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| 4. |
- Hartman, E. A. R., et al.
(author)
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Multifaceted antibiotic stewardship intervention using a participatory-action-research approach to improve antibiotic prescribing for urinary tract infections in frail elderly (ImpresU): study protocol for a European qualitative study followed by a pragmatic cluster randomised controlled trial
- 2021
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In: Bmj Open. - : BMJ. - 2044-6055. ; 11:10
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Journal article (peer-reviewed)abstract
- Introduction Almost 60% of antibiotics in frail elderly are prescribed for alleged urinary tract infections (UTIs). A substantial part of this comprises prescriptions in case of non-specific symptoms or asymptomatic bacteriuria, for which the latest guidelines promote restrictiveness with antibiotics. We aim to reduce inappropriate antibiotic use for UTIs through an antibiotic stewardship intervention (ASI) that encourages to prescribe according to these guidelines. To develop an effective ASI, we first need a better understanding of the complex decision-making process concerning suspected UTIs in frail elderly. Moreover, the implementation approach requires tailoring to the heterogeneous elderly care setting. Methods and analysis First, we conduct a qualitative study to explore factors contributing to antibiotic prescribing for UTIs in frail elderly, using semi-structured interviews with general practitioners, nursing staff, patients and informal caregivers. Next, we perform a pragmatic cluster randomised controlled trial in elderly care organisations. A multifaceted ASI is implemented in the intervention group; the control group receives care as usual. The ASI is centred around a decision tool that promotes restrictive antibiotic use, supported by a toolbox with educational materials. For the implementation, we use a modified participatory-action-research approach, guided by the results of the qualitative study. The primary outcome is the number of antibiotic prescriptions for suspected UTIs. We aim to recruit 34 clusters with in total 680 frail elderly residents >= 70 years. Data collection takes place during a 5-month baseline period and a 7-month follow-up period. Finally, we perform a process evaluation. The study has been delayed for 6 months due to COVID-19 and is expected to end in July 2021. Ethics and dissemination Ethical approvals and/or waivers were obtained from the ethical committees in Poland, the Netherlands, Norway and Sweden. The results will be disseminated through publication in peer-reviewed journals and conference presentations.
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| 5. |
- Fantini, R, et al.
(author)
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EU FP7 INFSO-ICT-317669 METIS, D3.2 First performance results for multi-node/multi-antenna transmission technologies
- 2014
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Reports (other academic/artistic)abstract
- This deliverable describes the current results of the multi-node/multi-antenna technologies investigated within METIS and analyses the interactions within and outside Work Package 3. Furthermore, it identifies the most promising technologies based on the current state of obtained results. This document provides a brief overview of the results in its first part. The second part, namely the Appendix, further details the results, describes the simulation alignment efforts conducted in the Work Package and the interaction of the Test Cases. The results described here show that the investigations conducted in Work Package 3 are maturing resulting in valuable innovative solutions for future 5G systems.
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| 6. |
- Hartman, E. A. R., et al.
(author)
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Decisions on antibiotic prescribing for suspected urinary tract infections in frail older adults: a qualitative study in four European countries
- 2022
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In: Age and ageing. - : Oxford University Press (OUP). - 0002-0729 .- 1468-2834. ; 51:6
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Journal article (peer-reviewed)abstract
- Background a suspected urinary tract infection (UTI) is the most common reason to prescribe antibiotics in a frail older patient. Frequently, antibiotics are prescribed unnecessarily. To increase appropriate antibiotic use for UTIs through antibiotic stewardship interventions, we need to thoroughly understand the factors that contribute to these prescribing decisions. Objectives (1) to obtain insight into factors contributing to antibiotic prescribing for suspected UTIs in frail older adults. (2) To develop an overarching model integrating these factors to guide the development of antibiotic stewardship interventions for UTIs in frail older adults. Methods we conducted an exploratory qualitative study with 61 semi-structured interviews in older adult care settings in Poland, the Netherlands, Norway and Sweden. We interviewed physicians, nursing staff, patients and informal caregivers. Results participants described a chain of decisions by patients, caregivers and/or nursing staff preceding the ultimate decision to prescribe antibiotics by the physician. We identified five themes of influence: (1) the clinical situation and its complexity within the frail older patient, (2) diagnostic factors, such as asymptomatic bacteriuria, (3) knowledge (gaps) and attitude, (4) communication: interprofessional, and with patients and relatives and (5) context and organisation of care, including factors such as availability of antibiotics (over the counter), antibiotic stewardship efforts and factors concerning out-of-hours care. Conclusions decision-making on suspected UTIs in frail older adults is a complex, multifactorial process. Due to the diverse international setting and stakeholder variety, we were able to provide a comprehensive overview of factors to guide the development of antibiotic stewardship interventions.
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| 7. |
- Carvalho, E. de, et al.
(author)
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EU FP7 INFSO-ICT-317669 METIS, D3.1 Positioning of multi-node/multi-antenna technologies
- 2013
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Reports (other academic/artistic)abstract
- This document describes the research activity in multi-node/multi-antenna technologies within METIS and positions it with respect to the state-of-the-art in the academic literature and in the standardization bodies. Based on the state-of-the-art and as well as on the METIS objectives,we set the research objectives and we group the different activities (or technology components) into research clusters with similar research objectives. The technologycomponents and the research objectives have been set to achieve an ambidextrous purpose. On one side we aim at providing the METIS system with those technological components that are a natural but non-trivial evolution of 4G. On the other side, we aim at seeking for disruptivetechnologies that could radically change 5G with respect to 4G. Moreover, we mapped the different technology components to METIS’ other activities and to the overall goals of theproject.
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| 8. |
- Bugaeva, Elizaveta Y, et al.
(author)
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Structural features of the tmRNA-ribosome interaction
- 2009
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In: RNA. - : RNA Society. - 1355-8382 .- 1469-9001. ; 15:12, s. 2312-2320
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Journal article (peer-reviewed)abstract
- Trans-translation is a process which switches the synthesis of a polypeptide chain encoded by a nonstop messenger RNA to the mRNA-like domain of a transfer-messenger RNA (tmRNA). It is used in bacterial cells for rescuing the ribosomes arrested during translation of damaged mRNA and directing this mRNA and the product polypeptide for degradation. The molecular basis of this process is not well understood. Earlier, we developed an approach that allowed isolation of tmRNA-ribosomal complexes arrested at a desired step of tmRNA passage through the ribosome. We have here exploited it to examine the tmRNA structure using chemical probing and cryo-electron microscopy tomography. Computer modeling has been used to develop a model for spatial organization of the tmRNA inside the ribosome at different stages of trans-translation.
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| 9. |
- Coulthard, Sally A, et al.
(author)
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Increased Sensitivity to Thiopurines in Methylthioadenosine Phosphorylase-Deleted Cancers
- 2011
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In: MOLECULAR CANCER THERAPEUTICS. - : AMER ASSOC CANCER RESEARCH, 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA. - 1535-7163. ; 10:3, s. 495-504
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Journal article (peer-reviewed)abstract
- The thiopurines, 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG), are used in the treatment of leukemia. Incorporation of deoxythioguanosine nucleotides (dG(s)) into the DNA of thiopurine-treated cells causes cell death, but there is also evidence that thiopurine metabolites, particularly the 6-MP metabolite methylthioinosine monophosphate (MeTIMP), inhibit de novo purine synthesis (DNPS). The toxicity of DNPS inhibitors is influenced by methylthioadenosine phosphorylase (MTAP), a gene frequently deleted in cancers. Because the growth of MTAP-deleted tumor cells is dependent on DNPS or hypoxanthine salvage, we would predict such cells to show differential sensitivity to 6-MP and 6-TG. To test this hypothesis, sensitivity to 6-MP and 6-TG was compared in relation to MTAP status using cytotoxicity assays in two MTAP-deficient cell lines transfected to express MTAP: the T-cell acute lymphoblastic leukemic cell line, Jurkat, transfected with MTAP cDNA under the control of a tetracycline-inducible promoter, and a lung cancer cell line (A549-MTAP(-)) transfected to express MTAP constitutively (A549-MTAP(+)). Sensitivity to 6-MP or methyl mercaptopurine riboside, which is converted intracellularly to MeTIMP, was markedly higher in both cell lines under MTAP(-) conditions. Measurement of thiopurine metabolites support the hypothesis that DNPS inhibition is a major cause of cell death with 6-MP, whereas dG(s) incorporation is the main cause of cytotoxicity with 6-TG. These data suggest that thiopurines, particularly 6-MP, may be more effective in patients with deleted MTAP.
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| 10. |
- Hoste, M. E., et al.
(author)
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The experiences of patients ill with COVID-19-like symptoms and the role of testing for SARS-CoV-2 in supporting them: A qualitative study in eight European countries during the first wave of the pandemic
- 2023
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In: European Journal of General Practice. - 1381-4788. ; 29:2
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Journal article (peer-reviewed)abstract
- BackgroundAccess to testing during the first wave of the COVID-19 pandemic was limited, impacting patients with COVID-19-like symptoms. Current qualitative studies have been limited to one country or were conducted outside Europe.ObjectivesTo explore - in eight European countries - the experiences of patients consulting in primary care with COVID-19-like symptoms during the first wave of the pandemic.MethodsSixty-six semi-structured interviews, informed by a topic guide, were conducted by telephone or in person between April and July 2020. Patients with COVID-19-like symptoms were purposively recruited in primary care sites in eight countries and sampled based on age, gender, and symptom presentation. Deductive and inductive thematic analysis techniques were used to develop a framework representing data across settings. Data adequacy was attained by collecting rich data.ResultsSeven themes were identified, which described the experiences of patients consulting. Two themes are reported in this manuscript describing the role of COVID-19 testing in this experience. Patients described significant distress due to their symptoms, especially those at higher risk of complications from COVID-19, and those with severe symptoms. Patients wanted access to testing to identify the cause of their illness and minimise the burden of managing uncertainty. Some patients testing positive for COVID-19 assumed they would be immune from future infection.ConclusionPatients experiencing novel and severe symptoms, particularly those with comorbidities, experienced a significant emotional and psychological burden due to concerns about COVID-19. Testing provided reassurance over health status and helped patients identify which guidance to follow. Testing positive for SARS-CoV-2 led to some patients thinking they were immune from future infection, thus influencing subsequent behaviour.
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| 11. |
- Lin, Audrey T., et al.
(author)
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The history of Coast Salish "woolly dogs" revealed by ancient genomics and Indigenous Knowledge
- 2023
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In: Science. - 0036-8075 .- 1095-9203. ; 382:6676, s. 1303-1308
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Journal article (peer-reviewed)abstract
- Ancestral Coast Salish societies in the Pacific Northwest kept long-haired woolly dogs that were bred and cared for over millennia. However, the dog wool-weaving tradition declined during the 19th century, and the population was lost. In this study, we analyzed genomic and isotopic data from a preserved woolly dog pelt from "Mutton", collected in 1859. Mutton is the only known example of an Indigenous North American dog with dominant precolonial ancestry postdating the onset of settler colonialism. We identified candidate genetic variants potentially linked with their distinct woolly phenotype. We integrated these data with interviews from Coast Salish Elders, Knowledge Keepers, and weavers about shared traditional knowledge and memories surrounding woolly dogs, their importance within Coast Salish societies, and how colonial policies led directly to their disappearance.
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| 12. |
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| 13. |
- Maguire, P., et al.
(author)
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Estrogen receptor beta (ESR2) polymorphisms in familial and sporadic breast cancer
- 2005
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In: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 0167-6806 .- 1573-7217. ; 94:2, s. 145-152
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Journal article (peer-reviewed)abstract
- Estrogen is involved in both normal mammary development and in breast carcinogenesis. A family history of disease and exposure to estrogen are major risk factors for developing breast cancer. Estrogen exerts its biological effects through binding to the estrogen receptors, estrogen receptor alpha (ESR1) and the more recently discovered estrogen receptor beta (ESR2). Genetic variation in genes involved in estrogen biosynthesis, metabolism and signal transduction have been suggested to play a role in breast cancer risk. We therefore tested the hypothesis that common genetic variants of the ESR2 gene may be associated with increased risk for breast cancer and this risk may vary between breast cancer groups. We investigated three common ESR2 polymorphisms, rs1256049 (G1082A), rs4986938 (G1730A) and rs928554 (Cx+56 A?G) for association to breast cancer risk. A total of 723 breast cancer cases and 480 controls were included in the study. Of the breast cancer cases, 323 were sporadic and 400 were familial, the familial cases were further divided into familial high-risk and familial low-risk breast cancer cases. We found no overall statistically significant association for any of the single polymorphisms studied. Haplotype analysis suggested one haplotype associated with increased risk in sporadic breast cancer patients (OR = 3.0, p = 0.03). Further analysis is needed to elucidate the role of estrogen receptor beta in breast cancer susceptibility. © Springer 2005.
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| 14. |
- Sinding, Mikkel-Holger S., et al.
(author)
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Arctic-adapted dogs emerged at the Pleistocene-Holocene transition
- 2020
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 368:6498
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Journal article (peer-reviewed)abstract
- Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an similar to 9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an similar to 33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog-specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.
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| 15. |
- Wanat, M., et al.
(author)
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Patients’ and clinicians’ perspectives on the primary care consultations for acute respiratory infections during the first wave of the COVID-19 pandemic: an eight-country qualitative study in Europe
- 2022
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In: BJGP Open. - 2398-3795. ; 6:2
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Journal article (peer-reviewed)abstract
- Background: The impact of the COVID-19 pandemic on patients’ and clinicians’ perceptions of healthcare-seeking behaviour and delivery of care is unclear. The pandemic accelerated the use of remote care, and understanding its benefits and drawbacks may inform its implementation during current and future healthcare emergencies. Aim: To explore patients’ and primary care professionals’ (PCPs) experiences of primary care delivery in the first wave of the pandemic. Design & setting: Qualitative study using semi-structured interviews in primary care in eight European countries (England, Ireland, Belgium, the Netherlands, Greece, Poland, Sweden, and Germany). Method: A total of 146 interviews were conducted with 80 PCPs and 66 patients consulting for respiratory tract infection (RTI) symptoms, in eight European countries. Data were collected between April and July 2020, and analysed using thematic analysis. Results: It was found that patients accepted telemedicine when PCPs spent time to understand and address their concerns, but a minority preferred in-person consultations. PCPs felt that remote consultations created emotional distance between themselves and patients, and they reported having to manage diverse COVID-19-related medical and social concerns. Conclusion: Remote consultations for RTI symptoms may be acceptable long term if both groups are happy to use this format, but it is important that PCPs take time to address patients’ concerns and provide safety-netting advice.
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| 16. |
- Wanat, M., et al.
(author)
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Supporting Primary Care Professionals to Stay in Work During the COVID-19 Pandemic: Views on Personal Risk and Access to Testing During the First Wave of Pandemic in Europe
- 2021
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In: Frontiers in Medicine. - : Frontiers Media SA. - 2296-858X. ; 8
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Journal article (peer-reviewed)abstract
- Background: Minimising primary care professionals' (PCPs) risk of SARS-CoV-2 infection is crucial to ensure their safety as well as functioning health care system. PCPs' perspectives on the support they needed in the early stages of a public health crisis can inform future preparedness. Aim: To understand PCPs' experiences of providing care during the COVID-19 pandemic, with focus on personal risk from COVID-19 and testing. Design and Setting: Qualitative study using semi-structured interviews with PCPs in England, Belgium, the Netherlands, Ireland, Germany, Poland, Greece and Sweden, between April and July 2020. Method: Interviews were analysed using a combination of inductive and deductive thematic analysis techniques. Results: Eighty interviews were conducted, showing that PCPs tried to make sense of their risk of both contracting and severity of COVID-19 by assessing individual risk factors and perceived effectiveness of Personal Protective Equipment (PPE). They had limited access to PPE yet continued providing care as their "duty." Some PCPs felt that they were put in high-risk situations when patients or colleagues were not flagging symptoms of COVID-19. Not having access to testing in the initial stages of the pandemic was somewhat accepted but when available, was valued. Conclusion: Access to adequate PPE and testing, as well as training for staff and education for patients about the importance of ensuring staff safety is crucial. Given PCPs' varied response in how they appraised personal risk and their tolerance for working, PCPs may benefit from the autonomy in deciding how they want to work during health emergencies.
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| 17. |
- Wanat, M., et al.
(author)
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Transformation of primary care during the COVID-19 pandemic: experiences of healthcare professionals in eight European countries
- 2021
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In: British Journal of General Practice. - : Royal College of General Practitioners. - 0960-1643 .- 1478-5242. ; 71:709
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Journal article (peer-reviewed)abstract
- Background I'm Tian/care has a crucial role in responding to the COVID-19 pandemic as the first point of patient care and gatekeeper to secondary care. Qualitative studies exploring the experiences of healthcare professionals during the COVID-19 pandemic have mainly focused on secondary care. Aim To gain an understanding of the experiences of European primary care professionals (PCPs) working during the first peak of the COVID-19 pandemic. Design and setting An exploratory qualitative study, using semi structured interviews in primary care in England, Belgium, the Netherlands. Ireland. Germany, Poland, Greece, and Sweden, between April and July 7020. Method Interviews were audiorecorded, transcribed, and analysed using a combination of inductive and deductive thematic analysis techniques. Results Fighty interviews were conducted with PCPs. PCPs had to make their own decisions on how to rapidly transform services in relation to COVID-19 and non-COVID-19 care. Despite being overwhelmed with guidance. they often lacked access to practical training. Consequently. PCPs turned to their colleagues for moral support and information to try to quickly adjust to new ways of working, including remote care. arid to deal with uncertainty. Conclusion PCPs rapidly transformed primary care delivery despite a number of challenges. Representation of primary care at policy level and engagement with local primary care champions are needed to facilitate easy and coordinated access to practical information on how to adapt services, ongoing training, and access to appropriate mental health support services for PCPs. Preservation of autonomy and responsiveness of primary care are critical to preserve the ability for rapid transformation in any future crisis of care delivery.
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| 18. |
- Bergström, Anders, et al.
(author)
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Grey wolf genomic history reveals a dual ancestry of dogs
- 2022
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 607:7918, s. 313-320
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Journal article (peer-reviewed)abstract
- The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.
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| 19. |
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| 20. |
- Floor, P. A., et al.
(author)
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Transmitting multiple correlated gaussian sources over a Gaussian MAC using delay-free mappings
- 2011
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In: ISABEL '11 Proceedings of the 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies. - New York, NY, USA : ACM. - 9781450309134
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Conference paper (peer-reviewed)abstract
- In this paper, we study the problem of communicating multiple correlated Gaussian memoryless sources over a Gaussian Multiple Access Channel (GMAC). We focus on distributed delay-free, low complexity, joint source-channel coding (JSCC) solutions to the problem. Theoretical performance bounds are derived and linear and nonlinear JSCC schemes are evaluated. The main contribution is a nonlinear hybrid discrete-analog mapping based on distributed quantization and a linear continuous mapping named Distributed Quantizer Linear Coder (DQLC). The proposed scheme shows promising performance which improve with increasing correlation and is robust against variations in noise level.
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| 21. |
- Gabry, Frédéric, et al.
(author)
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Energy Efficiency Analysis of Cooperative Jamming in Cognitive Radio Networks with Secrecy Constraints
- 2015
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In: IEEE Wireless Communications Letters. - 2162-2337 .- 2162-2345. ; 4:4, s. 437-440
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Journal article (peer-reviewed)abstract
- We investigate energy-efficient cooperation for secrecy in cognitive radio networks. In particular, we consider a four-node cognitive scenario where the secondary receiver is treated as a potential eavesdropper with respect to the primary transmission. The cognitive transmitter should ensure that the primary message is not leaked to the secondary user by using cooperative jamming. We investigate the optimal power allocation and power splitting at the secondary transmitter for our cognitive model to maximize the secondary energy efficiency (EE) under secrecy constraints. We formulate and analyze an important EE Stackelberg game between the two transmitters aiming at maximizing their utilities. We illustrate the analytical results through our geometrical model, highlighting the EE performance of the system and the impact of the Stackelberg game.
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| 22. |
- Hallen, Thomas, et al.
(author)
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Genome-Wide DNA Methylation Differences in Nonfunctioning Pituitary Adenomas With and Without Postsurgical Progression
- 2022
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In: Journal of Clinical Endocrinology & Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 107:8, s. 2318-2328
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Journal article (peer-reviewed)abstract
- Context Tumor progression in surgically treated patients with nonfunctioning pituitary adenomas (NFPAs) is associated with excess mortality. Reliable biomarkers allowing early identification of tumor progression are missing. Objective To explore DNA methylation patterns associated with tumor progression in NFPA patients. Methods This case-controlled exploratory trial at a university hospital studied patients who underwent surgery for NFPA that had immunohistochemical characteristics of a gonadotropinoma. Cases included patients requiring reintervention due to tumor progression (reintervention group, n = 26) and controls who had a postoperative residual tumor without tumor progression for at least 5 years (radiologically stable group, n = 17). Genome-wide methylation data from each tumor sample were analyzed using the Infinium MethylationEPIC BeadChip platform. Results The analysis showed that 605 CpG positions were significantly differently methylated (differently methylated positions, DMPs) between the patient groups (false discovery rate adjusted P value < 0.05, beta value > 0.2), mapping to 389 genes. The largest number of DMPs were detected in the genes NUP93 and LGALS1. The 3 hypomethylated DMPs and the 3 hypermethylated DMPs with the lowest P values were all significantly (P < 0.05) and individually associated with reintervention-free survival. One of the hypermethylated DMPs with the lowest P value was located in the gene GABRA1. Conclusion In this exploratory study, DNA methylation patterns in NFPA patients were associated with postoperative tumor progression requiring reintervention. The DMPs included genes that have been previously associated with tumor development. Our study is a step toward finding epigenetic signatures to predict tumor progression in patients with NFPA.
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| 23. |
- Hober, Sophia, Professor, 1965-, et al.
(author)
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Systematic evaluation of SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay
- 2021
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In: Clinical & Translational Immunology. - : Wiley. - 2050-0068. ; 10:7
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Journal article (peer-reviewed)abstract
- Objective. The COVID-19 pandemic poses an immense need for accurate, sensitive and high-throughput clinical tests, and serological assays are needed for both overarching epidemiological studies and evaluating vaccines. Here, we present the development and validation of a high-throughput multiplex bead-based serological assay. Methods. More than 100 representations of SARS-CoV-2 proteins were included for initial evaluation, including antigens produced in bacterial and mammalian hosts as well as synthetic peptides. The five best-performing antigens, three representing the spike glycoprotein and two representing the nucleocapsid protein, were further evaluated for detection of IgG antibodies in samples from 331 COVID-19 patients and convalescents, and in 2090 negative controls sampled before 2020. Results. Three antigens were finally selected, represented by a soluble trimeric form and the S1-domain of the spike glycoprotein as well as by the C-terminal domain of the nucleocapsid. The sensitivity for these three antigens individually was found to be 99.7%, 99.1% and 99.7%, and the specificity was found to be 98.1%, 98.7% and 95.7%. The best assay performance was although achieved when utilising two antigens in combination, enabling a sensitivity of up to 99.7% combined with a specificity of 100%. Requiring any two of the three antigens resulted in a sensitivity of 99.7% and a specificity of 99.4%. Conclusion. These observations demonstrate that a serological test based on a combination of several SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.
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| 24. |
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| 25. |
- Raghavan, Maanasa, et al.
(author)
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The genetic prehistory of the New World Arctic
- 2014
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 345:6200, s. 1020-
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Journal article (peer-reviewed)abstract
- The New World Arctic, the last region of the Americas to be populated by humans, has a relatively well-researched archaeology, but an understanding of its genetic history is lacking. We present genome-wide sequence data from ancient and present-day humans from Greenland, Arctic Canada, Alaska, Aleutian Islands, and Siberia. We show that Paleo-Eskimos (similar to 3000 BCE to 1300 CE) represent a migration pulse into the Americas independent of both Native American and Inuit expansions. Furthermore, the genetic continuity characterizing the Paleo-Eskimo period was interrupted by the arrival of a new population, representing the ancestors of present-day Inuit, with evidence of past gene flow between these lineages. Despite periodic abandonment of major Arctic regions, a single Paleo-Eskimo metapopulation likely survived in near-isolation for more than 4000 years, only to vanish around 700 years ago.
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| 26. |
- Skoglund, A., et al.
(author)
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Applying process monitoring with multivariate analysis through a knowledge-based systems approach to a paperboard machine
- 2005
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In: Computers in industry (Print). - : Elsevier BV. - 0166-3615 .- 1872-6194. ; 56:5, s. 472-478
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Journal article (peer-reviewed)abstract
- The utility of multivariate statistical process control (MSPC) in the process industry can be further improved by applying knowledge-based systems (KBS) principles. First, the extensive volumes of process data generated in a production process can be pre-assessed by the KBS according to set rules. Second, the KBS can make a selection between various MSPC model alternatives. Third, the KBS may support the plant operators when evaluating the MSPC output results. This is shown in this preliminary study where a KBS was applied to an existing MSPC application on a paperboard machine. It is suggested that these experiences may also successfully be applied with other continuous processes in the manufacturing industry. © 2005 Published by Elsevier B.V.
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| 27. |
- Skoglund, Elisabeth, et al.
(author)
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Functional improvements to 6 months of physical activity are not related to changes in size or density of multiple lower-extremity muscles in mobility-limited older individuals
- 2022
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In: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 157
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Journal article (peer-reviewed)abstract
- Older adults are encouraged to engage in multicomponent physical activity, which includes aerobic and muscle-strengthening activities. The current work is an extension of the Vitality, Independence, and Vigor in the Elderly 2 (VIVE2) study - a 6-month multicenter, randomized, placebo-controlled trial of physical activity and nutritional supplementation in community dwelling 70-year-old seniors. Here, we examined whether the magnitude of changes in muscle size and quality differed between major lower-extremity muscle groups and related these changes to functional outcomes. We also examined whether daily vitamin-D-enriched protein supplementation could augment the response to structured physical activity. Forty-nine men and women (77 ± 5 yrs) performed brisk walking, muscle-strengthening exercises for the lower limbs, and balance training 3 times weekly for 6 months. Participants were randomized to daily intake of a nutritional supplement (20 g whey protein + 800 IU vitamin D), or a placebo. Muscle cross-sectional area (CSA) and radiological attenuation (RA) were assessed in 8 different muscle groups using single-slice CT scans of the hip, thigh, and calf at baseline and after the intervention. Walking speed and performance in the Short Physical Performance Battery (SPPB) were also measured. For both CSA and RA, there were muscle group × time interactions (P < 0.01). Significant increases in CSA were observed in 2 of the 8 muscles studied, namely the knee extensors (1.9%) and the hip adductors (2.8%). For RA, increases were observed in 4 of 8 muscle groups, namely the hip flexors (1.1 HU), hip adductors (0.9 HU), knee extensors (1.2 HU), and ankle dorsiflexors (0.8 HU). No additive effect of nutritional supplementation was observed. While walking speed (13%) and SPPB performance (38%) improved markedly, multivariate analysis showed that these changes were not associated with the changes in muscle CSA and RA after the intervention. We conclude that this type of multicomponent physical activity program results in significant improvements in physical function despite relatively small changes in muscle size and quality of some, but not all, of the measured lower extremity muscles involved in locomotion.
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| 28. |
- Skoglund, Karin, et al.
(author)
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In vivo CYP3A activity and pharmacokinetics of imatinib in relation to therapeutic outcome in chronic myeloid leukemia patients
-
Other publication (other academic/artistic)abstract
- Introduction: The hepatic enzymes CYP3A4 and CYP3A5 metabolize the tyrosine kinase inhibitor imatinib into a large number of metabolites including the pharmacologically active N-desmethyl imatinib (CGP74588). Because the metabolic activity of CYP3A varies considerably between individuals and a previous pilot study suggested an inverse association between in vivo CYP3A metabolic activity and therapeutic outcome of imatinib, the primary aim of this study was to investigate the influence of CYP3A metabolic activity on the outcome of imatinib therapy in chronic myeloid leukemia patients.Methods: Fifty-five patients were included and CYP3A activity was estimated in vivo using quinine as a probe drug. Imatinib and CGP74588 trough concentrations in the plasma were determined at steady state in 34 patients. Cytogenetic and molecular responses after 12 months of first-line imatinib were retrospectively collected from patients’ medical records.Results: Patients with optimal response to imatinib (complete cytogenetic response (CCgR) or molecular response of BCR-ABL <1%) did not have different levels of CYP3A activity compared to non-optimal responders. Similar results were found when analyzing the molecular response and CCgR separately. Neither the imatinib trough concentration nor the CGP74588/imatinib ratio were significantly associated with CYP3A activity.Conclusion: CYP3A enzyme activity, as measured by quinine metabolic ratio, does not correlate with the plasma concentrations of imatinib or CGP74588 and is not predictive of imatinib therapeutic outcome. These results indicate that even though imatinib is metabolized by CYP3A enzymes, this activity is not the ratelimiting step in imatinib metabolism and excretion. Future studies should focus on other pharmacokinetic processes such as plasma protein binding or transport protein activity to look for the major contributor to patient variability in imatinib plasma concentration.
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| 29. |
- von Berens, A., et al.
(author)
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Sarcopenic obesity and associations with mortality in older women and men : a prospective observational study
- 2020
-
In: BMC Geriatrics. - 1471-2318 .- 1471-2318. ; 20:1
-
Journal article (peer-reviewed)abstract
- Background The combined effect of sarcopenia and obesity, i.e., sarcopenic obesity, has been associated with disability and worse outcomes in older adults, but results are conflicting. The objectives of this study were to describe the prevalence of sarcopenic obesity (SO) in older adults, and to examine how the risk of mortality is associated with SO and its various components. Methods Data were obtained from two Swedish population studies, the Gothenburg H70 Birth Cohort Studies of 521 women and men at the age of 75, and the Uppsala Longitudinal Study of Adult Men (ULSAM), which included 288 men aged 87 years. Sarcopenia was defined using the recently updated EWGSOP2 definition. Obesity was defined by any of three established definitions: body mass index >= 30 kg/m(2), fat mass > 30%/ > 42% or waist circumference >= 88 cm/>= 102 cm for women and men, respectively. The Kaplan-Meier survival curve and the Cox proportional hazard model were used for 10-year and 4-year survival analyses in the H70 and ULSAM cohorts, respectively. Results SO was observed in 4% of the women and 11% of the men in the H70 cohort, and in 10% of the ULSAM male cohort. The 75-year-old women with SO had a higher risk (HR 3.25, 95% confidence interval (1.2-8.9)) of dying within 10 years compared to those with a "normal" phenotype. A potential similar association with mortality among the 75-year-old men was not statistically significant. In the older men aged 87 years, obesity was associated with increased survival. Conclusions SO was observed in 4-11% of community-dwelling older adults. In 75-year-old women SO appeared to associate with an increased risk of dying within 10 years. In 87-year-old men, the results indicated that obesity without sarcopenia was related to a survival benefit over a four-year period.
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| 30. |
- Zaidi, A. A., et al.
(author)
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On the tightness of linear policies for stabilization of linear systems over Gaussian networks
- 2016
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In: Systems & control letters (Print). - : Elsevier. - 0167-6911 .- 1872-7956. ; 88, s. 32-38
-
Journal article (peer-reviewed)abstract
- In this paper, we consider stabilization of multi-dimensional linear systems driven by Gaussian noise controlled over parallel Gaussian channels. For such systems, it has been recognized that for stabilization in the sense of asymptotic stationarity or stability in probability, Shannon capacity of a channel is an appropriate measure on characterizing whether a system can be made stable when controlled over the channel. However, this is in general not the case for quadratic stabilization. On a related problem of joint-source channel coding, in the information theory literature, the source-channel matching principle has been shown to lead to optimality of uncoded or analog transmission and when such matching conditions occur, it has been shown that capacity is also a relevant figure of merit for quadratic stabilization. A special case of this result is applicable to a scalar LQG system controlled over a scalar Gaussian channel. In this paper, we show that even in the absence of source-channel matching, to achieve quadratic stability, it may suffice that information capacity (in Shannon’s sense) is greater than the sum of the logarithm of unstable eigenvalue magnitudes. In particular, we show that periodic linear time varying coding policies are optimal in the sense of obtaining a finite second moment for the state of the system with minimum transmit power requirements for a large class of vector Gaussian channels. Our findings also extend the literature which has considered noise-free systems.
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| 31. |
- Andersson, Agnes, et al.
(author)
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Headache Before and After Endoscopic Transsphenoidal Pituitary Tumor Surgery: A Prospective Study
- 2022
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In: Journal of Neurological Surgery Part B-Skull Base. - : Georg Thieme Verlag KG. - 2193-6331 .- 2193-634X. ; 83:suppl. 2
-
Journal article (peer-reviewed)abstract
- Objective Headache is a common symptom among patients with pituitary tumors, as it is in the general population. The aim of the study was to investigate headache as a symptom in patients with pituitary tumors before and 6 months after endoscopic transsphenoidal surgery (TSS). Design This is a prospective observational cohort study. Setting This study was conducted at university tertiary referral hospital. Participants A total of 110 adult patients underwent endoscopic TSS for pituitary tumors. Main Outcome Measures The Migraine Disability Assessment (MIDAS) questionnaire was used before and 6 months after surgery for the assessment of headache. Clinical variables with potential influence on headache were analyzed. Results Sixty-eight (62%) patients experienced headaches at least once during the 3 months before surgery. Thirty (27%) patients reported disabling headache before surgery, with younger age being an independent associated factor ( p <0.001). In patients with disabling headache before surgery, the median (interquartile range) MIDAS score improved from 78 (27-168) to 16 (2-145; p =0.049), headache frequency decreased from 45 (20-81) to 14 (4-35) days ( p =0.009), and headache intensity decreased from 6 (5-8) to 5 (4-7) ( p =0.011) after surgery. In total, 16 of the 30 (53%) patients reported a clinically relevant improvement and five (17%) a clinically relevant worsening. Four (5%) patients developed new disabling headache. No predictor for postoperative improvement of headache was identified. Conclusion In this prospective study, the results show that disabling headache improves following endoscopic TSS in a subset of patients with pituitary tumors. However, no predictive factors for improvement could be identified.
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| 32. |
- Andersson, Mattias, et al.
(author)
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Secure key agreement over reciprocal fading channels in the low SNR regime
- 2013
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In: 2013 IEEE 14th Workshop on Signal Processing Advances in Wireless Communications, SPAWC. - : IEEE. - 9781467355773 ; , s. 674-678
-
Conference paper (peer-reviewed)abstract
- We study the low SNR scaling of the non-coherent secret-key agreement capacity over a reciprocal, block-fading channel. For the restricted class of strategies, where one of the nodes is constrained to transmit pilot-only symbols, we show that the secret-key capacity scales as SNR ·log T if T ≤ 1/SNR, where T denotes the coherence period, and as SNR·log(1/SNR) otherwise. Our upper bound is inspired by the genie-aided argument of Borade and Zheng (IT-Trans 2010). Our lower bound is based on bursty communication, channel training, and secret message transmission.
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| 33. |
- Appelgren, Patrik, et al.
(author)
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Parametric studies of an electrohydrodynamic plasma actuator for boundary layer flow control
- 2009
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In: PPC '09. IEEE Pulsed Power Conference, 2009. - : IEEE. - 9781424440658 ; , s. 1069-1074
-
Conference paper (peer-reviewed)abstract
- An electrohydrodynamic plasma actuator can be used as an aerodynamic flow control device. A plasma actuator is realised as a surface-mounted dielectric barrier discharge (DBD) that transfers directed energy from ions in the discharge to the surrounding air. Parametric studies have been performed in order to investigate the relative efficiency in terms of electrical power into the actuator versus mechanical power in the generated boundary flow. The parametric study includes variations of the applied driving voltage and frequency as well as different electrode and dielectric materials. It is found that, within the range tested, for each value of electrical power into the actuator there exists an optimum driving frequency in terms of boundary layer flow velocity. It is also found that the same trend seems to be true when analyzing electric to mechanical efficiency of the device, i.e. for a given input power there exists an optimum driving frequency that produces the highest efficiency. However, this peak in efficiency of the actuator lies on the edge of the parametric space tested so that further experiments are needed to validate these results.
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| 34. |
- Axholt, Magnus, et al.
(author)
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Accuracy of Eyepoint Estimation in Optical See-Through Head-Mounted Displays Using the Single Point Active Alignment Method
- 2011
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Conference paper (other academic/artistic)abstract
- This paper studies the accuracy of the estimated eyepoint of an Optical See-Through Head-Mounted Display (OST HMD) calibrated using the Single Point Active Alignment Method (SPAAM). Quantitative evaluation of calibration procedures for OST HMDs is complicated as it is currently not possible to share the subject’s view. Temporarily replacing the subject’s eye with a camera during the calibration or evaluation stage has been proposed, but the uncertainty of a correct eyepoint estimation remains. In the experiment reported in this paper, subjects were used for all stages of calibration and the results were verified with a 3D measurement device. The nine participants constructed 25 visual alignments per calibration after which the estimated pinhole camera model was decomposed into its intrinsic and extrinsic parameters using two common methods. Unique to this experiment, compared to previous evaluations, is the measurement device used to cup the subject’s eyeball. It measures the eyepoint location relative to the head tracker, thereby establishing the calibration accuracy of the estimated eyepoint location. As the results on accuracy are expressed as individual pinhole camera parameters, rather than a compounded registration error, this paper complements previously published work on parameter variance as the former denotes bias and the latter represents noise. Results indicate that the calibrated eyepoint is on average 5 cm away from its measured location and exhibits a vertical bias which potentially causes dipvergence for stereoscopic vision for objects located further away than 5.6 m. Lastly, this paper closes with a discussion on the suitability of the traditional pinhole camera model for OST HMD calibration.
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| 35. |
- Bilal, Ibrahim, et al.
(author)
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An Optimized Linear Scheme for Stabilization Over Multi-User Gaussian Networks
- 2013
-
In: 2013 Information Theory And Applications Workshop (ITA). - New York : IEEE. - 9781467346481 ; , s. 290-297
-
Conference paper (peer-reviewed)abstract
- Remote stabilization of linear dynamical systems over Gaussian networks is studied. Two linear time invariant systems (plants) with arbitrary distributed initial states are monitored by two separate sensors. The sensors communicate their measurements to two remotely situated controllers over a Gaussian interference, possibly with the assistance from a relay node. The common goal of the sensors, relay, and controllers is to stabilize the plants in mean-square sense. An optimized linear delay-free sensing and control scheme is proposed and sufficient conditions for mean-square stability are derived. These conditions reveal the relationship between plants' stability and communication channel parameters. It is shown that the proposed linear scheme can significantly outperform the existing estimation based control scheme in multi-user Gaussian networks.
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| 36. |
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| 37. |
- Castroviejo-Fisher, Santiago, et al.
(author)
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Vanishing Native American dog lineages
- 2011
-
In: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 11, s. 73-
-
Journal article (peer-reviewed)abstract
- Background: Dogs were an important element in many native American cultures at the time Europeans arrived. Although previous ancient DNA studies revealed the existence of unique native American mitochondrial sequences, these have not been found in modern dogs, mainly purebred, studied so far. Results: We identified many previously undescribed mitochondrial control region sequences in 400 dogs from rural and isolated areas as well as street dogs from across the Americas. However, sequences of native American origin proved to be exceedingly rare, and we estimate that the native population contributed only a minor fraction of the gene pool that constitutes the modern population. Conclusions: The high number of previously unidentified haplotypes in our sample suggests that a lot of unsampled genetic variation exists in non-breed dogs. Our results also suggest that the arrival of European colonists to the Americas may have led to an extensive replacement of the native American dog population by the dogs of the invaders.
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| 38. |
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| 39. |
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| 40. |
- Favre-Felix, Antoine, et al.
(author)
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Absolute Eye Gaze Estimation With Biosensors in Hearing Aids
- 2019
-
In: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 13
-
Journal article (peer-reviewed)abstract
- People with hearing impairment typically have difficulties following conversations in multi-talker situations. Previous studies have shown that utilizing eye gaze to steer audio through beamformers could be a solution for those situations. Recent studies have shown that in-ear electrodes that capture electrooculography in the ear (EarEOG) can estimate the eye-gaze relative to the head, when the head was fixed. The head movement can be estimated using motion sensors around the ear to create an estimate of the absolute eye-gaze in the room. In this study, an experiment was designed to mimic a multi-talker situation in order to study and model the EarEOG signal when participants attempted to follow a conversation. Eleven hearing impaired participants were presented speech from the DAT speech corpus (Bo Nielsen et al., 2014), with three targets positioned at -30 degrees, 0 degrees and +30 degrees azimuth. The experiment was run in two setups: one where the participants had their head fixed in a chinrest, and the other where they were free to move their head. The participants task was to focus their visual attention on an LED-indicated target that changed regularly. A model was developed for the relative eye-gaze estimation, taking saccades, fixations, head movement and drift from the electrode-skin half-cell into account. This model explained 90.5% of the variance of the EarEOG when the head was fixed, and 82.6% when the head was free. The absolute eye-gaze was also estimated utilizing that model. When the head was fixed, the estimation of the absolute eye-gaze was reliable. However, due to hardware issues, the estimation of the absolute eye-gaze when the head was free had a variance that was too large to reliably estimate the attended target. Overall, this study demonstrated the potential of estimating absolute eye-gaze using EarEOG and motion sensors around the ear.
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| 41. |
- Ferraris, Sara, et al.
(author)
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Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications
- 2014
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 317, s. 131-139
-
Journal article (peer-reviewed)abstract
- This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications.The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions.The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating.The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles.The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles.The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.
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| 42. |
- Floor, Pal Anders, et al.
(author)
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Distributed zero-delay joint source-channel coding for a BI-variate Gaussian on a Gaussian MAC
- 2011
-
In: 19TH EUROPEAN SIGNAL PROCESSING CONFERENCE (EUSIPCO-2011). - : EURASIP. ; , s. 2084-2088
-
Conference paper (peer-reviewed)abstract
- In this paper delay-free distributed joint source-channel coding for communication of two correlated Gaussian sources over a Gaussian Multiple Access Channel (GMAC) are considered. Both discrete and hybrid discrete analog schemes arc proposed and optimized. The proposed schemes are noise robust and show promising performance which improve with increasing correlation.
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| 43. |
- Floor, Pal Anders, et al.
(author)
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On Joint Source-Channel Coding for a Multivariate Gaussian on a Gaussian MAC
- 2015
-
In: IEEE Transactions on Communications. - 0090-6778 .- 1558-0857. ; 63:5, s. 1824-1836
-
Journal article (peer-reviewed)abstract
- In this paper, nonlinear distributed joint source-channel coding (JSCC) schemes for transmission of multivariate Gaussian sources over a Gaussian multiple access channel are proposed and analyzed. The main contribution is a zero-delay JSCC named Distributed Quantizer Linear Coder (DQLC), which performs relatively close the information theoretical bounds, improves when the correlation among the sources increases, and does not level off as the signal-to-noise ratio (SNR) becomes large. Therefore it outperforms any linear solution for sufficiently large SNR. Further an extension of DQLC to an arbitrary code length named Vector Quantizer Linear Coder (VQLC) is analyzed. The VQLC closes in on the performance upper bound as the code length increases and can potentially achieve the bound for any number of independent sources. The VQLC leaves a gap to the bound whenever the sources are correlated, however. JSCC achieving the bound for arbitrary correlation has been found for the bivariate case, but that solution is significantly outperformed by the DQLC/VQLC when there is a low delay constraint. This indicates that different approaches are needed to perform close to the bounds when the code length is high and low. The VQLC/DQLC also apply for bandwidth compression of a multivariate Gaussian transmitted on point-to-point links.
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| 44. |
- Floor, Pål Anders, et al.
(author)
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Zero-Delay Joint Source-Channel Coding for a Bivariate Gaussian on a Gaussian MAC
- 2012
-
In: IEEE Transactions on Communications. - 0090-6778 .- 1558-0857. ; 60:10, s. 3091-3102
-
Journal article (peer-reviewed)abstract
- In this paper, delay-free, low complexity, joint source-channel coding (JSCC) for transmission of two correlated Gaussian memoryless sources over a Gaussian Multiple Access Channel (GMAC) is considered. The main contributions of the paper are two distributed JSCC schemes: one discrete scheme based on nested scalar quantization, and one hybrid discrete-analog scheme based on a scalar quantizer and a linear continuous mapping. The proposed schemes show promising performance which improves with increasing correlation and are robust against variations in noise level. Both schemes also exhibit a constant gap to the performance upper bound when the channel signal-to-noise ratio gets large.
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| 45. |
- Gabry, Frederic
(author)
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Cooperation for Secrecy in Wireless Networks
- 2012
-
Licentiate thesis (other academic/artistic)abstract
- The growth of wireless networks has been considerable over the last decades. Due to the broadcast nature of these networks, security issues have taken a critical role in today’s communications. A promising direction towards achieving secure communications is information theoretic secrecy, which is an approach exploiting the randomness of the channels to ensure secrecy. Based on this approach, there has been a recent surge of interest in a potential cooperation between users to enhance the secrecy of communications. In this thesis we investigate the interaction between cooperation and secrecy. In particular the contributions of the thesis can be divided into two parts.In the first part, we study cooperative strategies for secrecy for wireless channels. Our goal is to evaluate the effect of fading and limited CSI on the eavesdropper’s channels. In that purpose we consider a scenario where a helper aims at increasing the secrecy of the communication between a source and destination in the presence of an eavesdropper. Several strategies are discussed for the helper, namely decode-and-forward, amplify-and-forward, and cooperative jamming. We introduce the secrecy outage probability, the conditional secrecy outage probability and the secure throughput as secrecy measures. For each measure, we investigate and compare the secrecy performance of cooperation. We furthermore elaborate a system optimization in terms of strategy selection, node positioning, power allocation and rate design.In the second part, we consider cooperation in the 4-node scenario against a more sophisticated adversary: an active eavesdropper, which can either passively eavesdrop, or jam the transmission. A game-theoretic perspective is a natural way to analyze the competitive interaction between the helper and the eavesdropper. Therefore we define several secrecy games, for which we find the Nash and Stackelberg equilibria as well as the corresponding secrecy rate outcomes. Another important consideration in this scenario is the interaction between the source and the helper, which we model and solve as a Stackelberg game, and we illustrate its impact on the achievable secrecy rates.
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| 46. |
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| 47. |
- Ghourchian, Hamid, et al.
(author)
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Block Source Coding with Sequential Encoding
- 2019
-
In: 2019 IEEE Information Theory Workshop, ITW 2019. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538669006
-
Conference paper (peer-reviewed)abstract
- We introduce the concept of achievable cumulative rate distribution functions (CRDF) to characterize sequentially encoding processes that ensure a lossless or lossy reconstruction subject to an average distortion using a non-causal decoder. Utilizing tools from majorization theory, we derive necessary and sufficient conditions on the CRDF for a given IID source. It turns out that the optimal achievable distortion level can be adequately characterized by the concave-hull of the CRDF.
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| 48. |
- Ghourchian, Hamid, et al.
(author)
-
Secure Block Source Coding With Sequential Encoding
- 2021
-
In: IEEE Journal on Selected Areas in Information Theory. - : IEEE. - 2641-8770. ; 2:1
-
Journal article (peer-reviewed)abstract
- We introduce fundamental bounds on achievable cumulative rate distribution functions (CRDF) to characterize a sequential encoding process that ensures lossless or lossy reconstruction subject to an average distortion criterion using a non-causal decoder. The CRDF describes the rate resources spent sequentially to compress the sequence. We also include a security constraint that affects the set of achievable CRDF. The information leakage is defined sequentially based on the mutual information between the source and its compressed representation, as it evolves. To characterize the security constraints, we introduce the concept of cumulative leakage distribution functions (CLF), which determines the allowed information leakageas distributed over encoded sub-blocks. Utilizing tools from majorization theory, we derive necessary and sufficient conditions on the achievable CRDF for a given independent and identically distributed (IID) source and CLF. One primary result of this article is that the concave-hull of the CRDF characterizes the optimal achievable rate distribution.
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| 49. |
- Green, Henrik, et al.
(author)
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CYP3A activity influences imatinib response in patients with chronic myeloid leukemia: a pilot study on in vivo CYP3A activity
- 2010
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In: EUROPEAN JOURNAL OF CLINICAL PHARMACOLOGY. - : Springer Science and Business Media LLC. - 0031-6970 .- 1432-1041. ; 66:4, s. 383-386
-
Journal article (peer-reviewed)abstract
- Imatinib is currently used for the treatment of chronic myeloid leukemia (CML). The main metabolite CGP74588 has similar potency to that of imatinib and is a product of CYP3A4 and CYP3A5 metabolism. However, the clinical significance of the metabolism on therapeutic response and pharmacokinetics is still unclear. We designed this study to investigate the role of the CYP3A activity in the response to imatinib therapy. Fourteen CML patients were phenotyped for in vivo CYP3A activity using quinine as a probe drug. The plasma concentration ratio of quinine and its CYP3A metabolite was used for assessing CYP3A activity. The patients were divided into complete molecular responders with undetectable levels of BCR-ABL transcripts after 12 months of therapy and into partial molecular responders who had failed to achieve a complete molecular response. Patients that achieved complete molecular response showed significantly (Mann-Whitney U-test, p = 0.013) higher in vivo CYP3A activity (median quinine metabolic ratio = 10.1) than patients achieving partial molecular response (median = 15.9). These results indicate a clinical significance of the CYP3A activity and its metabolic products in CML patients treated with imatinib.
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| 50. |
- Gudmundsson, T., et al.
(author)
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Importance of hospital and clinical factors in predicting of 30-day mortality in Takotsubo syndrome : data from the Swedish Coronary Angiography and Angioplasty Registry
- 2023
-
In: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 44:Suppl. 2
-
Journal article (other academic/artistic)abstract
- Background: Takotsubo syndrome (TS) is an acute heart failure condition that presents with symptoms similar to acute myocardial infarction. TS is often triggered by emotional or physical stress and is an important cause of morbidity and mortality but predictors of mortality in TS patients are not well understood. There is a need to identify high-risk patients and tailor treatment accordingly.Purpose: The purpose of this study was to assess the importance of various clinical factors in predicting 30-day mortality in TS patients using a machine-learning algorithm capable of identifying complex relationships between variables.Methods: We analyzed data from the nationwide Swedish Coronary Angiography and Angioplasty Registry for all TS patients between 2015-2022. Gradient boosting was used to assess the relative importance of variables in predicting 30-day mortality in TS patients.Results: Of the 3,180 hospitalized TS patients, 76% were women. The average age was 68.3 ± 11.2 years. The crude all-cause mortality rate was 2.57% at 30 days. The most important variable in predicting 30-day mortality was the hospital where the patient was treated, with a relative importance of 35.5%. This was followed by the clinical presentation for angiography (21.1%), creatinine level (11.9%), Killip class (8.9%), and age at angioplasty (6.5%). Other less important factors included weight, height, and certain medical conditions such as hyperlipidemia, smoking status, and hypertension. Gender and previous stroke history had a low impact on 30-day mortality in TS patients.Conclusions: The treating hospital was the most important factor in predicting 30-day mortality in TS. Since the level of evidence for recommended treatments of TS is low, our findings highlight the importance of conducting randomized studies in this patient group to improve care.
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