157 results on '"Bak, Thomas"'
Search Results
2. Language Learning for People Living with Dementia and Their Caregivers: Feasibility and the Quality of Experience.
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Vega-Mendoza, Mariana, Norval, Robbie S., Blankinship, Brittany, and Bak, Thomas H.
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LANGUAGE & languages ,CURRICULUM ,FOCUS groups ,QUALITATIVE research ,RESEARCH funding ,INTERVIEWING ,CONTENT analysis ,CAREGIVERS ,MULTILINGUALISM ,THEMATIC analysis ,RESEARCH ,DATA analysis software ,DEMENTIA patients - Abstract
Background: A body of research from around the world has reported positive effects of bilingualism on cognitive ageing and dementia. However, little is known about whether foreign language learning could be applied as an intervention for people already living with dementia. Yet, before it is possible to determine the efficacy of language courses as an intervention for people living with dementia (PLWD), it is necessary to establish whether such an intervention is feasible. Our study explored this possibility. Methods: We conducted an exploratory study to examine the feasibility and tolerability of 2-week Italian beginner courses for PLWD in early stages and their family carers in two Scottish Dementia Resource Centres (DRCs). The courses were delivered by trained tutors from Lingo Flamingo, a social enterprise specialising in language teaching for older learners and learners with dementia. Twelve PLWD and seven carers participated in the study. Focus groups preceded and followed the courses. Additional post-course open interviews with the DRC managers were conducted, with a follow-up via telephone approximately one year later. Results: Qualitative content analysis resulted in 12 themes, 5 reflected in the interview schedule and 7 arising from the focus groups and interviews. Overall, the courses were perceived positively by PLWD, carers, and DRC managers, although a few logistically and linguistically challenging aspects were also mentioned. The courses were found to positively impact both the individual by increasing self-esteem and producing a sense of accomplishment as well as the group by creating a sense of community. Notably, no adverse effects (in particular no confusion or frustration) were reported. Conclusion: The positive outcomes of our study open a novel avenue for future research to explore foreign language training in dementia as an intervention and its implications. [ABSTRACT FROM AUTHOR]
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- 2024
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3. More than a piece of cake: Noun classifier processing in primary progressive aphasia.
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Tee, Boon Lead, Li‐Ying, Lorinda Kwan‐Chen, Chen, Ta‐Fu, Yan, Connie TY, Tsoh, Joshua, Chan, Andrew Lung‐Tat, Wong, Adrian, Lo, Raymond Y., Lu, Chien Jung, Sun, Yu, Wang, Pei‐Ning, Lee, YiChen, Chiu, Ming‐Jang, Allen, Isabel Elaine, Battistella, Giovanni, Bak, Thomas H., Chuang, Yu‐Chen, García, Adolfo M., and Gorno‐Tempini, Maria Luisa
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- 2024
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4. A longitudinal investigation of the effects of language instruction versus immersion on cognitive functions in young adult Chinese speakers learning English.
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Xia, Lihua, Bak, Thomas H., Vega-Mendoza, Mariana, and Sorace, Antonella
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YOUNG adults ,ENGLISH language ,COGNITIVE ability ,CHINESE language ,LINGUISTIC context ,LEARNING - Abstract
The current study examined cognitive effects of two pathways of second language (L2) acquisition longitudinally in Chinese speakers learning English in an L2-dominant environment. Thirty-nine participants who attended an intensive 10-week English course (L2-instruction group) were compared to 38 participants who attended regular university courses taught in English (L2-immersion group). Four repeated assessments were conducted over 10 weeks: precourse (baseline) and postcourse assessments, and two interim assessments every 3 weeks. Both groups matched on background variables (e.g., intelligence) and showed comparable cognitive performance in all measures at the baseline. The longitudinal results showed a similar improvement in both groups for most cognitive measures, such as visual and auditory inhibition. The only significant group difference was observed in the auditory inhibition test, where the L2-instruction group outperformed the L2-immersion group. Taken together, our results suggest a specific effect of language experience and an overall effect of linguistic context on cognitive functions. [ABSTRACT FROM AUTHOR]
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- 2023
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5. The Nairobi Declaration—Reducing the burden of dementia in low‐ and middle‐income countries (LMICs): Declaration of the 2022 Symposium on Dementia and Brain Aging in LMICs.
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Maestre, Gladys, Carrillo, Maria, Kalaria, Raj, Acosta, Daisy, Adams, Larry, Adoukonou, Thierry, Akinwande, Kazeem, Akinyemi, Joshua, Akinyemi, Rufus, Akpa, Onoja, Alladi, Suvarna, Allegri, Ricardo, Arizaga, Raul, Arshad, Faheem, Arulogun, Oyedunni, Babalola, David, Baiyewu, Olusegun, Bak, Thomas, Bellaj, Tarek, and Boshe, Judith
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- 2023
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6. Escaping Local Minima via Appraisal Driven Responses.
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Damgaard, Malte Rørmose, Pedersen, Rasmus, and Bak, Thomas
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COGNITIVE robotics ,ROBOTS - Abstract
Inspired by the reflective and deliberative control mechanisms used in cognitive architectures such as SOAR and Sigma, we propose an alternative decision mechanism driven by architectural appraisals allowing robots to overcome impasses. The presented work builds on and improves on our previous work on a generally applicable decision mechanism with roots in the Standard Model of the Mind and the Generalized Cognitive Hour-glass Model. The proposed decision mechanism provides automatic context-dependent switching between exploration-oriented, goal-oriented, and backtracking behavior, allowing a robot to overcome impasses. A simulation study of two applications utilizing the proposed decision mechanism is presented demonstrating the applicability of the proposed decision mechanism. [ABSTRACT FROM AUTHOR]
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- 2022
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7. Membrane Emulsification—A Novel Solution for Treatment and Reuse of Produced Water from Oil Field.
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Ali, Aamer, Syed, Usman Taqui, Bak, Thomas Skovfoged, and Quist-Jensen, Cejna Anna
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- 2022
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8. Utility of Chinese Versions of Addenbrooke's Cognitive Examination: A Narrative Review.
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Cao, Ling-Xiao, Wang, Gang, Guo, Qi-Hao, Zhang, Wei, Bak, Thomas, and Huang, Yue
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COGNITION disorders diagnosis ,COGNITION disorders ,ONLINE information services ,NEUROLOGICAL disorders ,SYSTEMATIC reviews ,RESEARCH funding ,MEDLINE - Abstract
Addenbrooke's cognitive examination (ACE) is a cognitive screening tool that has developed through three stages: ACE, ACE-Revised (ACE-R), and ACE-Ⅲ. In addition, mini-Addenbrooke's Cognitive Examination (M-ACE) and ACE mobile are the additional versions that is derived from ACE-III. ACE and its related versions show better performance than Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in detecting mild cognitive impairment in different neurological disorders. It has been translated into numerous languages, including Chinese. Through reviewing the history, validity, and comparison with other cognitive tests of Chinese versions of ACE, it aims to facilitate the clinical and scientific use, further development, improvement, and validation of Chinese versions of ACE in various neurological disorders and ultimately promote early identification and management of cognitive impairment in China. [ABSTRACT FROM AUTHOR]
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- 2022
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9. User Based Development and Test of the EXOTIC Exoskeleton: Empowering Individuals with Tetraplegia Using a Compact, Versatile, 5-DoF Upper Limb Exoskeleton Controlled through Intelligent Semi-Automated Shared Tongue Control.
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Thøgersen, Mikkel Berg, Mohammadi, Mostafa, Gull, Muhammad Ahsan, Bengtson, Stefan Hein, Kobbelgaard, Frederik Victor, Bentsen, Bo, Khan, Benjamin Yamin Ali, Severinsen, Kåre Eg, Bai, Shaoping, Bak, Thomas, Moeslund, Thomas Baltzer, Kanstrup, Anne Marie, and Andreasen Struijk, Lotte N. S.
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ANIMAL exoskeletons ,QUADRIPLEGIA ,INTELLIGENT control systems ,COMPUTER vision ,SPINAL cord injuries - Abstract
This paper presents the EXOTIC- a novel assistive upper limb exoskeleton for individuals with complete functional tetraplegia that provides an unprecedented level of versatility and control. The current literature on exoskeletons mainly focuses on the basic technical aspects of exoskeleton design and control while the context in which these exoskeletons should function is less or not prioritized even though it poses important technical requirements. We considered all sources of design requirements, from the basic technical functions to the real-world practical application. The EXOTIC features: (1) a compact, safe, wheelchair-mountable, easy to don and doff exoskeleton capable of facilitating multiple highly desired activities of daily living for individuals with tetraplegia; (2) a semi-automated computer vision guidance system that can be enabled by the user when relevant; (3) a tongue control interface allowing for full, volitional, and continuous control over all possible motions of the exoskeleton. The EXOTIC was tested on ten able-bodied individuals and three users with tetraplegia caused by spinal cord injury. During the tests the EXOTIC succeeded in fully assisting tasks such as drinking and picking up snacks, even for users with complete functional tetraplegia and the need for a ventilator. The users confirmed the usability of the EXOTIC. [ABSTRACT FROM AUTHOR]
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- 2022
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10. Coupling cognitive and brainstem dysfunction in multiple sclerosis-related chronic neuropathic limb pain.
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Foley, Peter, Yazhuo Kong, Dirvanskiene, Ramune, valdes-Hernandez, Maria, Bastiani, Matteo, Murnane, Jonathan, Sellar, Robin, Roberts, Neil, Pernet, Cyril, Weir, Christopher, Bak, Thomas, Colvin, Lesley, Chandran, Siddharthan, Fallon, Marie, and Tracey, Irene
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- 2022
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11. Computer Vision-Based Adaptive Semi-Autonomous Control of an Upper Limb Exoskeleton for Individuals with Tetraplegia.
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Bengtson, Stefan Hein, Thøgersen, Mikkel Berg, Mohammadi, Mostafa, Kobbelgaard, Frederik Victor, Gull, Muhammad Ahsan, Andreasen Struijk, Lotte N. S., Bak, Thomas, and Moeslund, Thomas B.
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ADAPTIVE control systems ,QUADRIPLEGIA ,COMPUTER vision ,AUTOMATION ,COMPUTERS - Abstract
We propose the use of computer vision for adaptive semi-autonomous control of an upper limb exoskeleton for assisting users with severe tetraplegia to increase independence and quality of life. A tongue-based interface was used together with the semi-autonomous control such that individuals with complete tetraplegia were able to use it despite being paralyzed from the neck down. The semi-autonomous control uses computer vision to detect nearby objects and estimate how to grasp them to assist the user in controlling the exoskeleton. Three control schemes were tested: non-autonomous (i.e., manual control using the tongue) control, semi-autonomous control with a fixed level of autonomy, and a semi-autonomous control with a confidence-based adaptive level of autonomy. Studies on experimental participants with and without tetraplegia were carried out. The control schemes were evaluated both in terms of their performance, such as the time and number of commands needed to complete a given task, as well as ratings from the users. The studies showed a clear and significant improvement in both performance and user ratings when using either of the semi-autonomous control schemes. The adaptive semi-autonomous control outperformed the fixed version in some scenarios, namely, in the more complex tasks and with users with more training in using the system. [ABSTRACT FROM AUTHOR]
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- 2022
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12. Study of Variational Inference for Flexible Distributed Probabilistic Robotics.
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Damgaard, Malte Rørmose, Pedersen, Rasmus, and Bak, Thomas
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MOBILE robots ,ROBOTICS ,MESSAGE passing (Computer science) ,ROBOTS - Abstract
By combining stochastic variational inference with message passing algorithms, we show how to solve the highly complex problem of navigation and avoidance in distributed multi-robot systems in a computationally tractable manner, allowing online implementation. Subsequently, the proposed variational method lends itself to more flexible solutions than prior methodologies. Furthermore, the derived method is verified both through simulations with multiple mobile robots and a real world experiment with two mobile robots. In both cases, the robots share the operating space and need to cross each other's paths multiple times without colliding. [ABSTRACT FROM AUTHOR]
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- 2022
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13. Interference suppression in bilingualism: Stimulus-Stimulus vs. Stimulus-Response conflict.
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Xia, Lihua, Bak, Thomas H., Sorace, Antonella, and Vega-Mendoza, Mariana
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INTERFERENCE suppression ,BILINGUALISM ,MONOLINGUALISM ,LANGUAGE ability ,CONTROL (Psychology) ,COGNITIVE ability ,YOUNG adults ,COGNITION - Abstract
Studies examining the potential effects of bilingualism on interference suppression show inconsistent results. Our study approaches this topic by distinguishing two potential subcomponents within interference suppression (i.e., Stimulus-Stimulus and Stimulus-Response conflict). We investigated the two subcomponents through their operationalisation in different tasks and examined the role of language proficiency in modulating it. A sample of 111 young adult participants performed four non-linguistic cognitive tasks measuring both visual and auditory domains of cognitive control. Bilinguals outperformed monolinguals in tasks involving Stimulus-Stimulus conflict, but showed comparable performance in tasks involving Stimulus-Response conflict. Specific effects of language proficiency on cognitive control were observed: group differences in auditory inhibition and visual orienting were only observed between high-proficient bilinguals and monolinguals. Taken together, types of conflicts involved in interference tasks and language proficiency could differentially affect performance in monolinguals and bilinguals. [ABSTRACT FROM AUTHOR]
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- 2022
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14. Dynamic modeling of an upper limb hybrid exoskeleton for simulations of load-lifting assistance.
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Gull, Muhammad Ahsan, Bak, Thomas, and Bai, Shaoping
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Work-related musculoskeletal disorders (MSDs) are among the most commonly reported issue in Europe. Using robotic exoskeletons to support users in performing heavy industrial tasks can effectively mitigate the work-related MSDs. In this paper, a dynamic model of a hybrid exoskeleton is presented to analyze the assistive effect. The exoskeleton in this study is able to passively support the human shoulder joint and actively support the human forearm movements by providing different levels of assistive torque. With the model, two different tasks are simulated, i.e., an overhead lifting task and a static load transferring task. The results show that the assistive torque provided by the passive spring-loaded mechanism reduces the maximum human upper arm effort by 22.65%. Moreover, the exoskeleton elbow joint's assistive torque reduces the peak torque of human forearm from 10.12 Nm to 5.1 Nm. All these results demonstrate the efficacy of the model developed in the simulation and analysis of human-exoskeleton systems. [ABSTRACT FROM AUTHOR]
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- 2022
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15. A normative study of the Czech Edinburgh Cognitive and Behavioural ALS Screen (ECAS): a brief report.
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Fazio, Raffaele, Soósová, Nina, Bak, Thomas, Růžička, Evžen, and Bezdicek, Ondrej
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AMYOTROPHIC lateral sclerosis ,COGNITION disorders ,MENTAL depression ,REFERENCE values - Abstract
Edinburgh Cognitive and Behavioural ALS Screen (ECAS) is a brief, standardized assessment of cognitiveimpairment inamyotrophic lateral sclerosis. Objective: We aimed to createa normative dataset for the ECAS Czech version (ECAS-CZ) in order to make the assessment applicable for clinical settings. Method: Included were 102 healthy participants (mean age: 54.92 ± 14.55; education: 14.52 ± 2.44; 54:48 females/males) that fulfilled rigorous exclusion criteria and controlled for depressive symptoms. Results: The internal consistency of ECAS-CZ was acceptable (Cronbach's α =.69). We found medium correlations (rho ≈.5) of age and education with ECAS-CZ Total score but not with gender. Cut-offs with −2 SD's threshold are presented for the differentiation of cognitive impairment. We report percentile values for ECAS-CZ Total including all subscales. Conclusion: We provide normative values for ECAS-CZ that are well suited for the detection of cognitive impairment in clinical settings especially for patients with ALS. Supplemental data for this article is available online at https://doi.org/10.1080/13854046.2021.1978553. [ABSTRACT FROM AUTHOR]
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- 2021
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16. Validation of The Edinburgh cognitive and behavioural ALS screen (ECAS) in behavioural variant frontotemporal dementia and Alzheimer's disease.
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De Icaza Valenzuela, Mónica M., Bak, Thomas H., Thompson, Harriet E., Colville, Shuna, Pal, Suvankar, and Abrahams, Sharon
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ALZHEIMER'S disease ,FRONTOTEMPORAL dementia ,FRONTAL lobe diseases ,SYMPATHY ,NEUROPSYCHOLOGICAL tests ,AMYOTROPHIC lateral sclerosis ,CLINICAL neuropsychology - Abstract
The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) was developed to assess cognitive and behavioural changes in an anterior frontotemporal syndrome (executive functions, language, fluency and behaviour), common in Amyotrophic Lateral Sclerosis (ALS) and also assesses posterior cerebral dysfunction (memory and visuospatial abilities). Objectives: To validate the ECAS in behavioural variant Frontotemporal Dementia (bvFTD) without ALS, as compared with Alzheimer's disease (AD), against comprehensive neuropsychological assessment. Compare its sensitivity to that of the Addenbrooke's Cognitive Examination (ACE‐III) and investigate behavioural changes in both types of dementia. Methods: Retrospective study of 16 people with bvFTD (without ALS), 32 with AD, and 48 healthy controls completed the ECAS, ACE‐III and extensive neuropsychological assessment. Results: The ECAS showed higher sensitivity (94%) and marginally lower specificity (96%) than the ACE‐III for both the bvFTD and AD groups. The anterior composite subscore was sensitive for bvFTD (94%), and slightly less so for AD (84%), while the posterior composite subscore was sensitive for AD (97%), and less so for bvFTD (75%). All people with bvFTD that were impaired on the ECAS total and anterior composite scores were also impaired on the anterior function's tests of the neuropsychological assessment. A cut‐off of four or more behavioural domains affected differentiated well between the bvFTD and AD groups, while a qualitative analysis of the behavioural interview found different themes between groups. Conclusions: The ECAS is a valid and sensitive assessment for bvFTD without ALS and for AD. The carer behavioural interview makes it particularly suitable to detect behavioural abnormalities related to frontal lobe disorders Key Points: The ECAS showed higher sensitivity (94%) and specificity (96%) for both the bvFTD and AD groups than the ACE‐III.The ECAS performed well against standard comprehensive neuropsychological assessment with perfect concordance between ECAS Total and Anterior functions composite scores, and performance on the anterior functions' tests of the neuropsychological assessment for the bvFTD group. The ECAS total and posterior functions composite scores also showed good validity against the posterior functions' tests of the neuropsychology assessment for the AD group.The most recurrent abnormal behaviour for the bvFTD group was loss of sympathy/empathy (100%), while the most recurrent theme for AD was loss of interest in normal activities (56%). Important thematic differences between diagnoses were (26%) lack of awareness and (66%) lack of manners in people with bvFTD, while AD patients (33%) had a loss of self‐confidence. [ABSTRACT FROM AUTHOR]
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- 2021
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17. Cognitive effects of Gaelic medium education on primary school children in Scotland.
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Cape, Ruth, Vega-Mendoza, Mariana, Bak, Thomas H., and Sorace, Antonella
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BILINGUALISM ,LINGUISTIC minorities ,ENGLISH language ,RESPONSE inhibition ,SECOND language acquisition ,DOMINANT language - Abstract
Research has shown that learning more than one language may have beneficial effects on executive functions, such as focused attention, inhibitory control, and switching between tasks. Evidence demonstrating these effects comes from studies with infants, children and adults from a range of language combinations. Much less direct evidence of such effects exists with regard to the bilingual experience of children acquiring regional minority languages. This study addresses the question of whether English-speaking children attending Gaelic Medium Education in Scotland exhibit differences of executive function compared with English-speaking children attending English Medium Education. Primary Five pupils from English-medium and Gaelic-medium schools in two Scottish towns were tested on three tasks of attentional control. One task, requiring verbal response inhibition, provided evidence of a significant positive effect for Gaelic-medium pupils. The results suggest that the cognitive effects of attending Gaelic Medium Education are specific to certain tasks and are affected by the characteristics of this particular bilingual setting (i.e. acquiring the second language in a domain-specific context with one dominant language). This supports the notion that the context of the bilingual experience is an important factor in shaping the cognitive effects which may be gained through exposure to more than one language. [ABSTRACT FROM AUTHOR]
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- 2021
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18. A 4-DOF Upper Limb Exoskeleton for Physical Assistance: Design, Modeling, Control and Performance Evaluation.
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Gull, Muhammad Ahsan, Thoegersen, Mikkel, Bengtson, Stefan Hein, Mohammadi, Mostafa, Andreasen Struijk, Lotte N. S., Moeslund, Thomas B., Bak, Thomas, and Bai, Shaoping
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ROBOTIC exoskeletons ,PEOPLE with disabilities ,ACTIVITIES of daily living ,DEGREES of freedom ,ENERGY consumption - Abstract
Wheelchair mounted upper limb exoskeletons offer an alternative way to support disabled individuals in their activities of daily living (ADL). Key challenges in exoskeleton technology include innovative mechanical design and implementation of a control method that can assure a safe and comfortable interaction between the human upper limb and exoskeleton. In this article, we present a mechanical design of a four degrees of freedom (DOF) wheelchair mounted upper limb exoskeleton. The design takes advantage of non-backdrivable mechanism that can hold the output position without energy consumption and provide assistance to the completely paralyzed users. Moreover, a PD-based trajectory tracking control is implemented to enhance the performance of human exoskeleton system for two different tasks. Preliminary results are provided to show the effectiveness and reliability of using the proposed design for physically disabled people. [ABSTRACT FROM AUTHOR]
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- 2021
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19. Ærø: A Platform Architecture for Mixed-Criticality Airborne Systems.
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Majumder, Shibarchi, Dalsgaard Nielsen, Jens Frederik, and Bak, Thomas
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AVIONICS ,COMPUTER architecture - Abstract
Real-time embedded platforms with resource constraints can take the benefits of mixed-criticality system where applications with different criticality-level share computational resources, with isolation in the temporal and spatial domain. A conventional software-based isolation mechanism adds additional overhead and requires certification with the highest level of criticality present in the system, which is often an expensive process. In this article, we present a different approach where the required isolation is established at the hardware-level by featuring partitions within the processor. A four-stage pipelined soft-processor with replicated resources in the data-path is introduced to establish isolation and avert interference between the partitions. A cycle-accurate scheduling mechanism is implemented in the hardware for hard-real-time partition scheduling that can accommodate different periodicity and execution time for each partition as per user needs, while preserving time-predictability at the individual application level. Applications running within a partition has no sense of the virtualization and can execute either on a host-software or directly on the hardware. The proposed architecture is implemented on FPGA thread and demonstrated with an avionics use case. [ABSTRACT FROM AUTHOR]
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- 2020
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20. A review of computer vision for semi-autonomous control of assistive robotic manipulators (ARMs).
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Bengtson, Stefan Hein, Bak, Thomas, Andreasen Struijk, Lotte N. S., and Moeslund, Thomas Baltzer
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AUTONOMY (Psychology) ,COMPUTERS ,DECISION making ,INFORMATION resources management ,MEDICAL information storage & retrieval systems ,PEOPLE with disabilities ,ROBOTICS ,VISION disorders ,SYSTEMATIC reviews ,ASSISTIVE technology - Abstract
Purpose: The advances in artificial intelligence have started to reach a level where autonomous systems are becoming increasingly popular as a way to aid people in their everyday life. Such intelligent systems may especially be beneficially for people struggling to complete common everyday tasks, such as individuals with movement-related disabilities. The focus of this paper is hence to review recent work in using computer vision for semi-autonomous control of assistive robotic manipulators (ARMs). Methods: Four databases were searched using a block search, yielding 257 papers which were reduced to 14 papers after applying various filtering criteria. Each paper was reviewed with focus on the hardware used, the autonomous behaviour achieved using computer vision and the scheme for semi-autonomous control of the system. Each of the reviewed systems were also sought characterized by grading their level of autonomy on a pre-defined scale. Conclusions: A re-occurring issue in the reviewed systems was the inability to handle arbitrary objects. This makes the systems unlikely to perform well outside a controlled environment, such as a lab. This issue could be addressed by having the systems recognize good grasping points or primitive shapes instead of specific pre-defined objects. Most of the reviewed systems did also use a rather simple strategy for the semi-autonomous control, where they switch either between full manual control or full automatic control. An alternative could be a control scheme relying on adaptive blending which could provide a more seamless experience for the user. Assistive robotic manipulators (ARMs) have the potential to empower individuals with disabilities by enabling them to complete common everyday tasks. This potential can be further enhanced by making the ARM semi-autonomous in order to actively aid the user. The scheme used for the semi-autonomous control of the ARM is crucial as it may be a hindrance if done incorrectly. Especially the ability to customize the semi-autonomous behaviour of the ARM is found to be important. Further research is needed to make the final move from the lab to the homes of the users. Most of the reviewed systems suffer from a rather fixed scheme for the semi-autonomous control and an inability to handle arbitrary objects. [ABSTRACT FROM AUTHOR]
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- 2020
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21. Unknown External Force Estimation and Collision Detection for a Cooperative Robot.
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Yousefizadeh, Shirin and Bak, Thomas
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KALMAN filtering ,ALGORITHMS ,ROBOTS ,TORQUEMETERS ,TASK forces - Abstract
SUMMARY: In human–robot cooperative industrial manipulators, safety issues are crucial. To control force safely, contact force information is necessary. Since force/torque sensors are expensive and hard to integrate into the robot design, estimation methods are used to estimate external forces. In this paper, the goal is to estimate external forces acting on the end-effector of the robot. The forces at the task space affect the joint space torques. Therefore, by employing an observer to estimate the torques, the task space forces can be obtained. To accomplish this, loadcells are employed to compute the net torques at the joints. The considered observers are extended Kalman filter (EKF) and nonlinear disturbance observer (NDOB). Utilizing the computed torque obtained based on the loadcells measurements and the observer, the estimates of external torques applied on the robot end-effector can be achieved. Moreover, to improve the degree of safety, an algorithm is proposed to distinguish between intentional contact force from an operator and accidental collisions. The proposed algorithms are demonstrated on a robot, namely WallMoBot, which is designed to help the operator to install heavy glass panels. Simulation results and preliminary experimental results are presented to demonstrate the effectiveness of the proposed methods in estimating the joint space torques generated by the external forces applied to the WallMoBot end-effector and to distinguish between the user-input force and accidental collisions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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22. Understudied factors contributing to variability in cognitive performance related to language learning.
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Long, Madeleine R., Vega-Mendoza, Mariana, Rohde, Hannah, Sorace, Antonella, Bak, Thomas H., Dong, Yanping, and Li, Ping
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FOREIGN language education ,BILINGUALISM ,SECOND language acquisition ,INDIVIDUAL differences ,PERFORMANCES ,COGNITION - Abstract
While much of the literature on bilingualism and cognition focuses on group comparisons (monolinguals vs bilinguals or language learners vs controls), here we examine the potential differential effects of intensive language learning on subjects with distinct language experiences and demographic profiles. Using an individual differences approach, we assessed attentional performance from 105 university-educated Gaelic learners aged 21–85. Participants were tested before and after beginner, elementary, and intermediate courses using tasks measuring i.) sustained attention, ii.) inhibition, and iii.) attention switching. We examined the relationship between attentional performance and Gaelic level, previous language experience, gender, and age. Gaelic level predicted attention switching performance: those in higher levels initially outperformed lower levels, however lower levels improved the most. Age also predicted performance: as age increased attention switching decreased. Nevertheless, age did not interact with session for any attentional measure, thus the impact of language learning on cognition was detectable across the lifespan. [ABSTRACT FROM AUTHOR]
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- 2020
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23. PaRTAA: A Real-Time Multiprocessor for Mixed-Criticality Airborne Systems.
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Majumder, Shibarchi, Nielsen, Jens Frederik Dalsgaard, and Bak, Thomas
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MULTIPROCESSORS ,TASK analysis ,RESOURCE management ,SCALABILITY - Abstract
Mixed-criticality systems, where multiple systems with varying criticality-levels share a single hardware platform, require isolation between tasks with different criticality-levels. Isolation can be achieved with software-based solutions or can be enforced by a hardware level partitioning. An asymmetric multiprocessor architecture offers hardware-based isolation at the cost of underutilized hardware resources, and the inter-core communication mechanism is often a single point of failure in such architectures. In contrast, a partitioned uniprocessor offers efficient resource utilization at the cost of limited scalability. We propose a partitioned real-time asymmetric architecture (PaRTAA) specifically designed for mixed-criticality airborne systems, featuring robust partitioning within processing elements for establishing isolation between tasks with varying criticality. The granularity in the processing element offers efficient resource utilization where inter-dependent tasks share the same processing element for sequential execution while preserving isolation, and independent tasks simultaneously execute on different processing elements as per system requirements. [ABSTRACT FROM AUTHOR]
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- 2020
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24. Executive, language and fluency dysfunction are markers of localised TDP-43 cerebral pathology in non-demented ALS.
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Gregory, Jenna M., McDade, Karina, Bak, Thomas H., Pal, Suvankar, Chandran, Siddharthan, Smith, Colin, and Abrahams, Sharon
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FRONTOTEMPORAL lobar degeneration ,PATHOLOGY ,AMYOTROPHIC lateral sclerosis ,EXECUTIVE function ,RESEARCH ,RESEARCH methodology ,EVALUATION research ,MEDICAL cooperation ,NEUROPSYCHOLOGICAL tests ,COMPARATIVE studies ,DNA-binding proteins ,VERBAL behavior ,RESEARCH funding ,LANGUAGE disorders ,CEREBRAL cortex ,DISEASE complications - Abstract
Objective: Approximately 35% of patients with amyotrophic lateral sclerosis (ALS) exhibit mild cognitive deficits in executive functions, language and fluency, without dementia. The precise pathology of these extramotor symptoms has remained unknown. This study aimed to determine the pathological correlate of cognitive impairment in patients with non-demented ALS.Methods: In-depth neuropathological analysis of 27 patients with non-demented ALS who had undergone cognitive testing (Edinburgh Cognitive and Behaviour ALS Screen (ECAS)) during life. Analysis involved assessing 43 kDa Tar-DNA binding protein (TDP-43) accumulation in brain regions specifically involved in executive functions, language functions and verbal fluency to ascertain whether functional deficits would relate to a specific regional distribution of pathology.Results: All patients with cognitive impairment had TDP-43 pathology in extramotor brain regions (positive predictive value of 100%). The ECAS also predicted TDP-43 pathology with 100% specificity in brain regions associated with executive, language and fluency domains. We also detected a subgroup with no cognitive dysfunction, despite having substantial TDP-43 pathology, so called mismatch cases.Conclusions: Cognitive impairment as detected by the ECAS is a valid predictor of TDP-43 pathology in non-demented ALS. The profile of mild cognitive deficits specifically predicts regional cerebral involvement. These findings highlight the utility of the ECAS in accurately assessing the pathological burden of disease. [ABSTRACT FROM AUTHOR]- Published
- 2020
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25. Reliable flight control system architecture for agile airborne platforms: an asymmetric multiprocessing approach.
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Majumder, Shibarchi, Dalsgaard Nielsen, Jens Frederik, Bak, Thomas, and la Cour-Harbo, Anders
- Abstract
System software subsystems in an unmanned aircraft system share hardware resources due to space, weight, and power constraints. Such subsystems have different criticality, requirements, and failure rates, and can cause undesired interference when sharing the same hardware. A component with high failure rate can reduce the reliability of the system unless a fault containment mechanism is adopted. This work proposes an asymmetric multiprocessor architecture to establish isolation at the hardware level for distributed implementation of safety-critical subsystems along with user defined payload subsystems on the same hardware with minimally reduced reliability of the system. To achieve that, subsystems are strategically segregated in separate processors, connected to an on-chip protective interconnect for inter-processor communications. A custom watchdog and reset mechanism are implemented to reset a specific processor without affecting the entire system if required. The architecture is demonstrated on a FPGA chip. In addition, an example of an optimised distribution is provided for a specific flight control system with five subsystems. [ABSTRACT FROM AUTHOR]
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- 2019
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26. Bilingualism and the severity of poststroke aphasia.
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Paplikar, Avanthi, Mekala, Shailaja, Bak, Thomas H., Dharamkar, Santosh, Alladi, Suvarna, and Kaul, Subhash
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APHASIA ,COGNITION disorders ,LANGUAGE disorders ,MULTILINGUALISM ,STROKE ,TREATMENT effectiveness ,DISEASE complications ,DISEASE risk factors - Abstract
Background: Bilingualism has been associated with cognitive benefits in healthy people as well as in patients with cognitive impairment due to stroke and dementia. However, the relationship between bilingualism and aphasia is more complex. While bilinguals are as likely as monolinguals to develop aphasia after stroke, studies of relationship between bilingualism and severity of poststroke language recovery are few and have produced conflicting results, with much evidence derived from immigrant populations or small case series. Aims: Against this background of limited number of studies, we set out to explore the relationship between bilingualism and severity of language impairment in stroke aphasia. We explored the hypothesis that enhanced cognitive abilities related to bilingualism may have a positive impact on recovery from aphasia. Methods & Procedures: We investigated 38 bilingual and 27 monolingual patients who participated in a longitudinal hospital-based stroke registry and were evaluated at least 3 months after stroke (mean 11.5 months). Patient performance on language and other cognitive functions was evaluated with Addenbrooke’s Cognitive Examination - Revised (ACE-R) validated for use in aphasia in local languages and for varying educational levels. The results of monolinguals and bilinguals were compared after accounting for confounding variables, including age, gender, education, occupation, medical, and stroke characteristics. Outcomes & Results: Aphasia severity as measured by the language domain sub-scores (total of language and fluency scores) of ACE-R was significantly higher in monolinguals compared with bilinguals (7.0 vs. 14.4, maximum score 40; p = 0.008, effect size = −0.691). Bilinguals performed significantly better than their monolingual counterparts in attention, memory, and visuospatial domains of ACE-R. A univariate general linear model analysis showed that bilingualism was significantly associated with higher language domain scores of ACE-R after adjusting for other confounding variables. Conclusions: The results suggest that although bilingual speakers are at equal risk of developing aphasia after stroke as monolingual ones, their aphasia is likely to be less severe. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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27. The Edinburgh Cognitive and Behavioral ALS screen: relationship to age, education, IQ and the Addenbrooke's Cognitive Examination-III.
- Author
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De Icaza Valenzuela, Mónica M., Bak, Thomas H., Pal, Suvankar, and Abrahams, Sharon
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COGNITIVE ability ,AMYOTROPHIC lateral sclerosis ,BEHAVIORAL assessment ,REGRESSION analysis ,MEDICAL education - Abstract
The Edinburgh Cognitive and Behavioral ALS Screen (ECAS) was developed to assess cognitive and behavioral changes common in Amyotrophic Lateral Sclerosis and other diseases affecting motor functions. It focuses on domains typically affected by the frontotemporal syndrome (executive and language functions, fluency and behavior), but assesses also memory and visuospatial functions. Objectives: (A) To investigate the relationship between the ECAS and the Addenbrooke's Cognitive Examination (ACE-III). (B) To investigate the effects of age, education, and IQ on the ECAS and create appropriate cutoff scores to determine abnormality. Methods: (A) 57 healthy participants (aged 35-80) were assessed with the ECAS, the Wechsler Abbreviated Scale of Intelligence (WASI-II), and the ACE-III. (B) 80 healthy participants (aged 51-80) were divided into four groups according to age and education; and were tested with the ECAS and the WASI-II. Results: The ECAS and the ACE-III have a good convergent validity with a significant correlation. Regression analysis revealed that IQ, followed by age, were the strongest predictors of the total ECAS score. IQ predicted 24% of the ECAS and 46% of the ACE-III variance. Education was not a significant predictor over and above IQ for both the ECAS and the ACE-III. Abnormality cutoff scores adjusted for age and education are presented. Conclusions: The ECAS shows good convergent validity with the ACE-III, but is less influenced by intelligence and presents less ceiling effects. The inclusion of an executive function assessment and behavioral interview in the ECAS makes it particularly useful for the assessment of frontal lobe disorders. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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28. From Bilingualism to Bilingualisms: Bilingual experience in Edinburgh and Singapore affects attentional control differently.
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OOI, SEOK HUI, GOH, WINSTON D., SORACE, ANTONELLA, BAK, THOMAS H., and Kupisch, Tanja
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BILINGUALISM ,ATTENTION ,INTERACTIONAL view theory (Communication) ,SEMANTIC computing ,REACTION time - Abstract
Recent theories propose that language-switching in bilinguals influences executive control. We investigated whether switching behaviour, shaped by the bilingual's interactional context as well as personal preferences impacted attentional control. We compared four groups – (i) Edinburgh monolinguals, (ii) Edinburgh non-switching late bilinguals, (iii) Edinburgh non-switching early bilinguals, and (iv) Singapore switching early bilinguals – on two tasks of attentional control. Effects of interactional context were observed, with Singapore bilinguals performing better on conflict resolution in the Attention Network Task and Edinburgh late bilinguals on attentional switching in the Elevator reversal (Test of Everyday Attention) subtest. Our results suggest that the interactional context of bilinguals could impact attentional control differently. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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29. Sensitivity and Specificity of the ECAS in Parkinson’s Disease and Progressive Supranuclear Palsy.
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Foley, Jennifer A., Niven, Elaine H., Paget, Andrew, Bhatia, Kailash P., Farmer, Simon F., Jarman, Paul R., Limousin, Patricia, Warner, Thomas T., Morris, Huw R., Bak, Thomas H., Abrahams, Sharon, and Cipolotti, Lisa
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COGNITION disorders diagnosis ,NEUROPSYCHOLOGICAL tests ,PARKINSON'S disease ,PROGRESSIVE supranuclear palsy ,DISABILITIES ,RESEARCH methodology evaluation - Abstract
Disentangling Parkinson’s disease (PD) and progressive supranuclear palsy (PSP) may be a diagnostic challenge. Cognitive signs may be useful, but existing screens are often insufficiently sensitive or unsuitable for assessing people with motor disorders. We investigated whether the newly developed ECAS, designed to be used with people with even severe motor disability, was sensitive to the cognitive impairment seen in PD and PSP and able to distinguish between these two disorders. Thirty patients with PD, 11 patients with PSP, and 40 healthy controls were assessed using the ECAS, as well as an extensive neuropsychological assessment. The ECAS detected cognitive impairment in 30% of the PD patients, all of whom fulfilled the diagnostic criteria for mild cognitive impairment. The ECAS was also able to detect cognitive impairment in PSP patients, with 81.8% of patients performing in the impaired range. The ECAS total score distinguished between the patients with PSP and healthy controls with high sensitivity (91.0) and specificity (86.8). Importantly, the ECAS was also able to distinguish between the two syndromes, with the measures of verbal fluency offering high sensitivity (82.0) and specificity (80.0). In sum, the ECAS is a quick, simple, and inexpensive test that can be used to support the differential diagnosis of PSP. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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30. The Role of Verb Fluency in the Detection of Early Cognitive Impairment in Alzheimer's Disease.
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Alegret, Montserrat, Peretó, Mar, Pérez, Alba, Valero, Sergi, Espinosa, Ana, Ortega, Gemma, Hernández, Isabel, Mauleón, Ana, Rosende-Roca, Maitée, Vargas, Liliana, Rodríguez-Gómez, Octavio, Abdelnour, Carla, Berthier, Marcelo L, Bak, Thomas H, Ruíz, Agustín, Tárraga, Lluís, and Boada, Mercè
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ALZHEIMER'S disease risk factors ,ALZHEIMER'S disease diagnosis ,MILD cognitive impairment ,FLUENCY (Language learning) ,VERBAL ability ,COGNITION ,DIAGNOSIS - Abstract
Background: Verb fluency (VF) is the less commonly used fluency test, despite several studies suggesting its potential as a neuropsychological assessment tool.Objective: To investigate the presence of VF deficits in mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) dementia; to assess the usefulness of VF in the detection of cognitively healthy (CH) people who will convert to MCI, and from MCI to dementia; and to establish the VF cut-offs useful in the cognitive assessment of Spanish population.Methods: 568 CH, 885 MCI, and 367 mild AD dementia individuals were administered the VF test and a complete neuropsychological battery. Longitudinal analyses were performed in 231 CH and 667 MCI subjects to search for VF predictors of diagnosis conversion.Results: A worsening on VF performance from CH, MCI to AD dementia groups was found. Lower performances on VF were significantly related to conversion from CH to MCI/MCI to dementia. When the effect of time to conversion was analyzed, a significant effect of VF was found on the faster conversion from CH to MCI, but not from MCI to dementia. Moreover, VF cut-off scores and sensitivity/specificity values were calculated for 6 conditions (3 age ranges by 2 educational levels).Conclusion: The VF test may be a useful tool for the differential diagnosis of cognitive failure in the elderly. Since VF deficits seem to take place in early stages of the disease, it is a suitable neuropsychological tool for the detection not only of CH people who will convert to MCI, but also from MCI to dementia. [ABSTRACT FROM AUTHOR]- Published
- 2018
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31. ECAS A-B-C: alternate forms of the Edinburgh Cognitive and Behavioural ALS Screen.
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Crockford, Christopher J., Kleynhans, Michaela, Wilton, Evelyn, Radakovic, Ratko, Newton, Judith, Niven, Elaine H., Al-Chalabi, Ammar, Hardiman, Orla, Bak, Thomas H., and Abrahams, Sharon
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AMYOTROPHIC lateral sclerosis ,MEDICAL screening ,BEHAVIOR modification ,NEUROPSYCHOLOGICAL tests ,ANALYSIS of variance ,DIAGNOSIS - Abstract
Background : The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) is a short assessment by which neuropsychological symptoms can be detected and quantified in people with ALS. To avoid potential practice effects with repeated administration, here we present alternative versions of the ECAS suitable for measuring change over time. Objective : To develop two alternate versions of the ECAS: ECAS-B and ECAS-C. Method : One hundred and forty-nine healthy adult participants were recruited. Thirty participants completed a pilot study in developing the alternate versions. Two groups of 40 participants were administered the ECAS-B or ECAS-C and compared to published data of the original ECAS (ECAS-A) to determine equivalence. An additional 39 participants were administered the ECAS consecutively, either repeating the original version (ECAS-A-A-A) serially or the different versions (ECAS-A-B-C) to determine potential practice effects. Recordings of assessments were scored by a second researcher to determine inter-rater reliability. Results : No significant differences were found between versions (A, B, C) of the composite performance measures of ALS Specific, ALS Non-Specific, and ECAS Total scores. Repeated serial administration of ECAS-A (A-A-A) produced some practice effects for composite scores, whereas no such effects were found when alternate versions were administered serially (A-B-C). Exceptionally high intra-class correlations were found for all three versions of the ECAS suggesting a high degree of rater agreement. Conclusion : The newly developed alternate forms of the ECAS are both highly equitable to the original ECAS-A and enable avoidance of practice effects, thus supporting their use in measuring cognition and behaviour over time. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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32. Dementia in Latin America: Assessing the present and envisioning the future.
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Parra, Mario A., Baez, Sandra, Allegri, Ricardo, Nitrini, Ricardo, Lopera, Francisco, Slachevsky, Andrea, Custodio, Nilton, Lira, David, Piguet, Olivier, Kumfor, Fiona, Huepe, David, Cogram, Patricia, Bak, Thomas, Manes, Facundo, and Ibanez, Agustin
- Published
- 2018
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33. Comparative Effects of Education and Bilingualism on the Onset of Mild Cognitive Impairment.
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Ramakrishnan, Subasree, Mekala, Shailaja, Mamidipudi, annapurna, Yareeda, Sireesha, Mridula, Rukmini, Bak, Thomas H., alladi, Suvarna, and Kaul, Subhash
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EDUCATIONAL attainment ,AGE factors in disease ,COMPARATIVE studies ,DEMENTIA ,MULTILINGUALISM ,PROBABILITY theory - Abstract
Background: Increasing evidence suggests that life course factors such as education and bilingualism may have a protective role against dementia due to Alzheimer disease. This study aimed to compare the effects of education and bilingualism on the onset of cognitive decline at the stage of mild cognitive impairment (MCI). Methods: A total of 115 patients with MCI evaluated in a specialty memory clinic in Hyderabad, India, formed the cohort. MCI was diagnosed according to Petersen's criteria following clinical evaluation and brain imaging. Age at onset of MCI was compared between bilinguals and monolinguals, and across subjects with high and low levels of education, adjusting for possible confounding variables. Results: The bilingual MCI patients were found to have a clinical onset of cognitive complaints 7.4 years later than monolinguals (65.2 vs. 58.1 years; p = 0.004), while years of education was not associated with delayed onset (1-10 years of education, 59.1 years; 11-15 years of education, 62.6 years; >15 years of education, 62.2 years; p = 0.426). Conclusion: The effect of bilingualism is protective against cognitive decline, and lies along a continuum from normal to pathological states. In comparison, the role of years of education is less robust. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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34. Baseline layout and design of a 0.8 GW reference wind farm in the North Sea.
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Bak, Thomas, Graham, Angus, Sapronova, Alla, Florian, Mihai, Dalsgaard Sørensen, John, Knudsen, Torben, Hou, Peng, and Chen, Zhe
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OFFSHORE wind power plants ,CLIMATOLOGY ,TURBULENCE ,CAPITAL investments ,COMPUTER simulation - Abstract
The paper presents a model of a reference wind farm. The model considers the wind and wave climatologies for a specific site from which two different wind farm layouts are derived. These layouts are examined through the effective wake-enhanced turbulence intensity at the hub height for a given climatology, and a simple model for the influence on capital expenditures is proposed. An electrical design is presented, the cable losses are calculated and the energy yield is determined. An operation and maintenance model is established, and the associated operating expenditure is obtained. All of the models are then summarized in terms of a levelized cost of energy using a numerical simulation tool, which allows the layouts to be compared. The data and models are freely available online for others to use and may serve as a baseline for benchmarking and allow researchers to compare and discuss their results. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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35. Consensus classification of posterior cortical atrophy.
- Author
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Crutch, Sebastian J., Schott, Jonathan M., Rabinovici, Gil D., Murray, Melissa, Snowden, Julie S., van der Flier, Wiesje M., Dickerson, Bradford C., Vandenberghe, Rik, Ahmed, Samrah, Bak, Thomas H., Boeve, Bradley F., Butler, Christopher, Cappa, Stefano F., Ceccaldi, Mathieu, de Souza, Leonardo Cruz, Dubois, Bruno, Felician, Olivier, Galasko, Douglas, Graff-Radford, Jonathan, and Graff-Radford, Neill R.
- Published
- 2017
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36. Towards an interdisciplinary lifetime approach to multilingualism: From implicit assumptions to current evidence.
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Mehmedbegovic, Dina and Bak, Thomas H.
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LANGUAGE policy ,LEARNING ,MULTILINGUALISM ,CURRICULUM ,COGNITIVE neuroscience - Abstract
Copyright of European Journal of Language Policy is the property of Liverpool University Press / Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
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37. The need for harmonisation and innovation of neuropsychological assessment in neurodegenerative dementias in Europe: consensus document of the Joint Program for Neurodegenerative Diseases Working Group.
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Costa, Alberto, Bak, Thomas, Caffarra, Paolo, Caltagirone, Carlo, Ceccaldi, Mathieu, Collette, Fabienne, Crutch, Sebastian, Della Sala, Sergio, Démonet, Jean François, Dubois, Bruno, Duzel, Emrah, Nestor, Peter, Papageorgiou, Sokratis G., Salmon, Eric, Sikkes, Sietske, Tiraboschi, Pietro, van der Flier, Wiesje M., Visser, Pieter Jelle, and Cappa, Stefano F.
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DEMENTIA ,NEUROPSYCHOLOGICAL tests ,FUNCTIONAL assessment ,COGNITIVE ability ,COGNITION - Abstract
Cognitive, behavioural, and functional assessment is crucial in longitudinal studies of neurodegenerative dementias (NDD). Central issues, such as the definition of the study population (asymptomatic, at risk, or individuals with dementia), the detection of change/decline, and the assessment of relevant outcomes depend on quantitative measures of cognitive, behavioural, and functional status. Currently, we are far from having available reliable protocols and tools for the assessment of dementias in Europe. The main problems are the heterogeneity of the tools used across different European countries, the lack of standardisation of administration and scoring methods across centres, and the limited information available about the psychometric properties of many tests currently in widespread use. This situation makes it hard to compare results across studies carried out in different centres, thus hampering research progress, in particular towards the contribution to a “big data” common data set. We present here the results of a project funded by the Joint Program for Neurodegenerative Diseases (JPND) and by the Italian Ministry of Health. The project aimed at providing a consensus framework for the harmonisation of assessment tools to be applied to research in neurodegenerative disorders affecting cognition across Europe. A panel of European experts reviewed the current methods of neuropsychological assessment, identified pending issues, and made recommendations for the harmonisation of neuropsychological assessment of neurodegenerative dementias in Europe. A consensus was achieved on the general recommendations to be followed in developing procedures and tools for neuropsychological assessment, with the aim of harmonising tools and procedures to achieve more reliable data on the cognitive-behavioural examination. The results of this study should be considered as a first step to enhancing a common view and practise on NDD assessment across European countries. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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38. Clinical Trials in Neurodegeneration.
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Hardiman, Orla, Kelly, Julie A., Bak, Thomas H., Elamin, Marwa, Mihaila, Dragos L., Shaw, Pamela J., Mitsumoto, Hiroshi, and Shefner, Jeremy M.
- Published
- 2016
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39. Fronto-Temporal Dementia (FTD).
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Elamin, Marwa, Omer, Taha, Hutchinson, Siobhan, Doherty, Colin P., and Bak, Thomas H.
- Published
- 2016
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40. Role of Neuropsychology in Neurodegeneration.
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Elamin, Marwa, Bak, Thomas H., Doherty, Colin P., Pender, Niall, and Abrahams, Sharon
- Published
- 2016
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41. Cooking pasta in La Paz.
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Bak, Thomas H.
- Subjects
BILINGUALISM ,LITERATURE ,COGNITION ,MONOLINGUALISM - Abstract
Literature on bilingualism and cognition is characterised by a large amount of conflicting evidence. In some studies, bilinguals perform better then monolinguals on executive tasks involving inhibition, monitoring and switching but are slower on tasks of lexical processing. Other studies don't find any significant effects and challenge the very existence of cognitive differences between monolinguals and bilinguals. In this paper I question the assumption that different studies performed in different parts of the world should yield the same results. I argue that the environment (in the widest sense of the word) in which an experiment is conducted can exert profound influence on its outcome. Against the background of the current debate about the replication crisis in science, I propose that conflicting evidence is not a threat to the trustworthiness of scientific research but a sign of the health of a discipline and a welcome opportunity to identify new relevant variables. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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42. The effects of language use on lexical processing in bilinguals.
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de Bruin, Angela, Della Sala, Sergio, and Bak, Thomas H.
- Abstract
Bilingualism has been associated with slower lexical processing in both languages, but it remains unclear to what extent this effect may be modulated by language use. We compared older English monolinguals with two groups of older bilinguals on lexical processing tasks. Both acquired English and Gaelic during childhood, but whileactive bilingualscontinued to use both languages,inactive bilingualsmostly used English. All three groups showed similar accuracy in English. However, in reaction times, active but not inactive bilinguals were slower than monolinguals. We conclude that language use can modulate effects of bilingualism on lexical tasks. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
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43. Novelty, Challenge, and Practice: The Impact of Intensive Language Learning on Attentional Functions.
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Bak, Thomas H., Long, Madeleine R., Vega-Mendoza, Mariana, and Sorace, Antonella
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SCOTTISH Gaelic language ,LANGUAGE & languages ,LEARNING ability ,AUDITORY selective attention ,AGE groups - Abstract
We investigated the impact of a short intensive language course on attentional functions. We examined 33 participants of a one-week Scottish Gaelic course and compared them to 34 controls: 16 active controls who participated in courses of comparable duration and intensity but not involving foreign language learning and 18 passive controls who followed their usual routines. Participants completed auditory tests of attentional inhibition and switching. There was no difference between the groups in any measures at the beginning of the course. At the end of the course, a significant improvement in attention switching was observed in the language group (p < .001) but not the control group (p = .127), independent of the age of participants (18–78 years). Half of the language participants (n = 17) were retested nine months after their course. All those who practiced Gaelic 5 hours or more per week improved from their baseline performance. In contrast, those who practiced 4 hours or fewer showed an inconsistent pattern: some improved while others stayed the same or deteriorated. Our results suggest that even a short period of intensive language learning can modulate attentional functions and that all age groups can benefit from this effect. Moreover, these short-term effects can be maintained through continuous practice. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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44. Neural correlates of cognitive resilience differ between experiences of bilingualism and education: A cortical surface‐based morphometry study in dementia.
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Alladi, Suvarna, Arshad, Faheem, Kenchaih, Raghavendra, Surampudi, Bapiraju, Paplikar, Avanthi, Varghese, Feba Anna, Ramakrishnan, Subasree, Saini, Jitender, SrInivasan, Narayanan, Khokhar, Sunil, and Bak, Thomas H
- Published
- 2021
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45. Impact of Bilingualism on Cognitive Outcome After Stroke.
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Alladi, Suvarna, Bak, Thomas H., Mekala, Shailaja, Rajan, Amulya, Chaudhuri, Jaydip Ray, Mioshi, Eneida, Krovvidi, Rajesh, Surampudi, Bapiraju, Duggirala, Vasanta, and Kaul, Subhash
- Published
- 2016
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46. The Utility of the Addenbrooke's Cognitive Examination Version Three in Early-Onset Dementia.
- Author
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Elamin, Marwa, Holloway, Guy, Bak, Thomas H., and Pal, Suvankar
- Subjects
DIAGNOSIS of dementia ,MEMORY disorders ,ALZHEIMER'S disease ,APHASIA ,COGNITIVE testing ,COMPARATIVE studies ,NEUROPSYCHOLOGICAL tests ,RESEARCH methodology ,RELIABILITY (Personality trait) ,RETROSPECTIVE studies ,RESEARCH methodology evaluation ,DIAGNOSIS - Abstract
Background/Aims: Early-onset dementia (EOD) is defined as functionally relevant cognitive decline with age of onset at less than 65 years. The aim of this study was to investigate the utility of the recently validated third version of the Addenbrooke's Cognitive Examination (ACE-III) in predicting dementia diagnoses in EOD. Methods: ACE-III scores of EOD patients were compared to those of healthy controls (HC) and individuals with subjective memory impairment (SMI). Results: The study included 71 EOD patients (Alzheimer's disease, n = 31; primary progressive aphasia, n = 11; behavioural-variant frontotemporal dementia, n = 18, and posterior cortical atrophy, n = 11); there were 28 HC and 15 individuals with SMI. At a cutoff score of 88/100, the ACE-III displayed high sensitivity and specificity in distinguishing EOD from HC (91.5 and 96.4%) and SMI (91.5 and 86.7%). Conclusions: The ACE-III is a reliable cognitive screening tool in EOD. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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47. The impact of bilingualism on cognitive ageing and dementia.
- Author
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Bak, Thomas H.
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BILINGUALISM ,COGNITION disorders in old age ,DEMENTIA prevention ,PSYCHOLOGICAL aspects of aging ,CONFOUNDING variables ,MONOLINGUALISM ,PREVENTION ,PSYCHOLOGY - Abstract
Within the current debates on cognitive reserve, cognitive ageing and dementia increasingly showing a positive effect of mental, social and physical activities on health in older age, bilingualism remains one of the most controversial issues. Some reasons for it might be social or even ideological. However, one of the most important genuine problems facing bilingualism research is the high number of potential confounding variables. Bilingual communities often differ from monolingual ones in a range of genetic and environmental variables. In addition, within the same population, bilingual individuals could be different from the outset from those who remain monolingual. We discuss the most common confounding variables in the study of bilingualism, aging and dementia, such as group heterogeneity, migration, social factors, differences in general intelligence and the related issue of reverse causality. We describe different ways in which they can be minimised by the choice of the studied populations and the collected data. In this way, the emerging picture of the interaction between bilingualism and cognitive aging becomes more complex, but also more convincing. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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48. Impaired affective and cognitive theory of mind and behavioural change in amyotrophic lateral sclerosis.
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van der Hulst, Egberdina-Józefa, Bak, Thomas H., and Abrahams, Sharon
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AMYOTROPHIC lateral sclerosis ,COGNITIVE learning theory ,BEHAVIOR modification ,AFFECTIVE disorders ,NEUROPSYCHOLOGICAL tests ,EMPATHY ,VERBAL behavior testing ,THOUGHT & thinking ,AFFECT (Psychology) ,COGNITION ,INTERPERSONAL relations ,JUDGMENT (Psychology) ,SELF-perception ,TREATMENT effectiveness ,PSYCHOLOGY - Abstract
Objectives: Executive and behavioural changes are well-recognised in classical amyotrophic lateral sclerosis (ALS), indicating a subclinical behavioural-variant frontotemporal dementia (bvFTD) in some patients. Social cognitive deficits in ALS have been recently described and an impairment was identified on a simple Theory of Mind (ToM) test, which assesses the judgement of the preference of another through direction of eye gaze. The present study further delineated this deficit, by distinguishing between Affective and Cognitive subcomponents, and determining the relationship to behavioural change, levels of empathy and self-awareness.Methods: The Cognitive-Affective Judgement of Preference Test was administered to 33 patients with ALS and 26 controls. Furthermore, a comprehensive neuropsychological battery and detailed behavioural assessment, with measures of empathy and awareness, were included.Results: Patients with ALS showed a significant impairment in Affective ToM only when compared with healthy controls, with a deficit in 36% of patients; 12% showed an isolated Affective ToM deficit while 24% showed more generic ToM dysfunction. A Cognitive ToM deficit was found in 27% of patients, with 3% showing an isolated Cognitive ToM deficit. The patients with ALS showed reduced empathy (Fantasy scale) and increased behavioural dysfunction with high levels of apathy. In addition, patients with either an Affective and/or Cognitive ToM deficit exhibited poor self-awareness of their performance and abnormalities on verbal fluency, while those with an Affective ToM deficit also displayed higher levels of apathy and a naming deficit.Conclusions: Dysfunctional ToM is a prominent feature of the cognitive profile of ALS. This specific difficulty in identifying and distinguishing the feelings and thoughts of another from a self-perspective may underpin the social behavioural abnormalities present in some patients with ALS, manifest as apathy and loss of awareness. [ABSTRACT FROM AUTHOR]- Published
- 2015
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49. The association of aphasia and right-sided motor impairment in corticobasal syndrome.
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Levin, Johannes, Bak, Thomas, Rominger, Axel, Mille, Erik, Arzberger, Thomas, Giese, Armin, Ackl, Nibal, Lorenzl, Stefan, Bader, Benedikt, Patzig, Maximilian, Bötzel, Kai, and Danek, Adrian
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APHASIA ,CEREBRAL cortex diseases ,BASAL ganglia diseases ,MOVEMENT disorders ,DYSARTHRIA - Abstract
Corticobasal syndrome is defined clinically on the basis of symptoms and findings related to dysfunction of the cerebral cortex and the basal ganglia. Usually, marked asymmetry of motor findings is observed. Although aphasia has now been recognized as a frequent feature of corticobasal syndrome, it remains unclear whether it is usually associated with right-sided motor symptoms, pointing to the involvement of the left hemisphere. Hence, we set out to examine the relationship between the presence of language symptoms and the side affected by extrapyramidal symptoms. We analyzed the electronic care records of patients seen in the years 2003-2013 in the Neurology Department of the University Hospital of Munich. The diagnosis of corticobasal syndrome was discussed in ninety-two individuals. Of those, 38 cases fulfilled diagnostic criteria for corticobasal syndrome. Aphasia correlated highly with a predominant right-sided movement disorder ( p = 0.002). In contrast, it was less common in patients with left-sided motor presentation. Dysarthria did not show a preferential correlation ( p = 0.25). Our analysis suggests a characteristic presentation of corticobasal syndrome in which motor dysfunction of the right side of the body is associated with aphasia. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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50. Survey of wind farm control-power and fatigue optimization.
- Author
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Knudsen, Torben, Bak, Thomas, and Svenstrup, Mikael
- Subjects
WIND power plants ,SIMULATION methods & models ,AERODYNAMICS research ,WIND turbines ,TURBINES - Abstract
The main goal of this paper is to establish the present state of the art for wind farm control. The control area that will be focused on is the mechanical/aerodynamic part, which includes the wind turbines, their power production, fatigue and wakes affecting neighbouring wind turbines. The sub-objectives in this area of research are as follows: (i) maximizing the total wind farm power production; (ii) following a reference for the total wind farm active power; and (iii) doing this in a manner that minimizes fatigue loading for the wind turbines in the farm. Each of these sub-objectives is discussed, including the following important control issues: choice of input and output, control method and modelling used for controller design and simulation. The available literature from industry is also considered. Finally, a conclusion is presented discussing the established results, open challenges and necessary research. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
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