| 1. |
- Bernin, Diana, 1979, et al.
(författare)
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Multi-scale characterization of pasta during cooking using microscopy and real-time magnetic resonance imaging
- 2014
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 66, s. 132-139
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Tidskriftsartikel (refereegranskat)abstract
- Macroscopic properties of pasta, such as the texture, are formed during cooking by a complex interplay of water and heat with the structuring agents starch and gluten. The impact of the starch-to-gluten ratio on microstructure and water distribution in pasta was analyzed by a multi-scale approach combining magnetic resonance imaging (MRI) and light microscopy. The cooking process and thus the water distribution was monitored non-invasively using 1H MRI in real-time with a temporal resolution of 45s. Our MRI set-up allowed following the water ingress by imaging the reduction of the uncooked core. The water ingress rate was neither dependent on pasta composition nor on the presence of salt in the cooking media (0.7% NaCl). Starch-rich samples showed a more homogeneous water distribution in the gelatinized zone, which was mirrored in a more homogeneous microstructure. In contrast, gluten-rich samples showed both a heterogeneous water distribution and microstructure. Thus, the gluten content affected local water content in the gelatinized zone but not the water ingress. © 2014 Elsevier Ltd.
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| 2. |
- Carlsson, Bo, et al.
(författare)
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The evolving domain of entrepreneurship research
- 2013
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Ingår i: Small Business Economics. - : Springer Science and Business Media LLC. - 0921-898X .- 1573-0913. ; 41:4, s. 913-930
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Tidskriftsartikel (refereegranskat)abstract
- Research on entrepreneurship has flourished in recent years and is evolving rapidly. This article explores the history of entrepreneurship research, how the research domain has evolved, and its current status as an academic field. The need to concretize these issues stems partly from a general interest in defining the current research domain and partly from the more specific tasks confronting the prize committee of the Global Award for Entrepreneurship Research. Entrepreneurship has developed in many sub-fields within several disciplines-primarily economics, management/business administration, sociology, psychology, economic and cultural anthropology, business history, strategy, marketing, finance, and geography-representing a variety of research traditions, perspectives, and methods. We present an analytical framework that organizes our thinking about the domain of entrepreneurship research by specifying elements, levels of analysis, and the process/context. An overview is provided of where the field stands today and how it is positioned relative to the existing disciplines and new research fields upon which it draws. Areas needed for future progress are highlighted, particularly the need for a rigorous dynamic theory of entrepreneurship that relates entrepreneurial activity to economic growth and human welfare. Moreover, applied work based on more careful design as well as on theoretical models yielding more credible and robust estimates seems also highly warranted.
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| 3. |
- Cronie, Ottmar, 1979, et al.
(författare)
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Spatiotemporal Modeling of Swedish Scots Pine Stands
- 2013
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Ingår i: Forest Science. - : Oxford University Press (OUP). - 0015-749X .- 1938-3738. ; 59:5, s. 505-516
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Tidskriftsartikel (refereegranskat)abstract
- The growth-interaction (GI) process is used for the spatiotemporal modeling of measurements of locations and radii at breast height made at three different time points of the individual trees in 10 Scots pine (Pinus sylvestris) plots from the Swedish National Forest Inventory. The GI process places trees at random locations in the study region and assigns sizes to the trees, which interact and grow with time. It has been used to model plots in previous studies and to improve the fit we suggest some modifications: a different location assignment strategy and a different open-growth (growth under negligible competition) function. We believe that the calibration data contain trees that are too small to reflect the open growth properly, which primarily affects the carrying capacity parameter. To better represent the open growth of Scots pines, we evaluate the open growth from a separate set of data (size and age measurements of older and larger single Scots pines). A linear relationship is found between the plot's estimated site indices and the sizes, and this is exploited in the estimation of the carrying capacity. We finally estimate the remaining GI process parameters and test the goodness of fit on simulated predictions from the fitted model.
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| 4. |
- Gerber, Lorenz, 1976, et al.
(författare)
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Using imaging ToF-SIMS data to determine the cell wall thickness of fibers in wood
- 2014
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Ingår i: Surface and Interface Analysis. - : Wiley. - 1096-9918 .- 0142-2421. ; 46:S1, s. 225-228
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Tidskriftsartikel (refereegranskat)abstract
- Here, we demonstrate the use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging data for estimation of cell wall thickness in wood samples. Current research in forest biotechnology focuses on transgenic trees with wood properties tailored to specific applications. Appropriate analytical methods to characterize the very heterogeneous wood material are constantly being developed and improved. Chemical imaging of wood by ToF-SIMS represents an interesting tool for this purpose with many applications. In addition to wood chemistry, the impact of specific genetic modifications on wood anatomy needs to be assessed. Cell wall thickness is an important anatomical parameter that among others is used for assessing biomass accumulation. We developed a strategy to estimate cell wall thickness from ToF-SIMS images and implemented it in the open source programming language R'. In brief, random lines are projected over the black and white mask of a ToF-SIMS image, and length values of all line sections that cut across a cell wall are collected. After enough iteration, the shortest values of the obtained count distribution represent the crossing sections normal to the cell walls, hence cell wall thickness. Compared with conventional light microscopy image analysis, TOF-SIMS data offers many advantages such as submicron resolution and additional spectral information for automated annotation of distinct anatomical features. This work underlines the importance of SIMS imaging for studies of wood chemistry and anatomy and provides a new approach to obtain an important wood anatomical parameter from ToF-SIMS data.
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| 5. |
- Hammar, Henrik, 1970, et al.
(författare)
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The kilometer tax and Swedish industry-effects on sectors and regions
- 2011
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Ingår i: Applied Economics. - London : Chapman and Hall. - 0003-6846 .- 1466-4283. ; 43, s. 2907-2917
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Tidskriftsartikel (refereegranskat)abstract
- An introduction of a kilometer tax for heavy goods vehicles can be constrained by the risk of that higher production costs than competitors in other countries will negatively affect regions and industries of policy concern. We estimate factor demand elasticities in the Swedish manufacturing industry using firm level data for the 1990 to 2001 period on input prices and quantities. The results show that the introduction of a kilometer tax for heavy goods vehicles decreases transport demand and increases labour demand. The effects are less pronounced in terms of changes in output, though some industries (e.g. wood, pulp and paper) can be expected to be affected more than others due to their dependence on road freight transport. The regional dimension regarding the consequences of a kilometer tax seems to be small or even nonexisting.
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| 6. |
- Hanrieder, Jörg, 1980, et al.
(författare)
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High Resolution Metabolite Imaging in the Hippocampus Following Neonatal Exposure to the Environmental Toxin BMAA Using ToF-SIMS
- 2014
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Ingår i: Acs Chemical Neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 5:7, s. 568-575
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Tidskriftsartikel (refereegranskat)abstract
- The environmental neurotoxin beta-N-methylamino-L-alanine (BMAA) is suggested to be linked with neurodegenerative disease. In a rat model, neonatal exposure to BMAA induced selective uptake in the hippocampus and caused cell loss, mineralization and astrogliosis as well as learning and memory impairments in adulthood. Moreover, neonatal exposure resulted in increased protein ubiquitination in the cornus ammonis 1 (CA1) region of the adult hippocampus indicating that BMAA may induce protein aggregation. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) based imaging is a powerful technology for spatial profiling of small molecular weight compounds in biological tissues with high chemical specificity and high spatial resolution. The aim of this study was to characterize neurochemical changes in the hippocampus of six month-old rats treated neonatally (postnatal days 9-10) with BMAA. Multivariate data analysis of whole section ToF-SIMS scans was performed to delineate anatomical regions of interest based on their chemical distribution pattern. Further analysis of spectral data obtained from the outlined anatomical regions, including CA1 and dentate gyms (DG) revealed BMAA-induced long-term changes. Increased levels of phospholipids and protein fragments in the histopathologically altered CA1 region as well as phosphate depletion in the DG were observed. Moreover, high resolution SIMS imaging revealed a specific localization of phosphatidylcholine lipids, protein signals and potassium in the histopathologically altered CA1 These findings demonstrate that ToF-SIMS based imaging is a powerful approach for probing biochemical changes in situ and might serve as promising technique for investigating neurotoxin-induced brain pathology.
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| 7. |
- Karlson, Martin, et al.
(författare)
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Tree Crown Mapping in Managed Woodlands (Parklands) of Semi-Arid West Africa Using WorldView-2 Imagery and Geographic Object Based Image Analysis
- 2014
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Ingår i: Sensors. - Basel : MDPI AG. - 1424-8220 .- 1424-3210. ; 14:12, s. 22643-22669
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Tidskriftsartikel (refereegranskat)abstract
- Detailed information on tree cover structure is critical for research and monitoring programs targeting African woodlands, including agroforestry parklands. High spatial resolution satellite imagery represents a potentially effective alternative to field-based surveys, but requires the development of accurate methods to automate information extraction. This study presents a method for tree crown mapping based on Geographic Object Based Image Analysis (GEOBIA) that use spectral and geometric information to detect and delineate individual tree crowns and crown clusters. The method was implemented on a WorldView-2 image acquired over the parklands of Saponé, Burkina Faso, and rigorously evaluated against field reference data. The overall detection rate was 85.4% for individual tree crowns and crown clusters, with lower accuracies in areas with high tree density and dense understory vegetation. The overall delineation error (expressed as the difference between area of delineated object and crown area measured in the field) was 45.6% for individual tree crowns and 61.5% for crown clusters. Delineation accuracies were higher for medium (35–100 m2) and large (?100 m2) trees compared to small (
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| 8. |
- Nilsson, R. Henrik, 1976, et al.
(författare)
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Improving ITS sequence data for identification of plant pathogenic fungi
- 2014
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Ingår i: Fungal Diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 67:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours. These taxa often have complex and poorly understood life cycles, lack observable, discriminatory morphological characters, and may not be amenable to in vitro culturing. As a result, species identification is frequently difficult. Molecular (DNA sequence) data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi, with the nuclear ribosomal internal transcribed spacer (ITS) region being the most popular marker. However, international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality, making their use in the molecular identification of plant pathogenic fungi problematic. Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages. A third objective was to enrich the sequences with geographical and ecological metadata. The results – a total of 31,954 changes – are incorporated in and made available through the UNITE database for molecular identification of fungi (http://unite.ut.ee), including standalone FASTA files of sequence data for local BLAST searches, use in the next-generation sequencing analysis platforms QIIME and mothur, and related applications. The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi, and we invite all researchers with pertinent expertise to join the annotation effort.
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| 9. |
- Steglich, Thomas, 1983, et al.
(författare)
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Microstructure and water distribution of commercial pasta studied by microscopy and 3D magnetic resonance imaging
- 2014
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 62, s. 644-652
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturing pasta is a rather well known process, but it is still challenging to tailor pasta products with new raw materials. In this study, we evaluated the effects of raw materials on the microstructure and water distribution in cooked pasta using H-1 magnetic resonance imaging (MRI) as well as bright field and polarized light microscopy. The MRI parameters initial intensity (I-0) and transverse dephasing time (T-2*) serve as indicators of the local water concentration and water-macromolecule interactions through chemical exchange, respectively. These parameters were mapped throughout the whole pasta volume with a spatial resolution of 78 mu m in all three dimensions. MRI was combined with light microscopy to link I-0 and T-2* to microstructure components such as fiber particles and the extent of starch gelatinization. Four commercial spaghetti samples were analyzed which were made of durum wheat flour, both plain and enriched with wheat fiber, as well as with wholegrain and soft wheat flour. Although all pasta samples showed similar macroscopic water absorption as measured by weight increase, the sample structures differed at the microscopic scale. Compared to durum wheat spaghetti, the presence of fiber particles decreased T-2*, while spaghetti enriched with soft wheat flour increased T-2*. In addition, light microscopy showed that large fiber particles partly acted as barriers against water migration and protected starch granules from swelling. Smaller wheat fiber particles did not affect local starch swelling. Thus, the combination of light microscopy and MRI is a powerful tool to study the microstructure and water distribution in pasta.
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| 10. |
- Sörensson, Carolin, et al.
(författare)
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Determination of primary sequence specificity of Arabidopsis MAPKs MPK3 and MPK6 leads to identification of new substrates
- 2012
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Ingår i: Biochemical Journal. - 0264-6021 .- 1470-8728. ; 446, s. 271-278
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Tidskriftsartikel (refereegranskat)abstract
- MAPKs (mitogen-activated protein kinases) are signalling components highly conserved among eukaryotes. Their diverse biological functions include cellular differentiation and responses to different extracellular stress stimuli. Although some substrates of MAPKs have been identified in plants, no information is available about whether amino acids in the primary sequence other than proline-directed phosphorylation (pS-P) contribute to kinase specificity towards substrates. in the present study, we used a random positional peptide library to search for consensus phosphorylation sequences for Arabidopsis MAPKs MPK3 and MPK6. These experiments indicated a preference towards the sequence L/P-P/X-S-P-R/K for both kinases. After bioinformatic processing, a number of novel candidate MAPK substrates were predicted and subsequently confirmed by in vitro kinase assays using bacterially expressed native Arabidopsis proteins as substrates. MPK3 and MPK6 phosphorylated all proteins tested more efficiently than did another MAPK, MPK4. These results indicate that the amino acid residues in the primary sequence surrounding the phosphorylation site of Arabidopsis MAPK substrates can contribute to MAPK specificity. Further characterization of one of these new substrates confirmed that AtIg80180.1 was phosphorylated in planta in a MAPK-dependent manner. Phenotypic analyses of Arabidopsis expressing phosphorylation site mutant forms of AtIg80180.1 showed clustered stomata and higher stomatal index in cotyledons expressing the phosphomimetic form of AtIg80180.1, providing a link between this new MAPK substrate and the defined role for MPK3 and MPK6 in stomatal patterning.
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