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- Agogo, George O., et al.
(författare)
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Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design : EPIC Case Study
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11, s. e113160-
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Tidskriftsartikel (refereegranskat)abstract
- In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted twopart regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.
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| 2. |
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| 3. |
- Eklöf, Anna, et al.
(författare)
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Can dispersal rescue metacommunities from extinction cascades?
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Climate change and habitat loss are increasingly affecting the structure and dynamics of ecological communities both at the local and regional scale. Changes in the spatial structure of landscapes as well as in the trophic structure of local communities can be expected to have important consequences for the long-term persistence of species in metacommunities. The aim of the present work is to investigate how the spatial structure of the landscape (patch density) and dispersal patterns of species (migration rate and dispersal distance) affect a metacommunities response to local loss of species and to increased mortality of individuals during dispersal. Using a spatially and dynamically explicit metacommunity model we find that the effect of dispersal on metacommunity persistence is two-sided: on the one hand, when dispersal involves no risk, high migration rate significantly reduces the risk of bottom-up extinction cascades following the local removal of a species. The explanation for this is that recolonization rates of the locally removed species increases with increasing migration rate. On the other hand, when dispersal imposes a risk to the dispersing individuals, high migration rate increases extinction risks, especially when dispersal is global (long dispersal distances). Largebodied species with long generation times at the highest trophic level are particularly vulnerable to extinction when dispersal involves a risk. These results suggest that decreasing the mortality risk of dispersing individuals by improving the quality of the habitat matrix might greatly increase the robustness of metacommunities to local loss of species by enhancing recolonizations and rescue effects.
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| 5. |
- Fred, Stig
(författare)
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Varför säger Herren så? Profeterna, kontexterna, retoriken. En jämförelse mellan Amos och Malaki
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Why does the Lord say thus? Prophets, Contexts, Rhetoric A Comparison Between Amos and Malachi When the prophets preached their messages they authorized their words by the old messenger formula "Thus says the Lord". The import of these words was to emphasize that the prophet was only the mouthpiece of the Lord. However, the prophetic literature of the Old Testament is highly varied in its scope and nature. It was of course natural that the content of the prophecies changed over time, but this is also true of their form. It also appears that the prophets changed the way in which they related to the people they were addressing. For a number of reasons it is therefore natural to ask: "Why does the Lord say thus?" This question is the main focus of this thesis. In the first part of the thesis a survey is given firstly about prophecy and the prophetical message, secondly about classical rhetoric and the rhetorical analysis. The main part of the thesis is a comparison between the first writing prophet, Amos, and one of the last, Malachi. The investigation comprises three steps: Firstly the shape of the text is discussed, its genres, when it, presumably, was written and by whom. Secondly a historical perspective with sociological circumstances is sketched. In this connection the rhetorical situation is defined and discussed. Finally the rhetorical analysis is realized. At the same time a survey of it constitutes a working programme with six points: 1. The rhetorical unit. - 2. Linguistic particularities. - 3. Rhetorical figures. - 4. Pragmatism. - 5. Argumentation. - 6. Rhetorical strategy. Connected with the presentation of the different steps of the investigation, fundamental problems are discussed and accounts for the author´s personal considerations and positions are given. Through the analysis is shown an obvious connection between the prophets´ respective rhetoric and the contextual conditions. Each one of the two, Amos and Malachi, was in his own way, in proportion to his ability, the Lord´s servant. However, they were, in thier service, also children of thier time. Herein we probably have the answer to the question "Why does the Lord say thus?"
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| 6. |
- Giannetti, Mariassunta, et al.
(författare)
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The Costs and Benefits of Shareholder Democracy: Gadflies and Low-Cost Activism
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We show that there is cross-sectional variation in the quality of shareholder proposals. On average, the proposals submitted by the most active individual sponsors are less likely to be supported by a majority of votes, but they may pass if shareholders mistakenly support them and may even be implemented due to directors’ career concerns. While gadflies’ proposals destroy shareholder value if they pass, shareholder proposals on average are value-enhancing in firms with more informed shareholders. Our results suggest that the voting process should be reformed, but that shareholders’ ability to submit proposals should not necessarily be restricted.
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| 7. |
- Giannetti, Mariassunta
(författare)
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The effects of integration on regional disparities : Convergence, divergence or both?
- 2002
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Ingår i: European economic review. - : Elsevier B.V. - 1873-572X .- 0014-2921. ; 46:3, s. 539-567
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Tidskriftsartikel (refereegranskat)abstract
- This paper offers an explanation for the coexistence of convergence across countries and the lack thereof at the regional level in the European Union. The model shows that, even if it accelerates growth and brings convergence across countries, the intensification of international knowledge spillovers due to more cross-country interaction may exacerbate within-country regional disparities, if regions with different specialization do not benefit evenly from the exchange of knowledge. The empirical evidence supports the implications of the model. In particular, the data show that regions specialized in advanced sectors at the beginning of the sample period became more similar in terms of per capita income, while regions specialized in traditional sectors lagged.
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| 9. |
- Ollech, Dirk, et al.
(författare)
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An optochemical tool for light-induced dissociation of adherens junctions to control mechanical coupling between cells
- 2020
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- The cadherin-catenin complex at adherens junctions (AJs) is essential for the formation of cell-cell adhesion and epithelium integrity; however, studying the dynamic regulation of AJs at high spatio-temporal resolution remains challenging. Here we present an optochemical tool which allows reconstitution of AJs by chemical dimerization of the force bearing structures and their precise light-induced dissociation. For the dimerization, we reconstitute acto-myosin connection of a tailless E-cadherin by two ways: direct recruitment of α-catenin, and linking its cytosolic tail to the transmembrane domain. Our approach enables a specific ON-OFF switch for mechanical coupling between cells that can be controlled spatially on subcellular or tissue scale via photocleavage. The combination with cell migration analysis and traction force microscopy shows a wide-range of applicability and confirms the mechanical contribution of the reconstituted AJs. Remarkably, in vivo our tool is able to control structural and functional integrity of the epidermal layer in developing Xenopus embryos.
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| 10. |
- Olleja, Pierluigi, 1995, et al.
(författare)
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Can non-crash naturalistic driving data be an alternative to crash data for use in virtual assessment of the safety performance of automated emergency braking systems?
- 2022
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Ingår i: Journal of Safety Research. - : Elsevier BV. - 0022-4375. ; 83, s. 139-151
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Developers of in-vehicle safety systems need to have data allowing them to identify traffic safety issues and to estimate the benefit of the systems in the region where it is to be used, before they are deployed on-road. Developers typically want in-depth crash data. However, such data are often not available. There is a need to identify and validate complementary data sources that can complement in-depth crash data, such as Naturalistic Driving Data (NDD). However, few crashes are found in such data. This paper investigates how rear-end crashes that are artificially generated from two different sources of non-crash NDD (highD and SHRP2) compare to rear-end in-depth crash data (GIDAS). Method: Crash characteristics and the performance of two conceptual automated emergency braking (AEB) systems were obtained through virtual simulations – simulating the time-series crash data from each data source. Results: Results show substantial differences in the estimated impact speeds between the artificially generated crashes based on both sources of NDD, and the in-depth crash data; both with and without AEB systems. Scenario types also differed substantially, where the NDD have many fewer scenarios where the following-vehicle is not following the lead vehicle, but instead catches-up at high speed. However, crashes based on NDD near-crashes show similar pre-crash criticality (time-to-collision) to in-depth crash data. Conclusions: If crashes based on near-crashes are to be used in the design and assessment of preventive safety systems, it has to be done with great care, and crashes created purely from small amounts of everyday driving NDD are not of much use in such assessment. Practical applications: Researchers and developers of in-vehicle safety systems can use the results from this study: (a) when deciding which data to use for virtual safety assessment of such systems, and (b) to understand the limitations of NDD.
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