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- Bergquist, Filip, et al.
(författare)
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Pharmacokinetics of Intravenously (DIZ101), Subcutaneously (DIZ102), and Intestinally (LCIG) Infused Levodopa in Advanced Parkinson Disease
- 2022
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Ingår i: Neurology. - : Lippincott, Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 99:10, s. E965-E976
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives Intestinal levodopa/carbidopa gel infusion (LCIG) is superior to oral treatment in advanced Parkinson disease. The primary objective of this trial was to investigate whether continuous subcutaneous or intravenous infusion with a continuously buffered acidic levodopa/carbidopa solution yields steady-state plasma concentrations of levodopa that are equivalent in magnitude, and noninferior in variability, to those obtained with LCIG in patients with advanced Parkinson disease. Methods A concentrated acidic levodopa/carbidopa (8:1) solution buffered continuously and administered intravenously (DIZ101) or subcutaneously (DIZ102) was compared with an approved LCIG in a randomized, 3-period crossover, open-label, multicenter trial. Formulations were infused for 16 hours to patients with Parkinson disease who were using LCIG as their regular treatment. Patients were recruited from several university neurology clinics but came to the same phase I unit for treatment. Pharmacokinetic variables and safety including dermal tolerance are reported. The primary outcomes were bioequivalence and noninferior variability of DIZ101 and DIZ102 vs LCIG with respect to levodopa plasma concentrations. Results With dosing adjusted to estimated bioavailability, DIZ101 and DIZ102 produced levodopa plasma levels within standard bioequivalence limits compared with LCIG in the 18 participants who received all treatments. Although the levodopa bioavailability for DIZ102 was complete, it was 80% for LCIG. Therapeutic concentrations of levodopa were reached as quickly with subcutaneous administration of DIZ102 as with LCIG and remained stable throughout the infusions. Owing to poor uptake of LCIG, carbidopa levels in plasma were higher with DIZ101 and DIZ102 than with the former. All individuals receiving any of the treatments (n = 20) were included in the evaluation of safety and tolerability. Reactions at the infusion sites were mild and transient. Discussion It is feasible to rapidly achieve high and stable levodopa concentrations by means of continuous buffering of a subcutaneously administered acidic levodopa/carbidopa-containing solution.
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- Ivars, Diego Mas, 1974-, et al.
(författare)
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A case study of the Odenplan station in the Stockholm City Link project - Analysis of in situ stresses and observed ground behaviour.
- 2016
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Rapport (refereegranskat)abstract
- The Odenplan Station in the Stockholm City Link project is located directly under theexisting subway station with a minimum rock cover of approximately 7 m. The span of theOdenplan Station is 25 m. When the Odenplan station was excavated, deformations largerthan anticipated in previous calculations were observed. The main reason for this discrepancyis believed to be high horizontal in situ and/or persistent fractures in the area parallel withthe excavation.The excavation of the Odenplan station constitutes a case study with well-documented rockmass characteristics, excavation sequences, support sequences and measured deformations.It therefore provides a unique project to analyse. Based on this case study, the main objectivesof this study was to (1) suggest a general technique for numerical back analyses based onmeasured deformations under geological conditions as those present in the Stockholm area,and (2) analyse the range of possible in situ stresses at Odenplan Station in the City Linkproject.The complex three-dimensional 3DEC model lead to rather long computational times. Ageneral technique for a real back analysis was therefore not possible to obtain in this study,since it would require unrealistically long computational time. Instead, a sensitivity study onthe in situ stresses and different types of continuum and discontinuum approaches wereperformed. The results from the analyses gave valuable insight into which types of modelsthat were able to properly recreate the observed ground behavior at Odenplan. The resultsfrom the study clearly showed that a continuum approach does not capture the true behaviorof the blocky rock mass at Odenplan. It is therefore recommended that discontinuumapproaches are used in the future when structurally controlled block movements could beexpected. However, the exact cause behind the discrepancy between the continuum and thediscontinuum model has not been determined in this report.The performed sensitivity analysis suggests that the in situ stresses are high and in the rangeof those previously measured. Maximum horizontal in situ stresses are probably in the rangeof 5.7-7.2 MPa at a depth of 0-20 m, which agrees well with the results of previous rockstress measurements, which were, on average, 8.1 MPa at a depth of 30 m.The encouraging results from this project indicate that further stress sensitivity analysesshould be performed to have a better estimation of the range of in situ stresses in theStockholm area by fitting displacements obtained from modeling to those measured in situ in different projects. These analyses are important in order to understand our present abilityto perform numerical simulations reflecting true rock mass behavior.
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3. |
- Johansson, Fredrik, 1974-
(författare)
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Essays on Measurement Error and Nonresponse
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay 1 deals with measurement errors. Matching survey data with administrative records provides unique opportunities to evaluate the statistical properties of respondents' answers. This paper focuses primarily on home ownership and wealth variables. For all analyzed variables we find that the classical assumption of no correlation between measurement error and true value is violated. In an empirical application explaining the housing tenure choice, LPM and Probit models are estimated using both survey and register data on gross financial wealth.Essay 2 (with N. Anders Klevmarken) also analyzes measurement errors. Survey measures of wealth are error prone with a relatively large error variance. The errors are not uncorrelated with the true values but tend to have a negative correlation, which implies that wealthy people tend to under-report and less wealthy to over-report their responses. There is no general tendency of survey data to under-estimate mean wealth with the exception of the last percentile. The under-estimate of the wealth of the very rich is however not due to under-reporting but rather to selective nonresponse. Using simple models this paper discusses consequences of error prone wealth data.Essay 3 (with N. Anders Klevmarken) studies the problem of nonresponse in survey data. Using rich register data to analyze response behavior in a survey on health and economic standard, a model to explain contact and participation probabilities is estimated. Previous attempts to build such models have been constrained by the very limited information available in the sampling frames. One main result is that both probabilities are lower among respondents out of the labor market, who are immigrants and on benefits.Essay 4 analyzes different approaches to adjust for nonresponse bias. When a survey response mechanism depends on the variable of interest measured within the same survey and observed for only part of the sample, the situation is one of nonignorable nonresponse. If the nonresponse is ignored it will most likely generate significant bias in the estimates of the model parameters of interest. To solve this, one option is the joint modelling of the response mechanism and the variable of interest. Another option is to calibrate each observation with weights constructed from auxiliary data. In an application where earnings equations are estimated these approaches are all applied and compared with reference estimates. These reference estimates are based on a large data set without any nonresponse.
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4. |
- Tahmasebi, Nina, 1982, et al.
(författare)
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Visions and open challenges for a knowledge-based culturomics
- 2015
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Ingår i: International Journal on Digital Libraries. - : Springer Science and Business Media LLC. - 1432-5012 .- 1432-1300. ; 15:2-4, s. 169-187
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Tidskriftsartikel (refereegranskat)abstract
- The concept of culturomics was born out of the availability of massive amounts of textual data and the interest to make sense of cultural and language phenomena over time. Thus far however, culturomics has only made use of, and shown the great potential of, statistical methods. In this paper, we present a vision for a knowledge-based culturomics that complements traditional culturomics. We discuss the possibilities and challenges of combining knowledge-based methods with statistical methods and address major challenges that arise due to the nature of the data; diversity of sources, changes in language over time as well as temporal dynamics of information in general. We address all layers needed for knowledge-based culturomics, from natural language processing and relations to summaries and opinions.
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6. |
- Alpizar, Francisco, 1974, et al.
(författare)
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Does context matter more for hypothetical than for actual contributions? Evidence from a natural field experiment
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We investigate the importance of the social context for people’s voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and provided information about the contributions of others influence subject contributions in the hypothesized direction. We do find a substantial hypothetical bias with regard to the amount contributed. However, the influence of the social contexts is about the same when the subjects make actual monetary contributions as when they state their hypothetical contributions. Our results have important implications for validity testing of stated preference methods: a comparison between hypothetical and actual behavior should be done for a given social context.
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8. |
- Alpizar, Francisco, 1974, et al.
(författare)
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How Much Do We Care About Absolute versus Relative Income and Consumption?
- 2005
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Ingår i: Journal of Economic Behavior and Organization. - : Elsevier BV. - 0167-2681. ; 56, s. 405-421
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Tidskriftsartikel (refereegranskat)abstract
- We find, using survey-experimental methods, that most individuals are concerned with both relative income and relative consumption of particular goods. The degree of concern varies in the expected direction depending on the properties of the good. However, contrary to what has been suggested in the previous literature, we find that relative consumption is also important for vacation and insurance, which are typically seen as non-positional goods. Further, absolute consumption is also found to be important for cars and housing, which are widely regarded as highly positional. © 2004 Published by Elsevier B.V.
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9. |
- Alpizar, Francisco, 1974, et al.
(författare)
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How Much Do We Care About Absolute Versus Relative Income and Consumption?
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We find, using survey-experimental methods, that most individuals are concerned with both relative income and relative consumption of particular goods. The degree of concern varies in the expected direction depending on the properties of the good. However, contrary to what has been suggested in the previous literature, we find that relative consumption is also important for vacation and insurance, which are typically seen as non-positional goods. Further, absolute consumption is also found to be important for cars and housing, which are widely regarded as highly positional. Implications for Pareto-efficient taxation are illustrated using the results from the experiment.
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10. |
- Andersson, Fredrik, 1974-, et al.
(författare)
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Female top management in family firms and non-family firms : Evidence from total population data
- 2018
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Ingår i: International Journal of Entrepreneurship and Small Business. - : InderScience Publishers. - 1476-1297 .- 1741-8054. ; 35:3, s. 303-326
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Tidskriftsartikel (refereegranskat)abstract
- We exploit information on ownership, management and kinship to study the representation of women in top management teams in Swedish family and non-family firms among domiciled limited liability firms over the years 2004 to 2010. The share of female top managers is analysed across listed and non-listed firms as well as across industries. We then estimate the likelihood that a woman is elected into the top management team in family and non-family firms using a probit regression model where we control for firm- A nd individual-level characteristics, including the gender distribution of the firm and kinship relations to existing board members and firm owners. We find that non-listed family firms are more likely to appoint female top managers, whereas we find no differences among listed firms. Moreover, we find that the gender composition and kinship structures of firms influence the appointment of female top managers.
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