| 1. |
- Basna, Rani, et al.
(författare)
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Spline-based methods for functional data on multivariate domains
- 2024
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Ingår i: Journal of Mathematics in Industry. - 2190-5983. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Functional data analysis is typically performed in two steps: first, functionally representing discrete observations, and then applying functional methods to the so-represented data. The initial choice of a functional representation may have a significant impact on the second phase of the analysis, as shown in recent research, where data-driven spline bases outperformed the predefined rigid choice of functional representation. The method chooses an initial functional basis by an efficient placement of the knots using a simple machine-learning algorithm. The knot selection approach does not apply directly when the data are defined on domains of a higher dimension than one such as, for example, images. The reason is that in higher dimensions the convenient and numerically efficient spline spaces use tensor bases that require knots located on a lattice. This fundamentally limits flexible knot placement which is fundamental for the approach. The goal of this research is two-fold: first, to propose modified approaches that circumvent the issue by coding the irregular knot selection into the topology of the spaces of tensor-based splines; second, to apply the approach to a classification problem workflow for functional data that utilizes knot selection. The performance is preliminarily accessed on a benchmark dataset and shown to be comparable to or better than the previous methods.
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| 2. |
- Basnakova, G, et al.
(författare)
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Identification of Nickel Uranyl Phosphate Deposits on Citrobacter sp. Cells by Electron Microscopy with Electron Probe X-ray Microanalysis and by Proton-Induced X-ray Emission Analysis
- 1998
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 32:6, s. 760-765
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Tidskriftsartikel (refereegranskat)abstract
- Immobilized cells of a Citrobacter sp. can remove heavy metals from wastewaters by deposition ofmetals with enzymatically liberated phosphate. Nickel is not removed effectively by this technique, but Ni2+ can be intercalated into cell-bound, crystalline HUO2PO4 previously deposited enzymatically. This technique for efficient removal of Ni from solution has been generically termed microbially enhanced chemisorption of heavy metals(MECHM). The nickel uranyl phosphate deposits bound to Citrobactersp. cells immobilized in polyacrylamide gel (FAG) were analyzed using scanning transmission electronmicroscopy with electron probe X-ray microanalysis (EPXMA) and proton-induced X-ray emissionanalysis(PIXE). Both methods gave the molar ratios of nickel, uranium, and phosphorus in the depositsas close to 1:2:2 in all analyzed parts of the sample. EPXMA proved that the deposits were localized onthe surface of cells inside FAG particles as well as those immobilized on the edge. Small deposits ofnickel uranyl phosphate were also found in FAG between the cells, indicating the possible involvementof extracellular polymeric substances (EPS) in the creation of intercellular deposits. These findings confirm the mechanism of MECHM and show that this mechanism operates throughout the immobilized cell matrix. The use of two independent methods of solid-state analysis in a common sample provides validation of both techniques for the spatial and quantitative analysis of biomass-bound elements.
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| 3. |
- Ekerwald, Hedvig
(författare)
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Om humorns ståndpunkt
- 1993
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Ingår i: Invandrare & Minoriteter. ; :3
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Forssen, Patrik, et al.
(författare)
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A model free method for estimation of complicated adsorption isotherms in liquid chromatography
- 2015
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1409, s. 108-115
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Tidskriftsartikel (refereegranskat)abstract
- Here we show that even extremely small variations in the adsorption isotherm can have a tremendous effect on the shape of the overloaded elution profiles and that the earlier in the adsorption isotherms the variation take place, the larger its impact on the shape of the elution profile. These variations are so small that they can be "hidden" by the discretization and in the general experimental noise when using traditional experimental methods, such as frontal analysis, to measure adsorption isotherms. But as the effects of these variations are more clearly visible in the elution profiles, the Inverse Method (IM) of adsorption isotherm estimation is an option. However, IM usually requires that one selects an adsorption isotherm model prior to the estimation process. Here we show that even complicated models might not be able to estimate the adsorption isotherms with multiple inflection points that small variations might give rise to. We therefore developed a modified IM that, instead of fixed adsorption isotherm models, uses monotone piecewise interpolation. We first validated the method with synthetic data and showed that it can be used to estimate an adsorption isotherm, which accurately predicts an extremely "strange" elution profile. For this case it was impossible to estimate the adsorption isotherm using IM with a fixed adsorption model. Finally, we will give an example of a real chromatographic system where adsorption isotherm with inflection points is estimated by the modified IM.
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| 5. |
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| 6. |
- Poudel, Bishnu Chandra, et al.
(författare)
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Effects of climate change on biomass production and substitution in north-central Sweden
- 2011
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 35:10, s. 4340-4355
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Tidskriftsartikel (refereegranskat)abstract
- In this study we estimate the effects of climate change on forest production in north-central Sweden, as well as the potential climate changemitigation feedback effects of the resulting increased carbon stock and forest product use. Our results show that an average regional temperature rise of 4 °C over the next 100 years may increase annual forest production by 33% and potential annual harvest by 32%, compared to a reference case without climate change. This increased biomass production, if used to substitute fossil fuels and energy-intensive materials, can result in a significant net carbon emission reduction. We find that carbon stock in forest biomass, forest soils, and wood products also increase, but this effect is less significant than biomass substitution. A total net reduction in carbon emissions of up to 104 Tg of carbon can occur over 100 years, depending on harvest level and reference fossil fuel. © 2011 Elsevier Ltd.
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| 7. |
- Poudel, Bishnu Chandra, et al.
(författare)
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Forest biomass production and their potential use to mitigate climate change
- 2012
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Ingår i: Tackling climate change. - Tours, France : INRA Editions.
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Konferensbidrag (refereegranskat)abstract
- This paper examines how forest products can be utilized to contribute tackling climate change. An integrated model-based system analysis approach is applied to estimate forest biomass production and substitution effects of climate change and forest management goals. We estimate net primary production with the use of process based model BIOMASS incorporating climate change effects according to IPCC SRES B2 scenario. BIOMASS considers the processes of radiation absorption, photosynthesis, phenology, allocation of photosynthesis among plant organs, litter-fall, and the stand water balance. The resulting output of net primary production from BIOMASS is input into the empirical model HUGIN to calculate tree growth functions in five scenarios representing different forest management goals. These growth functions determine the total growth and the potential harvestable forest biomass. The harvested products in terms of whole tree biomass and stem wood biomass are then assumed to substitute construction materials and fossil fuels, and the substitution effect is calculated in terms of net CO2 emission reduction. We use the Q-model to estimate soil carbon changes in the forest because of litter fall and soil decomposition processes in different scenarios. The results show that the climate change effect and intensive forestry practice can increase forest production and product harvest by up to 75% and 69% respectively compared to the production in the year 2010. If the harvested biomass is used to substitute fossil fuel and building construction materials a total net carbon emission reduction up to 249 Tg carbon is possible. The carbon stock in standing biomass, forest soils, and wood products all increases. The carbon stock changes are less significant than compared to the substitution benefits. This study can conclude that the climate change effect and improved forest management practices may increase forest biomass significantly, thus will give increased opportunity to reduce carbon emission significantly to contribute to the climate change mitigation.
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| 8. |
- Ahl, Rebecka, 1987-, et al.
(författare)
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Does early beta-blockade in isolated severe traumatic brain injury reduce the risk of post traumatic depression?
- 2017
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Ingår i: Injury. - : Elsevier. - 0020-1383 .- 1879-0267. ; 48:1, s. 101-105
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Depressive symptoms occur in approximately half of trauma patients, negatively impacting on functional outcome and quality of life following severe head injury. Pontine noradrenaline has been shown to increase upon trauma and associated beta-adrenergic receptor activation appears to consolidate memory formation of traumatic events. Blocking adrenergic activity reduces physiological stress responses during recall of traumatic memories and impairs memory, implying a potential therapeutic role of beta-blockers. This study examines the effect of pre-admission beta-blockade on post-traumatic depression.Methods: All adult trauma patients (>= 18 years) with severe, isolated traumatic brain injury (intracranial Abbreviated Injury Scale score (AIS) >= 3 and extracranial AIS <3) were recruited from the trauma registry of an urban university hospital between 2007 and 2011. Exclusion criteria were in-hospital deaths and prescription of antidepressants up to one year prior to admission. Pre- and post-admission beta-blocker and antidepressant therapy data was requested from the national drugs registry. Post-traumatic depression was defined as the prescription of antidepressants within one year of trauma. Patients with and without pre-admission beta-blockers were matched 1: 1 by age, gender, Glasgow Coma Scale, Injury Severity Score and head AIS. Analysis was carried out using McNemar's and Student's t-test for categorical and continuous data, respectively.Results: A total of 545 patients met the study criteria. Of these, 15% (n = 80) were prescribed beta-blockers. After propensity matching, 80 matched pairs were analyzed. 33% (n = 26) of non beta-blocked patients developed post-traumatic depression, compared to only 18% (n = 14) in the beta-blocked group (p = 0.04). There were no significant differences in ICU (mean days: 5.8 (SD 10.5) vs. 5.6 (SD 7.2), p = 0.85) or hospital length of stay (mean days: 21 (SD 21) vs. 21 (SD 20), p = 0.94) between cohorts.Conclusion: beta-blockade appears to act prophylactically and significantly reduces the risk of posttraumatic depression in patients suffering from isolated severe traumatic brain injuries. Further prospective randomized studies are warranted to validate this finding.
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| 9. |
- Basmarke-Wehelie, Rahma, et al.
(författare)
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The complement regulator CD46 is bactericidal to Helicobacter pylori and blocks urease activity
- 2011
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Ingår i: Gastroenterology. - Baltimore : Elsevier BV. - 0016-5085 .- 1528-0012. ; 141:3, s. 918-928
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: CD46 is a C3b/C4b binding complement regulator and a receptor for several human pathogens. We examined the interaction between CD46 and Helicobacter pylori (a bacterium that colonizes the human gastric mucosa and causes gastritis), peptic ulcers, and cancer.METHODS: Using gastric epithelial cells, we analyzed a set of H pylori strains and mutants for their ability to interact with CD46 and/or influence CD46 expression. Bacterial interaction with full-length CD46 and small CD46 peptides was evaluated by flow cytometry, fluorescence microscopy, enzyme-linked immunosorbent assay, and bacterial survival analyses.RESULTS: H pylori infection caused shedding of CD46 into the extracellular environment. A soluble form of CD46 bound to H pylori and inhibited growth, in a dose- and time-dependent manner, by interacting with urease and alkyl hydroperoxide reductase, which are essential bacterial pathogenicity-associated factors. Binding of CD46 or CD46-derived synthetic peptides blocked the urease activity and ability of bacteria to survive in acidic environments. Oral administration of one CD46 peptide eradicated H pylori from infected mice.CONCLUSIONS: CD46 is an antimicrobial agent that can eradicate H pylori. CD46 peptides might be developed to treat H pylori infection.
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| 10. |
- Basmo Ellingsen, Espen, et al.
(författare)
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Telomerase as a Target for Therapeutic Cancer Vaccines and Considerations for Optimizing Their Clinical Potential
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
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Forskningsöversikt (refereegranskat)abstract
- Telomerase-based therapeutic cancer vaccines (TCVs) have been under clinical investigation for the past two decades. Despite past failures, TCVs have gained renewed enthusiasm for their potential to improve the efficacy of checkpoint inhibition. Telomerase stands as an attractive target for TCVs due to its almost universal presence in cancer and its essential function promoting tumor growth. Herein, we review tumor telomerase biology that may affect the efficacy of therapeutic vaccination and provide insights on optimal vaccine design and treatment combinations. Tumor types possessing mechanisms of increased telomerase expression combined with an immune permissive tumor microenvironment are expected to increase the therapeutic potential of telomerase-targeting cancer vaccines. Regardless, rational treatment combinations, such as checkpoint inhibitors, are likely necessary to bring out the true clinical potential of TCVs.
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