| 41551. |
- Kleyko, Denis, 1990-, et al.
(författare)
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Vector-Based Analysis of the Similarity Between Breathing and Heart Rate During Paced Deep Breathing
- 2018
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Ingår i: Computing in Cardiology 2018. - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- The heart rate (HR) response to paced deep breathing (DB) is a common test of autonomic function, where the scoring is based on indices reflecting the overall heart rate variability (HRV), where high scores are considered as normal findings but can also reflect arrhythmias. This study presents a method based on hyperdimensional computing for assessment of the similarity between feature vectors derived from the HR and breathing signals. The proposed method was used to identify subjects where HR did not follow the paced breathing pattern in recordings from DB tests in 174 healthy subjects and 135 patients with cardiac autonomic neuropathy. Subjects were classified in 4 similarity classes, where the lowest similiarity class included 35 patients and 3 controls. In general, the autonomic function cannot be evaluated in subjects in the lowest similarity class if they also present with high HRV scores, since this combination is a strong indicator of the presence of arrhythmias. Thus, the proposed vector-based similarity analysis is one tool to identify subjects with high HRV but low cardiorespiratory synchronization during the DB test, which falsely can be interpreted as normal autonomic function.
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| 41552. |
- Kleyko, Denis, et al.
(författare)
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Vehicle Classification using Road Side Sensors and Feature-free Data Smashing Approach
- 2016
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Ingår i: 2016 IEEE 19th International Conference on Intelligent Transportation Systems (ITSC). - Piscataway : IEEE. - 9781509018895 - 9781509018888 - 9781509018901 ; , s. 1988-1993
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Konferensbidrag (refereegranskat)abstract
- The main contribution of this paper is a study of the applicability of data smashing - a recently proposed data mining method - for vehicle classification according to the "Nordic system for intelligent classification of vehicles" standard, using measurements of road surface vibrations and magnetic field disturbances caused by passing vehicles. The main advantage of the studied classification approach is that it, in contrast to the most of traditional machine learning algorithms, does not require the extraction of features from raw signals. The proposed classification approach was evaluated on a large dataset consisting of signals from 3074 vehicles. Hence, a good estimate of the actual classification rate was obtained. The performance was compared to the previously reported results on the same problem for logistic regression. Our results show the potential trade-off between classification accuracy and classification method's development efforts could be achieved.
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| 41553. |
- Kliemann, Nathalie, et al.
(författare)
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Metabolic signatures of greater body size and their associations with risk of colorectal and endometrial cancers in the European Prospective Investigation into Cancer and Nutrition
- 2021
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Ingår i: BMC Medicine. - : BioMed Central. - 1741-7015. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The mechanisms underlying the obesity-cancer relationship are incompletely understood. This study aimed to characterise metabolic signatures of greater body size and to investigate their association with two obesity-related malignancies, endometrial and colorectal cancers, and with weight loss within the context of an intervention study.Methods: Targeted mass spectrometry metabolomics data from 4326 participants enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort and 17 individuals from a single-arm pilot weight loss intervention (Intercept) were used in this analysis. Metabolic signatures of body size were first determined in discovery (N = 3029) and replication (N = 1297) sets among EPIC participants by testing the associations between 129 metabolites and body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) using linear regression models followed by partial least squares analyses. Conditional logistic regression models assessed the associations between the metabolic signatures with endometrial (N = 635 cases and 648 controls) and colorectal (N = 423 cases and 423 controls) cancer risk using nested case-control studies in EPIC. Pearson correlation between changes in the metabolic signatures and weight loss was tested among Intercept participants.Results: After adjustment for multiple comparisons, greater BMI, WC, and WHR were associated with higher levels of valine, isoleucine, glutamate, PC aa C38:3, and PC aa C38:4 and with lower levels of asparagine, glutamine, glycine, serine, lysoPC C17:0, lysoPC C18:1, lysoPC C18:2, PC aa C42:0, PC ae C34:3, PC ae C40:5, and PC ae C42:5. The metabolic signature of BMI (OR1-sd 1.50, 95% CI 1.30–1.74), WC (OR1-sd 1.46, 95% CI 1.27–1.69), and WHR (OR1-sd 1.54, 95% CI 1.33–1.79) were each associated with endometrial cancer risk. Risk of colorectal cancer was positively associated with the metabolic signature of WHR (OR1-sd: 1.26, 95% CI 1.07–1.49). In the Intercept study, a positive correlation was observed between weight loss and changes in the metabolic signatures of BMI (r = 0.5, 95% CI 0.06–0.94, p = 0.03), WC (r = 0.5, 95% CI 0.05–0.94, p = 0.03), and WHR (r = 0.6, 95% CI 0.32–0.87, p = 0.01).Conclusions: Obesity is associated with a distinct metabolic signature comprising changes in levels of specific amino acids and lipids which is positively associated with both colorectal and endometrial cancer and is potentially reversible following weight loss.
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| 41554. |
- Kliemann, Nathalie, et al.
(författare)
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Metabolically Defined Body Size Phenotypes and Risk of Endometrial Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2022
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : NLM. - 1055-9965 .- 1538-7755. ; 31:7, s. 1359-1367
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity is a risk factor for endometrial cancer but whether metabolic dysfunction is associated with endometrial cancer independent of body size is not known.METHODS: The association of metabolically defined body size phenotypes with endometrial cancer risk was investigated in a nested case-control study (817 cases/ 817 controls) within the European Prospective Investigation into Cancer and Nutrition (EPIC). Concentrations of C-peptide were used to define metabolically healthy (MH; <1st tertile) and metabolically unhealthy (MU; ≥1st tertile) status among the control participants. These metabolic health definitions were combined with normal weight (NW); body mass index (BMI)<25 kg/m2 or waist circumference (WC)<80 cm or waist-to-hip ratio (WHR)<0.8) and overweight (OW; BMI≥25 kg/m2 or WC≥80 cm or WHR≥0.8) status, generating four phenotype groups for each anthropometric measure: (i) MH/NW, (ii) MH/OW, (iii) MU/NW, and (iv) MU/OW.RESULTS: In a multivariable-adjusted conditional logistic regression model, compared with MH/NW individuals, endometrial cancer risk was higher among those classified as MU/NW [ORWC, 1.48; 95% confidence interval (CI), 1.05-2.10 and ORWHR, 1.68; 95% CI, 1.21-2.35] and MU/OW (ORBMI, 2.38; 95% CI, 1.73-3.27; ORWC, 2.69; 95% CI, 1.92-3.77 and ORWHR, 1.83; 95% CI, 1.32-2.54). MH/OW individuals were also at increased endometrial cancer risk compared with MH/NW individuals (ORWC, 1.94; 95% CI, 1.24-3.04).CONCLUSIONS: Women with metabolic dysfunction appear to have higher risk of endometrial cancer regardless of their body size. However, OW status raises endometrial cancer risk even among women with lower insulin levels, suggesting that obesity-related pathways are relevant for the development of this cancer beyond insulin.IMPACT: Classifying women by metabolic health may be of greater utility in identifying those at higher risk for endometrial cancer than anthropometry per se.
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| 41555. |
- Kliemann, Nathalie, et al.
(författare)
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Predicted basal metabolic rate and cancer risk in the European Prospective Investigation into Cancer and Nutrition
- 2020
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 147:3, s. 648-661
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Tidskriftsartikel (refereegranskat)abstract
- Emerging evidence suggests that a metabolic profile associated with obesity may be a more relevant risk factor for some cancers than adiposity per se. Basal metabolic rate (BMR) is an indicator of overall body metabolism and may be a proxy for the impact of a specific metabolic profile on cancer risk. Therefore, we investigated the association of predicted BMR with incidence of 13 obesity-related cancers in the European Prospective Investigation into Cancer and Nutrition (EPIC). BMR at baseline was calculated using the WHO/FAO/UNU equations and the relationships between BMR and cancer risk were investigated using multivariable Cox proportional hazards regression models. A total of 141,295 men and 317,613 women, with a mean follow-up of 14 years were included in the analysis. Overall, higher BMR was associated with a greater risk for most cancers that have been linked with obesity. However, among normal weight participants, higher BMR was associated with elevated risks of esophageal adenocarcinoma (hazard ratio per 1-standard deviation change in BMR [HR1-SD]: 2.46; 95% CI 1.20; 5.03) and distal colon cancer (HR1-SD: 1.33; 95% CI 1.001; 1.77) among men and with proximal colon (HR1-SD: 1.16; 95% CI 1.01; 1.35), pancreatic (HR1-SD: 1.37; 95% CI 1.13; 1.66), thyroid (HR1-SD: 1.65; 95% CI 1.33; 2.05), postmenopausal breast (HR1-SD: 1.17; 95% CI 1.11; 1.22) and endometrial (HR1-SD: 1.20; 95% CI 1.03; 1.40) cancers in women. These results indicate that higher BMR may be an indicator of a metabolic phenotype associated with risk of certain cancer types, and may be a useful predictor of cancer risk independent of body fatness.
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| 41556. |
- Kliest, Tessa, et al.
(författare)
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Clinical trials in pediatric ALS: a TRICALS feasibility study
- 2022
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Ingår i: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : Taylor & Francis Group. - 2167-8421 .- 2167-9223. ; 23:7-8, s. 481-488
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pediatric investigation plans (PIPs) describe how adult drugs can be studied in children. In 2015, PIPs for Amyotrophic Lateral Sclerosis (ALS) became mandatory for European marketing-authorization of adult treatments, unless a waiver is granted by the European Medicines Agency (EMA).Objective: To assess the feasibility of clinical studies on the effect of therapy in children (<18 years) with ALS in Europe.Methods: The EMA database was searched for submitted PIPs in ALS. A questionnaire was sent to 58 European ALS centers to collect the prevalence of pediatric ALS during the past ten years, the recruitment potential for future pediatric trials, and opinions of ALS experts concerning a waiver for ALS.Results: Four PIPs were identified; two were waived and two are planned for the future. In total, 49 (84.5%) centers responded to the questionnaire. The diagnosis of 44,858 patients with ALS was reported by 46 sites; 39 of the patients had an onset < 18 years (prevalence of 0.008 cases per 100,000 or 0.087% of all diagnosed patients). The estimated recruitment potential (47 sites) was 26 pediatric patients within five years. A majority of ALS experts (75.5%) recommend a waiver should apply for ALS due to the low prevalence of pediatric ALS.Conclusions: ALS with an onset before 18 years is extremely rare and may be a distinct entity from adult ALS. Conducting studies on the effect of disease-modifying therapy in pediatric ALS may involve lengthy recruitment periods, high costs, ethical/legal implications, challenges in trial design and limited information.
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| 41557. |
- Klievtsova, Nataliia, et al.
(författare)
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Conversational process modelling : state of the art, applications, and implications in practice
- 2023
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Ingår i: Business Process Management Forum. - : Springer Nature. - 9783031416224 - 9783031416231 ; , s. 319-336
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Konferensbidrag (refereegranskat)abstract
- Chatbots such as ChatGPT have caused tremendous hype lately. For BPM applications, it is often not clear how to apply chatbots to generate business value. Hence, this work aims at the systematic analysis of existing chatbots for their support of conversational process modelling as a process-oriented capability. Application scenarios are identified along the process life cycle. Then a systematic literature review on conversational process modelling is performed. The resulting taxonomy serves as input for the identification of application scenarios for conversational process modelling, including paraphrasing and improvement of process descriptions. The application scenarios are evaluated for existing chatbots based on a real-world test set from the higher education domain. It contains process descriptions as well as corresponding process models, together with an assessment of the model quality. Based on the literature and application scenario analyses, recommendations for the usage (practical implications) and further development (research directions) of conversational process modelling are derived.
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| 41558. |
- Klimmek, Frank, et al.
(författare)
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Abundantly and rarely expressed Lhc protein genes exhibit distinct regulation patterns in plants.
- 2006
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Ingår i: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 140:3, s. 793-804
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed gene regulation of the Lhc supergene family in poplar (Populus spp.) and Arabidopsis (Arabidopsis thaliana) using digital expression profiling. Multivariate analysis of the tissue-specific, environmental, and developmental Lhc expression patterns in Arabidopsis and poplar was employed to characterize four rarely expressed Lhc genes, Lhca5, Lhca6, Lhcb7, and Lhcb4.3. Those genes have high expression levels under different conditions and in different tissues than the abundantly expressed Lhca1 to 4 and Lhcb1 to 6 genes that code for the 10 major types of higher plant light-harvesting proteins. However, in some of the datasets analyzed, the Lhcb4 and Lhcb6 genes as well as an Arabidopsis gene not present in poplar (Lhcb2.3) exhibited minor differences to the main cooperative Lhc gene expression pattern. The pattern of the rarely expressed Lhc genes was always found to be more similar to that of PsbS and the various light-harvesting-like genes, which might indicate distinct physiological functions for the rarely and abundantly expressed Lhc proteins. The previously undetected Lhcb7 gene encodes a novel plant Lhcb-type protein that possibly contains an additional, fourth, transmembrane N-terminal helix with a highly conserved motif. As the Lhcb4.3 gene seems to be present only in Eurosid species and as its regulation pattern varies significantly from that of Lhcb4.1 and Lhcb4.2, we conclude it to encode a distinct Lhc protein type, Lhcb8.
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| 41559. |
- Klimmek, Frank, et al.
(författare)
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Structure of the higher plant light harvesting complex I : in vivo characterization and structural interdependence of the Lhca proteins.
- 2005
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Ingår i: Biochemistry. - 0006-2960. ; 44:8, s. 3065-73
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the structure of the higher plant light harvesting complex of photosystem I (LHCI) by analyzing PSI-LHCI particles isolated from a set of Arabidopsis plant lines, each lacking a specific Lhca (Lhca1-4) polypeptide. Functional antenna size measurements support the recent finding that there are four Lhca proteins per PSI in the crystal structure [Ben-Shem, A., Frolow, F., and Nelson, N. (2003) Nature 426, 630-635]. According to HPLC analyses the number of pigment molecules bound within the LHCI is higher than expected from reconstitution studies or analyses of isolated native LHCI. Comparison of the spectra of the particles from the different lines reveals chlorophyll absorption bands peaking at 696, 688, 665, and 655 nm that are not present in isolated PSI or LHCI. These bands presumably originate from "gap" or "linker" pigments that are cooperatively coordinated by the Lhca and/or PSI proteins, which we have tentatively localized in the PSI-LHCI complex.
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| 41560. |
- Kling, Anders, 1965-
(författare)
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5-HT2A : a serotonin receptor with a possible role in joint diseases
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundSerotonin (5-HT), an amino acid derivative and neurotransmitter, has for long been studied in relation to inflammation. It is an endogenous ligand for several different types of serotonin receptors. The serotonin receptor 5-HT2A has been reported to have a role in the pathophysiology of arthritis in animal experiment models. However, no studies into this subject have been reported in man.ObjectiveThe objectives of this project were firstly, to examine possible associations for the 5-HT2A receptor and also for the gene (HTR2A) encoding for the receptor with arthritis in man and secondly, to explore possible mechanisms underlying such associations.MethodsThe density and affinity of platelet 5-HT2A receptors were determined in 43 patients with a common inflammatory joint disease, i. e., rheumatoid arthritis (RA), in comparison with matched controls using a radio-ligand assay. The effects of treatment with prednisolone on 5-HT2A density and affinity were also examined in 27 individuals diagnosed with polymyalgia rheumatica before and after start of treatment. In addition, possible candidate HTR2A genes were studied in relation to RA in two Swedish cohorts incorporating a total of 2450 RA patients. Furthermore, a register study using reports of joint symptoms as adverse drug reactions (ADRs) in the Swedish and the WHO ADR databases was undertaken. The proportion of reports concerning joint symptoms in relation to all ADR reports and to sales figures was analysed for 5-HT2A blocking atypical antidepressant substances compared with another group of antidepressants, i. e., selective serotonin re-uptake inhibitors (SSRIs), used for similar clinical indications.ResultsThe mean density of 5-HT2A receptors in RA patients was significantly lower than in controls, 45.3 versus 57.4 fmol/mg protein (p = 0.004). There was no significant difference in affinity. Variation of four single nucleotide polymorphisms (SNPs) (rs6314, rs1328674, rs6313 and rs6311) in the HTR2A gene was associated with RA, although not significantly so for all SNPs after testing for multiple comparisons. The proportion of joint symptoms reported as ADRs, relative to all ADRs was significantly higher for the 5-HT2A blocking antidepressants compared with the SSRIs in both databases (p< 0.001). In the Swedish material the comparison of ADRs was also related to sales figures, showing a considerable higher frequency of joint symptoms for the 5-HT2A antagonists (p< 0.001). The density of 5-HT2A receptors increased after treatment with prednisolone in 23 out of 27 individuals. The mean density at baseline was 45.2 versus 64.9 fmol/mg protein at the end of the study (p=0.001). There were no significant differences in affinity during the treatment period, although a low affinity at baseline was a predictor for higher density following treatment with prednisolone.ConclusionsThe density of 5-HT2A receptors, reflecting the number of receptors, was markedly reduced in a cohort of patients with RA from Northern Sweden. This may depend, at least in part, on an association between RA and certain HTR2A SNPs. Genetically determined or acquired low levels of accessible 5-HT2A receptors may contribute to susceptibility for development of joint symptoms, not only in RA but more generally, e. g., joint ADRs caused by 5-HT2A blocking atypical antidepressants. The benefits of treatment with glucocorticoids may, at least partially, be mediated by an effect on 5-HT2A receptors.
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