, W.P., Schlapbach, Luregn Jan, Reiss, Irwin K M, MS Neonatologie, Child Health, Infection & Immunity, Molloy, Eleanor J, Wynn, J L, Bliss, J, Koenig, J M, Keij, Fleur M., McGovern, M, Simons, S H P, van den Hoogen, A, Boode, W.P., Schlapbach, Luregn Jan, and Reiss, Irwin K M
- Published
- 2020
19. Intravenous cyclophosphamide pulse therapy in interstitial lung disease associated with systemic sclerosis in a retrospective open-label study: influence of the extent of inflammation on pulmonary function
- Author
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Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., Vonk, M.C., Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., and Vonk, M.C.
- Abstract
Contains fulltext : 195603.pdf (publisher's version ) (Open Access)
- Published
- 2018
20. Intravenous cyclophosphamide pulse therapy in interstitial lung disease associated with systemic sclerosis in a retrospective open-label study: influence of the extent of inflammation on pulmonary function
- Author
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Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., Vonk, M.C., Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., and Vonk, M.C.
- Abstract
Contains fulltext : 195603.pdf (publisher's version ) (Open Access)
- Published
- 2018
21. Intravenous cyclophosphamide pulse therapy in interstitial lung disease associated with systemic sclerosis in a retrospective open-label study: influence of the extent of inflammation on pulmonary function
- Author
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Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., Vonk, M.C., Hombergh, W.M.T. van den, Simons, S., Teesselink, E., Knaapen-Hans, H.K.A., Hoogen, F.H.J. van den, Fransen, J., and Vonk, M.C.
- Abstract
Contains fulltext : 195603.pdf (publisher's version ) (Open Access)
- Published
- 2018
22. Evaluation of integrated ecological-economic models – Review and challenges for implementation
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Nielsen, J. Rasmus, Thunberg, E., Schmidt, J.O., Holland, Dan, Bastardie, Francois, Andersen, J. L., Bartelings, Heleen, Bertignac, M., Bethke, E., Buckworth, R., Carpenter, G., Da-Rocha, J.M., Deng, R., Dichmont, C., Döring, R., Esteban, A., Frost, Hans, Fulton, E. A., Garcia, D., Gasche, L., Gascuel, D., Gourguet, S., Groeneveld, R.A., Guillen, J., Guyader, O., Hamon, Katell, Hoff, Ayoe, Horbowy, J., Kaplan, I.C., Lehuta, Sigrid, Little, R., Lleonart J., Lleonart J., Macher, C., Mackinson, S., Mahevas, S., Mato-Amboage, R., Mapstone, B., Maynou F., Maynou F., Merzéréaud M., Merzéréaud M., Palacz, Artur, Pascoe, S., Paulrud, Anton, Prellezo, R., Punt, A., Quaas, M., Ravn-Jonsen, Lars, Sanchez , S., Simons, S., Thébaud, O., Tomczak, M.T., Ulrich, Clara, Van Dijk, D., Vermard, Youen, Voss, R., Waldo, Staffan, Nielsen, J. Rasmus, Thunberg, E., Schmidt, J.O., Holland, Dan, Bastardie, Francois, Andersen, J. L., Bartelings, Heleen, Bertignac, M., Bethke, E., Buckworth, R., Carpenter, G., Da-Rocha, J.M., Deng, R., Dichmont, C., Döring, R., Esteban, A., Frost, Hans, Fulton, E. A., Garcia, D., Gasche, L., Gascuel, D., Gourguet, S., Groeneveld, R.A., Guillen, J., Guyader, O., Hamon, Katell, Hoff, Ayoe, Horbowy, J., Kaplan, I.C., Lehuta, Sigrid, Little, R., Lleonart J., Lleonart J., Macher, C., Mackinson, S., Mahevas, S., Mato-Amboage, R., Mapstone, B., Maynou F., Maynou F., Merzéréaud M., Merzéréaud M., Palacz, Artur, Pascoe, S., Paulrud, Anton, Prellezo, R., Punt, A., Quaas, M., Ravn-Jonsen, Lars, Sanchez , S., Simons, S., Thébaud, O., Tomczak, M.T., Ulrich, Clara, Van Dijk, D., Vermard, Youen, Voss, R., and Waldo, Staffan
- Published
- 2015
23. Polar Subspaces and Automatic Maximality
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
This paper is about certain linear subspaces of Banach SN spaces (that is to say Banach spaces which have a symmetric nonexpansive linear map into their dual spaces). We apply our results to monotone linear subspaces of the product of a Banach space and its dual. In this paper, we establish several new results and also give improved proofs of some known ones in both the general and the special contexts. © 2013 Springer Science+Business Media Dordrecht.
- Published
- 2014
24. Polar Subspaces and Automatic Maximality
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
This paper is about certain linear subspaces of Banach SN spaces (that is to say Banach spaces which have a symmetric nonexpansive linear map into their dual spaces). We apply our results to monotone linear subspaces of the product of a Banach space and its dual. In this paper, we establish several new results and also give improved proofs of some known ones in both the general and the special contexts. © 2013 Springer Science+Business Media Dordrecht.
- Published
- 2014
25. Retrospective study shows that doxapram therapy avoided the need for endotracheal intubation in most premature neonates
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Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., Simons, S., Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., and Simons, S.
- Abstract
Contains fulltext : 174442.pdf (publisher's version ) (Closed access), AIM: Using doxapram to treat neonates with apnoea of prematurity might avoid the need for endotracheal intubation and invasive ventilation. We studied whether doxapram prevented the need for intubation and identified the predictors of the success. METHODS: This was a retrospective study of preterm infants born from January 2006 to August 2014 who received oral or intravenous doxapram. Success was defined as no need for endotracheal intubation, due to apnoea, during doxapram therapy. Univariable and multivariable logistic regression analyses identified predictors of success during the first 48 hours of doxapram therapy. RESULTS: Data on 203 patients with a median gestational age of 26.1 (interquartile range 25.1-27.4) weeks were analysed. During the first 48 hours of doxapram therapy, 157 (77%) patients did not need endotracheal intubation and 127 (63%) patients were successfully treated over the entire treatment course. The median postnatal age at the start of doxapram therapy was 20 days (interquartile range 12-30). Postnatal age and a lower fraction of inspired oxygen at the start of doxapram therapy were significant predictors of success (odds ratio 0.964, 95% confidence interval 0.938-0.991, p = 0.001). CONCLUSION: Oral and intravenous doxapram effectively treated most cases of apnoea in preterm infants, avoiding the need for intubation.
- Published
- 2017
26. Retrospective study shows that doxapram therapy avoided the need for endotracheal intubation in most premature neonates
- Author
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Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., Simons, S., Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., and Simons, S.
- Abstract
Contains fulltext : 174442.pdf (publisher's version ) (Closed access), AIM: Using doxapram to treat neonates with apnoea of prematurity might avoid the need for endotracheal intubation and invasive ventilation. We studied whether doxapram prevented the need for intubation and identified the predictors of the success. METHODS: This was a retrospective study of preterm infants born from January 2006 to August 2014 who received oral or intravenous doxapram. Success was defined as no need for endotracheal intubation, due to apnoea, during doxapram therapy. Univariable and multivariable logistic regression analyses identified predictors of success during the first 48 hours of doxapram therapy. RESULTS: Data on 203 patients with a median gestational age of 26.1 (interquartile range 25.1-27.4) weeks were analysed. During the first 48 hours of doxapram therapy, 157 (77%) patients did not need endotracheal intubation and 127 (63%) patients were successfully treated over the entire treatment course. The median postnatal age at the start of doxapram therapy was 20 days (interquartile range 12-30). Postnatal age and a lower fraction of inspired oxygen at the start of doxapram therapy were significant predictors of success (odds ratio 0.964, 95% confidence interval 0.938-0.991, p = 0.001). CONCLUSION: Oral and intravenous doxapram effectively treated most cases of apnoea in preterm infants, avoiding the need for intubation.
- Published
- 2017
27. Retrospective study shows that doxapram therapy avoided the need for endotracheal intubation in most premature neonates
- Author
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Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., Simons, S., Flint, R.B., Halbmeijer, N., Meesters, N., Rosmalen, J. van, Reiss, I., Dijk, M., and Simons, S.
- Abstract
Contains fulltext : 174442.pdf (publisher's version ) (Closed access), AIM: Using doxapram to treat neonates with apnoea of prematurity might avoid the need for endotracheal intubation and invasive ventilation. We studied whether doxapram prevented the need for intubation and identified the predictors of the success. METHODS: This was a retrospective study of preterm infants born from January 2006 to August 2014 who received oral or intravenous doxapram. Success was defined as no need for endotracheal intubation, due to apnoea, during doxapram therapy. Univariable and multivariable logistic regression analyses identified predictors of success during the first 48 hours of doxapram therapy. RESULTS: Data on 203 patients with a median gestational age of 26.1 (interquartile range 25.1-27.4) weeks were analysed. During the first 48 hours of doxapram therapy, 157 (77%) patients did not need endotracheal intubation and 127 (63%) patients were successfully treated over the entire treatment course. The median postnatal age at the start of doxapram therapy was 20 days (interquartile range 12-30). Postnatal age and a lower fraction of inspired oxygen at the start of doxapram therapy were significant predictors of success (odds ratio 0.964, 95% confidence interval 0.938-0.991, p = 0.001). CONCLUSION: Oral and intravenous doxapram effectively treated most cases of apnoea in preterm infants, avoiding the need for intubation.
- Published
- 2017
28. The asymmetric sandwich theorem
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
We discuss the asjTnmetric sandwich theorem, a generalization of the Hahn-Banach theorem. As appUcations, we derive various results on the existence of linear fanctionals that include bivariate, trivariate and quadrivariate generalizations of the Fenchel duahty theorem. Most of the results are about afhne functions defined on convex subsets of vector spaces, rather than Unear functions defined on vector spaces. We consider both results that use a simple boundedness hypothesis (as in Rockafellar's version of the Fenchel duaUty theorem) and also results that use Baire's theorem (as in the Robinson-Attouch-Brezis version of the Fendiel duaUty theorem). This paper also contams some new results about metrizable topological vector spaces that are not necessarily locally convex. © Heldermann Verlag.
- Published
- 2013
29. The asymmetric sandwich theorem
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
We discuss the asjTnmetric sandwich theorem, a generalization of the Hahn-Banach theorem. As appUcations, we derive various results on the existence of linear fanctionals that include bivariate, trivariate and quadrivariate generalizations of the Fenchel duahty theorem. Most of the results are about afhne functions defined on convex subsets of vector spaces, rather than Unear functions defined on vector spaces. We consider both results that use a simple boundedness hypothesis (as in Rockafellar's version of the Fenchel duaUty theorem) and also results that use Baire's theorem (as in the Robinson-Attouch-Brezis version of the Fendiel duaUty theorem). This paper also contams some new results about metrizable topological vector spaces that are not necessarily locally convex. © Heldermann Verlag.
- Published
- 2013
30. Linear L-Positive Sets and Their Polar Subspaces
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we define a Banach SNL space to be a Banach space with a certain kind of linear map from it into its dual, and we develop the theory of linear L-positive subsets of Banach SNL spaces with Banach SNL dual spaces. We use this theory to give simplified proofs of some recent results of Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder theorem. © 2012 Springer Science+Business Media B.V.
- Published
- 2012
31. Linear L-Positive Sets and Their Polar Subspaces
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we define a Banach SNL space to be a Banach space with a certain kind of linear map from it into its dual, and we develop the theory of linear L-positive subsets of Banach SNL spaces with Banach SNL dual spaces. We use this theory to give simplified proofs of some recent results of Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder theorem. © 2012 Springer Science+Business Media B.V.
- Published
- 2012
32. Linear L-Positive Sets and Their Polar Subspaces
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we define a Banach SNL space to be a Banach space with a certain kind of linear map from it into its dual, and we develop the theory of linear L-positive subsets of Banach SNL spaces with Banach SNL dual spaces. We use this theory to give simplified proofs of some recent results of Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder theorem. © 2012 Springer Science+Business Media B.V.
- Published
- 2012
33. Banach SSD spaces and classes of monotone sets
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we unify the theory of SSD spaces and the theory of strongly representable sets, and we apply our results to the theory of the various classes of maximally monotone sets. In particular, we prove that type (ED), dense type, type (D), type (NI) and strongly representable are equivalent concepts and, consequently, that the known properties of strongly representable sets follow from known properties of sets of type (ED). © Heldermann Verlag.
- Published
- 2011
34. Quadrivariate existence theorems and strong representability
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this article, we give conditions under which we can compute the conjugate of a convex function on the product of two Fréchet spaces defined in terms of another convex function on the product of two (possibly different) Fréchet spaces. We use this result to give simple proofs of some (both old and new) results for Banach spaces, and deduce some (both old and new) stability results for strongly representable multifunctions. We take as our starting point a result on closed convex cones in the product of two Fréchet spaces. © 2011 Taylor & Francis.
- Published
- 2011
35. Quadrivariate existence theorems and strong representability
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this article, we give conditions under which we can compute the conjugate of a convex function on the product of two Fréchet spaces defined in terms of another convex function on the product of two (possibly different) Fréchet spaces. We use this result to give simple proofs of some (both old and new) results for Banach spaces, and deduce some (both old and new) stability results for strongly representable multifunctions. We take as our starting point a result on closed convex cones in the product of two Fréchet spaces. © 2011 Taylor & Francis.
- Published
- 2011
36. Banach SSD spaces and classes of monotone sets
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we unify the theory of SSD spaces and the theory of strongly representable sets, and we apply our results to the theory of the various classes of maximally monotone sets. In particular, we prove that type (ED), dense type, type (D), type (NI) and strongly representable are equivalent concepts and, consequently, that the known properties of strongly representable sets follow from known properties of sets of type (ED). © Heldermann Verlag.
- Published
- 2011
37. A new proof of the maximal monotonicity of subdifferentials
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
We give a new proof based on the recent very elegant argument of Marques Alves and Svaiter that the sub differential of a proper, convex lower semicontinuous function on a real Banach space is maximally monotone. We also show how the argument can be simplified in the reflexive case. © Heldermann Verlag.
- Published
- 2009
38. A new proof of the maximal monotonicity of subdifferentials
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
We give a new proof based on the recent very elegant argument of Marques Alves and Svaiter that the sub differential of a proper, convex lower semicontinuous function on a real Banach space is maximally monotone. We also show how the argument can be simplified in the reflexive case. © Heldermann Verlag.
- Published
- 2009
39. Positive sets and monotone sets
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we show how convex analysis can be applied to the theory of sets that are "positive" with respect to a continuous quadratic form on a Banach space. Monotone sets can be considered as a special case of positive sets, and we show how our results lead to very efficient proofs of a number of results on monotone sets. One of the key techniques that we use is a generalization of the Fitzpatrick function from monotone set theory to an analogous function for positive sets. © Heldermann Verlag.
- Published
- 2007
40. Positive sets and monotone sets
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we show how convex analysis can be applied to the theory of sets that are "positive" with respect to a continuous quadratic form on a Banach space. Monotone sets can be considered as a special case of positive sets, and we show how our results lead to very efficient proofs of a number of results on monotone sets. One of the key techniques that we use is a generalization of the Fitzpatrick function from monotone set theory to an analogous function for positive sets. © Heldermann Verlag.
- Published
- 2007
41. The Fitzpatrick function and nonreflexive spaces
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we show how Fitzpatrick functions can be used to obtain various results on the local boundedness, domain and surjectivity of monotone and maximal monotone multifunctions on a Banach space, and also to clarify the relationships between different subclasses of the set of maximal monotone multifunctions. © Heldermann Verlag.
- Published
- 2006
42. The Fitzpatrick function and nonreflexive spaces
- Author
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Simons, S, Simons, S, Simons, S, and Simons, S
- Abstract
In this paper, we show how Fitzpatrick functions can be used to obtain various results on the local boundedness, domain and surjectivity of monotone and maximal monotone multifunctions on a Banach space, and also to clarify the relationships between different subclasses of the set of maximal monotone multifunctions. © Heldermann Verlag.
- Published
- 2006
43. Een onderzoek naar de werkbeleving van de medewerkers van Pernod Ricard Nederland en een evaluatie van de gehanteerde vragenlijst
- Author
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Simons, S., Simons, S., Simons, S., and Simons, S.
- Published
- 2002
44. Een onderzoek naar de werkbeleving van de medewerkers van Pernod Ricard Nederland en een evaluatie van de gehanteerde vragenlijst
- Author
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Simons, S., Simons, S., Simons, S., and Simons, S.
- Published
- 2002
45. Een onderzoek naar de werkbeleving van de medewerkers van Pernod Ricard Nederland en een evaluatie van de gehanteerde vragenlijst
- Author
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Simons, S., Simons, S., Simons, S., and Simons, S.
- Published
- 2002
46. Volume conduction effects on bivariate Lempel-Ziv Complexity of Alzheimer's disease electroencephalograms.
- Author
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Simons, S, Abásolo, D, Sauseng, P, Simons, S, Abásolo, D, and Sauseng, P
- Abstract
The spurious increase in coherence of electroencephalogram (EEG) signals between distant electrode points has long been understood to be due to volume conduction of the EEG signal. Reducing the volume conduction components of EEG recordings in pre-processing attenuates this. However, the effect of volume conduction on non-linear signal processing of EEG signals is yet to be fully described. This pilot study aimed to investigate the impact of volume conduction on results calculated with a distance based, bivariate form of Lempel-Ziv Complexity (dLZC) by analyzing EEG signals from Alzheimer's disease (AD) patients and healthy age-matched controls with and without pre-processing with Current Source Density (CSD) transformation. Spurious statistically significant differences between AD patients and control's EEG signals seen without CSD pre-processing were not seen with CSD volume conduction mitigation. There was, however, overlap in the region of electrodes which were seen to hold this statistically significant information. These results show that, while previously published findings are still valid, volume conduction mitigation is required to ensure non-linear signal processing methods identify changes in signals only due to the purely local signal alone.
- Published
- 2015
47. Lempel-Ziv complexity of cortical activity during sleep and waking in rats.
- Author
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Abásolo, D, Simons, S, Morgado da Silva, R, Tononi, G, Vyazovskiy, VV, Abásolo, D, Simons, S, Morgado da Silva, R, Tononi, G, and Vyazovskiy, VV
- Abstract
Understanding the dynamics of brain activity manifested in the EEG, local field potentials (LFP), and neuronal spiking is essential for explaining their underlying mechanisms and physiological significance. Much has been learned about sleep regulation using conventional EEG power spectrum, coherence, and period-amplitude analyses, which focus primarily on frequency and amplitude characteristics of the signals and on their spatio-temporal synchronicity. However, little is known about the effects of ongoing brain state or preceding sleep-wake history on the nonlinear dynamics of brain activity. Recent advances in developing novel mathematical approaches for investigating temporal structure of brain activity based on such measures, as Lempel-Ziv complexity (LZC) can provide insights that go beyond those obtained with conventional techniques of signal analysis. Here, we used extensive data sets obtained in spontaneously awake and sleeping adult male laboratory rats, as well as during and after sleep deprivation, to perform a detailed analysis of cortical LFP and neuronal activity with LZC approach. We found that activated brain states-waking and rapid eye movement (REM) sleep are characterized by higher LZC compared with non-rapid eye movement (NREM) sleep. Notably, LZC values derived from the LFP were especially low during early NREM sleep after sleep deprivation and toward the middle of individual NREM sleep episodes. We conclude that LZC is an important and yet largely unexplored measure with a high potential for investigating neurophysiological mechanisms of brain activity in health and disease.
- Published
- 2015
48. New results on q-positivity
- Author
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García Ramos, Y, García Ramos, Y, Martínez-Legaz, JE, Simons, S, García Ramos, Y, García Ramos, Y, Martínez-Legaz, JE, and Simons, S
- Abstract
In this paper we discuss symmetrically self-dual spaces, which are simply real vector spaces with a symmetric bilinear form. Certain subsets of the space will be called q-positive, where q is the quadratic form induced by the original bilinear form. The notion of q-positivity generalizes the classical notion of the monotonicity of a subset of a product of a Banach space and its dual. Maximal q-positivity then generalizes maximal monotonicity. We discuss concepts generalizing the representations of monotone sets by convex functions, as well as the number of maximally q -positive extensions of a q-positive set. We also discuss symmetrically self-dual Banach spaces, in which we add a Banach space structure, giving new characterizations of maximal q-positivity. The paper finishes with two new examples. © 2012 Springer Basel AG.
- Published
- 2012
49. The quest for companions to post-common envelope binaries: I. Searching a sample of stars from the CSS and SDSS
- Author
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Backhaus, U., Bauer, S., Beuermann, K., Diese, J., Dreizler, S., Hessman, F. V., Husser, T. -O., Klapdohr, K. -H., Moellmanns, J., Schuenecke, R., Dette, J., Dubbert, J., Miosga, T., Vogel, A. L. Rochus, Simons, S., Biriuk, S., Debrah, M., Griemens, M., Hahn, A., Moeller, T., Pawlowski, M., Schweizer, M., Speck, A. -L., Zapros, C., Bollmann, T., Habermann, F. N., Haustovich, N., Lauser, M., Liebig, F., Niederstadt, F., Hoppen, K., Kindermann, D., Kueppers, F., Rauch, B., Althoff, F., Horstmann, M., Kellermann, J. N., Kietz, R., Nienaber, T., Sauer, M., Secci, A., Wuellner, L., Backhaus, U., Bauer, S., Beuermann, K., Diese, J., Dreizler, S., Hessman, F. V., Husser, T. -O., Klapdohr, K. -H., Moellmanns, J., Schuenecke, R., Dette, J., Dubbert, J., Miosga, T., Vogel, A. L. Rochus, Simons, S., Biriuk, S., Debrah, M., Griemens, M., Hahn, A., Moeller, T., Pawlowski, M., Schweizer, M., Speck, A. -L., Zapros, C., Bollmann, T., Habermann, F. N., Haustovich, N., Lauser, M., Liebig, F., Niederstadt, F., Hoppen, K., Kindermann, D., Kueppers, F., Rauch, B., Althoff, F., Horstmann, M., Kellermann, J. N., Kietz, R., Nienaber, T., Sauer, M., Secci, A., and Wuellner, L.
- Abstract
As part of an ongoing collaboration between student groups at high schools and professional astronomers, we have searched for the presence of circum-binary planets in a bona-fide unbiased sample of twelve post-common envelope binaries (PCEBs) from the Catalina Sky Survey (CSS) and the Sloan Digital Sky Survey (SDSS). Although the present ephemerides are significantly more accurate than previous ones, we find no clear evidence for orbital period variations between 2005 and 2011 or during the 2011 observing season. The sparse long-term coverage still permits O-C variations with a period of years and an amplitude of tens of seconds, as found in other systems. Our observations provide the basis for future inferences about the frequency with which planet-sized or brown-dwarf companions have either formed in these evolved systems or survived the common envelope (CE) phase., Comment: accepted by A&A
- Published
- 2012
- Full Text
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50. New results on q-positivity
- Author
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García Ramos, Y, García Ramos, Y, Martínez-Legaz, JE, Simons, S, García Ramos, Y, García Ramos, Y, Martínez-Legaz, JE, and Simons, S
- Abstract
In this paper we discuss symmetrically self-dual spaces, which are simply real vector spaces with a symmetric bilinear form. Certain subsets of the space will be called q-positive, where q is the quadratic form induced by the original bilinear form. The notion of q-positivity generalizes the classical notion of the monotonicity of a subset of a product of a Banach space and its dual. Maximal q-positivity then generalizes maximal monotonicity. We discuss concepts generalizing the representations of monotone sets by convex functions, as well as the number of maximally q -positive extensions of a q-positive set. We also discuss symmetrically self-dual Banach spaces, in which we add a Banach space structure, giving new characterizations of maximal q-positivity. The paper finishes with two new examples. © 2012 Springer Basel AG.
- Published
- 2012
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