| 1. |
- Andersen, Randi Dovland, et al.
(författare)
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Pain burden in children with cerebral palsy (CPPain) survey : Study protocol
- 2022
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Ingår i: Paediatric and Neonatal Pain. - : John Wiley & Sons. - 2379-5824 .- 2637-3807. ; 4:1, s. 11-21
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Tidskriftsartikel (refereegranskat)abstract
- Pain is a significant health concern for children living with cerebral palsy (CP). There are no population-level or large-scale multi-national datasets using common measures characterizing pain experience and interference (ie, pain burden) and management practices for children with CP. The aim of the CPPain survey is to generate a comprehensive understanding of pain burden and current management of pain to change clinical practice in CP. The CPPain survey is a comprehensive cross-sectional study. Researchers plan to recruit approximately 1400 children with CP (primary participants) across several countries over 6-12 months using multimodal recruitment strategies. Data will be collected from parents or guardians of children with CP (0-17 years) and from children with CP (8-17 years) who are able to self-report. Siblings (12-17 years) will be invited to participate as controls. The CPPain survey consists of previously validated and study-specific questionnaires addressing demographic and diagnostic information, pain experience, pain management, pain interference, pain coping, activity and participation in everyday life, nutritional status, mental health, health-related quality of life, and the effect of the COVID-19 pandemic on pain and access to pain care. The survey will be distributed primarily online. Data will be analyzed using appropriate statistical methods for comparing groups. Stratification will be used to investigate subgroups, and analyses will be adjusted for appropriate sociodemographic variables. The Norwegian Regional Committee for Medical and Health Research Ethics and the Research Ethics Board at the University of Minnesota in USA have approved the study. Ethics approval in Canada, Sweden, and Finland is pending. In addition to dissemination through peer-reviewed journals and conferences, findings will be communicated through the CPPain Web site (www.sthf.no/cppain), Web sites directed toward users or clinicians, social media, special interest groups, stakeholder engagement activities, articles in user organization journals, and presentations in public media.
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| 2. |
- Andersen, Olav, et al.
(författare)
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A Test-Bed Designed to Utilize Zhu’s General Sampling Theorem to Characterize Power Amplifiers
- 2009
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Ingår i: Instrumentation and measurement technology conference 2009 I2MTC '09 IEEE. - Singapore. - 9781424433537 ; , s. 201-204
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Konferensbidrag (refereegranskat)abstract
- Characterizing power amplifiers require test set-ups with performance superior to the power amplifiers. A commonly used method is to use an IQ-demodulator. However, problem arises due to imperfections in the demodulator such as IQ-imbalance; an alternative method is to use a direct down converter to intermediate frequency. The drawback then is the limited bandwidth. However, the required bandwidth of the ADC does not need to be exceptional. According to Zhu’s general sampling theorem is it enough to sample the output signal at the Nyquist rate of the input. However, even though the required sampling rate is reduced the demands on the analog bandwidth remains. Unfortunately, commercially available instruments such as vector signal analyzers can not be used for this purpose since their analog bandwidth is too small. In this paper a test-bed is designed to utilize the Zhu’s general sampling theorem. The RF front-end has frequency range of 500 MHz – 2.7 GHz and a bandwidth of 1 GHz. All performance data are verified with measurements.
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| 3. |
- Andersen, Olav, et al.
(författare)
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Extending the Bandwidth and Dynamic Range of Old RF Instruments to Meet State-of-the-Art Performance, Using a Synthetic Instrument Approach
- 2009
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 58:2, s. 248-254
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Tidskriftsartikel (refereegranskat)abstract
- A decrease in life cycle cost is a key issue for testing mobile communication systems. The rapid development and edge technology requires high-performance instruments and state-of-the-art measurement technology. New investments are expensive, but even older generation instruments are capable of extending their bandwidth and dynamic range to meet even the latest Third-Generation Partnership Project (3GPP) cellular measurement requirements by the addition of external hardware using a synthetic instrument approach. The novelty of this paper is the high performance on the most crucial parameters, i.e., the dynamic range and bandwidth achieved by only replacing some parts of the legacy instrument. Moreover, the demonstrated direct IF synthesis has a high degree of novelty at wide modulation bandwidths. It is desired to use virtual/synthetic instruments and make the signal processing in the software independent of the hardware, i.e., software-defined measurements (SDMs). In this paper, a state-of-the-art experimental setup for signal generation and signal analysis is demonstrated. A direct IF synthesis is used to generate a wideband code-division multiple-access (WCDMA) carrier with more than 72-dB adjacent carrier leakage ratio (ACLR) up to 12 parallel carriers with more than 68-dBc ACLR over a total bandwidth of 100 MHz. The signal analysis capabilities (e.g., ACLR performance) for a WCDMA carrier is better than -70 dBc and for a continuous wave better than -85 dBc over a bandwidth of 42.5 MHz. The critical RF downconverter in the setup is carefully designed not to degrade the dynamic range performance.
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| 4. |
- Aslam, Tayyba N., et al.
(författare)
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A survey of preferences for respiratory support in the intensive care unit for patients with acute hypoxaemic respiratory failure
- 2023
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Ingår i: Acta Anaesthesiologica Scandinavica. - : WILEY. - 0001-5172 .- 1399-6576. ; 67:10, s. 1383-1394
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWhen caring for mechanically ventilated adults with acute hypoxaemic respiratory failure (AHRF), clinicians are faced with an uncertain choice between ventilator modes allowing for spontaneous breaths or ventilation fully controlled by the ventilator. The preferences of clinicians managing such patients, and what motivates their choice of ventilator mode, are largely unknown. To better understand how clinicians preferences may impact the choice of ventilatory support for patients with AHRF, we issued a survey to an international network of intensive care unit (ICU) researchers.MethodsWe distributed an online survey with 32 broadly similar and interlinked questions on how clinicians prioritise spontaneous or controlled ventilation in invasively ventilated patients with AHRF of different severity, and which factors determine their choice.ResultsThe survey was distributed to 1337 recipients in 12 countries. Of these, 415 (31%) completed the survey either fully (52%) or partially (48%). Most respondents were identified as medical specialists (87%) or physicians in training (11%). Modes allowing for spontaneous ventilation were considered preferable in mild AHRF, with controlled ventilation considered as progressively more important in moderate and severe AHRF. Among respondents there was strong support (90%) for a randomised clinical trial comparing spontaneous with controlled ventilation in patients with moderate AHRF.ConclusionsThe responses from this international survey suggest that there is clinical equipoise for the preferred ventilator mode in patients with AHRF of moderate severity. We found strong support for a randomised trial comparing modes of ventilation in patients with moderate AHRF.
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| 5. |
- Björsell, Niclas, et al.
(författare)
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High dynamic range test-bed for characterization of analog-to-digital converters up to 500 MSPS
- 2005
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Ingår i: 14th Symposium on New Technologies in Measurement and Instrumentation and 10th Workshop on ADC Modelling and Testing. - : IMEKO-International Measurement Federation Secretariat. - 9788389786371 ; , s. 601-604, s. 601-604
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Konferensbidrag (refereegranskat)abstract
- A measurement set-up of for the characterization of analog-to-digital converters (ADCs) is described. The measurement set-up characterizes ADCs up to 16 bits at 350 MHz (option for >500 MHz). Testing dynamic performance of high-speed ADCs is regarded as difficult and expensive. By using existing state-of-the-art instruments in combination with specially designed amplifiers and filters, a high performance, cost efficient test-bed has been built-up. Practical performance corresponds to ADC datasheet and exceeds the performance obtained if using commercial instruments only. Consequently, the measurement results represent the true performance of the ADC without impact from the test-bed
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| 6. |
- Breznau, Nate, et al.
(författare)
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Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:44
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Tidskriftsartikel (refereegranskat)abstract
- This study explores how researchers analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each teams workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings.
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| 7. |
- Goncalves, Nadia P., et al.
(författare)
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Peripheral Nerve Regeneration Is Independent From Schwann Cell p75(NTR) Expression
- 2019
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Ingår i: Frontiers in Cellular Neuroscience. - : FRONTIERS MEDIA SA. - 1662-5102. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Schwann cell reprogramming and differentiation are crucial prerequisites for neuronal regeneration and re-myelination to occur following injury to peripheral nerves. The neurotrophin receptor p75(NTR) has been identified as a positive modulator for Schwann cell myelination during development and implicated in promoting nerve regeneration after injury. However, most studies base this conclusion on results obtained from complete p75(NTR) knockout mouse models and cannot dissect the specific role of p75(NTR) expressed by Schwann cells. In this present study, a conditional knockout model selectively deleting p75(NTR) expression in Schwann cells was generated, where p75(NTR) expression is replaced with that of an mCherry reporter. Silencing of Schwann cell p75(NTR) expression was confirmed in the sciatic nerve in vivo and in vitro, without altering axonal expression of p75(NTR). No difference in sciatic nerve myelination during development or following sciatic nerve crush injury was observed, as determined by quantification of both myelinated and unmyelinated nerve fiber densities, myelinated axonal diameter and myelin thickness. However, the absence of Schwann cell p75(NTR) reduced motor nerve conduction velocity after crush injury. Our data indicate that the absence of Schwann cell p75(NTR) expression in vivo is not critical for axonal regrowth or remyelination following sciatic nerve crush injury, but does play a key role in functional recovery. Overall, this represents the first step in redefining the role of p75(NTR) in the peripheral nervous system, suggesting that the Schwann cell-axon unit functions as a syncytium, with the previous published involvement of p75(NTR) in remyelination most likely depending on axonal/neuronal p75(NTR) and/or mutual glial-axonal interactions.
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| 8. |
- Gustafsson, Lars L., et al.
(författare)
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The 'wise list'- a comprehensive concept to select, communicate and achieve adherence to recommendations of essential drugs in ambulatory care in Stockholm
- 2011
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - Copenhagen : Blackwell Publishing. - 1742-7835 .- 1742-7843. ; 108:4, s. 224-233
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to present and evaluate the impact of a comprehensive strategy over 10 years to select, communicate and achieve adherence to essential drug recommendations (EDR) in ambulatory care in a metropolitan healthcare region. EDRs were issued and launched as a 'Wise List' by the regional Drug and Therapeutics Committee in Stockholm. This study presents the concept by: (i) documenting the process for selecting, communicating and monitoring the impact of the 'Wise List'; (ii) analysing the variation in the number of drug substances recommended between 2000 and 2010; (iii) assessing the attitudes to the 'Wise List' among prescribers and the public; (iv) evaluating the adherence to recommendations between 2003 and 2009. The 'Wise List' consistently contained 200 drug substances for treating common diseases. The drugs were selected based on their efficacy, safety, suitability and cost-effectiveness. The 'Wise List' was known among one-third of a surveyed sample of the public in 2002 after initial marketing campaigns. All surveyed prescribers knew about the concept and 81% found the recommendations trustworthy in 2005. Adherence to recommendations increased from 69% in 1999 to 77% in 2009. In primary care, adherence increased from 83% to 87% from 2003 to 2009. The coefficient of variation (CV%) decreased from 6.1% to 3.8% for 156 healthcare centres between these years. The acceptance of the 'Wise List' in terms of trust among physicians and among the public and increased adherence may be explained by clear criteria for drug recommendations, a comprehensive communication strategy, electronic access to recommendations, continuous medical education and involvement of professional networks and patients.
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| 9. |
- Herfindal, Ivar, et al.
(författare)
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Population persistence in a landscape context : the case of endangered arctic fox populations in Fennoscandia
- 2010
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 33:5, s. 932-941
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic fragmentation of habitat and populations is recognized as one of the most important factors influencing loss of biodiversity. Since it is difficult to quantify demographic parameters in small populations, we need alternative methods to elucidate important factors affecting the viability of local populations. The Fennoscandian arctic fox inhabits a naturally fragmented alpine tundra environment, but historic anthropogenic impacts have further fragmented its distribution. After almost 80 yr of protection, the population remains critically endangered. Both intrinsic factors (related to the isolation and size of sub-populations) and extrinsic factors (related to environmental conditions influencing patch quality and interspecific competition) have been proposed as explanations for the lack of population growth. To distinguish between these hypotheses, we conducted a spatially explicit analysis that compares areas where the species has persisted with areas where it has become locally extinct. We used characteristics of the fragments of alpine tundra habitat and individual arctic fox breeding dens (including both currently active dens and historically active dens) within the fragments to evaluate the importance of habitat characteristics and connectivity in explaining variation in persistence within a fragment. The number of reproductive events in a fragment was related to the size of the fragment, but not more than expected following a 1:1 relationship, suggesting little effect of fragment size on the relative number of reproductions. The likelihood of a den being used for breeding was positively associated with factors minimising interspecific competition as well as increasing within-fragment connectivity. These results support the idea that the failure of Fennoscandian arctic fox to recover is caused by demographic factors that can be related to fine-scale Allee or Allee-like effects, as well as environmental influences related to increased competition and exclusion by red foxes
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| 10. |
- Hidalgo Migueles, Jairo Hidalgo, et al.
(författare)
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GRANADA consensus on analytical approaches to assess associations with accelerometer-determined physical behaviours (physical activity, sedentary behaviour and sleep) in epidemiological studies
- 2022
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Ingår i: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 56:7, s. 376-384
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Tidskriftsartikel (refereegranskat)abstract
- The inter-relationship between physical activity, sedentary behaviour and sleep (collectively defined as physical behaviours) is of interest to researchers from different fields. Each of these physical behaviours has been investigated in epidemiological studies, yet their codependency and interactions need to be further explored and accounted for in data analysis. Modern accelerometers capture continuous movement through the day, which presents the challenge of how to best use the richness of these data. In recent years, analytical approaches first applied in other scientific fields have been applied to physical behaviour epidemiology (eg, isotemporal substitution models, compositional data analysis, multivariate pattern analysis, functional data analysis and machine learning). A comprehensive description, discussion, and consensus on the strengths and limitations of these analytical approaches will help researchers decide which approach to use in different situations. In this context, a scientific workshop and meeting were held in Granada to discuss: (1) analytical approaches currently used in the scientific literature on physical behaviour, highlighting strengths and limitations, providing practical recommendations on their use and including a decision tree for assisting researchers decision-making; and (2) current gaps and future research directions around the analysis and use of accelerometer data. Advances in analytical approaches to accelerometer-determined physical behaviours in epidemiological studies are expected to influence the interpretation of current and future evidence, and ultimately impact on future physical behaviour guidelines.
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