| 41. |
- Aktürk-Drake, Memet, 1977-
(författare)
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Phonological Adoption through Bilingual Borrowing : Comparing Elite Bilinguals and Heritage Bilinguals
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the phonological integration of loanwords, the original structures of the donor language can either be adopted as innovations or adapted to the recipient language. This dissertation investigates how structural (i.e. phonetic, phonological, morpho-phonological) and non-structural (i.e. sociolinguistic and psycholinguistic) factors interact in determining which of these two integration strategies is preferred. Factors that affect the accuracy of the structure’s perception and production in the donor language as a result of its acquisition as a second language are given special consideration. The three studies in the dissertation examine how the same phonological structure from different donor languages is integrated into the same recipient language Turkish by two different types of initial borrowers: elite bilinguals in Turkey and heritage bilinguals in Sweden. The three investigated structures are word-final [l] after back vowels, long segments in word-final closed syllables, and word-initial onset clusters. The main hypothesis is that adoption will be more prevalent in heritage bilinguals than in elite bilinguals. Four necessary conditions for adoption are identified in the analysis. Firstly, the donor-language structure must have high perceptual salience. Secondly, the borrowers must have acquired the linguistic competence to produce a structure accurately. Thirdly, the borrowers must have sufficient sociolinguistic incentive to adopt a structure as an innovation. Fourthly, prosodic structures require higher incentive to be adopted than segments and clusters of segments. The main hypothesis is partially confirmed. The counterexamples involve either cases where the salience of the structure was high in the elite bilinguals’ borrowing but low in the heritage bilinguals’ borrowing, or cases where the structure’s degree of acquisition difficulty was low. Therefore, it is concluded that structural factors have the final say in the choice of integration strategy.
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| 42. |
- Almby, Kristina E., et al.
(författare)
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Effects of Gastric Bypass Surgery on the Brain : Simultaneous Assessment of Glucose Uptake, Blood Flow, Neural Activity, and Cognitive Function During Normo- and Hypoglycemia
- 2021
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 70:6, s. 1265-1277
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Tidskriftsartikel (refereegranskat)abstract
- While Roux-en-Y gastric bypass (RYGB) surgery in obese individuals typically improves glycemic control and prevents diabetes, it also frequently causes asymptomatic hypoglycemia. Previous work showed attenuated counterregulatory responses following RYGB. The underlying mechanisms as well as the clinical consequences are unclear. In this study, 11 subjects without diabetes with severe obesity were investigated pre- and post-RYGB during hyperinsulinemic normo-hypoglycemic clamps. Assessments were made of hormones, cognitive function, cerebral blood flow by arterial spin labeling, brain glucose metabolism by F-18-fluorodeoxyglucose (FDG) positron emission tomography, and activation of brain networks by functional MRI. Post- versus presurgery, we found a general increase of cerebral blood flow but a decrease of total brain FDG uptake during normoglycemia. During hypoglycemia, there was a marked increase in total brain FDG uptake, and this was similar for post- and presurgery, whereas hypothalamic FDG uptake was reduced during hypoglycemia. During hypoglycemia, attenuated responses of counterregulatory hormones and improvements in cognitive function were seen postsurgery. In early hypoglycemia, there was increased activation post- versus presurgery of neural networks in brain regions implicated in glucose regulation, such as the thalamus and hypothalamus. The results suggest adaptive responses of the brain that contribute to lowering of glycemia following RYGB, and the underlying mechanisms should be further elucidated.
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| 43. |
- Almby, Kristina E., et al.
(författare)
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Effects of GLP-1 on counter-regulatory responses during hypoglycemia after GBP surgery
- 2019
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Ingår i: European Journal of Endocrinology. - : Bioscientifica. - 0804-4643 .- 1479-683X. ; 181:2, s. 161-171
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the study was to explore the role of GLP-1 receptor activation on the counter-regulation and symptoms of hypoglycemia in subjects who have undergone gastric bypass surgery (GBP).Design: Experimental hyperinsulinemic–hypoglycemic clamp study.Methods: Twelve post-GBP subjects participated in a randomized cross-over study with two hyperinsulinemic, hypoglycemic clamps (glucose nadir 2.7 mmol/L) performed on separate days with concomitant infusions of the GLP-1 analog exenatide or with saline, respectively. Continuous measurements of metabolites and counter-regulatory hormones as well as assessments of heart rate variability and symptoms of hypoglycemia were performed throughout the clamps.Results: No effect of GLP-1 receptor activation on counter-regulatory hormones (glucagon, catecholamines, cortisol, GH) or glucose infusion rate was seen, but we found indications of a downregulation of the sympathetic relative to the parasympathetic nerve activity, as reflected in heart rate variability. No significant differences in symptom of hypoglycemia were observed.Conclusions/interpretation: Short-term exposure to a GLP-1 receptor agonist does not seem to impact the counter-regulatory hormonal and metabolic responses in post-GBP subjects during hypoglycemic conditions, suggesting that the improvement in symptomatic hypoglycemia post-GBP seen following treatment with GLP-1 receptor agonists may be mediated by mechanism not directly involved in counter-regulation.
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| 44. |
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| 45. |
- Andersson, Niclas, et al.
(författare)
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Comparison of Stimuli for Nonlinear System Response Classification
- 2020
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Ingår i: SAE International Journal of Vehicle Dynamics, Stability, and NVH. - : SAE International. - 2380-2162 .- 2380-2170. ; 4:3, s. 197-219
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Tidskriftsartikel (refereegranskat)abstract
- As part of the development of an automated virtual design classification approach for nonlinear structural dynamics, alternative excitation functions are evaluated with respect to their overall performance and efficiency in feature-based response analysis. Robust design of nonlinear structures requires analysis of extensive parameter variations. Both the character of the stimulus and feature metrics used are central to the performance of a response classification approach. The main purpose of this study is to compare stimulus candidates with respect to their efficiency in response classification. A deterministic multilevel, multifrequency stepped-sine periodic test function is used as a baseline. Order-wise differences between generalized and linearized system frequency response functions are evaluated by a selected feature metric to allow categorization into primary, sub and super harmonic responses, as well as odd and even order response distortions. An alternative excitation function type is the pseudorandom phase multi-sine. Its robust variant estimates the best linear approximation of the generalized frequency response function and related nonlinear and noise variances, which can be used for response classification. The fast variant of this method further detects and classifies occurring even and odd order nonlinear responses using a hypothesis test. This article describes the application of these three methods to a virtually running two-piece rotor shaft model. Time response signals from simulated test parameter variations are used to calculate selected nonlinear feature metric values. The total simulation and measurement time, as well as the predictive performance in a few typical nonlinear response cases are evaluated.
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| 46. |
- Andersson, Niclas S, 1971, et al.
(författare)
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Efficient Component Reductions in a Large-Scale Flexible Multibody Model
- 2018
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Ingår i: SAE International Journal of Vehicle Dynamics, Stability, and NVH. - : SAE International. - 2380-2162 .- 2380-2170. ; 2:1, s. 5-26
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Tidskriftsartikel (refereegranskat)abstract
- To make better use of simulations in the automotive driveline design process there is a need for both improved predictive capabilities of typical system models and increased number of variant evaluations carried out during system concept design phase. A previously developed large-scale multibody rotor dynamical powertrain model that combines detailed linear-elastic finite element components and nonlinear joints is used to more accurately simulate system response modes and their variations across the operating-range. However, the total simulation time is too long to include extensive parameter evaluations during the rapid design iterations, which will have a negative influence on the total understanding of the designed system's behaviour. Therefore this paper is about reducing such a large-scale model to one that runs faster, but without losing the ability to predict the most fundamental system characteristics. Reduction methods considering defined stimuli-response relations are well established and used within the field of control systems, to balance prediction accuracy and evaluation effort, but are not yet commonly applied to large-scaled structural models and analysis of vibrations in continuous and lightly damped structures. Here, an implementation of two such state-space reduction methods into a common computational software workflow is described and their overall efficiency is compared to standard methods. Reductions are applied to two major structural components of the powertrain model. Steady-state simulations are performed for multiple engine speeds and responses related to vehicle noise and vibrations are compared using a quantitative error metric. The prediction accuracy, reduction and response simulation times of different model orders are evaluated, as well as the corresponding mode frequency spectra.
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| 47. |
- Andersson, Niclas S, 1971, et al.
(författare)
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Feature-Based Response Classification in Nonlinear Structural Design Simulations
- 2018
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Ingår i: SAE International Journal of Vehicle Dynamics, Stability, and NVH. - : SAE International. - 2380-2162 .- 2380-2170. ; 2:3, s. 185-202
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Tidskriftsartikel (refereegranskat)abstract
- An applied system design analysis approach for automated processing and classification of simulated structural responses is presented. Deterministic and nonlinear dynamics are studied under ideal loading and low noise conditions to determine fundamental system properties, how they vary and possibly interact. Using powerful computer resources, large amounts of simulated raw data can be produced in a short period of time. Efficient tools for data processing and interpretation are then needed, but existing ones often require much manual preparation and direct human judgement. Thus, there is a need to develop techniques that help to treat more virtual prototype variants and efficiently extract useful information from them. For this, time signals are evaluated by methods commonly used within structural dynamics and statistical learning. A multi-level multi-frequency stimulus function is constructed and simulated response signals are combined into frequency domain functions. These are associated with qualitative system features, such as being periodic or aperiodic, linear or nonlinear and further into subcategories of nonlinear systems, such as fundamental, sub or super harmonic and even or odd order types. Appropriate classes are then determined from selected feature metrics and rules-of-thumb criteria. To automate the classification of large data sets, a support vector machine is trained on categorised responses to determine whether a single feature, or combinations of features, applies or not. The trained classifier can then efficiently process new sets of data and pick out cases that are associated with possible vibrational problems, which subsequently can be further analysed and understood. This article describes elements of the analysis, discuss the effectiveness of evaluated feature metrics, reports practical considerations and results from two separate training study examples.
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| 48. |
- Bishop, Kevin, et al.
(författare)
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Nature as the "Natural" Goal for Water Management : A Conversation
- 2009
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Ingår i: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; Volume 38:Issue 4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The goals for water-quality and ecosystem integrity are often defined relative to "natural" reference conditions in many water-management systems, including the European Union Water Framework Directive. This paper examines the difficulties created for water management by using "natural" as the goal. These difficulties are articulated from different perspectives in an informal (fictional) conversation that takes place after a workshop on reference conditions in water-resources management. The difficulties include defining the natural state and modeling how a system might be progressed toward the natural, as well as the feasibility and desirability of restoring a natural state. The paper also considers the appropriateness for developing countries to adopt the use of natural as the goal for water management. We conclude that failure to critically examine the complexities of having "natural" as the goal will compromise the ability to manage the issues that arise in real basins by not making the ambiguities associated with this "natural" goal explicit. This is unfortunate both for the western world that has embraced this model of "natural as the goal" and for the developing world in so far as they are encouraged to adopt this model.
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| 49. |
- Bylund, Emanuel, et al.
(författare)
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Age of acquisition effects or effects of bilingualism in second language ultimate attainment?
- 2013
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Ingår i: Sensitive Periods, Language Aptitude, and Ultimate L2 Attainment. - Amsterdam : John Benjamins Publishing Company. - 9789027213112 ; , s. 69-102
-
Bokkapitel (refereegranskat)abstract
- One of the most robust findings in the field of SLA is the different rates of success with which children and adults achieve nativelike proficiency in a L2. Age-related differences have traditionally been explained in terms of the maturational state of the learner. Recently, however, a growing number of accounts hold that age effects in ultimate attainment are due to L1 entrenchment (e.g. Flege 1999; MacWhinney 2005; Ventureyra, Pallier & Yoo 2004). In this view, an increase in L1 proficiency leads to the progressive entrenchment of L1 representations, with the consequence that L2 acquisition becomes more difficult. Inherent in this interpretation is the assumption that the “less L1”, the less it will interfere with the L2. In this paper, we analyse the theoretical underpinnings of the “L1 entrenchment accounts”, and evaluate the existing evidence for and against such claims.
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| 50. |
- Bylund, Emanuel, et al.
(författare)
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Age of acquisition – not bilingualism – is the primary determinant of less than nativelike L2 ultimate attainment
- 2021
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Ingår i: Bilingualism. - 1366-7289 .- 1469-1841. ; 24:1, s. 18-30
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Tidskriftsartikel (refereegranskat)abstract
- It has recently been suggested that bilingualism, rather than age of acquisition, is what underlies less than nativelike attainment in childhood L2 acquisition. Currently, however, the empirical evidence in favor of or against this interpretation remains scarce. The present study sets out to fill this gap, implementing a novel factorial design in which the variables age of acquisition and bilingualism have been fully crossed. Eighty speakers of Swedish, who were either L1 monolinguals, L1 simultaneous bilinguals, L2 sequential monolinguals (international adoptees), or L2 sequential bilinguals (childhood immigrants), were tested on phonetic, grammatical, and lexical measures. The results indicate consistent effects of age of acquisition, but only limited effects of bilingualism, on ultimate attainment. These findings thus show that age of acquisition – not bilingualism – is the primary determinant of L2 ultimate attainment.
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