| 1. |
- Karlsson, A., et al.
(författare)
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Nanofluidic networks based on surfactant membrane technology
- 2003
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Ingår i: Analytical Chemistry. - 0003-2700 .- 1520-6882. ; 75:11, s. 2529-37
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Tidskriftsartikel (refereegranskat)abstract
- We explore possibilities to construct nanoscale analytical devices based on lipid membrane technology. As a step toward this goal, we present nanotube-vesicle networks with fluidic control, where the nanotube segments reside at, or very close (<2 microm) to optically transparent surfaces. These nanofluidic systems allow controlled transport as well as LIF detection of single nanoparticles. In the weak-adhesion regime, immobilized vesicles can be approximated as perfect spheres with nanotubes attached at half the height of the vesicle in the axial (z) dimension. In the strong-adhesion regime (relative contact area, Sr* approximately 0.3), nanotubes can be adsorbed to the surface with a distance to the interior of the nanotubes defined by the membrane thickness of approximately 5 nm. Strong surface adsorption restricts nanotube self-organization, enabling networks of nanotubes with arbitrary geometries. We demonstrate LIF detection of single nanoparticles (30-nm-diameter fluorescent beads) inside single nanotubes. Transport of nanoparticles was induced by a surface tension differential applied across nanotubes using a hydrodynamic injection protocol. Controlled transport in nanotubes together with LIF detection enables construction of nanoscale fluidic devices with potential to operate with single molecules. This opens up possibilities to construct analytical platforms with characteristic length scales and volume orders of magnitudes smaller than employed in traditional microfluidic devices.
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| 2. |
- Karlsson, A., et al.
(författare)
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Nanofluidic networks based on surfactant membrane technology
- 2003
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Ingår i: Analytical Chemistry. - 0003-2700 .- 1520-6882. ; 75:11, s. 2529-37
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Tidskriftsartikel (refereegranskat)abstract
- We explore possibilities to construct nanoscale analytical devices based on lipid membrane technology. As a step toward this goal, we present nanotube-vesicle networks with fluidic control, where the nanotube segments reside at, or very close (
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| 3. |
- Karlsson, Mattias, 1980, et al.
(författare)
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Micropipet-assisted formation of microscopic networks of unilamellar lipid bilayer nanotubes and containers
- 2001
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 17:22, s. 6754-6758
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Tidskriftsartikel (refereegranskat)abstract
- We describe a novel micropipet-assisted technique for the construction of complex, surface-immobilized two-dimensional microscopic networks of unilamellar phospholipid bilayer vesicles (1-50 pm in diameter, 10(-15)-10(-12) L) interconnected by lipid nanotubes (100-300 nm in diameter). As starting material for the construction of networks, we used twinned vesicle pairs, one of which is multilamellar and functions as a membrane donor and the other unilamellar and functions as a membrane acceptor upon manipulation. By electromechanical insertion of a pipet tip into the unilamellar vesicle followed by lateral pulling of the micropipet away from the vesicle, a nanotube was formed. Buffer solution contained in the pipet was then injected into the nanotube orifice, forming a vesicle of controlled size that was immobilized on the surface. The networks have controlled connectivity and are well-defined with regard to the container size, angle between nanotube extensions, and nanotube length. The internal fluid composition of individual vesicles is defined during the formation of a network by selection of the solution contained in the micropipet.
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| 4. |
- Baverel, Paul G, et al.
(författare)
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Predictive performance of internal and external validation procedures
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: To compare estimates of predictive performance between internal (IV) and external data-splitting (EV) validation procedures. Methods: Datasets of different study size (n=6, 12, 24, 48, 96, 192, or 384 individuals) were simulated from a one compartment, first-order absorption, pharmacokinetic model and both parametric (FOCE), and nonparametric (NONP) parameter estimates were obtained in NONMEM. From these, three different validation procedures (IV, EV, and a population validation (PV)) were undertaken by means of numerical predictive checks (NPCs) to provide estimates of predictive performance, the PV procedure serving as a reference to assess performance of IV and EV. The predictive performance of NONP versus FOCE estimates was further assessed. Results: Estimates of predictive performance for predicting the median of the population distribution had in general significantly lower imprecision for IV than EV, with little bias for both procedures. For small study sizes, n=6-12 (FOCE) or n=6-24 (NONP), the tails of the population distribution were significantly more biased with IV than EV, but similar imprecision was obtained. The predictive performance for FOCE was similar or superior to that of NONP. Conclusions: Data-splitting is inferior to IV when evaluating predictive models to retain sufficient precision both in predictions and in estimates of predictive performance.
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| 5. |
- Bergström, Ann-Kristin, et al.
(författare)
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Contrasting plankton stoichiometry and nutrient regeneration in northern arctic and boreal lakes
- 2018
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Ingår i: Aquatic Sciences. - : Springer. - 1015-1621 .- 1420-9055. ; 80:2
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Tidskriftsartikel (refereegranskat)abstract
- Contrasting carbon: nitrogen: phosphorus (C: N: P) stoichiometry between phytoplankton and zooplankton affect consumer growth and phytoplankton nutrient limitation via nutrient recycling by zooplankton. However, no study has assessed how regional differences in terrestrial loadings of organic matter affect plankton N: P stoichiometry and recycling in systems with low N deposition and N-limited phytoplankton. We address this question by using data from 14 unproductive headwater arctic and boreal lakes. We found that boreal lakes had higher lake water-and seston C, N and P concentrations than arctic lakes, whereas seston C: N, C: P and N: P ratios did not differ among regions. Boreal zooplankton were also richer in N and P relative to C, with lower somatic N: P ratios, compared to arctic lakes. Consequently, the estimated N: P imbalances between seston and zooplankton were negative in arctic lakes, indicating zooplankton feeding on phytoplankton of suboptimal N content, resulting in low consumer driven N: P recycling (medians arctic sub-mid and high altitude lakes: 11 and 13). In boreal lakes, estimated N: P imbalance did not differ from zero, with a seston N: P stoichiometry matching the N: P requirements of zooplankton, which resulted in higher consumer driven N: P recycling (median 18). Our results imply that regional climate induced catchment differences, through enhanced terrestrial nutrient inputs, affect plankton stoichiometry by raising consumer N: P recycling ratio and changing zooplankton from being mainly N-(arctic) to NP co-limited (boreal). Browning of lakes, in regions with low N deposition, may therefore promote large-scale regional changes in plankton nutrient limitation with potential feedbacks on pelagic food webs.
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| 6. |
- Bergström, Ann-Kristin, et al.
(författare)
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N-limited consumer growth and low nutrient regeneration N:P ratios in lakes with low N deposition
- 2015
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Ingår i: Ecosphere. - 2150-8925 .- 2150-8925. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient limitation of primary producers and their consumers can have a large influence on ecosystem productivity. The nature and strength of nutrient limitation is driven both by external factors (e.g., nutrient loading) and internal processes (e.g., consumer-driven nutrient regeneration). Here we present results from a field study in 10 low productive headwater lakes in northern subarctic Sweden, where nitrogen (N) deposition is low and phytoplankton is primarily N-limited. We assessed the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of seston and zooplankton and estimated the N:P ratio of consumer-driven nutrient regeneration. Based on stoichiometric models, the estimated elemental imbalances between seston and zooplankton suggest that zooplankton were mainly N-limited and regenerated nutrients with low N:P ratios (median 11.9, atomic ratio). The predicted N:P regeneration ratios were consistent with results from phytoplankton nutrient limitation bioassays in mid-summer, i.e., the N:P regeneration was predicted to be low when phytoplankton were N-limited, and high when phytoplankton were P-limited. During other seasons, when water discharge was high, nutrient loading from the surrounding catchments apparently had the strongest effect on phytoplankton nutrient limitation. We propose that lakes with higher N:P ratios than the open ocean is an effect of N deposition, that N-limitation of consumers and phytoplankton is further enhanced by low nutrient regeneration N:P ratios, and that in the absence of N deposition, lake and ocean N:P stoichiometry are similar.
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| 7. |
- Bergström, Ann-Kristin, et al.
(författare)
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Nitrogen deposition and warming – effects on phytoplankton nutrient limitation in subarctic lakes
- 2013
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Ingår i: Global Change Biology. - Hoboken, NJ : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 19:8, s. 2557-2568
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to predict the combined effects of enhanced nitrogen (N) deposition and warming on phytoplankton development in high latitude and mountain lakes. Consequently, we assessed, in a series of enclosureexperiments, how lake water nutrient stoichiometry and phytoplankton nutrient limitation varied over the growingseason in 11 lakes situated along an altitudinal/climate gradient with low N-deposition (<1 kg N ha1yr1) in northern subarctic Sweden. Short-term bioassay experiments with N- and P-additions revealed that phytoplankton inhigh-alpine lakes were more prone to P-limitation, and with decreasing altitude became increasingly N- andNP-colimited. Nutrient limitation was additionally most obvious in midsummer. There was also a strong positivecorrelation between phytoplankton growth and water temperature in the bioassays. Although excess nutrients wereavailable in spring and autumn, on these occasions growth was likely constrained by low water temperatures. Theseresults imply that enhanced N-deposition over the Swedish mountain areas will, with the exception of high-alpinelakes, enhance biomass and drive phytoplankton from N- to P-limitation. However, if not accompanied by warming,N-input from deposition will stimulate limited phytoplankton growth due to low water temperatures during largeparts of the growing season. Direct effects of warming, allowing increased metabolic rates and an extension of thegrowing season, seem equally crucial to synergistically enhance phytoplankton development in these lakes.
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| 8. |
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| 9. |
- Karlsson, Kristin C., et al.
(författare)
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A population pharmacokinetic model of gabapentin developed in nonparametric adaptive grid and nonlinear mixed effects modeling
- 2009
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Ingår i: Therapeutic Drug Monitoring. - 0163-4356 .- 1536-3694. ; 31:1, s. 86-94
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Tidskriftsartikel (refereegranskat)abstract
- Gabapentin is used in analgesic treatment of neuropathic pain, and large interindividual variation has been observed in the pharmacokinetics (PK) of the drug. The aim of this study was to develop a population PK model for gabapentin appropriate for monitoring patients with neuropathic pain and for individualizing their dose regimens. Steady-state serum concentrations of gabapentin, distributed over a dosage interval, were obtained from 16 adult patients. Data were analyzed with an iterative 2-stage Bayesian and a nonparametric adaptive grid algorithm (NPAG) (USC*PACK) and with nonlinear mixed effects modeling (NONMEM). Compartmental population models for gabapentin PK were developed in NPAG and NONMEM using creatinine clearance and body weight as covariates. Bioavailability was included in the models as a function of dose by using a hyperbolic function derived from data previously reported in the literature. The mean population parameter estimates from the final NPAG model predicted individual serum concentrations reasonably well. The models developed in NONMEM provided additional information about the relevance of the various possible covariates and also allowed for further evaluation by simulation from the model. The population PK model may be utilized in the MM-USCPACK monitoring software (MM: multiple model dosage design) for predicting and achieving individually optimized steady-state serum concentrations of gabapentin.
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| 10. |
- Karlsson, Kristin C., et al.
(författare)
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Modeling subpopulations with the $MIXTURE subroutine in NONMEM : finding the individual probability of belonging to a subpopulation for the use in model analysis and improved decision making
- 2009
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Ingår i: AAPS Journal. - : Springer. - 1550-7416. ; 11:1, s. 148-154
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Tidskriftsartikel (refereegranskat)abstract
- In nonlinear mixed effects modeling using NONMEM, mixture models can be used for multimodal distributions of parameters. The fraction of individuals belonging to each of the subpopulations can be estimated, and the most probable subpopulation for each patient is output (MIXEST(k)). The objective function value (OFV) that is minimized is the sum of the OFVs for each patient (OFV(i)), which in turn is the sum across the k subpopulations (OFV(i,k)). The OFV(i,k) values can be used together with the total probability in the population of belonging to subpopulation k to calculate the individual probability of belonging to the subpopulation (IP(k)). Our objective was to explore the information gained by using IP(k) instead of or in addition to MIXEST(k) in the analysis of mixture models. Two real data sets described previously by mixture models as well as simulations were used to explore the use of IP(k) and the precision of individual parameter values based on IP(k) and MIXEST(k). For both real data-based mixture models, a substantial fraction (11% and 26%) of the patients had IP(k) values not close to 0 or 1 (IP(k) between 0.25 and 0.75). Simulations of eight different scenarios showed that individual parameter estimates based on MIXEST were less precise than those based on IP(k), as the root mean squared error was reduced for IP(k) in all scenarios. A probability estimate such as IP(k) provides more detailed information about each individual than the discrete MIXEST(k). Individual parameter estimates based on IP(k) should be preferable whenever individual parameter estimates are to be used as study output or for simulations.
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| 11. |
- Karlsson, Kristin E, 1975-
(författare)
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Benefits of Pharmacometric Model-Based Design and Analysis of Clinical Trials
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Quantitative pharmacokinetic-pharmacodynamic and disease progression models are the core of the science of pharmacometrics which has been identified as one of the strategies that can make drug development more effective. To adequately develop and utilize these models one needs to carefully consider the nature of the data, choice of appropriate estimation methods, model evaluation strategies, and, most importantly, the intended use of the model. The general aim of this thesis was to investigate how the use of pharmacometric models can improve the design and analysis of clinical trials within drug development. The development of pharmacometric models for clinical assessment scales in stroke and graded severity events, in this thesis, show the benefit of describing data as close to its true nature as possible, as it increases the predictive abilities and allows for mechanistic interpretations of the models. Performance of three estimation methods implemented in the mixed-effects modeling software NONMEM; 1) Laplace, 2) SAEM, and 3) Importance sampling, applied when modeling repeated time-to-event data, was investigated. The two latter methods are to be preferred if less than approximately half of the individuals experience events. In addition, predictive performance of two validation procedures, internal and external validation, was explored, with internal validation being preferred in most cases. Model-based analysis was compared to conventional methods by the use of clinical trial simulations and the power to detect a drug effect was improved with a pharmacometric design and analysis. Throughout this thesis several examples have shown the possibility of significantly reducing sample sizes in clinical trials with a pharmacometric model-based analysis. This approach will reduce time and costs spent in the development of new drug therapies, but foremost reduce the number of healthy volunteers and patients exposed to experimental drugs.
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| 12. |
- Karlsson, Kristin E, et al.
(författare)
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Comparisons of Analysis Methods for Proof-of-Concept Trials
- 2013
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Ingår i: CPT. - : Wiley. - 2163-8306. ; 2, s. e23-
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Tidskriftsartikel (refereegranskat)abstract
- Drug development struggles with high costs and time consuming processes. Hence, a need for new strategies has been accentuated by many stakeholders in drug development. This study proposes the use of pharmacometric models to rationalize drug development. Two simulated examples, within the therapeutic areas of acute stroke and type 2 diabetes, are utilized to compare a pharmacometric model–based analysis to a t-test with respect to study power of proof-of-concept (POC) trials. In all investigated examples and scenarios, the conventional statistical analysis resulted in several fold larger study sizes to achieve 80% power. For a scenario with a parallel design of one placebo group and one active dose arm, the difference between the conventional and pharmacometric approach was 4.3- and 8.4-fold, for the stroke and diabetes example, respectively. Although the model-based power depend on the model assumptions, in these scenarios, the pharmacometric model–based approach was demonstrated to permit drastic streamlining of POC trials.
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| 13. |
- Karlsson, Kristin E., et al.
(författare)
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Modeling Disease Progression in Acute Stroke Using Clinical Assessment Scales
- 2010
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Ingår i: AAPS Journal. - : Springer Science and Business Media LLC. - 1550-7416. ; 12:4, s. 683-691
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Tidskriftsartikel (refereegranskat)abstract
- This article demonstrates techniques for describing and predicting disease progression in acute stroke by modeling scores measured using clinical assessment scales, accommodating dropout as an additional source of information. Scores assessed using the National Institutes of Health Stroke Scale and the Barthel Index in acute stroke patients were used to model the time course of disease progression. Simultaneous continuous and probabilistic models for describing the nature and magnitude of score changes were developed, and used to model the trajectory of disease progression using scale scores. The models described the observed data well, and exhibited good simulation properties. Applications include longitudinal analysis of stroke scale data, clinical trial simulation, and prognostic forecasting. Based upon experience in other areas, it is likely that application of this modeling methodology will enable reductions in the number of patients needed to carry out clinical studies of treatments for acute stroke.
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| 14. |
- Karlsson, Kristin E., et al.
(författare)
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Performance of three estimation methods in repeated time-to-event modeling
- 2011
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Ingår i: AAPS Journal. - : Springer Science and Business Media LLC. - 1550-7416. ; 13:1, s. 83-91
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Tidskriftsartikel (refereegranskat)abstract
- It is not uncommon that the outcome measurements, symptoms or side effects, of a clinical trial belong to the family of event type data, e.g., bleeding episodes or emesis events. Event data is often low in information content and the mixed-effects modeling software NONMEM has previously been shown to perform poorly with low information ordered categorical data. The aim of this investigation was to assess the performance of the Laplace method, the stochastic approximation expectation-maximization (SAEM) method, and the importance sampling method when modeling repeated time-to-event data. The Laplace method already existed, whereas the two latter methods have recently become available in NONMEM 7. A stochastic simulation and estimation study was performed to assess the performance of the three estimation methods when applied to a repeated time-to-event model with a constant hazard associated with an exponential interindividual variability. Various conditions were investigated, ranging from rare to frequent events and from low to high interindividual variability. The method performance was assessed by parameter bias and precision. Due to the lack of information content under conditions where very few events were observed, all three methods exhibit parameter bias and imprecision, however most pronounced by the Laplace method. The performance of the SAEM and importance sampling were generally higher than Laplace when the frequency of individuals with events was less than 43%, while at frequencies above that all methods were equal in performance.
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| 15. |
- Karlsson, Kristin E., et al.
(författare)
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Randomized exposure-controlled trials : Impact of randomization and analysis strategies
- 2007
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley. - 0306-5251 .- 1365-2125. ; 64:3, s. 266-277
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Tidskriftsartikel (refereegranskat)abstract
- Aims: In the literature, five potential benefits of randomizing clinical trials on concentration levels, rather than dose, have been proposed: (i) statistical study power will increase; (ii) study power will be less sensitive to high variability in the pharmacokinetics (PK); (iii) the power of establishing an exposure-response relationship will be robust to correlations between PK and pharmacodynamics (PD); (iv) estimates of the exposure-response relationship are likely to be less biased; and (v) studies will provide a better control of exposure in situations with toxicity issues. The main aim of this study was to investigate if these five statements are valid when the trial results are evaluated using a model-based analysis. Methods: Quantitative relationships between drug dose, concentration, biomarker and clinical end-point were defined using pharmacometric models. Three randomization schemes for exposure-controlled trials, dose-controlled (RDCT), concentration-controlled (RCCT) and biomarker-controlled (RBCT), were simulated and analysed according to the models. Results: (i) The RCCT and RBCT had lower statistical power than RDCT in a model-based analysis; (ii) with a model-based analysis the power for an RDCT increased with increasing PK variability; (iii) the statistical power in a model-based analysis was robust to correlations between CL and EC 50 or Emax; (iv) under all conditions the bias was negligible (<3%); and (v) for studies with equal power RCCT could produce either more or fewer adverse events compared with an RDCT. Conclusion: Alternative randomization schemes may not have the proposed advantages if a model-based analysis is employed.
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| 16. |
- Karlsson, Per Erik, 1957, et al.
(författare)
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Evidence for Impacts of Near-ambient Ozone Concentrations on Vegetation in Southern Sweden
- 2009
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Ingår i: Ambio. - : Royal Swedish Academy of Sciences. ; 38:8, s. 425-431
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Tidskriftsartikel (refereegranskat)abstract
- Substantial impacts of near-ambient ozone concentrations on agricultural crops, trees, and seminatural vegetation are demonstrated for southern Sweden. Impacts of ambient ozone levels (2–15 μL L-¹ hr annual accumulated ozone exposure over a threshold of 40 nL L-¹ [AOT40]) range from a 2%–10% reduction for trees (e.g., leaf chlorophyll, tree growth) up to a 15% reduction for crops (e.g., yield, wheat/potato). Visible leaf injury on bioindicator plants caused by ambient ozone levels has been clearly demonstrated. The humid climatic conditions in Sweden promote high rates of leaf ozone uptake at a certain ozone concentration. This likely explains the comparatively large ozone impacts found for vegetation in southern Sweden at relatively low ozone concentrations in the air. It is important that the future methods used for the representation of ozone impacts on vegetation across Europe are based on the leaf ozone uptake concept and not on concentration-based exposure indices, such as AOT40.
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| 17. |
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| 18. |
- Krekels, Elke H. J., et al.
(författare)
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Population Pharmacokinetics of Edoxaban in Patients with Non-Valvular Atrial Fibrillation in the ENGAGE AF-TIMI 48 Study, a Phase III Clinical Trial
- 2016
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Ingår i: Clinical Pharmacokinetics. - : Springer Science and Business Media LLC. - 0312-5963 .- 1179-1926. ; 55:9, s. 1079-1090
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Edoxaban is a novel factor Xa inhibitor. This study characterizes the population pharmacokinetics of edoxaban in patients with non-valvular atrial fibrillation (NVAF) included in the phase III ENGAGE AF-TIMI 48 study, evaluates covariates for the dose-exposure relationship in this population, and assesses the impact of protocol-specified dose reductions on exposure using simulations.Methods: Model development was performed using NONMEMA (R) and based on sparse data from the ENGAGE AF-TIMI 48 study augmented with dense data from 13 phase I studies to inform and stabilize the model. The influence of body weight (WT), creatinine clearance (CLCR), concomitant P-glycoprotein (P-gp) inhibitors, age, sex, race, and NVAF on pharmacokinetic parameters was evaluated based on statistical significance and clinical relevance.Results: A two-compartment model with first-order elimination and first-order absorption after an absorption lag-time best described the data. Apparent volume and clearance terms increased with increasing WT. Apparent renal clearance increased with increasing CLCR. Apparent non-renal, renal, and inter-compartmental clearance terms differed between phase I volunteers and NVAF patients. Asian patients were found to have increased apparent central volume of distribution, bioavailability, and total apparent clearance. Concomitant P-gp inhibitors increased the bioavailability statistically significantly, but this did not reach clinical relevance.Conclusion: Edoxaban disposition and the variability in this disposition, including influence of covariates, after oral administration were adequately characterized in patients with NVAF. The 50 % dose reduction in patients with low WT (aecurrency sign60 kg), moderate renal impairment (CLCR aecurrency sign50 mL/min), or concomitant P-gp inhibitors led to 30 % lower exposure than in the other patients.
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| 19. |
- Land, Kristin, et al.
(författare)
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A Future Legal Coordinated Cadastre for Sweden?
- 2005
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Konferensbidrag (refereegranskat)abstract
- This paper initially presents an introduction to the Swedish land administration system, particularly focusing on the parts of the Real Property Register that compose the cadastre. Here, a brief retrospect of the long tradition of land related registration follows by an account of the current components, functions and parties concerned. The second part of the paper then discusses a vision, expressed by the National Land Survey of Sweden, of implementing a legal coordinated cadastre. In short, that would mean making the boundary point coordinates, mirrored in the digital cadastral map, conclusive evidence of the location of boundaries. The aim of such a cadastre is to make possible more efficient and secure handlings with land within cadastral work, physical planning, infrastructure projects etc. Due to the present hierarchy of evidence, the “monuments before measurements” principle stated in the Land Code, a future reform of that kind would give rise to great challenges in respect of technical, economical and legal aspects. Some of these issues have become subject of a doctoral study at Lund University, Sweden. The aim of the study is to identify and analyse probable consequences of an implementation of a Swedish legal coordinated cadastre. The question of legislation and legal security, both in regard to the public sector and private interests, will be especially emphasised. The last part of this paper breifly presents this ongoing doctoral study.
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| 20. |
- Land, Kristin, et al.
(författare)
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Fastighetens gränser
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lantmäteriverket har uttryckt en vision om koordinatbestämda fastighetsgränser, med avsikt att skapa en i gränshänseende korrekt digital registerkarta. Ett förverkligande av visionen skulle kräva en förändring av gällande rätt, eftersom dagens gränssystem bygger på principen att gränsmärken på marken gäller framför andra uppgifter om gränsers sträckning. Hur en eventuell övergång till koordinatbestämda gränser skulle kunna gå till och vilka konsekvenser den skulle få behöver därför utredas. Ett underlag för en sådan analys är denna redogörelse för det nuvarande systemet. Huvudsyftet med licentiatuppsatsen är att belysa och analysera de regler och andra faktorer som kan påverka avgöranden av fastighetsgränsers rättsliga sträckning i Sverige idag. Särskilt vikt har lagts vid frågan om vilken rättsverkan bevismedel såsom redovisning av gränssträckning i ursprungshandlingar, markeringar på marken samt hävder har för olika slags gränser. För att öka förståelsen för alternativa tillvägagångssätt har den förra svenska gränsreformen (påbörjad 1933) studerats, liksom de nuvarande gränssystemen i England-Wales och Österrike. Traditionell juridisk metod har tillämpats. Intervjuer med registermyndigheter och andra gränsexperter har också gjorts, särskilt inom utlandsstudierna. Det kan konstateras att de svenska materiella gränsreglerna finns samlade i sju paragrafer i första kapitlet JB samt i JP. Alla slags gränser är precist definierade och de är, med undantag av gränser mot allmänt vatten och sådana som sammanfaller med riksgränser, orörliga. De materiella gränsregelerna är heltäckande men kan ge upphov till tolknings- och tillämpningssvårigheter. Exempelvis är några normer språkligt lika men har olika innebörd. Ett annat problem är att gränsmärken kan ha olika rättsverkan beroende på när och hur de fixerades i marken. Processuella gränsregler rörande fastighetsbestämningsinstitutet finns i fjortonde kapitlet FBL. Dessa ger fastighetsägare och lantmäterimyndigheter vissa möjligheter att göra mindre avvikelser från den sträckning som gäller enligt de materiella reglerna. Aktuella bestämmelser om tekniska åtgärder (utmärkning på marken, kartering m.m.) vid gränsers tillkomst och bestämning finns framför allt i FBL. Vidare finns särskilda regler i FBL, FL och RB som möjliggör rättelser av fel. Fastighetsägare har exempelvis rätt att klaga på felplacerade gränsmärken i upp till ett års tid. Ett särdrag för det svenska gränssystemet är att det i praktiken inte tillåter partiell markåtkomst genom hävd. Urminnes hävd är mycket svår att bevisa, och för att 20 års oklandrat innehav skall kunna ”flytta” en gräns krävs att innehavssituationen baseras på en senast 1971 ingången överenskommelse. Det finns alltså inga regler om det som på engelska kallas adverse possession. Studien av England-Wales visar att tillämpningen av den så kallade general boundary-principen i samband med registrering av mark är förenlig med ett fungerande gränssystem där tvister kan lösas på många olika sätt. Sedan hösten 2003 möjliggör dock lagstiftningen bestämning av gränser till precisa lägen genom ett relativt enkelt förfarande. I fallet Österrike är alla gränser precist definierade och ingår i ett kataster. Sedan 1969 har en successiv övergång till koordinatbestämda gränser skett för ca 12 % av parcellerna, vilka därmed ingår i det av staten garanterade registret Grenzkataster. De resterande, traditionella gränserna får vid eventuella tvister fortfarande avgöras i domstol, varvid alla slags bevismedel kan beaktas.
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| 21. |
- Land, Kristin, et al.
(författare)
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Här går gränsen
- 2004
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Ingår i: Nya Lantmätaren. ; :7/04
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 22. |
- Nyberg, Joakim, 1978-, et al.
(författare)
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Edoxaban Exposure-Response Analysis and Clinical Utility Index Assessment in Patients With Symptomatic Deep-Vein Thrombosis or Pulmonary Embolism
- 2016
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Ingår i: CPT. - : Wiley. - 2163-8306. ; 5:4, s. 222-232
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Tidskriftsartikel (refereegranskat)abstract
- Edoxaban exposure-response relationships from the phase III study evaluating edoxaban for prevention and treatment of venous thromboembolism (VTE) in patients with acute deep vein thrombosis (DVT) and/or pulmonary embolism (PE) were assessed by parametric time-to-event analysis. Statistical significant exposure-response relationships were recurrent VTE with hazard ratio (HR) based on average edoxaban concentration at steady state (C-av) (HRCav) 50.98 (i.e., change in the HR with every 1 ng/mL increase of C-av); the composite of recurrent DVT and nonfatal PE with HRC(av)50.99; and the composite of recurrent DVT, nonfatal PE, and all-cause mortality HRC(av)50.98, and all death using maximal edoxaban concentration (C-max) with HR (C-max) 50.99. No statistical significant exposure-response relationships were found for clinically relevant bleeding or major adverse cardiovascular event. Results support the recommendation of once-daily edoxaban 60 mg, and a reduced 30 mg dose in patients with moderate renal impairment, body weight <= 60 kg, or use of P-glycoprotein inhibitors verapamil or quinidine.
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| 23. |
- Piikki, Kristin, et al.
(författare)
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Estimates of AOT ozone indices from time-integrated ozone data and hourly air temperature measurements in southwest Sweden
- 2009
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 157:11, s. 3051-3058
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Tidskriftsartikel (refereegranskat)abstract
- Surface ozone concentration and surface air temperature was measured hourly at three coastal sites, four low elevation inland sites and two high elevation inland sites in southwestern Sweden. Diurnal ozone concentration range (DOR) and diurnal temperature range (DTR) were strongly correlated, both spatially and temporally, most likely because both depended on atmospheric stability. Accumulated ozone exposure above a threshold concentration of x nmol mol(-1) (AOTx) was estimated from time-integrated ozone concentration (as from diffusive sampling) and measures of ozone concentration variability. Two methods both estimated 24-h AOTx with high accuracy (modelling efficiencies >90% for x <= 40 nmol mol(-1)). Daytime (08:00-20:00) AOTx could not be equally well estimated. Estimates were better for lower AOT thresholds. Diffusive ozone concentration sampling, combined with hourly temperature monitoring, could be a valuable complement to ozone concentration monitoring with continuous instruments. (C) 2009 Elsevier Ltd. All rights reserved.
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| 24. |
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| 25. |
- Piikki, Kristin, 1975, et al.
(författare)
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Mätningar av marknära ozon och meteorologi vid kustnära och urbana miljöer i Halland, Skåne och Västra Götalands län
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under sommaren 2007 mättes ozon- (O3) halter samt meteorologi kontinuerligt under ca en månads tid vardera, på en ö i havet (Nidingen, N län), vid en kustnära plats med förväntat höga ozonhalter (Backåkra, M län) samt i en urban parkmiljö (Göteborg, O län). På dessa platser samt på ytterligare fyra olika platser i Göteborg mättes även O3- och kväveoxid- (NOx = NO2 + NO) halter med diffusionsprovtagare på vecko-basis. Mätningarna vid Nidingen, Backåkra samt parkmiljön i Göteborg gjordes inte samtidigt utan under olika perioder under olika delar av sommarhalvåret. Jämförelser med andra kustnära platser (Råö, som ligger strax söder om Göteborg, och Malmö), där ozonhalten mättes under hela sommaren, visade att den kustnära ozondynamiken med hög medelhalt och liten dygnsvariation fanns vid båda mätplatserna, men var mer utpräglad på Nidingen än i Backåkra. Värdena för några olika ozonindex, bland annat 8-timmars-medelvärde, som används i miljömålet Frisk Luft samt inom Miljökvalitetsnormerna, var högre på Nidingen, trots att landets högsta ozonbelastning, enligt vissa modellberäkningar, kan förväntas i Skåne. En slutsats blir att små öar i havet kan vara mycket utsatta för ozon. Mätningarna i Göteborg visade att ozonförekomsten kan skilja sig väsentligt mellan olika urbana platser beroende på vindförhållanden och närhet till NOx-utsläpp, och att det bara är på platser med mycket hög trafiktäthet som titrering med NO har stor betydelse för den lokala ozonhalten. Ozonförekomsten i urban parkmiljö (Slottsskogen) kan vara relativt hög. Diffusionsprovtagarna fungerade bra för ozon och NO2.. I rapporten utvärderas olika enkla matematiska modeller för att uppskatta olika ozonindex utifrån mätningar med diffusionsprovtagare i kombination med temperaturmätningar eller genom att ta hänsyn till lokalens topografiska läge. Flera olika metoder fungerade väl och rekommendationer ges för hur de bör tillämpas i olika situationer.
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| 26. |
- Plan, Elodie L., et al.
(författare)
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Approaches to simultaneous analysis of frequency and severity of symptoms
- 2010
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Ingår i: Clinical Pharmacology and Therapeutics. - : Springer Science and Business Media LLC. - 0009-9236 .- 1532-6535. ; 88:2, s. 255-259
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Tidskriftsartikel (refereegranskat)abstract
- Mechanistic models that synthesize pharmacological and (patho) physiological process information provide a rich basis for the characterization of drug action. However, the underlying clinical data are often simplified in a manner that does not allow models to fully elucidate the structure of the drug effect. In this article, we describe data-simplification strategies that are in routine use to describe disease symptoms and compare them with a model developed for handling the true complexities of the data.
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| 27. |
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| 28. |
- Abelsson, Tobias, et al.
(författare)
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A Feeling of Ambiguity: A Qualitative Content Analysis of Managers’ Experiences of Evidence-Based Practice in Swedish Primary Care
- 2022
-
Ingår i: Journal of Healthcare Leadership. - 1179-3201. ; 14, s. 143-153
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Primary care manager plays a vital role in promoting a research culture in the healthcare center. The position involves both the implementation of organizational directives and patient care. The research culture and use of evidence influence each individual healthcare professional and ultimately the quality of patient care. Purpose: To describe primary healthcare managers’ understanding of evidence-based practice in the Swedish primary healthcare context and their ability to influence its implementation. Methodology: Qualitative content analysis of data collected in individual interviews. Results: In general, managers expressed a positive view toward the use of evidence in daily practice. However, they were sometimes hesitant about fully implementing evidence-based results. This was mostly attributed to the struggle of balancing finances and allocating sufficient time for staff to keep up with and engage in evidence-based practice. Conclusion: The organizational culture impacts the mind-set of all co-workers including managers. Those managers influenced by traditions and norms may fall into the trap of devaluing the benefit of research and evidence. The inherent feeling of being alone and without guidance in some matters related to evidence-based practice inevitably leads to inconsistency and ambiguity. The use of clinical pathways that constitute one form of evidence has become a substitute for proper, careful, individual investigation, implementation, and evaluation of each patient case. This means that managers experience moral and physical stress when trying to meet organizational, staff, and patient demands. Practice Implication: Awareness of managers’ influence and experience of working according to evidence-based practice is valuable to gain an insight into how Swedish primary healthcare functions at local level. Illuminating and discussing evidence-based practice is an assurance of quality that contributes to many aspects of the overall safety of care. © 2022 Abelsson et al.
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| 29. |
- Abelsson, Tobias, et al.
(författare)
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Quality and availability of information in primary healthcare: the patient perspective
- 2020
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Ingår i: Scandinavian Journal of Primary Health Care. - : Informa UK Limited. - 0281-3432 .- 1502-7724. ; 38:1, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To explore lived experiences of patients communicating with and receiving information from primary health care. Design: Qualitative study analysing transcribed interviews by descriptive content analysis. Setting: Recruitment and interviews took place in southern Sweden in three primary care centres where privacy and undisturbed interview environments was ensured. Subjects: 17 primary care patient informants, 9 men and 8 women aged 31 - 84 years with varying educational levels from primary school to post graduates. Main outcome measures: Thematic categories and subcategories reporting the lived experience of the patients. Results: The analysis yielded three categories and identified as a main theme a feeling of unpredictability based on the emotional aspects of feeling lost and vulnerable when trying to access primary care. The category" Need for easy access" illustrated emotional aspects of importance to patients when contacting primary health care." Need for individual adaptation" described the need to individually adapt health related information." Information exchange" comprised experiences of information evaluation and understanding new information. Conclusions: Patients generally trusted the information received, but experienced a lack of communication, which evoked feelings of unpredictability and abandonment. Experiences of limited access to primary health care and the need for varying degrees of adaptation on the part of the individual were factors of concern for how patients experienced the care.
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| 30. |
- Abelsson, Tobias, et al.
(författare)
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The dilemma of the split between theory and reality as experienced by primary healthcare professionals: a mixed methods study of evidence-based practice in a primary care context
- 2024
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Ingår i: BMC PRIMARY CARE. - 2731-4553. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPrimary care depends upon a good information flow across professional and structural boundaries to provide the best care for patients. Previous research has mainly focused on Evidence-Based Practice (EBP) within specific professions. Mapping of pan-professional experiences of and attitudes to EBP in publicly funded clinical practice is necessary to deepen the understanding of EBP and its implementation. Thus, this study aimed to investigate healthcare professionals' experiences of and attitudes towards working in accordance with EBP in primary care.MethodsThe study used a convergent mixed methods design divided into two strands: a quantitative enquiry tool (Evidence-Based Practice Attitude Scale, EBPAS) and a set of qualitative interviews analysed by means of qualitative content analysis. Both strands included all primary care employees with patient interaction in the studied county (n = 625), including doctors, nurses, physiotherapists, psychologists and assistant nurses. Out of the original 625 healthcare professionals, 191 finished the first strand and 8 volunteered for the second strand (2 nurses, 2 physiotherapists, 1 psychiatrist and 3 doctors).ResultsThe EBPAS value of 2.8 (max 4) indicated a generally positive attitude towards EBP amongst the population, which was also evident in the interviews. However, there were additional experiences of not having the ability or resources to engage in EBP. This was illustrated by the theme that emerged from the qualitative content analysis: "The dilemma of the split between theory and reality". Due to the organisational and managerial focus on efficiency rather than quality of care, there were few or no incentives for promoting individual educational or research development.ConclusionsAlthough the general attitude towards EBP is positive, experiences of practising it differ. There is a need to increase knowledge of EBP concepts, requirements and implementation in the clinical setting. The absence of opportunities to do research and collegial debate about new ways of finding and implementing research-based evidence results might influence the quality of care.
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| 31. |
- Adenskog, Magnus, 1985-, et al.
(författare)
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Balancing Potential and Risk : The Living Lab Approach in Mobile Participation Research
- 2017
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Ingår i: Lecture Notes in Computer Science. - Cham : Springer Berlin/Heidelberg. - 0302-9743 .- 1611-3349. ; :10429, s. 12-23
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Tidskriftsartikel (refereegranskat)abstract
- Living labs as a research approach have been said to hold many promises regarding the evaluation of state-of-the art technologies in real-world contexts, for instance by allowing close cooperation with various stakeholders. At the same time, a living lab approach is connected with substantial complexity and increased risk. This paper elaborates on a conducted living lab with the objective to explore challenges and opportunities of mobile participation. For this purpose, a novel mobile application enabling interaction between citizens and city authorities was tested over a period of five months in Turku, Finland. In this paper, we describe identified risks associated with a living lab approach to mobile participation research. We conclude with an overall evaluation regarding the appropriateness of the living lab approach within the e-participation research field and provide recommendations on how to balance potential and risk in future projects.
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| 32. |
- Adman, Per, et al.
(författare)
-
171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
-
Ingår i: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 33. |
- Al-kharusi, Enass Said., et al.
(författare)
-
Large-Scale Retrieval of Coloured Dissolved Organic Matter in Northern Lakes Using Sentinel-2 Data
- 2020
-
Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 12:1, s. 157-157
-
Tidskriftsartikel (refereegranskat)abstract
- Owing to the significant societal value of inland water resources, there is a need for cost-effective monitoring of water quality on large scales. We tested the suitability of the recently launched Sentinel-2A to monitor a key water quality parameter, coloured dissolved organic matter (CDOM), in various types of lakes in northern Sweden. Values of a(420)CDOM (CDOM absorption at 420 nm wavelength) were obtained by analyzing water samples from 46 lakes in five districts across Sweden within an area of approximately 800 km2. We evaluated the relationships between a(420)CDOM and band ratios derived from Sentinel-2A Level-1C and Level-2A products. The band ratios B2/B3 (460 nm/560 nm) and B3/B5 (560 nm/705 nm) showed poor relationships with a(420)CDOM in Level-1C and 2A data both before and after the removal of outliers. However, there was a slightly stronger power relationship between the atmospherically-corrected B3/B4 ratio and a(420)CDOM (R2 = 0.28, n = 46), and this relationship was further improved (R2 = 0.65, n = 41) by removing observations affected by light haze and cirrus clouds. This study covered a wide range of lakes in different landscape settings and demonstrates the broad applicability of a(420)CDOM retrieval algorithms based on the B3/B4 ratio derived from Sentinel-2A. View Full-Text
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| 34. |
- Alexandersson, Karin, et al.
(författare)
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Let´s Come Together : A Macro-Oriented Model for Organizing the Support o EBP
- 2012
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Ingår i: Implementing Evicence-Informed Practice. International Perspectives. - : Canadian Scholars' Press. - 9781551304014 ; , s. 156-169
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Bokkapitel (refereegranskat)abstract
- In this chapter a macro oriented model for understanding what is needed to develope EBP in socialt welfare work is developed and illustrated.
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| 35. |
- Andersson, M. L. E., et al.
(författare)
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Diurnal variation in serum levels of cartilage oligomeric matrix protein in patients with knee osteoarthritis or rheumatoid arthritis
- 2006
-
Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 65:11, s. 1490-1494
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To monitor changes in serum concentrations of cartilage oligomeric matrix protein (COMP) during a 24-h period to determine any diurnal variation, and to estimate the half life of COMP in the circulation in patients with symptomatic knee osteoarthritis and in those with rheumatoid arthritis. Methods: Serum samples were drawn every 4 h (7 samples/patient over 24 h) in 10 patients with knee osteoarthritis and 14 patients with rheumatoid arthritis. Osteoarthritis was defined radiographically and clinically (American College of Rheumatology (ACR) criteria) and rheumatoid arthritis according to the 1987 ACR criteria. Serum COMP was measured by sandwich ELISA. A statistical model for the diurnal variation in the COMP levels was developed using the computer program NONMEM. Results: No considerable changes in COMP levels were observed during the day between 08:00 and 21:00 in either group. A significant decrease in serum COMP was apparent during bed rest at night, reaching the lowest levels between 04:00 and 05:00 (p < 0.03 or better v all other time points) in patients with osteoarthritis and in those with rheumatoid arthritis. From the rate of decreasing serum COMP levels, a putative half life of COMP in the circulation was estimated to be 7.4 h. Conclusion: During normal daytime activities, serum COMP levels are constant. The decrease during the night indicates a rapid elimination of COMP once it has reached the circulation. The stable COMP levels during the day suggest that it is not necessary to further standardise the time of serum sampling in clinical practice.
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| 36. |
- Axelsson, Christer, et al.
(författare)
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A description of the prehospital phase of aortic dissection in terms of early suspicion and treatment.
- 2015
-
Ingår i: Prehospital and Disaster Medicine. - 1049-023X .- 1945-1938. ; 30:2
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Aortic dissection is difficult to detect in the early phase due to a variety of symptoms. This report describes the prehospital setting of aortic dissection in terms of symptoms, treatment, and suspicion by the Emergency Medical Service (EMS) staff.BASIC PROCEDURES: All patients in the Municipality of Gothenburg, Sweden, who, in 2010 and 2011, had a hospital discharge diagnosis of aortic dissection (international classification of disease (ICD) I 71,0) were included. The exclusion criteria were: age<18 years of age and having a planned operation. This was a retrospective, descriptive study based on patient records. In the statistical analyses, Fisher's exact test and the Mann-Whitney U test were used for analyses of dichotomous and continuous/ordered variables.MAIN FINDINGS: Of 92 patients, 78% were transported to the hospital by the EMS. The most common symptom was pain (94%). Pain was intensive or very intensive in 89% of patients, with no significant difference in relation to the use of the EMS. Only 47% of those using the EMS were given pain relief with narcotic analgesics. Only 12% were free from pain on admission to the hospital. A suspicion of aortic dissection was reported by the EMS staff in only 17% of cases. The most common preliminary diagnosis at the dispatch center (31%) and by EMS clinicians (52%) was chest pain or angina pectoris. In all, 79% of patients were discharged alive from the hospital (75% of those that used the EMS and 95% of those that did not).CONCLUSION: Among patients who were hospitalized due to aortic dissection in Gothenburg, 78% used the EMS. Despite severe pain in the majority of patients, fewer than half received narcotic analgesics, and only 12% were free from pain on admission to the hospital. In fewer than one-in-five patients was a suspicion of aortic dissection reported by the EMS staff.
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| 37. |
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| 38. |
- Backman, Ellen, MSc, 1981-, et al.
(författare)
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Children's perspectives on mealtimes when living with a gastrostomy tube : A qualitative study
- 2021
-
Ingår i: Journal of Pediatric Nursing. - Philadelphia, PA : Elsevier. - 0882-5963 .- 1532-8449. ; 58, s. 53-59
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To explore children's experiences of mealtimes when living with a gastrostomy tube.Design and methods: The study used a qualitative descriptive design framed within ecocultural theory. Seven children, three girls and four boys, aged 6–12 years with long-term health conditions and a gastrostomy tube participated in individual interviews. The interviews were qualitatively analysed by means of systematic text condensation.Results: Four main categories comprised the findings of the children's mealtimes experiences: “Stable in form, open to variation,” “An individual, and a shared activity,” “An object that needs to be dealt with” and “A part of me.” A complex picture emerged, where the children experienced nutrition, whether through the gastrostomy tube or orally, as necessary for a healthy body, although this did not suffice to make the mealtime experience positive.Conclusions: Regardless of the children's amount of oral intake, everyday mealtimes were valued as opportunities for social interaction and experienced as a predictable, routine activity no different from the mealtimes of other families. The accounts illustrated that in many situations the children knew precisely what they needed and did not need, what they liked and disliked and why.Practice implications: Healthcare professionals should take children's knowledge into consideration to a greater extent when planning follow-up and intervention. The study illuminates that children can take an active part in their healthcare when offered flexible and carefully designed communication material, even in the presence of communicative and/or intellectual disability. © 2020 The Author(s).
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| 39. |
- Backman, Ellen, 1981-, et al.
(författare)
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Documentation of everyday life and health care following gastrostomy tube placement in children : a content analysis of medical records
- 2020
-
Ingår i: Disability and Rehabilitation. - Abingdon : Taylor & Francis. - 0963-8288 .- 1464-5165. ; 42:19, s. 2747-2757
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Everyday routines play a vital role in child functioning and development. This study explored health professionals' documentation of everyday life and health care during the first year following gastrostomy tube placement in children and the content of intervention goals.METHODS: The medical records of 39 children (median age 38 months, min-max: 15-192) in one region of Sweden were analysed. A content analysis approach was used with an inductive qualitative analysis supplemented by a deductive, quantitative analysis of documented intervention goals following the ICF-CY.RESULTS: One overall theme, "Seeking a balance", captured the view of life with a gastrostomy and the health care provided. Two categories, "Striving for physical health" and "Depicting everyday life" with seven sub-categories, captured the key aspects of the documentation. Twenty-one children (54%) had intervention goals related to the gastrostomy, and these goals primarily focused on the ICF-CY component "Body functions".CONCLUSIONS: To some extent the medical records reflected different dimensions of everyday life, but the intervention goals clearly focused on bodily aspects. Understanding how health care for children using a gastrostomy is documented and planned by applying an ecocultural framework adds a valuable perspective and can contribute to family-centred interventions for children using a gastrostomy. Implications for Rehabilitation There is a need for increased awareness in healthcare professionals for a more consistent and holistic healthcare approach in the management of children with gastrostomy tube feeding. This study suggests that an expanded focus on children's participation in everyday mealtimes and in the healthcare follow-up of gastrostomy tube feeding is important in enhancing the intervention outcome. Multidisciplinary teams with a shared bio-psycho-social understanding of health would contribute to a situation in which the everyday lives of households adapt to living with gastrostomy. Routine care for children with gastrostomy should follow a checklist combining crucial physiological aspects of gastrostomy tube feeding with seemingly mundane family functions in order to achieve a successful gastrostomy tube feeding intervention.
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| 40. |
- Backman, Ellen, 1981-, et al.
(författare)
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Gastrostomy tube feeding in children with developmental or acquired disorders : A longitudinal comparison on health care provision, and eating outcomes four years after gastrostomy
- 2018
-
Ingår i: Nutrition in clinical practice. - Thousand Oaks : Sage Publications. - 0884-5336. ; 33:4, s. 576-583
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies on long‐term feeding and eating outcomes in children requiring gastrostomy tube feeding (GT) are scarce. The aim of this study was to describe children with developmental or acquired disorders receiving GT and to compare longitudinal eating and feeding outcomes. A secondary aim was to explore healthcare provision related to eating and feeding.Methods: This retrospective cohort study reviewed medical records of children in 1 administrative region of Sweden with GT placement between 2005 and 2012. Patient demographics, primary diagnoses, age at GT placement, and professional healthcare contacts prior to and after GT placement were recorded and compared. Feeding and eating outcomes were assessed 4 years after GT placement.Results: The medical records of 51 children, 28 boys and 23 girls, were analyzed and grouped according to “acquired” (n = 13) or “developmental” (n = 38) primary diagnoses. At 4 years after GT placement, 67% were still using GT. Only 6 of 37 (16%) children with developmental disorders transferred to eating all orally, as opposed to 10 of 11 (91%) children with acquired disorders. Children with developmental disorders were younger at the time of GT placement and displayed a longer duration of GT activity when compared with children with acquired disorders.Conclusions: This study demonstrates a clear difference between children with developmental or acquired disorders in duration of GT activity and age at GT placement. The study further shows that healthcare provided to children with GT is in some cases multidisciplinary, but primarily focuses on feeding rather than eating.
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| 41. |
- Backman, Ellen, MSc, 1981-
(författare)
-
Ordinary mealtimes under extraordinary circumstances : Routines and rituals of nutrition, feeding and eating in children with a gastrostomy and their families
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to explore routines and rituals related to feeding, eating, and mealtimes in families that have a child with a gastrostomy tube (G-tube), from the perspectives of healthcare professionals, the children, and their parents. The thesis is based on four empirical studies. Study I is a longitudinal, quantitative study with the aim to describe children with developmental or acquired disorders receiving a G-tube, and to compare characteristics, contacts with healthcare professionals, and longitudinal eating outcomes. Findings from Study I demonstrated that children with developmental disorders needed G-tube feeding for longer than children with acquired disorders. Children with developmental disorders were also younger at G-tube placement, and had more multidisciplinary healthcare. These findings led to the subsequent studies focused specifically on children with developmental disorders. Study II applies mixed methods and explores everyday life, health care, and intervention goals during the first year following G-tube placement through the documentation in medical records. In Studies III and IV, the experiences of family mealtimes for children with a G-tube and their parents are collected through individual interviews that are analysed qualitatively. Triangulation of methods, participants, researchers, and data across the four studies is applied to search for confirmation between findings, as well as to identify areas of discrepancy. Ecocultural theory, the WHO framework ICF, and the concept of participation form the conceptual framework of the thesis. Taken together, findings from the studies describe how the main experiences of feeding, eating, and mealtime relate to specific impairments of the child, the collective value attached to family mealtimes, and the parental responsibility to harmonise competing interests and conflicts among family members and/or healthcare professionals. This thesis extends previous research by focusing on the ecocultural context of the child in combination with a dimensional understanding of health. The findings shed light on measures taken by the families themselves to adjust to and handle their daily lives, as well as spell out areas where more support is needed. Furthermore, this thesis suggests that an expanded focus on children’s participation in everyday mealtimes, and in the healthcare follow-up of G-tube feeding, is important in enhancing intervention outcomes.
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| 42. |
- Backman, Ellen, MSc, 1981-, et al.
(författare)
-
Parental Perspectives on Family Mealtimes Related to Gastrostomy Tube Feeding in Children
- 2021
-
Ingår i: Qualitative Health Research. - Thousand Oaks, CA : Sage Publications. - 1049-7323 .- 1552-7557. ; 31:9, s. 1596-1608
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Tidskriftsartikel (refereegranskat)abstract
- Built on the important functions daily routines serve families and child health, this study aimed to explore parents’ descriptions of mealtimes and food-related challenges when living with a child using a gastrostomy feeding tube. The study was informed by ecocultural theory and based on in-depth interviews combined with stimulated recall. The interviews of 10 parents were inductively analyzed by means of qualitative content analysis. Four main categories comprised the parents’ descriptions: “One situation, different functions,” “On the child’s terms,” “Doing something to me,” and “An unpredictable pattern,” with one overarching theme. The analyses showed that the parents strived to establish mealtimes in line with their cultural context, although they struggled to reach a point of satisfaction. The study highlights the importance of health care professionals to address the medical aspects of caring for a child with a G-tube, but also the potential psychological and social consequences for ordinary family life. © The Author(s) 2021.
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| 43. |
- Backman, Ellen, 1981-, et al.
(författare)
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The use of gastrostomy in Swedish children – indications, and trends between 2005 and 2015
- 2017
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Konferensbidrag (refereegranskat)abstract
- Children with complex medical needs requiring nutritional support are growing in number. This presentation will add new knowledge regarding gastrostomy in children by reporting primary diagnosis, and indications for the use of gastrostomy. Furthermore, the presentation will discuss and analyse data evolution trends from 2005 to 2015 in Sweden.Methods: The first part of the study used national statistics to provide a broad picture of gastrostomy use in Swedish children. The second part applied a retrospective observational study design, reviewing medical charts in order to obtain an in-depth picture of the children in need for gastrostomy, and its use in a five-year perspective.Results: The number of gastrostomy cases recorded in the national database was 3 946, 53% male, and 47% female. The distribution of age groups was: 0-4 years: 61% , 5-9 years: 17%, 10-14 years: 12%, and 15-19: years 10%. When observing trends on a national level, the number of children receiving gastrostomy increased in average by 13% per year. Changes in the separate age groups were analysed. An increase was noted for children aged 0-4 years and for children aged 5-9 years. In the age groups 10-14 years and 15-19 years, there was no progressive increase. The results from the national statistics database will be discussed in relation to the medical chart-analyses of 75 children receiving gastrostomy in one Swedish administrative region between 2005 and 2015. Conclusions: As in many parts of Europe, the number of children in need for gastrostomy is also growing in Sweden, with the youngest children seeming to be the group increasing most.Clinical implications: Nutritional support in Sweden is publicly financed, therefore these findings may be useful when planning both monetary and human resources in meeting the future challenges of paediatric health care.
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| 44. |
- Bartels, Pia, et al.
(författare)
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Terrestrial subsidies to lake food webs : an experimental approach
- 2012
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Ingår i: Oecologia. - New York : Springer. - 0029-8549 .- 1432-1939. ; 168:3, s. 807-818
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Tidskriftsartikel (refereegranskat)abstract
- Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less is known about allochthonous particulate organic carbon (POC). Similarly, most studies showing the effects of allochthonous organic carbon (OC) on aquatic consumers have investigated pelagic habitats; the effects of allochthonous OC on benthic communities are less well studied. Allochthonous inputs might further decrease primary production through light reduction, thereby potentially affecting autotrophic resource availability to consumers. Here, an enclosure experiment was carried out to test the importance of POC input and light availability on the resource use in a benthic food web of a clear-water lake. Corn starch (a C-4 plant) was used as a POC source due to its insoluble nature and its distinct carbon stable isotope value (delta C-13). The starch carbon was closely dispersed over the bottom of the enclosures to study the fate of a POC source exclusively available to sediment biota. The addition of starch carbon resulted in a clear shift in the isotopic signature of surface-dwelling herbivorous and predatory invertebrates. Although the starch carbon was added solely to the sediment surface, the carbon originating from the starch reached zooplankton. We suggest that allochthonous POC can subsidize benthic food webs directly and can be further transferred to pelagic systems, thereby highlighting the importance of benthic pathways for pelagic habitats.
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| 45. |
- Berggren, Martin, et al.
(författare)
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Allochthony in major groups of crustacean zooplankton in boreal lakes – strongly contrasting patterns across space and time
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The role of terrestrial organic carbon for recipient aquatic ecosystems is intensively researched. A multitude of studies now show that terrestrially-derived carbon supports a significant share (allochthony) of consumer biomass in many freshwaters. However, little is known about the mechanisms by which terrestrially-derived carbon is transferred to the level of metazoan zooplankton, and whether these pathways vary among taxonomic and functional groups. Here we present stable isotope-inferred allochthony in three major groups of crustacean zooplankton – Cladocera, Calanoida and Cyclopoida – measured both seasonally and across wide ranges of environmental gradients in boreal areas of Canada and Sweden. Our data show strongly contrasting patterns between taxa in the allochthony regulation. Whereas allochthony in calanoids was regulated by shortage of phytoplankton particles per se, both across space and time, allochthony in cyclopoids was related to food chains supported by dissolved organic carbon. Cladocerans showed the highest allochthony, but a more complex regulation. Terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, but it can also sustain otherwise herbivorous calanoids during low productivity conditions, e.g. in winter.
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| 46. |
- Berggren, Martin, et al.
(författare)
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Intraspecific autochthonous and allochthonous resource use by zooplankton in a humic lake during the transitions between winter, summer and fall
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin) in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden). The use of allochthonous resources was important for sustaining a small population of calanoids in the water column during late winter. However, in summer the calanoids shifted to 100% herbivory, increasing their biomass several-fold by making efficient use of the pelagic primary production. In contrast, the cyclopoids and cladocerans remained at high levels of allochthony throughout the seasons, both groups showing the mean allochthony of 0.56 (range in mean 0.17-0.79 and 0.34-0.75, for the respective group, depending on model parameters). Our study shows that terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, forming a significant link between terrestrial organic matter and the higher trophic levels of the food web, but it can also be important for sustaining otherwise herbivorous calanoids during periods of low primary production in late winter.
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| 47. |
- Berggren, Martin, et al.
(författare)
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Lake secondary production fueled by rapid transfer of low molecular weight organic carbon from terrestrial sources to aquatic consumers
- 2010
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 13:7, s. 870-880
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Tidskriftsartikel (refereegranskat)abstract
- P>Carbon of terrestrial origin often makes up a significant share of consumer biomass in unproductive lake ecosystems. However, the mechanisms for terrestrial support of lake secondary production are largely unclear. By using a modelling approach, we show that terrestrial export of dissolved labile low molecular weight carbon (LMWC) compounds supported 80% (34-95%), 54% (19-90%) and 23% (7-45%) of the secondary production by bacteria, protozoa and metazoa, respectively, in a 7-km2 boreal lake (conservative to liberal estimates in brackets). Bacterial growth on LMWC was of similar magnitude as that of primary production (PP), and grazing on bacteria effectively channelled the LMWC carbon to higher trophic levels. We suggest that rapid turnover of forest LMWC pools enables continuous export of fresh photosynthates and other labile metabolites to aquatic systems, and that substantial transfer of LMWC from terrestrial sources to lake consumers can occur within a few days. Sequestration of LMWC of terrestrial origin, thus, helps explain high shares of terrestrial carbon in lake organisms and implies that lake food webs can be closely dependent on recent terrestrial PP.
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| 48. |
- Berggren, Martin, et al.
(författare)
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Nutrient limitation masks the dissolved organic matter composition effects on bacterial metabolism in unproductive freshwaters
- 2023
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Ingår i: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 68:9, s. 2059-2069
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Tidskriftsartikel (refereegranskat)abstract
- Aquatic microbial responses to changes in the amount and composition of dissolved organic carbon (DOC) are of fundamental ecological and biogeochemical importance. Parallel factor (PARAFAC) analysis of excitation–emission fluorescence spectra is a common tool to characterize DOC, yet its ability to predict bacterial production (BP), bacterial respiration (BR), and bacterial growth efficiency (BGE) vary widely, potentially because inorganic nutrient limitation decouples microbial processes from their dependence on DOC composition. We used 28-d bioassays with water from 19 lakes, streams, and rivers in northern Sweden to test how much the links between bacterial metabolism and fluorescence PARAFAC components depend on experimental additions of inorganic nutrients. We found a significant interaction effect between nutrient addition and fluorescence on carbon-specific BP, and weak evidence for influence on BGE by the same interaction (p = 0.1), but no corresponding interaction effect on BR. A practical implication of this interaction was that fluorescence components could explain more than twice as much of the variability in carbon-specific BP (R2 = 0.90) and BGE (R2 = 0.70) after nitrogen and phosphorus addition, compared with control incubations. Our results suggest that an increased supply of labile DOC relative to ambient phosphorus and nitrogen induces gradually larger degrees of nutrient limitation of BP, which in turn decouple BP and BGE from fluorescence signals. Thus, while fluorescence does contain precise information about the degree to which DOC can support microbial processes, this information may be hidden in field studies due to nutrient limitation of bacterial metabolism.
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| 49. |
- Bergström, Ann-Kristin, 1968-, et al.
(författare)
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Effects of nitrogen enrichment on zooplankton biomass and N:P recycling ratios across a DOC gradient in northern-latitude lakes
- 2021
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Ingår i: Hydrobiologia. - : Springer. - 0018-8158 .- 1573-5117. ; 848:21, s. 4991-5010
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Tidskriftsartikel (refereegranskat)abstract
- We used data from whole-lake studies to assess how changes in food quantity (phytoplankton biomass) and quality (phytoplankton community composition, seston C:P and N:P) with N fertilization affect zooplankton biomass, community composition and C:N:P stoichiometry, and their N:P recycling ratio along a gradient in lake DOC concentrations. We found that despite major differences in phytoplankton biomass with DOC (unimodal distributions, especially with N fertilization), no major differences in zooplankton biomass were detectable. Instead, phytoplankton to zooplankton biomass ratios were high, especially at intermediate DOC and after N fertilization, implying low trophic transfer efficiencies. An explanation for the observed low phytoplankton resource use, and biomass responses in zooplankton, was dominance of colony forming chlorophytes of reduced edibility at intermediate lake DOC, combined with reduced phytoplankton mineral quality (enhanced seston N:P) with N fertilization. N fertilization, however, increased zooplankton N:P recycling ratios, with largest impact at low DOC where phytoplankton benefitted from light sufficiently to cause enhanced seston N:P. Our results suggest that although N enrichment and increased phytoplankton biomass do not necessarily increase zooplankton biomass, bottom-up effects may still impact zooplankton and their N:P recycling ratio through promotion of phytoplankton species of low edibility and altered mineral quality.
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| 50. |
- Bergström, Ann-Kristin, 1968-, et al.
(författare)
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Light and nutrient control phytoplankton biomass responses to global change in northern lakes
- 2019
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 25:6, s. 2021-2029
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Tidskriftsartikel (refereegranskat)abstract
- Global change affects terrestrial loadings of colored dissolved organic carbon (DOC) and nutrients to northern lakes. Still, little is known about how phytoplankton respond to changes in light and nutrient availability across gradients in lake DOC. In this study, we used results from whole-lake studies in northern Sweden to show that annual mean phytoplankton biomass expressed unimodal curved relationships across lake DOC gradients, peaking at threshold DOC levels of around 11 mg/L. Whole-lake single nutrient enrichment in selected lakes caused elevated biomass, with most pronounced effect at the threshold DOC level. These patterns give support to the suggested dual control by DOC on phytoplankton via nutrient (positively) and light (negatively) availability and imply that the lakes' location along the DOC axis is critical in determining to what extent phytoplankton respond to changes in DOC and/or nutrient loadings. By using data from the large Swedish Lake Monitoring Survey, we further estimated that 80% of northern Swedish lakes are below the DOC threshold, potentially experiencing increased phytoplankton biomass with browning alone, and/or combined with nutrient enrichment. The results support the previous model results on effects of browning and eutrophication on lake phytoplankton, and provide important understanding of how northern lakes may respond to future global changes.
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