| 1. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 2. |
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| 3. |
- McMurray, J., et al.
(författare)
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A putative placebo analysis of the effects of LCZ696 on clinical outcomes in heart failure
- 2015
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 36:7, s. 434-439
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Although active-controlled trials with renin-angiotensin inhibitors are ethically mandated in heart failure with reduced ejection fraction, clinicians and regulators often want to know how the experimental therapy would perform compared with placebo. The angiotensin receptor-neprilysin inhibitor LCZ696 was compared with enalapril in PARADIGM-HF. We made indirect comparisons of the effects of LCZ696 with putative placebos. METHODS AND RESULTS: We used the treatment-arm of the Studies Of Left Ventricular Dysfunction (SOLVD-T) as the reference trial for comparison of an ACE inhibitor to placebo and the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity-Alternative trial (CHARM-Alternative) as the reference trial for comparison of an ARB to placebo. The hazard ratio of LCZ696 vs. a putative placebo was estimated through the product of the hazard ratio of LCZ696 vs. enalapril (active-control) and that of the historical active-control (enalapril or candesartan) vs. placebo. For the primary composite outcome of cardiovascular death or heart failure hospitalization in PARADIGM-HF, the relative risk reduction with LCZ696 vs. a putative placebo from SOLVD-T was 43% (95%CI 34-50%; P < 0.0001) with similarly large effects on cardiovascular death (34%, 21-44%; P < 0.0001) and heart failure hospitalization (49%, 39-58%; P < 0.0001). For all-cause mortality, the reduction compared with a putative placebo was 28% (95%CI 15-39%; P < 0.0001). Putative placebo analyses based on CHARM-Alternative gave relative risk reductions of 39% (95%CI 27-48%; P < 0.0001) for the composite outcome of cardiovascular death or heart failure hospitalization, 32% (95%CI 16-45%; P < 0.0001) for cardiovascular death, 46% (33-56%; P < 0.0001) for heart failure hospitalization, and 26% (95%CI 11-39%; P < 0.0001) for all-cause mortality. CONCLUSION: These indirect comparisons of LCZ696 with a putative placebo show that the strategy of combined angiotensin receptor blockade and neprilysin inhibition led to striking reductions in cardiovascular and all-cause mortality, as well as heart failure hospitalization. These benefits were obtained even though LCZ696 was added to comprehensive background beta-blocker and mineralocorticoid receptor antagonist therapy.
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| 4. |
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| 5. |
- Yulug, B., et al.
(författare)
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Combined metabolic activators improve cognitive functions in Alzheimer's disease patients: a randomised, double-blinded, placebo-controlled phase-II trial
- 2023
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Ingår i: Translational Neurodegeneration. - : Springer Science and Business Media LLC. - 2047-9158. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Alzheimer's disease (AD) is associated with metabolic abnormalities linked to critical elements of neurodegeneration. We recently administered combined metabolic activators (CMA) to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals. CMA promotes mitochondrial fatty acid uptake from the cytosol, facilitates fatty acid oxidation in the mitochondria, and alleviates oxidative stress.Methods Here, we designed a randomised, double-blinded, placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients. One-dose CMA included 12.35 g L-serine (61.75%), 1 g nicotinamide riboside (5%), 2.55 g N-acetyl-L-cysteine (12.75%), and 3.73 g L-carnitine tartrate (18.65%). AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84. The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms. The secondary aim of this study was to evaluate the safety and tolerability of CMA. A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients.Results We showed a significant decrease of AD Assessment Scale-cognitive subscale (ADAS-Cog) score on day 84 vs day 0 (P = 0.00001, 29% improvement) in the CMA group. Moreover, there was a significant decline (P = 0.0073) in ADAS-Cog scores (improvement of cognitive functions) in the CMA compared to the placebo group in patients with higher ADAS-Cog scores. Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis. Moreover, the plasma levels of proteins and metabolites associated with NAD + and glutathione metabolism were significantly improved after CMA treatment.Conclusion Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters associated with phenomics, metabolomics, proteomics and imaging analysis.
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| 6. |
- Groenewold, Nynke A., et al.
(författare)
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Volume of subcortical brain regions in social anxiety disorder : mega-analytic results from 37 samples in the ENIGMA-Anxiety Working Group
- 2023
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Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 28:3, s. 1079-1089
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Tidskriftsartikel (refereegranskat)abstract
- There is limited convergence in neuroimaging investigations into volumes of subcortical brain regions in social anxiety disorder (SAD). The inconsistent findings may arise from variations in methodological approaches across studies, including sample selection based on age and clinical characteristics. The ENIGMA-Anxiety Working Group initiated a global mega-analysis to determine whether differences in subcortical volumes can be detected in adults and adolescents with SAD relative to healthy controls. Volumetric data from 37 international samples with 1115 SAD patients and 2775 controls were obtained from ENIGMA-standardized protocols for image segmentation and quality assurance. Linear mixed-effects analyses were adjusted for comparisons across seven subcortical regions in each hemisphere using family-wise error (FWE)-correction. Mixed-effects d effect sizes were calculated. In the full sample, SAD patients showed smaller bilateral putamen volume than controls (left: d = −0.077, pFWE = 0.037; right: d = −0.104, pFWE = 0.001), and a significant interaction between SAD and age was found for the left putamen (r = −0.034, pFWE = 0.045). Smaller bilateral putamen volumes (left: d = −0.141, pFWE < 0.001; right: d = −0.158, pFWE < 0.001) and larger bilateral pallidum volumes (left: d = 0.129, pFWE = 0.006; right: d = 0.099, pFWE = 0.046) were detected in adult SAD patients relative to controls, but no volumetric differences were apparent in adolescent SAD patients relative to controls. Comorbid anxiety disorders and age of SAD onset were additional determinants of SAD-related volumetric differences in subcortical regions. To conclude, subtle volumetric alterations in subcortical regions in SAD were detected. Heterogeneity in age and clinical characteristics may partly explain inconsistencies in previous findings. The association between alterations in subcortical volumes and SAD illness progression deserves further investigation, especially from adolescence into adulthood.
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| 7. |
- Jhund, P. S., et al.
(författare)
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Efficacy and safety of LCZ696 (sacubitril-valsartan) according to age: insights from PARADIGM-HF
- 2015
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 36:38, s. 2576-2584
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Tidskriftsartikel (refereegranskat)abstract
- Background The age at which heart failure develops varies widely between countries and drug tolerance and outcomes also vary by age. We have examined the efficacy and safety of LCZ696 according to age in the Prospective comparison of angiotensin receptor neprilysin inhibitor with angiotensin converting enzyme inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure trial (PARADIGM-HF). Methods In PARADIGM-HF, 8399 patients aged 18-96 years and in New York Heart Association functional class II-IV with an LVEF <= 40% were randomized to either enalapril or LCZ696. We examined the pre-specified efficacy and safety outcomes according to age category (years): <55 (n = 1624), 55-64 (n = 2655), 65-74 (n = 2557), and >= 75 (n = 1563). Findings The rate (per 100 patient-years) of the primary outcome of cardiovascular (CV) death or heart failure hospitalization (HFH) increased from 13.4 to 14.8 across the age categories. The LCZ696: enalapril hazard ratio (HR) was <1.0 in all categories (P for interaction between age category and treatment = 0.94) with an overall HR of 0.80 (0.73, 0.87), P < 0.001. The findings for HFH were similar for CV and all-cause mortality and the age category by treatment interactions were not significant. The pre-specified safety outcomes of hypotension, renal impairment and hyperkalaemia increased in both treatment groups with age, although the differences between treatment (more hypotension but less renal impairment and hyperkalaemia with LCZ696) were consistent across age categories. Interpretation LCZ696 was more beneficial than enalapril across the spectrum of age in PARADIGM-HF with a favourable benefit-risk profile in all age groups.
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| 8. |
- Peker, Yüksel, 1961, et al.
(författare)
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Effect of High-Risk Obstructive Sleep Apnea on Clinical Outcomes in Adults with Coronavirus Disease 2019 A Multicenter, Prospective, Observational Clinical Trial
- 2021
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Ingår i: Annals of the American Thoracic Society. - 1546-3222. ; 18:9, s. 1548-1559
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: Coronavirus disease (COVID-19) is an ongoing pandemic, in which obesity, hypertension, and diabetes have been linked to poor outcomes. Obstructive sleep apnea (OSA) is associated with these conditions and may influence the prognosis of adults with COVID-19. Objectives: To determine the effect of OSA on clinical outcomes in patients with COVID-19. Methods: The current prospective observational study was conducted in three hospitals in Istanbul, Turkey from March 10 to June 22, 2020. The participants were categorized as high-risk or low-risk OSA according to the Berlin questionnaire that was administered in the out-patient clinic, in hospital, or shortly after discharge from hospital blinded to the clinical outcomes. A modified high-risk (mHR)-OSA score based on the snoring patterns (intensity and/or frequency), breathing pauses, and morning/daytime sleepiness, without taking obesity and hypertension into account, were used in the regression models. Results: The primary outcome was the clinical improvement defined as a decline of two categories from admission on a 7-category ordinal scale that ranges from 1 (discharged with normal activity) to 7 (death) on Days 7, 14, 21, and 28, respectively. Secondary outcomes included clinical worsening (an increase of 1 category), need for hospitalization, supplemental oxygen, and intensive care. In total, 320 eligible patients (median [interquartile range] age, 53.2 [41.3-63.0] yr; 45.9% female) were enrolled. In all, 121 (37.8%) were categorized as known (n = 3) or high-risk OSA (n = 118). According to the modified scoring, 70 (21.9%) had mHR-OSA. Among 242 patients requiring hospitalization, clinical improvement within 2 weeks occurred in 75.4% of the mHR-OSA group compared with 88.4% of the modified low-risk-OSA group (P = 0.014). In multivariate regression analyses, mHR-OSA (adjusted odds ratio [OR], 0.42; 95% confidence interval [CI], 0.19-0.92) and male sex (OR, 0.39; 95% CI, 0.17-0.86) predicted the delayed clinical improvement. In the entire study population (n = 320), including the nonhospitalized patients, mHR-OSA was associated with clinical worsening (adjusted hazard ratio, 1.55; 95% CI, 1.00-2.39) and with the need for supplemental oxygen (OR, 1.95; 95% CI, 1.06-3.59). Snoring patterns, especially louder snoring, significantly predicted delayed clinical improvement, worsening, need for hospitalization, supplemental oxygen, and intensive care. Conclusions: Adults with mHR-OSA in our COVID-19 cohort had poorer clinical outcomes than those with modified low-risk OSA independent of age, sex, and comorbidities.
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| 9. |
- Battisti, Umberto Maria, et al.
(författare)
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Ellagic Acid and Its Metabolites as Potent and Selective Allosteric Inhibitors of Liver Pyruvate Kinase
- 2023
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Liver pyruvate kinase (PKL) has recently emerged as a new target for non-alcoholic fatty liver disease (NAFLD), and inhibitors of this enzyme could represent a new therapeutic option. However, this breakthrough is complicated by selectivity issues since pyruvate kinase exists in four different isoforms. In this work, we report that ellagic acid (EA) and its derivatives, present in numerous fruits and vegetables, can inhibit PKL potently and selectively. Several polyphenolic analogues of EA were synthesized and tested to identify the chemical features responsible for the desired activity. Molecular modelling studies suggested that this inhibition is related to the stabilization of the PKL inactive state. This unique inhibition mechanism could potentially herald the development of new therapeutics for NAFLD.
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| 10. |
- Gezici, S., et al.
(författare)
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Jamming of Wireless Localization Systems
- 2016
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Ingår i: IEEE Transactions on Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0090-6778 .- 1558-0857. ; 64:6, s. 2660-2676
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the optimal jamming of wireless localization systems is investigated. Two optimal power allocation schemes are proposed for jammer nodes in the presence of total and peak power constraints. In the first scheme, power is allocated to jammer nodes in order to maximize the average Cramér-Rao lower bound (CRLB) of target nodes, whereas in the second scheme, the power allocation is performed for the aim of maximizing the minimum CRLB of target nodes. Both the schemes are formulated as linear programs, and a closed-form solution is obtained for the first scheme. For the second scheme, under certain conditions, the property of full total power utilization is specified, and a closed-form solution is obtained when the total power is lower than a specific threshold. In addition, it is shown that non-zero power is allocated to at most NT jammer nodes according to the second scheme in the absence of peak power constraints, where NT is the number of target nodes. In the presence of parameter uncertainty, robust versions of the power allocation schemes are proposed. Simulation results are presented to investigate the performance of the proposed schemes and to illustrate the theoretical results.
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| 11. |
- Gezici, S., et al.
(författare)
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Optimal jammer placement in wireless localization networks
- 2015
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Ingår i: IEEE Workshop on Signal Processing Advances in Wireless Communications, SPAWC. - : IEEE conference proceedings. - 9781479919307 ; , s. 665-669
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Konferensbidrag (refereegranskat)abstract
- The optimal jammer placement problem is proposed for a wireless localization network, where the aim is to degrade the accuracy of locating target nodes as much as possible. In particular, the optimal location of a jammer node is obtained in order to maximize the minimum of the Cramér-Rao lower bounds for a number of target nodes under location related constraints for the jammer node. Theoretical results are derived to specify scenarios in which the jammer node should be located as close to a certain target node as possible, or the optimal location of the jammer node is determined by two or three of the target nodes. In addition, explicit expressions for the optimal location of the jammer node are derived in the presence of two target nodes. Numerical examples are presented to illustrate the theoretical results.
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| 12. |
- Stray-Pedersen, Asbjorg, et al.
(författare)
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Primary immunodeficiency diseases : Genomic approaches delineate heterogeneous Mendelian disorders
- 2017
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Ingår i: Journal of Allergy and Clinical Immunology. - : MOSBY-ELSEVIER. - 0091-6749 .- 1097-6825. ; 139:1, s. 232-245
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Tidskriftsartikel (refereegranskat)abstract
- Background: Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes can overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions. Objective: We sought to investigate the ability of whole-exome screening methods to detect disease-causing variants in patients with PIDDs. Methods: Patients with PIDDs from 278 families from 22 countries were investigated by using whole-exome sequencing. Computational copy number variant (CNV) prediction pipelines and an exome-tiling chromosomal microarray were also applied to identify intragenic CNVs. Analytic approaches initially focused on 475 known or candidate PIDD genes but were nonexclusive and further tailored based on clinical data, family history, and immunophenotyping. Results: A likely molecular diagnosis was achieved in 110 (40%) unrelated probands. Clinical diagnosis was revised in about half (60/ 110) and management was directly altered in nearly a quarter (26/ 110) of families based on molecular findings. Twelve PIDD-causing CNVs were detected, including 7 smaller than 30 Kb that would not have been detected with conventional diagnostic CNV arrays. Conclusion: This high-throughput genomic approach enabled detection of disease-related variants in unexpected genes; permitted detection of low-grade constitutional, somatic, and revertant mosaicism; and provided evidence of a mutational burden in mixed PIDD immunophenotypes.
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| 13. |
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| 14. |
- Zhang, Cheng, et al.
(författare)
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Discovery of therapeutic agents targeting PKLR for NAFLD using drug repositioning
- 2022
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Ingår i: eBioMedicine. - : Elsevier BV. - 2352-3964. ; 83
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Tidskriftsartikel (refereegranskat)abstract
- Background Non-alcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of liver pathologies. However, no medical treatment has been approved for the treatment of NAFLD. In our previous study, we found that PKLR could be a potential target for treatment of NALFD. Here, we investigated the effect of PKLR in in vivo model and performed drug repositioning to identify a drug candidate for treatment of NAFLD. Methods Tissue samples from liver, muscle, white adipose and heart were obtained from control and PKLR knock-out mice fed with chow and high sucrose diets. Lipidomics as well as transcriptomics analyses were conducted using these tissue samples. In addition, a computational drug repositioning analysis was performed and drug candidates were identified. The drug candidates were both tested in in vitro and in vivo models to evaluate their toxicity and efficacy. Findings The Pklr KO reversed the increased hepatic triglyceride level in mice fed with high sucrose diet and partly recovered the transcriptomic changes in the liver as well as in other three tissues. Both liver and white adipose tissues exhibited dysregulated circadian transcriptomic profiles, and these dysregulations were reversed by hepatic knockout of Pklr. In addition, 10 small molecule drug candidates were identified as potential inhibitor of PKLR using our drug repositioning pipeline, and two of them significantly inhibited both the PKLR expression and triglyceride level in in vitro model. Finally, the two selected small molecule drugs were evaluated in in vivo rat models and we found that these drugs attenuate the hepatic steatosis without side effect on other tissues. Interpretation In conclusion, our study provided biological insights about the critical role of PKLR in NAFLD progression and proposed a treatment strategy for NAFLD patients, which has been validated in preclinical studies. Copyright (C) 2022 The Authors. Published by Elsevier B.V.
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| 15. |
- Bayram, Firas, et al.
(författare)
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A domain-region based evaluation of ML performance robustness to covariate shift
- 2023
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Ingår i: Neural Computing & Applications. - : Springer. - 0941-0643 .- 1433-3058. ; 35:24, s. 17555-17577
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Tidskriftsartikel (refereegranskat)abstract
- Most machine learning methods assume that the input data distribution is the same in the training and testing phases.However, in practice, this stationarity is usually not met and the distribution of inputs differs, leading to unexpectedperformance of the learned model in deployment. The issue in which the training and test data inputs follow differentprobability distributions while the input–output relationship remains unchanged is referred to as covariate shift. In thispaper, the performance of conventional machine learning models was experimentally evaluated in the presence of covariateshift. Furthermore, a region-based evaluation was performed by decomposing the domain of probability density function ofthe input data to assess the classifier’s performance per domain region. Distributional changes were simulated in a twodimensional classification problem. Subsequently, a higher four-dimensional experiments were conducted. Based on theexperimental analysis, the Random Forests algorithm is the most robust classifier in the two-dimensional case, showing thelowest degradation rate for accuracy and F1-score metrics, with a range between 0.1% and 2.08%. Moreover, the resultsreveal that in higher-dimensional experiments, the performance of the models is predominantly influenced by the complexity of the classification function, leading to degradation rates exceeding 25% in most cases. It is also concluded that themodels exhibit high bias toward the region with high density in the input space domain of the training samples.
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| 16. |
- Bayram, Firas, et al.
(författare)
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A Drift Handling Approach for Self-Adaptive ML Software in Scalable Industrial Processes
- 2022
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Ingår i: Proceedings of the 37th IEEE/ACM International Conference on Automated Software Engineering. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450394758 ; , s. 1-5
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Konferensbidrag (refereegranskat)abstract
- Most industrial processes in real-world manufacturing applications are characterized by the scalability property, which requires an automated strategy to self-adapt machine learning (ML) software systems to the new conditions. In this paper, we investigate an Electroslag Remelting (ESR) use case process from the Uddeholms AB steel company. The use case involves predicting the minimum pressure value for a vacuum pumping event. Taking into account the long time required to collect new records and efficiently integrate the new machines with the built ML software system. Additionally, to accommodate the changes and satisfy the non-functional requirement of the software system, namely adaptability, we propose an automated and adaptive approach based on a drift handling technique called importance weighting. The aim is to address the problem of adding a new furnace to production and enable the adaptability attribute of the ML software. The overall results demonstrate the improvements in ML software performance achieved by implementing the proposed approach over the classical non-adaptive approach.
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| 17. |
- Bayram, Firas, et al.
(författare)
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DA-LSTM: A dynamic drift-adaptive learning framework for interval load forecasting with LSTM networks
- 2023
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Ingår i: Engineering applications of artificial intelligence. - : Elsevier. - 0952-1976 .- 1873-6769. ; 123
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Tidskriftsartikel (refereegranskat)abstract
- Load forecasting is a crucial topic in energy management systems (EMS) due to its vital role in optimizing energy scheduling and enabling more flexible and intelligent power grid systems. As a result, these systems allow power utility companies to respond promptly to demands in the electricity market. Deep learning (DL) models have been commonly employed in load forecasting problems supported by adaptation mechanisms to cope with the changing pattern of consumption by customers, known as concept drift. A drift magnitude threshold should be defined to design change detection methods to identify drifts. While the drift magnitude in load forecasting problems can vary significantly over time, existing literature often assumes a fixed drift magnitude threshold, which should be dynamically adjusted rather than fixed during system evolution. To address this gap, in this paper, we propose a dynamic drift-adaptive Long Short-Term Memory (DA-LSTM) framework that can improve the performance of load forecasting models without requiring a drift threshold setting. We integrate several strategies into the framework based on active and passive adaptation approaches. To evaluate DA-LSTM in real-life settings, we thoroughly analyze the proposed framework and deploy it in a real-world problem through a cloud-based environment. Efficiency is evaluated in terms of the prediction performance of each approach and computational cost. The experiments show performance improvements on multiple evaluation metrics achieved by our framework compared to baseline methods from the literature. Finally, we present a trade-off analysis between prediction performance and computational costs.
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| 18. |
- Bayram, Firas, et al.
(författare)
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DQSOps : Data Quality Scoring Operations Framework for Data-Driven Applications
- 2023
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Ingår i: EASE '23: Proceedings of the 27<sup>th</sup> International Conference on Evaluation and Assessment in Software Engineering. - : Association for Computing Machinery (ACM). - 9798400700446 ; , s. 32-41
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Konferensbidrag (refereegranskat)abstract
- Data quality assessment has become a prominent component in the successful execution of complex data-driven artificial intelligence (AI) software systems. In practice, real-world applications generate huge volumes of data at speeds. These data streams require analysis and preprocessing before being permanently stored or used in a learning task. Therefore, significant attention has been paid to the systematic management and construction of high-quality datasets. Nevertheless, managing voluminous and high-velocity data streams is usually performed manually (i.e. offline), making it an impractical strategy in production environments. To address this challenge, DataOps has emerged to achieve life-cycle automation of data processes using DevOps principles. However, determining the data quality based on a fitness scale constitutes a complex task within the framework of DataOps. This paper presents a novel Data Quality Scoring Operations (DQSOps) framework that yields a quality score for production data in DataOps workflows. The framework incorporates two scoring approaches, an ML prediction-based approach that predicts the data quality score and a standard-based approach that periodically produces the ground-truth scores based on assessing several data quality dimensions. We deploy the DQSOps framework in a real-world industrial use case. The results show that DQSOps achieves significant computational speedup rates compared to the conventional approach of data quality scoring while maintaining high prediction performance.
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| 19. |
- Bayram, Firas, et al.
(författare)
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From concept drift to model degradation : An overview on performance-aware drift detectors
- 2022
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Ingår i: Knowledge-Based Systems. - : Elsevier BV. - 0950-7051 .- 1872-7409. ; 245
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Forskningsöversikt (refereegranskat)abstract
- The dynamicity of real-world systems poses a significant challenge to deployed predictive machine learning (ML) models. Changes in the system on which the ML model has been trained may lead to performance degradation during the system’s life cycle. Recent advances that study non-stationary environments have mainly focused on identifying and addressing such changes caused by a phenomenon called concept drift. Different terms have been used in the literature to refer to the same type of concept drift and the same term for various types. This lack of unified terminology is set out to create confusion on distinguishing between different concept drift variants. In this paper, we start by grouping concept drift types by their mathematical definitions and survey the different terms used in the literature to build a consolidated taxonomy of the field. We also review and classify performance-based concept drift detection methods proposed in the last decade. These methods utilize the predictive model’s performance degradation to signal substantial changes in the systems. The classification is outlined in a hierarchical diagram to provide an orderly navigation between the methods. We present a comprehensive analysis of the main attributes and strategies for tracking and evaluating the model’s performance in the predictive system. The paper concludes by discussing open research challenges and possible research directions.
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| 20. |
- Bayram, Firas, 1992-
(författare)
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Towards Robust and Adaptive Machine Learning : A Fresh Perspective on Evaluation and Adaptation Methodologies in Non-Stationary Environments
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Machine learning (ML) has become ubiquitous in various disciplines and applications, serving as a powerful tool for developing predictive models to analyze diverse variables of interest. With the advent of the digital era, the proliferation of data has presented numerous opportunities for growth and expansion across various domains. However, along with these opportunities, there is a unique set of challenges that arises due to the dynamic and ever-changing nature of data. These challenges include concept drift, which refers to shifting data distributions over time, and other data-related issues that can be framed as learning problems. Traditional static models are inadequate in handling these issues, underscoring the need for novel approaches to enhance the performance robustness and reliability of ML models to effectively navigate the inherent non-stationarity in the online world. The field of concept drift is characterized by several intricate aspects that challenge learning algorithms, including the analysis of model performance, which requires evaluating and understanding how the ML model's predictive capability is affected by different problem settings. Additionally, determining the magnitude of drift necessary for change detection is an indispensable task, as it involves identifying substantial shifts in data distributions. Moreover, the integration of adaptive methodologies is essential for updating ML models in response to data dynamics, enabling them to maintain their effectiveness and reliability in evolving environments. In light of the significance and complexity of the topic, this dissertation offers a fresh perspective on the performance robustness and adaptivity of ML models in non-stationary environments. The main contributions of this research include exploring and organizing the literature, analyzing the performance of ML models in the presence of different types of drift, and proposing innovative methodologies for drift detection and adaptation that solve real-world problems. By addressing these challenges, this research paves the way for the development of more robust and adaptive ML solutions capable of thriving in dynamic and evolving data landscapes.
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| 21. |
- Bayram Özdemir, Sevgi, 1981-, et al.
(författare)
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Conceptualization and assessment of multiple forms of social withdrawal in Turkey
- 2015
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Ingår i: Social development (Oxford. Print). - : Wiley. - 0961-205X .- 1467-9507. ; 24:1, s. 142-165
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Tidskriftsartikel (refereegranskat)abstract
- We examined the meaning, assessment, and implications of different forms of social withdrawal in Turkey across two studies. In study 1, semi-structured interviews were conducted with children, mothers, and teachers to identify descriptors of social withdrawal. Shyness and unsociability were confirmed through content analyses, and regulated withdrawal, a new subtype characterized by overregulation of behaviors and suppression of own desires during social interactions, was revealed. Based on these findings, the child social preference scale, an established North American measure of social withdrawal, was revised. In study 2, a confirmatory factor analysis on a sample of 599 9–11-year-old children revealed three distinct forms of social withdrawal. Shyness was related to a wider range of child adjustment difficulties than unsociability and regulated withdrawal, although all forms of withdrawal were associated with child adjustment difficulties, providing support for the importance of children's active involvement in social relationships for their positive development and well-being.
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| 22. |
- Bayram Özdemir, Sevgi, 1981-, et al.
(författare)
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Mothers’ Reactions to Preschoolers’ Proactive and Reactive Aggressive Behaviors
- 2017
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Ingår i: Infant and Child Development. - : John Wiley & Sons. - 1522-7227 .- 1522-7219. ; 26:2
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Tidskriftsartikel (refereegranskat)abstract
- The present study was designed to examine mothers' emotional reactions, causal attributions, and socialization strategies in response to preschool children's engagement in proactive and reactive physical aggression with peers during free play at school. Participants were 84 mothers (Mage=31.83, SD=4.48) with preschool-aged children (Mage=4.92, SD=0. 97), residing in Ankara, Turkey. Supporting our expectations, mothers reacted with negative emotions to both functions of aggressive behaviours, with less anxiety, disappointment, embarrassment, and guilt for reactive aggression. They also believed that reactive aggression is more contextually dependent and intentional and reported more indirect (e.g., asking the child, teacher, or other children to find out more about the situation and aggressive episode) and other-oriented strategies (e.g., telling the other child to behave properly) to address these behaviours. Overall, our findings suggest that Turkish mothers' feelings, perceptions, and socialization approaches to childhood aggression vary depending on the functions of aggression, and mothers perceive preschool-aged children's engagement in reactive aggression in the school setting as relatively more acceptable than proactive aggression.
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| 23. |
- Bayram Özdemir, Sevgi, 1981-, et al.
(författare)
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Processes and conditions underlying the link between shyness and school adjustment among Turkish children
- 2017
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Ingår i: British Journal of Developmental Psychology. - Hoboken NJ, USA : John Wiley & Sons. - 0261-510X .- 2044-835X. ; 35:2, s. 218-236
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the underlying processes and conditions that contribute to the school adjustment of shy children in Turkey, where children's interpersonal relationships in social settings and academic achievement are highly emphasized. First, we examined the unique mediating roles of children's feelings of social anxiety, depressive symptoms, and loneliness in the associations between shyness and indices of school outcomes (academic achievement and school liking/avoidance). Second, we explored the moderating role of children's peer acceptance in these associations. Fourth- and fifth-grade children (N = 599; Mage = 10.11 years, SD = 0.65; 48% girls) provided information on shyness, social anxiety, depressive symptoms, loneliness, and school liking/avoidance. Head teachers in each classroom reported on students' academic performance. The peer nomination method was used to assess children's peer relationships. Results revealed that when children displayed shy behaviours, they reported more depressive symptoms that were, in turn, associated with poorer academic performance, less school liking, and higher school avoidance. Moreover, shyness negatively predicted school liking at low levels of peer acceptance, suggesting that difficulties in peer relationships increased shy children's risk of school dissatisfaction. Overall, our findings support the importance of the interpersonal relationship context for children's adjustment within the Turkish cultural context. Statement of contribution What is already known on this subject? Shy children have difficulties initiating and maintaining social interactions, which put them at risk for a wide range of socio-emotional difficulties. Shy children have poor academic performance and experience school adjustment difficulties in North America. What does this study add? Shyness is an important risk factor for poorer academic performance and adjustment among children in Turkey. The association between shyness and difficulties at school is explained by children's experience of depressive symptoms. Difficulties with peer relationships increase shy children's risk of school dissatisfaction.
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| 24. |
- Bayram Özdemir, Sevgi, 1981-, et al.
(författare)
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Turkish mothers’ parenting beliefs in response to preschoolers’ aggressive and socially withdrawn behaviors
- 2015
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Ingår i: Journal of Child and Family Studies. - : Springer Science and Business Media LLC. - 1062-1024 .- 1573-2843. ; 24:3, s. 687-702
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to examine Turkish mothers’ reactive parenting beliefs (reactive emotional appraisals, causal attributions, anticipated strategies, and underlying goals for their anticipated strategies) in response to children’s aggressive and socially withdrawn behaviors. Participants included 84 mothers with preschool-aged children residing in Ankara, Turkey. Supporting our expectations, the results showed that the degree of mothers’ negative emotional responses varied based on the child maladaptive behaviors. Moreover, mothers perceived aggressive behaviors as more temporary and contextually dependent, but intentional than withdrawn behaviors. More directive strategies and parent-centered goals were reported for aggression, whereas more indirect strategies and emphatic goals were reported for social withdrawal. Overall, the present study provided evidence that Turkish mothers’ perceptions and evaluations of maladaptive behaviors may have universal characteristics as well as aspects that are particular to the Turkish socio-cultural context.
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| 25. |
- Chahed, Hamza, et al.
(författare)
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AIDA—Aholistic AI-driven networking and processing framework for industrial IoT applications
- 2023
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Ingår i: Internet of Things. - : Elsevier. - 2542-6605. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- Industry 4.0 is characterized by digitalized production facilities, where a large volume of sensors collect a vast amount of data that is used to increase the sustainability of the production by e.g. optimizing process parameters, reducing machine downtime and material waste, and the like. However, making intelligent data-driven decisions under timeliness constraints requires the integration of time-sensitive networks with reliable data ingestion and processing infrastructure with plug-in support of Machine Learning (ML) pipelines. However, such integration is difficult due to the lack of frameworks that flexibly integrate and program the networking and computing infrastructures, while allowing ML pipelines to ingest the collected data and make trustworthy decisions in real time. In this paper, we present AIDA - a novel holistic AI-driven network and processing framework for reliable data-driven real-time industrial IoT applications. AIDA manages and configures Time-Sensitive networks (TSN) to enable real-time data ingestion into an observable AI-powered edge/cloud continuum. Pluggable and trustworthy ML components that make timely decisions for various industrial IoT applications and the infrastructure itself are an intrinsic part of AIDA. We introduce the AIDA architecture, demonstrate the building blocks of our framework and illustrate it with two use cases.
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| 26. |
- Cheah, Charissa S. L., et al.
(författare)
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Chinese Malaysian Adolescents’ Social Cognitive Reasoning regarding Filial Piety Dilemmas
- 2018
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Ingår i: Child Development. - : John Wiley & Sons. - 0009-3920 .- 1467-8624. ; 89:2, s. 383-396
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the social-cognitive reasoning of 52 Chinese Malaysian preadolescents (9-12 years old; M = 11.02, SD = 0.94) and 68 adolescents (13-18 years old; M = 14.76, SD = 1.39) in resolving filial dilemmas within the personal and moral domain. Preadolescents deferred to parental authority, whereas adolescents endorsed filial obligation reasoning to justify compliance in the personal domain. Both appealed to filial obligation, pragmatic, or welfare and safety reasoning to justify compliance but fairness or rights reasoning to justify their noncompliance, for the moral issue. Distinctions between authoritarian and reciprocal filial piety reasoning were revealed. Findings demonstrated complex decision-making and cognitive reasoning processes among Chinese Malaysian adolescents as they negotiate their filial obligations and autonomy development.
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| 27. |
- Cheah, Charissa S. L., et al.
(författare)
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Parenting hassles mediate predictors of Chinese and Korean immigrants' psychologically controlling parenting
- 2016
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Ingår i: Journal of applied developmental psychology. - : Elsevier. - 0193-3973 .- 1873-7900. ; 47, s. 13-22
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Tidskriftsartikel (refereegranskat)abstract
- We examined: (1) the mediating role of parenting daily hassles in the associations between three predictors (child temperament, maternal psychological well-being, and marital quality) and psychologically controlling practices in two Asian immigrant samples. We also explored the moderating role of maternal acculturation in the path from parenting daily hassles to psychological control. Participants were 152 Chinese and 165 Korean immigrant mothers with preschool children in the U.S. Multi-group path analysis revealed that easier child temperament, higher psychological well-being, and better marital quality were each associated with fewer parenting daily hassles, which in turn were associated with less psychological control. These general mediating effects held for both groups. However, the indirect effects of child temperament, maternal psychological well-being, and marital quality through parenting daily hassles were further moderated by acculturation for Chinese immigrant mothers, but not Korean immigrant mothers. The culturally similar and different findings across the two groups were discussed.
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| 28. |
- Cheah, Charissa S. L., et al.
(författare)
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Predicting filial behaviors of Chinese-Malaysian adolescents from perceived parental investments, filial emotions, and parental warmth and support
- 2012
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Ingår i: Journal of Adolescence. - : Wiley. - 0140-1971 .- 1095-9254. ; 35:3, s. 628-637
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Tidskriftsartikel (refereegranskat)abstract
- The present study examined the mediating role of perceived parental warmth and support in predicting Chinese Malaysian adolescents' filial behaviors from their age, perceived parental investments, and positive filial emotions toward their parents. The effects of these predictors were examined separately for mothers and fathers. Participants included 122 Chinese adolescents (. M = 13.14 years; . SD = 2.22) in Malaysia. Adolescents' perceived parental investments, filial emotions, and warmth and support from each parent were positively, and age was negatively associated with their filial behaviors. No gender differences were found. Perceived maternal warmth and support significantly mediated the effect of age, perceived investments from, and filial emotions toward mothers on adolescents' filial behaviors, but perceived paternal warmth and support did not have a mediating role. The present study sheds light on the unique maternal versus paternal filial role, and important familial processes in Chinese-Malaysian children and adolescents from a cultural perspective.
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| 29. |
- Cummings, Damian M, et al.
(författare)
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First effects of rising amyloid-β in transgenic mouse brain: synaptic transmission and gene expression.
- 2015
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 138:Pt 7, s. 1992-2004
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Tidskriftsartikel (refereegranskat)abstract
- Detecting and treating Alzheimer's disease, before cognitive deficits occur, has become the health challenge of our time. The earliest known event in Alzheimer's disease is rising amyloid-β. Previous studies have suggested that effects on synaptic transmission may precede plaque deposition. Here we report how relative levels of different soluble amyloid-β peptides in hippocampus, preceding plaque deposition, relate to synaptic and genomic changes. Immunoprecipitation-mass spectrometry was used to measure the early rise of different amyloid-β peptides in a mouse model of increasing amyloid-β ('TASTPM', transgenic for familial Alzheimer's disease genes APP/PSEN1). In the third postnatal week, several amyloid-β peptides were above the limit of detection, including amyloid-β40, amyloid-β38 and amyloid-β42 with an intensity ratio of 6:3:2, respectively. By 2 months amyloid-β levels had only increased by 50% and although the ratio of the different peptides remained constant, the first changes in synaptic currents, compared to wild-type mice could be detected with patch-clamp recordings. Between 2 and 4 months old, levels of amyloid-β40 rose by ∼7-fold, but amyloid-β42 rose by 25-fold, increasing the amyloid-β42:amyloid-β40 ratio to 1:1. Only at 4 months did plaque deposition become detectable and only in some mice; however, synaptic changes were evident in all hippocampal fields. These changes included increased glutamate release probability (P < 0.001, n = 7-9; consistent with the proposed physiological effect of amyloid-β) and loss of spontaneous action potential-mediated activity in the cornu ammonis 1 (CA1) and dentate gyrus regions of the hippocampus (P < 0.001, n = 7). Hence synaptic changes occur when the amyloid-β levels and amyloid-β42:amyloid-β40 ratio are still low compared to those necessary for plaque deposition. Genome-wide microarray analysis revealed changes in gene expression at 2-4 months including synaptic genes being strongly affected but often showing significant changes only by 4 months. We thus demonstrate that, in a mouse model of rising amyloid-β, the initial deposition of plaques does not occur until several months after the first amyloid-β becomes detectable but coincides with a rapid acceleration in the rise of amyloid-β levels and the amyloid-β42:amyloid-β40 ratio. Prior to acceleration, however, there is already a pronounced synaptic dysfunction, reflected as changes in synaptic transmission and altered gene expression, indicating that restoring synaptic function early in the disease progression may represent the earliest possible target for intervention in the onset of Alzheimer's disease.
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| 30. |
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| 31. |
- Ismailogullari, S., et al.
(författare)
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Impact of long-term gonadotropin replacement treatment on sleep in men with idiopathic hypogonadotropic hypogonadism
- 2011
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Ingår i: The journal of sexual medicine. - : Oxford University Press (OUP). - 1743-6109 .- 1743-6095. ; 8:7, s. 2090-7
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Concern has been expressed in recently published literature that gonadotropin replacement therapy (GnRT) in hypogonadism may alter sleep architecture and induce, or worsen, obstructive sleep apnea (OSA). AIM: To investigate the sleep stages and sleep-breathing parameters in young men with idiopathic hypogonadotropic hypogonadism (IHH)-a treatable form of male infertility and sexual dysfunction-before and 12 months following GnRT. METHODS: Sixteen male patients with IHH (mean age 27.5 +/- 10.5 years, range 17-48 years) and 16 individually age-matched healthy men were included in the study. Human chorionic gonadotropin (HCG) was administered 1,500 U intramuscularly three times/week for 6 months, and then 75 U twice/week, recombinant follicle stimulating hormone (FSH) was added to HCG for the following 6 months. Polysomnography (PSG) recordings were performed at baseline in all and following the GnRT in the patient group. MAIN OUTCOME MEASURES: Sleep stages and sleep-breathing parameters on PSG. RESULTS: Patients with IHH had a higher percentage of slow-wave-sleep (SWS) (22.3 +/- 6.3%) compared to that in the healthy controls (14.5 +/- 9.5%; P = 0.009). Four patients and one control subject had OSA (Apnea-Hypopnea Index [AHI] > 5(-h) ) at baseline (not significant). Following the GnRT in the patient group, there was a slight decrease in SWS (18.6 +/- 6.4%; P = 0.05) without any significant changes regarding the sleep-breathing parameters in the whole patient group. However, of the four patients with OSA at baseline, the GnRT was associated with worsening of the AHI in three of them. CONCLUSIONS: IHH in men is associated with a higher percentage of SWS. One-year GnRT slightly decreases SWS and does not induce OSA. However, in patients with OSA at baseline long-term GnRT should be exercised with caution.
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| 32. |
- Seo, You Jung, et al.
(författare)
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The Mediating Role of Korean Immigrant Mothers' Psychological Well-Being in the Associations between Social Support and Authoritarian Parenting Style
- 2018
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Ingår i: Journal of Child and Family Studies. - : Springer. - 1062-1024 .- 1573-2843. ; 27:3, s. 979-989
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Tidskriftsartikel (refereegranskat)abstract
- We examined the mediating role of Korean immigrant mothers' psychological well-being in the associations between mothers' emotional vs. instrumental support received from their kin, and their authoritarian parenting style with their preschoolers using longitudinal data. First-generation Korean immigrant mothers with preschool-aged children (N = 158; M (maternal age) = 36.11 years, SD = 3.90; M (child age) = 4.43 years, SD = 1.10) residing in Maryland, U.S., participated in three assessment waves. Each assessment wave was 6 months apart. Mothers reported on the amount of perceived emotional and instrumental support they received from their kin, their behavioral acculturation towards the American culture, and their family demographic information at Wave 1, their psychological well-being at Wave 2, and their authoritarian parenting style at Wave 3. The results revealed that higher levels of perceived instrumental support (but not emotional support) received from kin predicted higher levels of maternal psychological well-being 6 months later, which in turn predicted lower levels of reported authoritarian parenting style 6 months later. Our findings highlighted the importance of psychological well-being as a mechanism that explains how instrumental support can impact Korean immigrant mothers' parenting style, and the importance of distinguishing between types of support. Services providing instrumental support (e.g., childcare assistance) for first-generation immigrant mothers, particularly those with smaller or less effective kin networks, appear important to implement.
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| 33. |
- Shin, Ji Youn, et al.
(författare)
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The parenting practices and child outcomes of Korean immigrant mothers with different acculturative strategies
- 2010
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Ingår i: Korean Journal of Child Studies. - : Korean Association of Child Studies. - 1226-1688 .- 2234-408X. ; 31:1, s. 179-195
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Tidskriftsartikel (refereegranskat)abstract
- Downloadable article in English: http://ocean.kisti.re.kr/downfile/volume/kacs/ODHHBP/2010/v31n1/ODHHBP_2010_v31n1_179.pdf미국의한국계이민가정이해마다증가하고있으나부모의문화적응과자녀양육에관한연구는미흡한실정이다.본연구는미국동부지역의88명의한인이민어머니와(M=35.9세SD=3.77)2-6세유아를(M=4.29세SD=1.06;49.4%여아)대상으로실시되었다.어머니의문화적응유형에따라1)양육실제에어떠한차이가있는지,2)유아의사회ᆞ정서적행동에는어떠한차이가있는지,3)양육실제와아동의사회ᆞ정서적행동간에어떠한상관이있는지를살펴보았다.연구결과,한국과미국문화를균형지게통합한어머니들이미국문화에서고립되거나,두문화에서모두소외된어머니들보다자녀에게더욱긍정적인(애정표현,합리적문제해결,자율성격려)양육실제를사용하였으며자녀들또한정서적문제행동은적은반면친사회적행동은높은것으로나타났다
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