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| 2. |
- Thompson, Paul M., et al.
(författare)
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The ENIGMA Consortium : large-scale collaborative analyses of neuroimaging and genetic data
- 2014
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Ingår i: BRAIN IMAGING BEHAV. - : Springer Science and Business Media LLC. - 1931-7557 .- 1931-7565. ; 8:2, s. 153-182
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Tidskriftsartikel (refereegranskat)abstract
- The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of findings, in a total of 24,997 subjects. By meta-analyzing results from many sites, ENIGMA has detected factors that affect the brain that no individual site could detect on its own, and that require larger numbers of subjects than any individual neuroimaging study has currently collected. ENIGMA's first project was a genome-wide association study identifying common variants in the genome associated with hippocampal volume or intracranial volume. Continuing work is exploring genetic associations with subcortical volumes (ENIGMA2) and white matter microstructure (ENIGMA-DTI). Working groups also focus on understanding how schizophrenia, bipolar illness, major depression and attention deficit/hyperactivity disorder (ADHD) affect the brain. We review the current progress of the ENIGMA Consortium, along with challenges and unexpected discoveries made on the way.
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| 3. |
- Mohnke, Sebastian, et al.
(författare)
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Further evidence for the impact of a genome-wide-supported psychosis risk variant in ZNF804A on the Theory of Mind network
- 2014
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Ingår i: Neuropsychopharmacology. - : Nature Publishing Group. - 0893-133X .- 1740-634X. ; 39:5, s. 1196-1205
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Tidskriftsartikel (refereegranskat)abstract
- The single-nucleotide polymorphism (SNP) rs1344706 in ZNF804A is one of the best-supported risk variants for psychosis. We hypothesized that this SNP contributes to the development of schizophrenia by affecting the ability to understand other people's mental states. This skill, commonly referred to as Theory of Mind (ToM), has consistently been found to be impaired in schizophrenia. Using functional magnetic resonance imaging, we previously showed that in healthy individuals rs1344706 impacted on activity and connectivity of key areas of the ToM network, including the dorsomedial prefrontal cortex, temporo-parietal junction, and the posterior cingulate cortex, which show aberrant activity in schizophrenia patients, too. We aimed to replicate these results in an independent sample of 188 healthy German volunteers. In order to assess the reliability of brain activity elicited by the ToM task, 25 participants performed the task twice with an interval of 14 days showing excellent accordance in recruitment of key ToM areas. Confirming our previous results, we observed decreasing activity of the left temporo-parietal junction, dorsomedial prefrontal cortex, and the posterior cingulate cortex with increasing number of risk alleles during ToM. Complementing our replication sample with the discovery sample, analyzed in a previous report (total N=297), further revealed negative genotype effects in the left dorsomedial prefrontal cortex as well as in the temporal and parietal regions. In addition, as shown previously, rs1344706 risk allele dose positively predicted increased frontal-temporo-parietal connectivity. These findings confirm the effects of the psychosis risk variant in ZNF804A on the dysfunction of the ToM network.
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| 4. |
- Gammelgaard, Jens, et al.
(författare)
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The impact of increases in subsidiary autonomy and network relationships on performance
- 2012
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Ingår i: International Business Review. - : Elsevier. - 0969-5931 .- 1873-6149. ; 21:6, s. 1158-1172
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Tidskriftsartikel (refereegranskat)abstract
- This paper uses network approaches to subsidiary theory to investigate the performance impacts of interactions among the factors of autonomy, intra-organizational network relationships, and inter-organizational network relationships. The paper offers an analysis of both direct and indirect interactions among these factors. This study develops and extends existing research that uses network-based approaches in studies of subsidiary performance by considering the roles of autonomy and network relationships. In addition, the study examines changes in terms of increases in the interactions between the main factors rather than the levels of these factors. The examination of the interactions between increases in autonomy and networks and the subsequent impact of this change on performance contributes to a better understanding of subsidiary evolution. The results, which are based on data gathered from a survey of 350 foreign-owned subsidiaries in the UK, Germany, and Denmark, reveal complex interactions between increases in autonomy and network relationships, and the subsequent impact of these changes on performance. The results also highlight the central role of inter-organizational network relationships in the interaction between the factors, which produce significant and positive effects.
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| 5. |
- Deserno, Lorenz, et al.
(författare)
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Volatility Estimates Increase Choice Switching and Relate to Prefrontal Activity in Schizophrenia
- 2020
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Ingår i: Biological Psychiatry. - : ELSEVIER. - 2451-9022. ; 5:2, s. 173-183
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Reward-based decision making is impaired in patients with schizophrenia (PSZ), as reflected by increased choice switching. The underlying cognitive and motivational processes as well as associated neural signatures remain unknown. Reinforcement learning and hierarchical Bayesian learning account for choice switching in different ways. We hypothesized that enhanced choice switching, as seen in PSZ during reward-based decision making, relates to higher-order beliefs about environmental volatility, and we examined the associated neural activity. METHODS: In total, 46 medicated PSZ and 43 healthy control subjects performed a reward-based decision-making task requiring flexible responses to changing action-outcome contingencies during functional magnetic resonance imaging. Detailed computational modeling of choice data was performed, including reinforcement learning and the hierarchical Gaussian filter. Trajectories of learning from computational modeling informed the analysis of functional magnetic resonance imaging data. RESULTS: A 3-level hierarchical Gaussian filter accounted best for the observed choice data. This model revealed a heightened initial belief about environmental volatility and a stronger influence of volatility on lower-level learning of action-outcome contingencies in PSZ as compared with healthy control subjects. This was replicated in an independent sample of nonmedicated PSZ. Beliefs about environmental volatility were reflected by higher activity in dorsolateral prefrontal cortex of PSZ as compared with healthy control subjects. CONCLUSIONS: Our study suggests that PSZ inferred the environment as overly volatile, which may explain increased choice switching. In PSZ, activity in dorsolateral prefrontal cortex was more strongly related to beliefs about environmental volatility. Our computational phenotyping approach may provide useful information to dissect clinical heterogeneity and could improve prediction of outcome.
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| 6. |
- Gammelgaard, Jens, et al.
(författare)
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Subsidiary Role and Skilled Labour Effects in Small Developed Countries
- 2009
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Ingår i: Management International Review. - : Gabler Verlag/GWV Fachverlage GmbH. - 0025-181X .- 0938-8249 .- 1861-8901. ; 49, s. 27-42
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers the proportion of skilled labour employed by subsidiaries in small countries in the context of the strategic role of subsidiaries. Strategic role is connected to autonomy and intra-organisational relationships and the mandates given to the subsidiary. In the paper, we draw on the literature on the strategic development of multinational corporations, and insights from inward foreign direct investments in small developed countries. This ispresented in a unifying framework in order to predict diverse categorizations of the impact of subsidiary role on the proportion of their employment of skilled labour. The paper derives two propositions that postulate interactions between three roles containing different levels of autonomy and intra-organisational relationships in small developed countries that lead to different proportions of skilled labour in subsidiaries. We predict the highest proportion of skilled labour by subsidiaries located in small developed countries in the case of world mandates when autonomous-based operations are emphasized. When there is an emphasis on intra-organizational relationships, measured by product flowsand integrated international value-chain configurations, we predict the proportion of skilled labour to be highest in the cases of specialized contributors. We propose the proportion of skilled labour to be lowest in the case of local implementers.
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| 7. |
- Gammelgard, Jens, et al.
(författare)
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Characteristics of Low-Autonomy Foreign Subsidiaries : Value Chains, Staffing, and Intra-Organizational Relationships
- 2012
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Ingår i: Journal of International Business and Economics. - 1544-8037 .- 2378-9174. ; 13:1, s. 65-95
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines several characteristics of foreign subsidiaries with low autonomy. Data derived from a survey of 381 MNC subsidiaries located in Denmark, Germany and the UK demonstrate that low-autonomy subsidiaries are highly embedded in their respective MNC networks and that they establish a high number of intra-organizational relationships. Furthermore, such subsidiaries are typically managed by nationals of the MNC’s headquarters home country. Despite the fact that such subsidiaries have low autonomy, they employ a high proportion of professional staff members. We find a negative relationship between lower autonomy and the production activities carried out by the subsidiary. In fact, low-autonomy subsidiaries appear to be specialized in that they focus on a few value-chain activities and they typically serve as marketing outlets.
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