| 1. |
- Almkvist, Ove, et al.
(författare)
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Cognitive decline from estimated premorbid status predicts neurodegeneration in Alzheimer's disease
- 2009
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Ingår i: Neuropsychology. - : American Psychological Association. - 0894-4105 .- 1931-1559. ; 23:1, s. 117-124
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the relationship between premorbid and current cognitive function with respect to the clinical features of patients with various types of neurodegeneration in the form of Alzheimer's disease (AD), mild cognitive impairment (MCI), and subjective cognitive impairment (SCI), as compared with a healthy control group (C). Clinical features (MMSE, cognitive and depressive symptoms), genetics (apolipoprotein E; APOE) and measures of neurodegeneration (Aβ-sub(42), t-tau, and p-tau) were examined, as well as present cognitive function. Various methods of assessing premorbid cognitive function were compared, including a Swedish NART-analogous test (Irregularly Spelled Words; ISW), a Swedish lexical decision test (SLDT), a Hold test (Information in WAIS-R), Best current performance test, and combined demographic characteristics. Results showed that cognitive decline (premorbid minus current cognitive function) based on SLDT and ISW was a significant predictor for MMSE and Aβ-sub(42), whereas corresponding associations for present cognitive function and decline measures based on other methods were less powerful. Results also showed that specific verbal abilities (e.g., SLDT and ISW) were insensitive to AD and that these abilities indicated premorbid cognitive function in retrospect. In conclusion, cognitive decline from premorbid status reflects the disease processes.
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| 2. |
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| 3. |
- Bellander, Martin, et al.
(författare)
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Lower baseline performance but greater plasticity of working memory for carriers of the val allele of the comt val158met polymorphism
- 2015
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 29:2, s. 247-254
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Little is known about genetic contributions to individual differences in cognitive plasticity. Given that the neurotransmitter dopamine is critical for cognition and associated with cognitive plasticity, we investigated the effects of 3 polymorphisms of dopamine-related genes (LMX1A, DRD2, COMT) on baseline performance and plasticity of working memory (WM), perceptual speed, and reasoning. Method: One hundred one younger and 103 older adults underwent approximately 100 days of cognitive training, and extensive testing before and after training. We analyzed the baseline and posttest data using latent change score models. Results: For working memory, carriers of the val allele of the COMT polymorphism had lower baseline performance and larger performance gains from training than carriers of the met allele. There was no significant effect of the other genes or on other cognitive domains. Conclusions: We relate this result to available evidence indicating that met carriers perform better than val carriers in WM tasks taxing maintenance, whereas val carriers perform better at updating tasks. We suggest that val carriers may show larger training gains because updating operations carry greater potential for plasticity than maintenance operations.
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| 4. |
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| 5. |
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| 6. |
- Bruno, D., et al.
(författare)
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Cross-Sectional Associations of CSF Tau Levels With Rey's AVLT: A Recency Ratio Study
- 2023
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 37:6, s. 628-635
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The preeminent in vivo cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are amyloid beta 1-42 (A1342), phosphorylated Tau (p-tau), and total Tau (t-tau). The goal of this study was to examine how well traditional (total and delayed recall) and process-based (recency ratio [Rr]) measures derived from Rey's Auditory Verbal Learning test (AVLT) were associated with these biomarkers. Method: Data from 235 participants (M-age = 65.5, SD = 6.9), who ranged from cognitively unimpaired to mild cognitive impairment, and for whom CSF values were available, were extracted from the Wisconsin Registry for Alzheimer's Prevention. Bayesian regression analyses were carried out using CSF scores as outcomes, AVLT scores as predictors, and controlling for demographic data and diagnosis. Results: We found moderate evidence that Rr was associated with both CSF p-tau (Bayesian factor [BFM] = 5.55) and t-tau (BFM = 7.28), above and beyond the control variables, while it did not correlate with CSF A1342 levels. In contrast, total and delayed recall scores were not linked with any of the AD biomarkers, in separate analyses. When comparing all memory predictors in a single regression, Rr remained the strongest predictor of CSF t-tau levels (BFM = 3.57). Conclusions: Our findings suggest that Rr may be a better cognitive measure than commonly used AVLT scores to assess CSF levels of p-tau and t-tau in nondemented individuals.
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| 7. |
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| 8. |
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| 9. |
- Castegren, Elias, et al.
(författare)
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OOlong : A Concurrent Object Calculus for Extensibility and Reuse
- 2019
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Ingår i: ACM SIGAPP Applied Computing Review. - : ACM Press. - 1559-6915 .- 1931-0161. ; 18:4, s. 47-60
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Tidskriftsartikel (refereegranskat)abstract
- We present OOlong, an object calculus with interface inheritance, structured concurrency and locks. The goal of the calculus is extensibility and reuse. The semantics are therefore available in a version for LATEX typesetting (written in Ott), a mechanised version for doing rigorous proofs in Coq, and a prototype interpreter (written in OCaml) for typechecking an running OOlong programs.
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| 10. |
- de Frias, Cindy M., et al.
(författare)
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Characterizing executive functioning in older special populations : From cognitively elite to cognitively impaired
- 2009
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Ingår i: Neuropsychology. - : American Psychological Association. - 0894-4105 .- 1931-1559. ; 23:6, s. 778-791
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Tidskriftsartikel (refereegranskat)abstract
- The authors examined the structure and invariance of executive functions (EF) across (a) a continuum of cognitive status in 3 groups of older adults (cognitively elite [CE], cognitively normal [CN], and cognitively impaired [CI]) and (b) a 3-year longitudinal interval. Using latent variable analyses (LISREL 8.80), the authors tested 3-factor models (“Inhibition”: Hayling [Burgess & Shallice, 1997], Stroop [Regard, 1981]; “Shifting”: Brixton [Burgess & Shallice, 1997], Color Trails [D’Elia et al., 1996]; and “Updating”: Reading and Computational Span [Salthouse & Babcock, 1991]) and 1-factor models within each group. Participants (initial N = 570; 53–90 years) were from the Victoria Longitudinal Study (Sample 3, Waves 1 and 2). Cross-sectionally, the authors observed a 3-factor EF structure especially for the CE group and 1-factor solutions for all 3 groups. Longitudinally, temporal invariance was supported for the 3-factor model (CE and CN groups) and the 1-factor model (CI and CN groups). Subgroups with higher cognitive status and greater 3-year stability performed better on EF factors than corresponding groups with lower cognitive status and less stability. Studies of EF structure, performance, dedifferentiation, and dysfunction will benefit from considering initial cognitive status and longitudinal stability.
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| 11. |
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| 12. |
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| 13. |
- Elbe, Pia, et al.
(författare)
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Computerized Cognitive Interventions for Adults With ADHD: A Systematic Review and Meta-Analysis
- 2023
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 37:5, s. 519-530
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Forskningsöversikt (refereegranskat)abstract
- Objective: Treatments for adults with attention-deficit hyperactivity disorder (ADHD) are understudied, compared to children and adolescents with the same condition. In this systematic review and random-effects meta-analysis, we aim to evaluate the outcomes of computerized cognitive training (CCT) interventions in randomized controlled trials (RCTs) including adults with ADHD.Method: Cognitive outcomes and ADHD symptom severity were analyzed separately. In addition, the Cattell–Horn–Carroll (CHC) theory of cognitive abilities was used to categorize outcome variables into subdomains, which were analyzed separately in a subsequent analysis.Results: The results revealed a small positive change in overall cognitive functioning, a measure of all cognitive outcomes in each study, for individuals who took part in CCT compared to controls (k = 9, Hedge’s g = 0.235, 95% CI [0.002, 0.467], p = 0.048, τ2 = 0.000, I2 = 0.000). However, neither symptom severity nor specific cognitive outcomes (executive functioning, cognitive speed, or working memory) showed a significant improvement.Conclusions: We analyzed the risk of bias in the chosen studies and discuss the findings in terms of effect size. It is concluded that CCT has a small positive effect in adults with ADHD. Due to the lack of heterogeneity in intervention designs across the included studies, increased heterogeneity in future studies could help inform clinicians about the aspects of CCT, such as training type and length, that are most beneficial for this group.
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| 14. |
- Eliassen, I. V., et al.
(författare)
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Predictive and diagnostic utility of brief neuropsychological assessment in detecting Alzheimer's pathology and progression to dementia
- 2020
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 1931-1559 .- 0894-4105. ; 34:8, s. 851-861
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess the role of brief neuropsychological assessments in prediction and identification of Alzheimer's disease (AD) pathology and progression to AD dementia. Method: Adults (N = 255; range = 40-81 years) with self-reported cognitive decline underwent baseline and 2-year follow-up clinical assessment, including a brief neuropsychological screening and lumbar puncture. Five different mild cognitive impairment (MCI) algorithms were applied on baseline cognitive test results: one conventional, three amnestic (lenient, stringent, multidomain), and one comprehensive criterion. We compared predictive and diagnostic accuracy of these MCI criteria by performing logistic regression analyses and calculating diagnostic accuracy measures for 2-year outcomes of (1) clinical diagnosis of AD dementia and (2) cerebrospinal fluid biomarkers in the Alzheimer's continuum. Results: The lenient amnestic MCI criterion showed the largest effect size for predicting progression to AD dementia (OR = 13.762, 99% CI = 1.969-96.194, p = .001) and AD biomarkers (OR = 4.855, 99% CI = 1.974-11.924, p < .001) after 2 years. This criterion was sensitive for progression to dementia (sensitivity = 92.0%, specificity = 54.8%, positive likelihood ratio [LR+] = 2.03, LR- = 0.15) and showed the highest overall diagnostic accuracy for AD biomarkers (sensitivity = 72.7%, specificity = 59.1%, LR+ = 1.78, negative likelihood ratio [LR-] = 0.46). The multidomain amnestic MCI criterion produced the highest specificity for dementia (sensitivity = 76.0%, specificity = 73.0%, LR+ = 2.82, LR- = 0.33) and AD biomarkers (sensitivity = 46.8% specificity = 70.9% LR+ = 1.61, LR- = 0.75). Conclusions: Defining MCI using a brief neuropsychological battery provided limited accuracy for progression to AD dementia and cerebrospinal fluid Aβ. The lenient amnestic MCI criterion identified the highest number of individuals who progressed to clinical AD or showed biomarker pathology, but this approach included a substantial number of false positives. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
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| 15. |
- Eliassen, Ingvild Vøllo, et al.
(författare)
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Regression-Based Cognitive Change Norms Applied in Biochemically Defined Predementia Alzheimer’s Disease
- 2023
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 37:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We aim to develop 2-year cognitive change norms for adults ages 41–84 for six cognitive tests, and to evaluate these norms in groups with AD biomarkers. Background: Practice effects are common in repeated neuropsychological testing. Not accounting for practice effects may obscure cognitive decline in early Alzheimer’s disease (AD). Method: We developed standardized regression-based change norms from normative samples consisting of healthy controls from the Dementia Disease Initiation study (n = 125), the Trønderbrain study (n = 57), and the Gothenburg mild cognitive impairment (MCI) study (n = 65). Norms were applied in a sample with cognitive symptoms (subjective cognitive decline or MCI) and AD cerebrospinal fluid (CSF) biomarkers (n = 246), classified according to the A/T/N system. Results: The change norms adjusted for pertinent demographics and practice effects. The group with cognitive complaints displayed a trend toward cognitive decline compared to the normative group, with the A+T/N+ subgroup showing the most marked decline. This was observed in tests of episodic memory and cognitive flexibility/divided attention. Conclusions: We present 2-year cognitive change norms for adults between 41 and 84 years, adjusted for practice and demographics. A web-based change norm calculator is provided.
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| 16. |
- Eriksson, Allison, et al.
(författare)
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Changes in emotion processing in early Parkinson's disease reflect disease progression
- 2022
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Ingår i: Neuropsychology. - : American Psychological Association. - 0894-4105 .- 1931-1559. ; 36:3, s. 206-215
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Parkinson’s disease (PD) is a neurodegenerative disorder which can substantially affect nonmotor functions related to emotional processing. We aimed to examine the underlying differences in emotional processing in PD by comparing how early-stage PD patients recognize, rate, and react to facial, bodily, and vocal emotional stimuli to that of healthy controls (HC).Method: We compared emotion recognition, emotional rating bias, and emotional response range between a PD patient group (n = 33) and a HC group (n = 29). Pearson’s correlations were conducted to evaluate the relationship between emotion processing measures and clinical outcome measures in each group.Results: PD patients showed an enhanced emotion processing as compared to HC. They were overall more accurate than HC’s at identifying correct emotions and furthermore showed an increase in emotional ratings and reactions to both positive and negative stimuli that scaled with increased symptom severity, thereby yielding significant correlations between clinical outcomes and emotional range in the PD patient group.Conclusion: Our results suggest that alterations in emotional processing reflect disease progression in early PD.
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| 17. |
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| 18. |
- Feeney, Laura Marie, et al.
(författare)
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Leveraging a power save protocol to improve performance in ad hoc networks
- 2007
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Ingår i: ACM SIGMOBILE Mobile Computing and Communications Review. - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222. ; 11:2, s. 51-52
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Tidskriftsartikel (refereegranskat)abstract
- Power save protocols reduce energy consumption in ad hoc and sensor networks by allowing nodes to put their network interface into a low power consumption sleep state. The power save protocol must allow neighboring nodes to establish intervals during which they are mutually awake and available to exchange traffic. Many such protocols are based on a coordinated election of a covering set that is responsible for buffering traffic for sleeping nodes, but uncoordinated (i.e. asynchronous) protocols have also proven an attractive option.
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| 19. |
- Filipovikj, Predrag, et al.
(författare)
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Automated SMT-based Consistency Checking of Industrial Critical Requirements
- 2017
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Ingår i: ACM SIGAPP Applied Computing Review. - United States : ACM. - 1559-6915 .- 1931-0161. ; 17:4, s. 15-28
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Tidskriftsartikel (refereegranskat)abstract
- With the ever-increasing size, complexity and intricacy of system requirements specifications, it becomes difficult to ensure their correctness with respect to certain criteria such as consistency. Automated formal techniques for consistency checking of requirements, mostly by means of model checking, have been proposed in academia. Sometimes such techniques incur a high modeling cost or analysis time, or are not applicable. To address such problems, in this paper we propose an automated consistency analysis technique of requirements that are formalized based on patterns, and checked using state-of-the-art Satisfiability Modulo Theories solvers. Our method assumes several transformation steps, from textual requirements to formal logic, and next into the format suited for the SMT tool. To automate such steps, we propose a tool, called PROPAS, that does not require any user intervention during the transformation and analysis phases, thus making the consistency analysis usable by non-expert practitioners. For validation, we apply our method on a set of timed computation tree logic requirements of an industrial automotive system called the Fuel Level Display.
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| 20. |
- Frick, Andreas, et al.
(författare)
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Relationships between the National Adult Reading Test and memory.
- 2011
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 25:3, s. 397-403
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aims of this study were to investigate the relationships between performance on the National Adult Reading Test (NART) and retrospective, concurrent, and prospective memory functioning, as well as between the NART and change in memory functioning over time.METHOD: NART administered in 2005 was used as a predictor for memory functioning in 2001, 2005, and 2008, and change in memory functioning from 2001 to 2008. Outcome measures were Logical Memory II, Letter-Number Sequencing, and Spatial Span from the Wechsler Memory Scale. Participants were 319 healthy women aged 40-79 years at baseline (2001).RESULTS: Significant correlations were found between the number of errors on the NART and memory measures in 2001, 2005, and 2008; Logical Memory II (r = -.41, -.38, -.39, respectively), Letter-Number Sequencing (r = -.38, -.35, -.36, respectively) and Spatial Span (r = -.23, -.22, -.19, respectively; all p values < .001). NART significantly added to predictions of all three measures of memory, after controlling for age, level of education and socioeconomic status. NART also significantly added to predictions of change in Logical Memory II and Letter-Number Sequencing over a 7-year period.CONCLUSIONS: The results indicate that the NART is correlated with episodic and working memory, and that the NART added to predictions of change in verbal episodic and working memory. Although the relationships are only moderate at best, the NART may be used in conjunction with demographic information and clinical reasoning to estimate premorbid memory functioning.
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| 21. |
- Fullerton, Angelica F., et al.
(författare)
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Early Childhood Head Injury Attenuates Declines in Impulsivity and Aggression Across Adolescent Development in Twins
- 2019
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Ingår i: Neuropsychology. - : American Psychological Association. - 0894-4105 .- 1931-1559. ; 33:8, s. 1035-1044
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Head injury during development has been associated with behavioral changes such as impulsivity and antisocial behavior. This study investigates the extent to which behavioral changes associated with childhood head injury are sustained through adolescence and emerging adulthood.Method: Survey data was collected at 5 waves spanning 12 years (ages 9-20) from the University of Southern California Risk Factors for Antisocial Behavior twin study. Impulsivity was measured by errors of commission in a Go/NoGo behavioral task, and aggression was measured through youth self-report using the Reactive-Proactive Aggression Questionnaire. Head injury was assessed retrospectively using caregiver questionnaires at twin ages 14-15 years and self-reported at ages 19-20 years.Results: Participants with a head injury in early childhood showed significant delay in the normative developmental decline of impulsivity relative to the noninjured by mid-adolescence (ages 14-15.) Moreover, earlier age at injury was related to a slower decrease in impulsivity and greater increase in reactive aggression scores. Finally, among discordant monozygotic twin pairs, the twin with a head injury experienced significantly less decline in impulsivity by ages 19-20 than the noninjured co-twin.Conclusions: These findings indicate early childhood head injury may play a significant role in blunting the decline in impulsivity across development, exposing an additional risk factor for antisocial behavior.
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| 22. |
- Hedenius, Martina, et al.
(författare)
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Alterations of procedural memory consolidation in children with developmental dyslexia
- 2021
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 35:2, s. 185-196
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the present study was to determine if consolidation of procedural memory in developmental dyslexia (DD) may be supported by prolonging the initial learning session. Method: Children with DD (n = 31) and typically developing (TD) children (n = 34) were given a procedural (implicit sequence) learning task over two sessions, separated by a 24-hr interval. Session 1 was prolonged with 50% compared with previous studies of procedural memory consolidation in DD. Results: The amount of sequence learning was similar in the two groups at the end of Session 1 (p = .797, ηρ² = .001). At the follow-up session after 24 hr, performance in the DD group was poorer compared with the TD group (p = .003, ηρ² = .129). The amount of sequence knowledge in Session 2 predicted unique variance in reading fluency (p = .024, ηρ² = 0.083), independent of children's phoneme awareness and inattention symptoms. Conclusion: The present study shows that consolidation of procedural memory is impaired in DD, even when the initial learning session is prolonged. The findings encourage further research on the mechanisms supporting procedural memory consolidation in children with DD, and how these may be strengthened.
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| 23. |
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| 24. |
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| 25. |
- Kargl, F., et al.
(författare)
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ACM WiSec 2011 poster and demo session
- 2011
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Ingår i: ACM Mobile Computing and Communications Review (ACM MC2R). - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222. ; 15:3, s. 34-34
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Tidskriftsartikel (refereegranskat)abstract
- This edited article of MC2R features abstracts of posters and demos that were shown at the ACM Wireless Security Conference (ACM WiSec 2011).
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| 26. |
- Khatib, Iyad Al, et al.
(författare)
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Wireless LAN Access Points as Queuing Systems : Performance Analysis and Service Time
- 2003
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Ingår i: Mobile Computing and Communications Review. - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222. ; 7:1, s. 28-30
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Tidskriftsartikel (refereegranskat)abstract
- Since the approval of the IEEE 802.11b by the IEEE in 1999, the demand for WLAN equipment and networks has been growing quickly. We present a queuing model of wireless LAN (WLAN) access points (APs) for IEEE 802.11b. We use experimentation to obtain the characteristic parameters of our analytic model. The model can be used to compare the performance of different WLAN APs as well as the QoS of different applications in the presence of an AP. We focus on the delay introduced by an AP. The major observations are that the delay to serve a packet going from the WLAN medium to the wired medium (on the uplink) is less than the delay to serve a packet, with identical payload, but travelling from the wired medium to the WLAN medium (on the downlink). A key result is an analytic solution showing that the average service time of a packet is a strictly increasing function of payload.
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| 27. |
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| 28. |
- Larsson, Maria U., et al.
(författare)
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Phonemic fluency deficits in asymptomatic gene carriers for Huntington's disease
- 2008
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 22:5, s. 596-605
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate verbal fluency in preclinical Huntington's disease (HD). Phonemic and semantic fluency and the rate of word production over time were assessed for 29 asymptomatic gene carriers and 34 noncarriers of HD. The relationship between fluency tasks and other cognitive domains was investigated. Compared to noncarriers, carriers produced fewer words and produced them more slowly in the phonemic fluency task but not in the semantic fluency task. When the carrier group was divided on the basis of Predicted-Years-To-Onset (PYTO), only carriers with <12 PYTO performed worse than noncarriers on both fluency tasks. Correlational analyses revealed that phonemic fluency was associated with cognitive speed and working memory, while semantic fluency was linked with crystallized abilities. The difference between carriers and noncarriers in phonemic fluency and a difference between the two carrier groups (<12 PYTO and ≥12 PYTO) in semantic fluency, but not in phonemic fluency, suggest that frontostriatal deficits may precede temporal involvement in preclinical HD.
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| 29. |
- Larsson, Peter, 1966-
(författare)
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Selection diversity forwarding in a multihop packet radio network with fading channel and capture
- 2001
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Ingår i: ACM SIGMOBILE Mobile Computing and Communications Review. - : ACM Press. - 1559-1662 .- 1931-1222. ; 5:4, s. 47-54
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Tidskriftsartikel (refereegranskat)abstract
- Recent and increased interest of wireless mobile ad hoc networking motivates detailed examination of routing schemes specifically targeted for the demanding constraints that an unreliable, time varying and broadcast like wireless medium imposes. Incorporation and exploitation of radio characteristics are fundamental keys to successful and near optimal operation of routing schemes in a wireless environment. In this paper, forwarding methods for wireless mobile multihop networking in Rayleigh fading and non-fading channels are examined. An adaptive forwarding scheme denoted Selection Diversity Forwarding (SDF) is introduced and compared with two classical forwarding methods. It is shown that SDF presents significant performance improvements. In particular and in contrast to the reference methods NFP and MFR, the performance of SDF is enhanced under fading channel conditions. It is found that local path adaptation has potential to perform better than routing approaches along a single path.
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| 30. |
- Laukka, Erika J., et al.
(författare)
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Combined Genetic Influences on Episodic Memory Decline in Older Adults Without Dementia
- 2020
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 34:6, s. 654-666
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Although heritability explains a large proportion of the variance in old-age cognition, studies on the influence of specific genes have been inconclusive. We investigated the individual and combined effects of four single polymorphisms, previously associated with episodic memory, on cognitive or performance and rate of change. Method: Participants were 2490 individuals without dementia (mean age = 72 years) from the population-based Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Genotyping was performed for APOE (rs429358, rs7412), BDNF (rs6265), KIBRA (rs17070145), and CLSTN2 (rs6439886). We used latent difference score models to estimate the effects of age and genetic variation on level and change in five latent cognitive factors: episodic and semantic memory, letter and category fluency, and perceptual speed. Results: Of the individual genes, only APOE was associated with cognitive performance; epsilon 4 carriers showed lower perceptual speed performance and faster category fluency decline. A cumulative score, combining APOE, BDNF, KIBRA and CLSTN2, was associated with faster cognitive decline that was specific to the episodic memory domain (regression coefficient -0.064, p < .01). Similar results were obtained for a score not including APOE. Conclusions: Results suggest a benefit of investigating the combined influence of polymorphisms related to specific mechanistic factors.
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| 31. |
- Laukka, Erika J., et al.
(författare)
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Lower Ankle-Brachial Index Is Related to Worse Cognitive Performance in Old Age
- 2014
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Ingår i: Neuropsychology. - : AMER PSYCHOLOGICAL ASSOC. - 0894-4105 .- 1931-1559. ; 28:2, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We aimed to study the associations between peripheral artery disease (PAD) and ankle-brachial index (ABI) and performance in a range of cognitive domains in nondemented elderly persons. Methods: Data were collected within the Lothian Birth Cohort 1921 and 1936 studies. These are two narrow-age cohorts at age 87 (n = 170) and 73 (n = 748) years. ABI was analyzed as a dichotomous (PAD vs. no PAD) and a continuous measure. PAD was defined as having an ABI less than 0.90. Measures of nonverbal reasoning, verbal declarative memory, verbal fluency, working memory, and processing speed were administered. Both samples were screened for dementia. Results: We observed no significant differences in cognitive performance between persons with or without PAD. However, higher ABI was associated with better general cognition (beta = .23, p = .02, R-2 change = .05) and processing speed (beta = .29, p < .01, R-2 change = .08) in the older cohort and better processing speed (beta = .12, p < .01, R-2 change = .01) in the younger cohort. This was after controlling for age, sex, and childhood mental ability and excluding persons with abnormally high ABI (>1.40) and a history of cardiovascular or cerebrovascular disease. Conclusion: Lower ABI is associated with worse cognitive performance in old age, especially in the oldest old (>85 years), possibly because of long-term exposure to atherosclerotic disease. Interventions targeting PAD in persons free of manifest cardiovascular and cerebrovascular disease may reduce the incidence of cognitive impairment and dementia.
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| 32. |
- Lewin, Catharina, et al.
(författare)
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Sex differences favoring women in verbal but not in visuospatial episodic memory
- 2001
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 15:2, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- Sex differences favoring women have been found in a number of studies of episodic memory. This study examined sex differences in verbal, nonverbal, and visuospatial episodic memory tasks. Results showed that although women performed at a higher level on a composite verbal and nonverbal episodic memory score, men performed at a higher level on a composite score of episodic memory tasks requiring visuospatial processing. Thus, men can use their superior visuospatial abilities to excel in highly visuospatial episodic memory tasks, whereas women seem to excel in episodic memory tasks in which a verbalization of the material is possible.
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| 33. |
- Lindgren, Anders, et al.
(författare)
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Multi-path admission control for mobile ad hoc networks
- 2004
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Ingår i: Mobile Computing and Communications Review. - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222. ; 8:4, s. 68-71
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Tidskriftsartikel (refereegranskat)abstract
- To enable the use of applications that require real-time communication in ad hoc networks, an admission control mechanism must be in place to prevent the network from becoming congested, since congestion results in reduced quality of service for applications. Current admission control solutions encounter problems in the face of mobility, resulting in unacceptable disruptions in communication. To solve this problem, we apply multi-path routing mechanisms and propose a new admission control protocol. We show through simulation that our solution is able to prevent communication disruptions and meet the QoS needs of the application.
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| 34. |
- Lindgren, Anders, et al.
(författare)
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Probabilistic routing in intermittently connected networks
- 2003
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Ingår i: ACM SIGMOBILE Mobile Computing and Communications Review. - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We consider the problem of routing in intermittently connected networks. In such networks there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts. We propose a probabilistic routing protocol for such networks.
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| 35. |
- Litun, Vladimir, et al.
(författare)
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Experimental Study of a Low-profile Wideband Antenna Array Unit Cell with Integrated EBG Structure
- 2019
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. - 9781728134031 ; 2019-June, s. 1378-1382
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Konferensbidrag (refereegranskat)abstract
- The present paper considers the essential peculiarities of simulation and experimental procedures for a performance study of the C-band low-profile antenna array unit cell. Finite array domain decomposition analysis approach employed for numerical analysis. The good agreement was found between simulated S-parameters for the 6-rings model and measured results of the 3-rings test fragment in frequency and space domains. Simulation results validated the 3-rings fragment as a sufficiently large to provide a reliable assessment of the active reflection coefficient magnitude in the required frequency range and beam steering angular sector.
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| 36. |
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| 37. |
- Lundqvist, Daniel, et al.
(författare)
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Patients with Parkinson’s disease display a dopamine therapy related negative bias and an enlarged range in emotional responses to facial emotional stimuli
- 2017
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 31:6, s. 605-612
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The literature on emotional processing in Parkinson's disease (PD) patients shows mixed results. This may be because of various methodological and/or patient-related differences, such as failing to adjust for cognitive functioning, depression, and/or mood. Method: In the current study, we tested PD patients and healthy controls (HCs) using emotional stimuli across a variety of tasks, including visual search, short-term memory (STM), categorical perception, and emotional stimulus rating. The PD and HC groups were matched on cognitive ability, depression, and mood. We also explored possible relationships between task results and antiparkinsonian treatment effects, as measured by levodopa equivalent dosages (LED), in the PD group. Results: The results show that PD patients use a larger emotional range compared with HCs when reporting their impression of emotional faces on rated emotional valence, arousal, and potency. The results also show that dopaminergic therapy was correlated with stimulus rating results such that PD patients with higher LED scores rated negative faces as less arousing, less negative, and less powerful. Finally, results also show that PD patients display a general slowing effect in the visual search tasks compared with HCs, indicating overall slowed responses. There were no group differences observed in the STM or categorical perception tasks. Conclusions: Our results indicate a relationship between emotional responses, PD, and dopaminergic therapy, in which PD per se is associated with stronger emotional responses, whereas LED levels are negatively correlated with the strength of emotional responses.
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| 38. |
- Mansouri Moghaddam, Sadegh, 1987, et al.
(författare)
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Double broadband balun structure using CRLH TL for differential excitation of dual-polarized self-grounded bow-tie antenna
- 2015
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. ; 2015-January:2015, s. 1966-1970
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Konferensbidrag (refereegranskat)abstract
- A broadband compact balun comprising two composite right-left handed transmission lines (CRLH TL) is designed to excite a self-grounded bow-tie antenna. The design is based on a fractal shaped CRLH TL balun modified to the frequency band of interest. This balun consists of one +90° branch and three-90° branches to produce the desired 180° phase difference at the output. The simulated results show an amplitude imbalance of less than 1dB and a phase imbalance of less than 10°over most of the target bandwidth, i.e., 1.6-3 GHz. Two of the designed baluns were integrated with the bow-tie antenna in such a way that the feeding network could totally fit at the back of the antenna. The performance of the whole structure was also evaluated showing a return loss below-10 dB. The radiation pattern and the gain of the antenna with baluns are in good agreement with the ideal differential excitation, with gain degradation of only about 0.5 dB in the worst case.
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| 39. |
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| 40. |
- Nilsson, Lars-Göran, et al.
(författare)
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The influence of APOE status on episodic and semantic memory : data from a population-based study
- 2006
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Ingår i: Neuropsychology. - Washington : American Psychological Association. - 0894-4105 .- 1931-1559. ; 20:6, s. 645-57
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Tidskriftsartikel (refereegranskat)abstract
- In a prospective cohort study, the authors demonstrated a more pronounced epsilon4-related deficit for participants 70 years of age and older in tasks assessing episodic recall. Apolipoprotein E (APOE) and age interacted for episodic memory tasks, whereas the interaction for semantic memory tasks was between APOE and test wave. Heterozygotes of epsilon4 between middle-age and young-old participants performed at a higher level than noncarriers of this allele in recall tasks. A dose effect was found such that carriers of 2 epsilon4 alleles failed more profoundly in acquiring and recollecting episodic information than carriers of 1 epsilon4 allele, who in turn failed more than carriers of non-epsilon4 alleles. The pattern of findings observed for older epsilon4 carriers suggests that these individuals have particular difficulty when the executive task demands are high. Several factors (e.g., smaller hippocampal volumes, less effective neural repair mechanisms) may account for these findings. On the basis of the data obtained, the authors argue that analyses of the effect of specific genes in cognition should be accompanied by assessment of performance at a specific level, with due attention to the individual's age.
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| 41. |
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| 42. |
- Nordström, Erik, et al.
(författare)
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Comparison of Forwarding Strategies in Internet Connected MANETs
- 2004
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Ingår i: ACM SIGMOBILE Mobile Computing Reviews. - : Association for Computing Machinery (ACM). ; 1:2
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Tidskriftsartikel (refereegranskat)abstract
- For efficient Internet Connectivity in MANETs, multiple gateways and potentially multihoming and hand-over need to be supported. We compare two forwarding strategies; default routes and tunneling to gateways, and how they support this. We find that tunneling is more efficient and flexible compared to default routes. In fact, we show that default routes will not operate correctly in some situations, particularly when there are multiple gateways.
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| 43. |
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| 44. |
- Papadimitratos, Panagiotis, et al.
(författare)
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Secure Routing for Mobile Ad Hoc Networks
- 2003
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Ingår i: ACM SIGMOBILE Mobile Computing and Communications Review (MC2R) - Special Issue: Report on a Working Session on Security in Wireless Ad hoc Networks. - : ACM. ; 7:1, s. 79-80
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Tidskriftsartikel (refereegranskat)
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| 45. |
- Piórkowski, M., et al.
(författare)
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TraNS : Realistic Joint Traffic and Network Simulator for VANETs
- 2008
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Ingår i: ACM SIGMOBILE Mobile Computing and Communications Review (MC2R). - : Association for Computing Machinery (ACM). - 1559-1662 .- 1931-1222. ; 12:1, s. 31-33
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Tidskriftsartikel (refereegranskat)abstract
- Realistic simulation is a necessary tool for the proper evaluation of newly developed protocols for Vehicular Ad Hoc Networks (VANETs). Several recent efforts focus on achieving this goal. Yet, to this date, none of the proposed solutions fulfil all the requirements of the VANET environment. This is so mainly because road traffic and communication network simulators evolve in disjoint research communities. We are developing TraNS, an open-source simulation environment, as a step towards bridging this gap. This short paper describes the TraNS architecture and our ongoing development efforts.
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| 46. |
- Razani, Jill, et al.
(författare)
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Semantic networks for odors and colors in Alzheimer´s disease
- 2010
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Ingår i: Neuropsychology. - Washington, DC., USA : American Psychological Association. - 0894-4105 .- 1931-1559. ; 24:3, s. 291-299
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Impairment in odor-naming ability and in verbal and visual semantic networks raised the hypothesis of a breakdown in the semantic network for odors in Alzheimer’s disease (AD). The current study addressed this hypothesis. Method: Twenty-four individuals, half patients with probable AD and half control participants, performed triadic-similarity judgments for odors and colors, separately, which, utilizing the multidimensional scaling (MDS) technique of individual difference scaling analysis (INDSCAL), generated two-dimensional configurations of similarity. The abilities to match odors and colors with written name labels were assessed to investigate disease-related differences in ability to identify and conceptualize the stimuli. In addition, responses on attribute-sorting tasks, requiring the odor and color perceptions to be categorized as one polarity of a certain dimension, were obtained to allow for objective interpretation of the MDS spatial maps. Results: Whereas comparison subjects generated patial maps based predominantly on relatively abstract characteristics, patients with AD classified odors on perceptual characteristics. The maps for patients with AD also showed disorganized groupings and loose associations between od rs. Their normal configurations for colors imply that the patients were able to comprehend the task per se. The data for label matching and for attribute sorting provide furtherevidence for a disturbance in semantic odor memory in AD. The patients performed poorer than controls on both these odor tasks, implying that the ability to identify and/or conceptualize odors is impaired in AD. Conclusion: The results provide clear evidence for deterioration of the structure of semantic knowledge for odors in AD.
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| 47. |
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| 48. |
- Saeeda, Hina, et al.
(författare)
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Identifying and Categorizing Challenges in Large-Scale Agile Software Development Projects : Insights from Two Swedish Companies
- 2023
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Ingår i: ACM SIGAPP Applied Computing Review. - : Association for Computing Machinery (ACM). - 1559-6915 .- 1931-0161. ; 23:2, s. 23-43
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Tidskriftsartikel (refereegranskat)abstract
- We conducted a case study to examine the challenges encountered in large-scale agile development (LSAD) within two Swedish software companies. While agile methodologies have proven successful in small and medium-sized projects, their implementation in large-scale software development projects can be problematic. To identify these challenges, we employed thematic analysis, which revealed a total of 26 distinct challenges. These challenges were categorized into three main themes: Processes and practices, Teams, and Organizational-level challenges in LSAD. By recognizing and addressing these challenges, projects operating in similar contexts can synchronize their activities and harness the advantages of agile methodologies at a large scale. The article delves into comprehensive discussions on these challenges, offering valuable insights and directions for future research endeavors.
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| 49. |
- Savelev, Roman S., et al.
(författare)
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Ultrafast Tunable Hybrid Yagi-Uda Nanoantenna
- 2017
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. ; , s. 3854-3858
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Konferensbidrag (refereegranskat)abstract
- We study radiation from Yagi-Uda nanoantennas composed of metal-dielectric core-shell nanoparticles. We have found an interesting operation regime in such nanoantennas determined by their hybrid nature. This regime rests on the excitation of the Van Hove singularity, supporting high values of directivity and Purcell factor within the same narrow frequency range. In this regime, a strong dynamical tuning of the emission pattern via electron-hole plasma photoexcitation by a femtosecond pumping can be achieved.
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| 50. |
- Shepeleva, Elena, et al.
(författare)
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MM-wave Patch Antenna with Embedded Photoconductive Elements for 1-bit Phase Shifting
- 2019
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. - 9781728134031 ; 2019-June, s. 578-581
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Konferensbidrag (refereegranskat)abstract
- The paper presents a development approach for mm-wave patch antenna with 1-bit (0/180 degrees) phase shifting. The proposed design employs a stacked patches structure, where the lower patch is excited symmetrically from an embedded single-pole double-throw switch. The switch is based on controllable photoconductive elements, where each element represents a high-resistivity silicon piece, which conductivity is modulated by a light source. Measured results demonstrate achievable (23-26) GHz -10-dB matching bandwidth and radiated field phase switching of (170-173)degrees. The approach can find its applications in beam steering antenna arrays and switchable monopulse antennas.
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