| 1. |
- Engström, Gunnar, et al.
(författare)
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The Swedish CArdioPulmonary BioImage Study : objectives and design
- 2015
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 278:6, s. 645-659
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Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.
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| 2. |
- Johansson, Jonas, et al.
(författare)
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Parlament i världen : Riksdagen och Interparlamentariska unionen
- 2017
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Under mer än hundra år har världens parlament och folkvalda haft en återkommande mötesplats för tankeutbyte och gemensamma aktioner i Interparlamentariska unionen, IPU.Från början var IPU en del av förra sekelskiftets framväxande rörelse för demokrati och fred i Europa. Samarbete mellan världens parlamentariker skulle demokratisera utrikespolitiken och skapa förutsättningar för en hållbar fred. Inom loppet av ett drygt kvartssekel hedrades hela åtta företrädare för IPU med Nobels fredspris.Trots två förödande världskrig på 1900-talet och hotet om kärnvapenkrig sedan dess har IPU behållit sin roll som mötesplats och samtalsforum. Arbetet med utvecklings- och biståndsarbete har vuxit kring frågor om hållbar utveckling och mänskliga rättigheter. Att främja kvinnors deltagande i politiken har blivit en profilfråga. Sedan millennieskiftet betonar IPU särskilt sin roll som parlamentarisk partner till FN.
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| 3. |
- Johansson, Per, 1966, et al.
(författare)
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Cerebrospinal fluid substance P concentrations are elevated in patients with Alzheimer's disease.
- 2015
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Ingår i: Neuroscience letters. - : Elsevier BV. - 1872-7972 .- 0304-3940. ; 609, s. 58-62
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Tidskriftsartikel (refereegranskat)abstract
- The neuropeptides substance P, orexin A (hypocretin-1) and neurotensin are signaling molecules that influence brain activity. We examined their cerebrospinal fluid (CSF) levels in a study population consisting of Alzheimer's disease (AD) dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n=32), stable MCI (SMCI, n=13), other dementias (n=15), and healthy controls (n=20). CSF substance P level was increased in AD patients compared to patients with other dementias and healthy controls (P<0.05 and P<0.01, respectively). Patients with other dementia or SMCI had lower CSF orexin A level than AD patients (both P<0.05) and marginally lower level than healthy controls (both P=0.05). CSF neurotensin level was similar in all groups. In the total study population (n=80), CSF substance P level correlated positively with CSF levels of T-tau and P-tau, and in AD patients (n=32), CSF substance P level correlated positively with CSF Aβ1-42 level. In conclusion, CSF substance P level was elevated in AD patients and correlated with CSF Aβ1-42 level, a well established marker of senile plaque pathology. The role of low CSF orexin A level in other dementias or SMCI needs to be explored in further studies.
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| 4. |
- Johansson, Per, 1966, et al.
(författare)
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Reduced Cerebrospinal Fluid Concentration of Apolipoprotein A-I in Patients with Alzheimer's Disease.
- 2017
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 59:3, s. 1017-1026
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E (ApoE) has been extensively studied in Alzheimer's disease (AD), but little is known of apolipoprotein A-I (ApoA-I) in cerebrospinal fluid (CSF).Plasma lipids as well as ApoA-I and ApoE in plasma and CSF were determined and related to Mini-Mental State Examination (MMSE) score, APOE genotype, and CSF AD biomarkers.Consecutive patients with AD (n=29), stable mild cognitive impairment (n=13), other dementias (n=14), and healthy controls (n=18) were included at a single center.AD patients had higher plasma triglycerides and lower CSF ApoA-I concentration than controls (both p<0.05). CSF ApoE concentration was reduced in other dementias (p<0.01). In AD as well as other dementias, the ratios between CSF and plasma concentrations of both ApoA-I and ApoE were lower than those in the controls. ApoA-I and ApoE in plasma and CSF were not influenced by APOEɛ4 allele distribution. In the total study population (n=74), CSF ApoA-I correlated positively with MMSE score (r=0.26, p<0.05) and negatively with CSF P-tau (r=-0.25, p<0.05). CSF ApoE correlated positively with CSF concentrations of T-tau and P-tau in the total study population and in AD patients.CSF ApoA-I was reduced in AD patients and associated with measures of cognitive function and AD disease status. The mechanisms underlying the decreased CSF:plasma ratios of ApoA-I and ApoE in AD and other dementias need to be explored in further studies.
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| 5. |
- Johansson, Per, 1966, et al.
(författare)
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Reduced cerebrospinal fluid concentration of interleukin-12/23 subunit p40 in patients with cognitive impairment.
- 2017
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- The role of inflammation in Alzheimer's disease (AD) and other cognitive disorders is unclear. In a well-defined mono-center population, we measured cytokines and chemokines in paired serum and cerebrospinal fluid (CSF) samples.Consecutive patients with AD (n = 30), stable mild cognitive impairment (SMCI, n = 11), other dementias (n = 11), and healthy controls (n = 18) were included. None of the subjects was treated with glucocorticoids, cholinesterase inhibitors, or non-steroidal anti-inflammatory drugs. Serum and CSF concentrations of interleukin-6 (IL-6), IL-8, IL-12/23 p40, IL-15, IL-16, vascular endothelial growth factor-A (VEGF-A), and three chemokines were measured using a multiplex panel.After correction for multiple comparisons, only CSF IL-12/23 p40 concentration differed significantly between the total patient group (n = 52) and controls (n = 18; p = 0.002). Further analyses showed that CSF IL-12/23 p40 concentration was decreased in all patient subgroups (AD, other dementias, and SMCI) compared to healthy controls (p < 0.01, p < 0.05, and p < 0.05, respectively). In the total study population (n = 70), CSF IL-12/23 p40 concentrations correlated positively with CSF concentrations of β-amyloid1-42 (Aβ1-42) and phosphorylated tau protein (P-tau) whereas in AD patients (n = 30), CSF IL-12/23 p40 only correlated positively with CSF P-Tau (r = 0.46, p = 0.01).Most cytokines and chemokines were similar in patients and controls, but CSF IL-12/23 subunit p40 concentration was decreased in patients with cognitive impairment, and correlated with markers of AD disease status. Further studies are needed to evaluate the role of CSF IL-12/23 p40 in other dementias and SMCI.
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| 6. |
- Karalija, Nina, 1984-, et al.
(författare)
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C957T-mediated Variation in Ligand Affinity Affects the Association between C-11-raclopride Binding Potential and Cognition
- 2019
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Ingår i: Journal of cognitive neuroscience. - : MIT Press. - 0898-929X .- 1530-8898. ; 31:2, s. 314-325
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Tidskriftsartikel (refereegranskat)abstract
- The dopamine (DA) system plays an important role in cognition. Accordingly, normal variation in DA genes has been found to predict individual differences in cognitive performance. However, little is known of the impact of genetic differences on the link between empirical indicators of the DA system and cognition in humans. The present work used PET with C-11-raclopride to assess DA D2-receptor binding potential (BP) and links to episodic memory, working memory, and perceptual speed in 179 healthy adults aged 64-68 years. Previously, the T-allele of a DA D2-receptor single-nucleotide polymorphism, C957T, was associated with increased apparent affinity of C-11-raclopride, giving rise to higher BP values despite similar receptor density values between allelic groups. Consequently, we hypothesized that C-11-raclopride BP measures inflated by affinity rather than D2-receptor density in T-allele carriers would not be predictive of DA integrity and therefore prevent finding an association between C-11-raclopride BP and cognitive performance. In accordance with previous findings, we show that C-11-raclopride BP was increased in T-homozygotes. Importantly, C-11-raclopride BP was only associated with cognitive performance in groups with low or average ligand affinity (C-allele carriers of C957T, n = 124), but not in the high-affinity group (T-homozygotes, n = 55). The strongest C-11-raclopride BP-cognition associations and the highest level of performance were found in C-homozygotes. These findings show that genetic differences modulate the link between BP and cognition and thus have important implications for the interpretation of DA assessments with PET and C-11-raclopride in multiple disciplines ranging from cognitive neuroscience to psychiatry and neurology.
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| 7. |
- Karalija, Nina, 1984-, et al.
(författare)
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Cardiovascular factors are related to dopamine integrity and cognition in aging
- 2019
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Ingår i: Annals of Clinical and Translational Neurology. - : Wiley-Blackwell. - 2328-9503. ; 6:11, s. 2291-2303
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aging brain undergoes several changes, including reduced vascular, structural, and dopamine (DA) system integrity. Such brain changes have been associated with age‐related cognitive deficits. However, their relative importance, interrelations, and links to risk factors remain elusive.Methods: The present work used magnetic resonance imaging and positron emission tomography with 11C‐raclopride to jointly examine vascular parameters (white‐matter lesions and perfusion), DA D2‐receptor availability, brain structure, and cognitive performance in healthy older adults (n = 181, age: 64–68 years) from the Cognition, Brain, and Aging (COBRA) study.Results: Covariance was found among several brain indicators, where top predictors of cognitive performance included caudate and hippocampal integrity (D2DR availability and volumes), and cortical blood flow and regional volumes. White‐matter lesion burden was negatively correlated with caudate DA D2‐receptor availability and white‐matter microstructure. Compared to individuals with smaller lesions, individuals with confluent lesions (exceeding 20 mm in diameter) had reductions in cortical and hippocampal perfusion, striatal and hippocampal D2‐receptor availability, white‐matter microstructure, and reduced performance on tests of episodic memory, sequence learning, and processing speed. Higher cardiovascular risk as assessed by treatment for hypertension, systolic blood pressure, overweight, and smoking was associated with lower frontal cortical perfusion, lower putaminal D2DR availability, smaller grey‐matter volumes, a larger number of white‐matter lesions, and lower episodic memory performance.Interpretation: Taken together, these findings suggest that reduced cardiovascular health is associated with poorer status for brain variables that are central to age‐sensitive cognitive functions, with emphasis on DA integrity.
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| 8. |
- Lindgren, Petter, et al.
(författare)
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A likelihood ratio-based approach for improved source attribution in microbiological forensic investigations
- 2019
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Ingår i: Forensic Science International. - : Elsevier. - 0379-0738 .- 1872-6283. ; 302
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Tidskriftsartikel (refereegranskat)abstract
- A common objective in microbial forensic investigations is to identify the origin of a recovered pathogenic bacterium by DNA sequencing. However, there is currently no consensus about how degrees of belief in such origin hypotheses should be quantified, interpreted, and communicated to wider audiences. To fill this gap, we have developed a concept based on calculating probabilistic evidential values for microbial forensic hypotheses. The likelihood-ratio method underpinning this concept is widely used in other forensic fields, such as human DNA matching, where results are readily interpretable and have been successfully communicated in juridical hearings. The concept was applied to two case scenarios of interest in microbial forensics: (1) identifying source cultures among series of very similar cultures generated by parallel serial passage of the Tier 1 pathogen Francisella tularensis, and (2) finding the production facilities of strains isolated in a real disease outbreak caused by the human pathogen Listeria monocytogenes. Evidence values for the studied hypotheses were computed based on signatures derived from whole genome sequencing data, including deep-sequenced low-frequency variants and structural variants such as duplications and deletions acquired during serial passages. In the F. tularensis case study, we were able to correctly assign fictive evidence samples to the correct culture batches of origin on the basis of structural variant data. By setting up relevant hypotheses and using data on cultivated batch sources to define the reference populations under each hypothesis, evidential values could be calculated. The results show that extremely similar strains can be separated on the basis of amplified mutational patterns identified by high-throughput sequencing. In the L. monocytogenes scenario, analyses of whole genome sequence data conclusively assigned the clinical samples to specific sources of origin, and conclusions were formulated to facilitate communication of the findings. Taken together, these findings demonstrate the potential of using bacterial whole genome sequencing data, including data on both low frequency SNP signatures and structural variants, to calculate evidence values that facilitate interpretation and communication of the results. The concept could be applied in diverse scenarios, including both epidemiological and forensic source tracking of bacterial infectious disease outbreaks.
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| 9. |
- Lundgren, Anders, 1978, et al.
(författare)
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Affinity Purification and Single-Molecule Analysis of Integral Membrane Proteins from Crude Cell-Membrane Preparations
- 2018
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 18:1, s. 381-385
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Tidskriftsartikel (refereegranskat)abstract
- The function of integral membrane proteins is critically dependent on their naturally surrounding lipid membrane. Detergent-solubilized and purified membrane proteins are therefore often reconstituted into cell-membrane mimics and analyzed for their function with single-molecule microscopy. Expansion of this approach toward a broad range of pharmaceutically interesting drug targets and biomarkers however remains hampered by the fact that these proteins have low expression levels, and that detergent solubilization and reconstitution often cause protein conformational changes and loss of membrane-specific cofactors, which may impair protein function. To overcome this limitation, we here demonstrate how antibody-modified nanoparticles can be used to achieve affinity purification and enrichment of selected integral membrane proteins directly from cell membrane preparations. Nanoparticles were first bound to the ectodomain of β-secretase 1 (BACE1) contained in cell-derived membrane vesicles. In a subsequent step, these were merged into a continuous supported membrane in a microfluidic channel. Through the extended nanoparticle tag, a weak (∼fN) hydrodynamic force could be applied, inducing directed in-membrane movement of targeted BACE1 exclusively. This enabled selective thousand-fold enrichment of the targeted membrane protein while preserving a natural lipid environment. In addition, nanoparticle-targeting also enabled simultaneous tracking analysis of each individual manipulated protein, revealing how their mobility changed when moved from one lipid environment to another. We therefore believe this approach will be particularly useful for separation in-line with single-molecule analysis, eventually opening up for membrane-protein sorting devices analogous to fluorescence-activated cell sorting.
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| 10. |
- Müller, Daniel C., et al.
(författare)
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Phospholipid Levels in Blood during Community-Acquired Pneumonia
- 2019
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- Phospholipids, major constituents of bilayer cell membranes, are present in large amounts in pulmonary surfactant and play key roles in cell signaling. Here, we aim at finding clinically useful disease markers in community-acquired pneumonia (CAP) using comprehensive phospholipid profiling in blood and modeling of changes between sampling time points. Serum samples from 33 patients hospitalized with CAP were collected at admission, three hours after the start of intravenous antibiotics, Day 1 (at 12–24 h), Day 2 (at 36–48 h), and several weeks after recovery. A profile of 75 phospholipid species including quantification of the bioactive lysophosphatidylcholines (LPCs) was determined using liquid chromatography coupled to time-of-flight mass spectrometry. To control for possible enzymatic degradation of LPCs, serum autotaxin levels were examined. Twenty-two of the 33 patients with a clinical diagnosis of CAP received a laboratory-verified CAP diagnosis by microbial culture or microbial DNA detection by qPCR. All major phospholipid species, especially the LPCs, were pronouncedly decreased in the acute stage of illness. Total and individual LPC concentrations increased shortly after the initiation of antibiotic treatment, concentrations were at their lowest 3h after the initiation, and increased after Day 1. The total LPC concentration increased by a change ratio of 1.6–1.7 between acute illness and Day 2, and by a ratio of 3.7 between acute illness and full disease resolution. Autotaxin levels were low in acute illness and showed little changes over time, contradicting a hypothesis of enzymatic degradation causing the low levels of LPCs. In this sample of patients with CAP, the results demonstrate that LPC concentration changes in serum of patients with CAP closely mirrored the early transition from acute illness to recovery after the initiation of antibiotics. LPCs should be further explored as potential disease stage biomarkers in CAP and for their potential physiological role during recovery.
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| 11. |
- Papenberg, Goran, et al.
(författare)
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Mapping the landscape of human dopamine D2/3 receptors with [11C]raclopride
- 2019
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Ingår i: Brain Structure and Function. - : Springer Science and Business Media LLC. - 1863-2653 .- 1863-2661. ; 224:8, s. 2871-2882
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Tidskriftsartikel (refereegranskat)abstract
- The dopamine D2/3 system is fundamental for sensory, motor, emotional, and cognitive aspects of behavior. Small-scale human histopathological and animal studies show high density of D2/3 dopamine receptors (D2/3DR) in striatum, but also demonstrate the existence of such receptors across cortical and limbic regions. Assessment of D2/3DR BPND in the extrastriatal regions with [C-11]raclopride has long been considered unreliable due to the relatively low density of D2/3DR outside the striatum. We describe the distribution and interregional links of D2/3DR availability measured with PET and [C-11]raclopride across the human brain in a large sample (N = 176; age range 64-68 years). Structural equation modeling revealed that D2/3DR availability can be organized according to anatomical (nigrostriatal, mesolimbic, mesocortical) and functional (limbic, associative, sensorimotor) dopamine pathways. D2/3DR availability in corticolimbic functional subdivisions showed differential associations to corresponding striatal subdivisions, extending animal and pharmacological work. Our findings provide evidence on the dimensionality and organization of [C-11]raclopride D2/3DR availability in the living human brain that conforms to known dopaminergic pathways.
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| 12. |
- Salami, Alireza, et al.
(författare)
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Dopamine D-2/3 Binding Potential Modulates Neural Signatures of Working Memory in a Load-Dependent Fashion
- 2019
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Ingår i: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 39:3, s. 537-547
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Tidskriftsartikel (refereegranskat)abstract
- Dopamine (DA) modulates corticostriatal connections. Studies in which imaging of the DA system is integrated with functional imaging during cognitive performance have yielded mixed findings. Some work has shown a link between striatal DA(measured by PET) and fMRI activations, whereas others have failed to observe such a relationship. One possible reason for these discrepant findings is differences in task demands, such that a more demanding task with greater prefrontal activations may yield a stronger association with DA. Moreover, a potential DA-BOLD association may be modulated by task performance. We studied 155 (104 normal-performing and 51 low-performing) healthy older adults (43% females) who underwent fMRI scanning while performing a working memory (WM) n-back task along with DA D-2/3 PET assessment using [C-11] raclopride. Using multivariate partial-least-squares analysis, we observed a significant pattern revealing positive associations of striatal as well as extrastriatal DA D-2/3 receptors to BOLD response in the thalamo-striatalcortical circuit, which supports WM functioning. Critically, the DA-BOLD association in normal-performing, but not low-performing, individuals was expressed in a load-dependent fashion, with stronger associations during 3-back than 1-/2-back conditions. Moreover, normal-performing adults expressing upregulated BOLD in response to increasing task demands showed a stronger DA-BOLD association during 3-back, whereas low-performing individuals expressed a stronger association during 2-back conditions. This pattern suggests a nonlinear DA-BOLD performance association, with the strongest link at the maximum capacity level. Together, our results suggest that DA may have a stronger impact on functional brain responses during more demanding cognitive tasks.
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| 13. |
- Wallin, Anders, 1950, et al.
(författare)
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Cognitive medicine - a new approach in health care science.
- 2018
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Ingår i: BMC psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- The challenges of today's society call for more knowledge about how to maintain all aspects of cognitive health, such as speed/attention, memory/learning, visuospatial ability, language, executive capacity and social cognition during the life course.Medical advances have improved treatments of numerous diseases, but the cognitive implications have not been sufficiently addressed. Disability induced by cognitive dysfunction is also a major issue in groups of patients not suffering from Alzheimer's disease or related disorders. Recent studies indicate that several negative lifestyle factors can contribute to the development of cognitive impairment, but intervention and prevention strategies have not been implemented. Disability due to cognitive failure among the workforce has become a major challenge. Globally, the changing aging pyramid results in increased prevalence of cognitive disorders, and the diversity of cultures influences the expression, manifestation and consequences of cognitive dysfunction.Major tasks in the field of cognitive medicine are basic neuroscience research to uncover diverse disease mechanisms, determinations of the prevalence of cognitive dysfunction, health-economical evaluations, and intervention studies. Raising awareness for cognitive medicine as a clinical topic would also highlight the importance of specialized health care units for an integrative approach to the treatment of cognitive dysfunctions.
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| 14. |
- Åberg, Daniel, 1973, et al.
(författare)
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Increased Cerebrospinal Fluid Level of Insulin-like Growth Factor-II in Male Patients with Alzheimer's Disease
- 2015
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 48:3, s. 637-646
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Tidskriftsartikel (refereegranskat)abstract
- Background: Insulin-like growth factor-II (IGF-II) is important for brain development. Although IGF-II is abundant also in adult life, little is known of the role of IGF-II in Alzheimer's disease (AD). Objective and methods: This was a cross-sectional study of 60 consecutive patients under primary evaluation of cognitive impairment and 20 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n = 32), stable MCI (SMCI, n = 13), or other dementias (n = 15). IGF-II, IGF-binding protein-1 (IGFBP-1), and IGFBP-2 were analyzed in serum and cerebrospinal fluid (CSF). Results: Levels of IGF-II, IGFBP-1, and IGFBP-2 were similar in all groups in the total study population. Gender-specific analyses showed that in men (n = 40), CSF IGF-II level was higher in AD compared to SMCI and controls (p < 0.01 and p < 0.05, respectively). Furthermore, CSF IGFBP-2 levelwas increased inADmen versus SMCI men (p < 0.01) and tended to be increased versus control men (p = 0.09). There were no between-group differences in women (n = 40). In the total study population (n = 80) as well as in men (n = 40), CSF levels of IGF-II and IGFBP-2 correlated positively with CSF levels of the AD biomarkers total-tau and phosphorylated tau protein. Conclusion: In men, but not women, in the early stages of AD, CSF IGF-II level was elevated, and CSF IGFBP-2 level tended to be increased, compared to healthy controls.
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| 15. |
- Birdsell, D. N., et al.
(författare)
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Coinfections identified from metagenomic analysis of cervical lymph nodes from tularemia patients
- 2018
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Ingår i: BMC Infectious Diseases. - : BMC. - 1471-2334. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Underlying coinfections may complicate infectious disease states but commonly go unnoticed because an a priori clinical suspicion is usually required so they can be detected via targeted diagnostic tools. Shotgun metagenomics is a broad diagnostic tool that can be useful for identifying multiple microbes simultaneously especially if coupled with lymph node aspirates, a clinical matrix known to house disparate pathogens. The objective of this study was to analyze the utility of this unconventional diagnostic approach (shotgun metagenomics) using clinical samples from human tularemia cases as a test model. Tularemia, caused by the bacterium Francisella tularensis, is an emerging infectious disease in Turkey. This disease commonly manifests as swelling of the lymph nodes nearest to the entry of infection. Because swollen cervical nodes are observed from many different types of human infections we used these clinical sample types to analyze the utility of shotgun metagenomics.Methods: We conducted an unbiased molecular survey using shotgun metagenomics sequencing of DNA extracts from fine-needle aspirates of neck lymph nodes from eight tularemia patients who displayed protracted symptoms. The resulting metagenomics data were searched for microbial sequences (bacterial and viral).Results: F. tularensis sequences were detected in all samples. In addition, we detected DNA of other known pathogens in three patients. Both Hepatitis B virus (HBV) and Human Parvovirus B-19 were detected in one individual and Human Parvovirus B-19 alone was detected in two other individuals. Subsequent PCR coupled with Sanger sequencing verified the metagenomics results. The HBV status was independently confirmed via serological diagnostics, despite evading notice during the initial assessment.Conclusion: Our data highlight that shotgun metagenomics of fine-needle lymph node aspirates is a promising clinical diagnostic strategy to identify coinfections. Given the feasibility of the diagnostic approach demonstrated here, further steps to promote integration of this type of diagnostic capability into mainstream clinical practice are warranted.
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| 16. |
- Block, Stephan, 1978, et al.
(författare)
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Two-dimensional flow nanometry of biological nanoparticles for accurate determination of their size and emission intensity
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 7, s. art no 12956 -
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Tidskriftsartikel (refereegranskat)abstract
- Biological nanoparticles (BNPs) are of high interest due to their key role in various biological processes and use as biomarkers. BNP size and composition are decisive for their functions, but simultaneous determination of both properties with high accuracy remains challenging. Optical microscopy allows precise determination of fluorescence/scattering intensity, but not the size of individual BNPs. The latter is better determined by tracking their random motion in bulk, but the limited illumination volume for tracking this motion impedes reliable intensity determination. Here, we show that by attaching BNPs to a supported lipid bilayer, subjecting them to hydrodynamic flows and tracking their motion via surface-sensitive optical imaging enable determination of their diffusion coefficients and flow-induced drifts, from which accurate quantification of both BNP size and emission intensity can be made. For vesicles, the accuracy of this approach is demonstrated by resolving the expected radius-squared dependence of their fluorescence intensity for radii down to 15 nm.
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| 17. |
- Carlander, Anders, 1979, et al.
(författare)
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The role of perceived quality of personal service in influencing trust and satisfaction with banks
- 2018
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Ingår i: Financial Services Review. - 1057-0810. ; 27, s. 83-98
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Tidskriftsartikel (refereegranskat)abstract
- Trust is of paramount importance to banks. Previous research has shown that trust increases with repeated personal contacts. We investigate if this applies to the customer-employee relationship in banks. Data from an on-line survey of 293 customers of Swedish retail banks are used to construct indicator measures. By means of structural equation modeling we find that trust in the bank is influenced by perceived quality of personal service through employees’ perceived competence, perceived benevolence, and perceived transparency, and that satisfaction with the bank is influenced by perceived quality of personal service through perceived competence, perceived benevolence, perceived transparency, and trust.
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| 18. |
- Dwibedi, Chinmay Kumar, 1987-
(författare)
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Francisella tularensis: persistence, dissemination and source attribution : a theoretical and computational approach
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The bacterium Francisella tularensis causing tularemia in humans and other mammals displays little genetic diversity among genomes across temporal and spatial scales. F. tularensis infects humans with an extremely low infectious dose and causes natural seasonal tularemia outbreaks. During the Cold War, this bacterium was developed as a biological weapon.In paper I, we aimed at investigating the genetic diversity of F. tularensis over space and time and were especially interested in the influence of spatial dispersal on the genetic diversity. By analyses of single-nucleotide polymorphisms (SNPs) among 205 F. tularensis genomes, we found that tularemia had moved from East to West over the European continent by dispersal patterns characterized by multiple long-range dispersal events. Evolutionary rate estimates based on the year of bacterial isolation from 1947 to 2012 indicated non-measurable rates. In outbreak areas with multiple recent outbreaks, however, there was a measurable rate of 0.4 SNPs/genome/year indicating that in areas with more intense disease activity, there is a detectable evolutionary rate. The findings suggest that long-range geographical dispersal events and mostly very low evolutionary rates are important factors contributing to a very low genetic diversity of F. tularensis populations.In paper II, we focused on a geographically restricted area with a history of frequent tularemia outbreaks to study F. tularensis persistence. By analyzing F. tularensis genomes from 138 individuals infected from 1994 to 2010 in Örebro County in Sweden and performing a long-term laboratory storage experiment, we explored the microbial population concept of a pathogen seed-bank. We found that eight indistinguishable genomes – each of them defined by no SNPs across 1.65 million whole-genome nucleotides – locally persisted over 2-9 years. We found unmeasurable SNP accumulation rates and overlapping bacterial generations among the outbreak genomes and that F. tularensis survived in saline for four years without nutrients. By these findings, and analyses of nucleotide substitution patterns, we suggest that a pathogen seed-bank effect is an important feature of F. tularensis ecology influencing genetic diversity.In paper III, we developed a new concept for source attribution of a F. tularensis sample. We aimed to identify genetic variation that is characteristic to laboratory culturing and we used culture amplification to identify genetic variation present at exceedingly low frequencies in a sample. Based on a biological enrichment scheme followed by high-throughput sequencing, we could track genetic variation back to a source sample. These results suggest that the concept has potential for linking a F. tularensis sample to its laboratory source sample.Taken together, the results presented in this thesis provide new understanding of the dissemination patterns and local persistence of tularemia. This is important for the interpretation of molecular epidemiology investigations of the disease. In a wider context, the results demonstrate how spatial dispersal and a microbial seed-bank effect may contribute to the diversity of a disease-causing agent. Finally, we have described a promising concept for source attribution of F. tularensis samples
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| 19. |
- Gustafsson, Mats, 1966-, et al.
(författare)
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Particles in road and railroad tunnel air : sources, properties and abatement measures
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- High levels of air pollution are a common problem in both road and railroad tunnels. Sources and emission processes however differ significantly, as reflected by aerosols physical and chemical properties. As particle concentrations and properties affect exposure of and health effects for people on platforms and in vehicles, effective ways to reduce emissions and exposure are important. This study aims to improve the knowledge of the differences between PM10 in the rail and road tunnel environments, their sources and the possibilities to address problems with high particulate levels. Measurement campaigns were carried out at Arlanda Central, a railroad tunnel station below Arlanda airport and in Söderleden road tunnel, a road tunnel in central Stockholm.The results show large differences in concentration levels, size distributions and in composition of the particles. The railroad tunnel aerosol consisted of coarse particles with high iron content, while the properties of the coarse particles in the road tunnel were strongly influenced by whether the road surface was wet or dry. In wet conditions, concentrations were relatively low and iron and sulfur dominating elements, while silicon, potassium, calcium and iron from suspension and road wear dominated during dry conditions. The content of elemental carbon, most likely from the pantograph, were unexpectedly high in the railroad tunnel. An older type of train with a large proportion of mechanical brakes were suggested to be responsible to the main particle emissions in the railway tunnel. The report concludes with a discussion and proposals for action against particle sources in the various underground environments.
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| 20. |
- Hosseinzadeh, Ava, et al.
(författare)
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Stable Redox-Cycling Nitroxide Tempol has Antifungal and Immune-modulatory Properties
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Invasive mycoses remain underdiagnosed and difficult to treat. Hospitalized individuals with compromised immunity increase in number and constitute the main risk group for severe fungal infections. Current antifungal therapy is hampered by slow and insensitive diagnostics and frequent toxic side effects of standard antifungal drugs. Identification of new antifungal compounds with high efficacy and low toxicity is therefore urgently required. We investigated the antifungal activity of tempol, a cell-permeable nitroxide. To narrow down possible mode of action we used RNA-seq technology and metabolomics to probe for pathways specifically disrupted in the human fungal pathogen Candida albicans due to tempol administration. We found genes upregulated which are involved in iron homeostasis, mitochondrial stress, steroid synthesis, and amino acid metabolism. In an ex vivo whole blood infection, tempol treatment reduced C. albicans colony forming units and at the same time increased the release of pro-inflammatory cytokines, such as interleukin 8 (IL-8, monocyte chemoattractant protein-1, and macrophage migration inhibitory factor). In a systemic mouse model, tempol was partially protective with a significant reduction of fungal burden in the kidneys of infected animals during infection onset. The results obtained propose tempol as a promising new antifungal compound and open new opportunities for the future development of novel therapies.
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| 21. |
- Jeansson, Åsa, 1966-
(författare)
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Vad, hur och varför i slöjdämnet : textillärares uppfattningar om innehåll och undervisning i relation till kursplanen
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis deals with questions of how the purpose and content in the Swedish school subject Sloyd can be understood in the present, some years after a new curriculum came into effect in 2011. Through sloyd teachers’ stories of their knowledge and the historical traces that have left a mark on their teaching, such as older syllabuses and mediated experiences, the intention is to examine the pedagogical thinking that forms the classroom’s activities. The overall purpose is to develop knowledge of what shapes the design of sloyd, based on how the subject is expressed in the syllabus and in teachers' understandings of teaching and the subject. Based on previous knowledge and interviews, a hermeneutic research process has been designed and developed over time. Seventeen semi-structured interviews with textiles teachers where conducted, recorded and transcribed for the study. The hermeneutic interpretation process involved repeatedly reading and listening, and the material was coded using the digital analysis tool ATLAS.ti. Through repeated reading of the codes, three overarching themes were found: Textiles teachers' perceptions of Sloyd’s purpose and content, Textiles teachers’ teaching, and Manual and intellectual work in unity. The perspective of curriculum theory using a frame factor model is intended to highlight how Sloyd manifests itself at different levels of interpretation, which may impact how sloyd takes shape in the classroom. For a functional perspective on the study's data, didactic theory is used with a focus on subject didactics. The transformation phase is central to the shaping of Sloyd, where teachers’ beliefs and perceptions about the subject will influence their interpretation of the syllabus. Shulman's model of pedagogical thinking and action linked to pedagogical content knowledge, PCK, form the basis for the analysis together with theoretical perspectives on teachers’ pedagogical thinking as Kansanen and Hansén describes it. In summary, two levels of pedagogical thinking are distinguished by analysis. Firstly, based on those teachers who transform and implement teaching in sloyd based on an interpretation that follows the syllabus closely, and secondly, based on those who proceed from an interpretation that is closer to sloyd’s field of knowledge, based on handicraft. This results in two subject conceptions relating to sloyd. Teachers can ascribe to one of these, or move between them in the different phases of pedagogical planning and reflection. The conclusions also include an understanding of why the knowledge requirements in the syllabus largely relate to the students expressing themselves in words regarding their learning and their choices during the process. The curriculum is results-oriented and the knowledge that is evaluated must therefore be measurable and comparable, and be made possible to learn through the subject content. It can also be interpreted as an approximation of a practical knowledge culture to a theoretical knowledge culture, and therefore a legitimation of a practical subject in the school context that elementary school constitutes.
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| 22. |
- Johansson, Peter, 1962-, et al.
(författare)
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An internet-based cognitive behavioral therapy program adapted to patients with cardiovascular disease and depression : Randomized controlled trial
- 2019
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Ingår i: Journal of Medical Internet Research. - Toronto, Canada : Journal of Medical Internet Research. - 1438-8871. ; 21:10, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Depression is a common cause of reduced well-being and prognosis in patients with cardiovascular disease (CVD). However, there is a lack of effective intervention strategies targeting depression.Objective: The study aimed to evaluate the effects of a nurse-delivered and adapted internet-based cognitive behavioral therapy (iCBT) program aimed at reducing depression in patients with CVD.Methods: A randomized controlled trial was conducted. A total of 144 patients with CVD with at least mild depression (Patient Health Questionnaire–9 [PHQ-9] score ≥5) were randomized 1:1 to a 9-week program of iCBT (n=72) or an active control participating in a Web-based discussion forum (online discussion forum [ODF], n=72). The iCBT program, which included 7 modules, was adapted to fit patients with CVD. Nurses with an experience of CVD care provided feedback and a short introduction to cognitive behavioral therapy. The primary outcome, depression, was measured using PHQ-9. Secondary outcomes were depression measured using the Montgomery-Åsberg Depression Rating Scale–self-rating version (MADRS-S), health-related quality of life (HRQoL) measured using Short Form 12 (SF-12) survey and EuroQol Visual Analogue Scale (EQ-VAS), and the level of adherence. An intention-to-treat analysis with multiple imputations was used. Between-group differences in the primary and secondary outcomes were determined by the analysis of covariance, and a sensitivity analysis was performed using mixed models. Results: Compared with ODF, iCBT had a significant and moderate treatment effect on the primary outcome depression (ie, PHQ-9; mean group difference=−2.34 [95% CI −3.58 to −1.10], P<.001, Cohen d=0.62). In the secondary outcomes, compared with ODF, iCBT had a significant and large effect on depression (ie, MADRS-S; P<.001, Cohen d=0.86) and a significant and moderate effect on the mental component scale of the SF-12 (P<.001, Cohen d=0.66) and the EQ-VAS (P<.001, Cohen d=0.62). Overall, 60% (n=43) of the iCBT group completed all 7 modules, whereas 82% (n=59) completed at least half of the modules. No patients were discontinued from the study owing to a high risk of suicide or deterioration in depression.Conclusions: Nurse-delivered iCBT can reduce depression and improve HRQoL in patients with CVD, enabling treatment for depression in their own homes and at their preferred time.
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| 23. |
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| 24. |
- Mostafavi, Ehsan, et al.
(författare)
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Molecular Survey of Tularemia and Plague in Small Mammals From Iran
- 2018
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media S.A.. - 2235-2988. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Plague and tularemia are zoonoses and their causative bacteria are circulating in certain regions of Iran. This study was conducted to investigate potential disease reservoirs amongst small wildlife species in different regions of Iran.Methods: Rodents, insectivores and hares from 17 different provinces of the country were collected in 2014 and 2015. Samples were taken from the spleens of the animals and Real-time PCR was applied to detect nucleic acid sequences that are specific to Francisella tularensis and Yersinia pestis, respectively.Results: Among 140 collected rodents, 25 distinct species were identified out of which five were the most common: Microtus paradoxus (21% out of 140 rodents), Apodemus witherbyi (12%), Microtus irani (11%), Mus musculus (11%) and Microtus socialis (10%). Seventeen insectivores were collected and identified as Crocidura suaveolens (82%) and C. leucodon (18%). Fifty-one hares were collected and identified as Lepus europaeus (57%), Lepus tolai (14%) and Lepus sp. (29%). Three out of 140 explored rodents (1.91%) were positive for F. tularensis, an A. witherbyi, a Mus musculus domesticus, and a Chionomys nivalis collected from Golestan, Khuzestan and Razavi Khorasan provinces, respectively. Two hares (3.92%) were F. tularensis-positive, a L. europaeus from Khuzestan and a Lepus sp. from the Sistan and Baluchistan province. None of the tested animals were positive for Y. pestis.Conclusion: This is the first report of direct detection of F. tularensis in mammals of Iran and the first-time observation of the agent in a snow vole, C. nivalis worldwide. The results indicate that tularemia is more widespread in Iran than previously reported including the Northeast and Southwestern parts of the country. Future studies should address genetic characterization of F. tularensis positive DNA samples from Iran to achieve molecular subtyping and rule out assay cross-reactivity with near neighbor Francisella species.
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| 25. |
- Muthumanickam, Prithiviraj, 1987-
(författare)
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Data Abstraction and Pattern Identification in Time-series Data
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Data sources such as simulations, sensor networks across many application domains generate large volumes of time-series data which exhibit characteristics that evolve over time. Visual data analysis methods can help us in exploring and understanding the underlying patterns present in time-series data but, due to their ever-increasing size, the visual data analysis process can become complex. Large data sets can be handled using data abstraction techniques by transforming the raw data into a simpler format while, at the same time, preserving significant features that are important for the user. When dealing with time-series data, abstraction techniques should also take into account the underlying temporal characteristics. This thesis focuses on different data abstraction and pattern identification methods particularly in the cases of large 1D time-series and 2D spatio-temporal time-series data which exhibit spatiotemporal discontinuity. Based on the dimensionality and characteristics of the data, this thesis proposes a variety of efficient data-adaptive and user-controlled data abstraction methods that transform the raw data into a symbol sequence. The transformation of raw time-series into a symbol sequence can act as input to different sequence analysis methods from data mining and machine learning communities to identify interesting patterns of user behavior. In the case of very long duration 1D time-series, locally adaptive and user-controlled data approximation methods were presented to simplify the data, while at the same time retaining the perceptually important features. The simplified data were converted into a symbol sequence and a sketch-based pattern identification was then used to identify patterns in the symbolic data using regular expression based pattern matching. The method was applied to financial time-series and patterns such as head-and-shoulders, double and triple-top patterns were identified using hand drawn sketches in an interactive manner. Through data smoothing, the data approximation step also enables visualization of inherent patterns in the time-series representation while at the same time retaining perceptually important points. Very long duration 2D spatio-temporal eye tracking data sets that exhibit spatio-temporal discontinuity was transformed into symbolic data using scalable clustering and hierarchical cluster merging processes, each of which can be parallelized. The raw data is transformed into a symbol sequence with each symbol representing a region of interest in the eye gaze data. The identified regions of interest can also be displayed in a Space-Time Cube (STC) that captures both the temporal and contextual information. Through interactive filtering, zooming and geometric transformation, the STC representation along with linked views enables interactive data exploration. Using different sequence analysis methods, the symbol sequences are analyzed further to identify temporal patterns in the data set. Data collected from air traffic control officers from the domain of Air traffic control were used as application examples to demonstrate the results.
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| 26. |
- Myrtennäs, Kerstin, et al.
(författare)
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Authors' reply
- 2017
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Ingår i: Infection Ecology & Epidemiology. - : Taylor & Francis. - 2000-8686. ; 210:1, s. 84-84
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Tidskriftsartikel (refereegranskat)
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| 27. |
- Nilsson, Martin, 1966, et al.
(författare)
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Fall Risk Assessment Predicts Fall-Related Injury, Hip Fracture, and Head Injury in Older Adults
- 2016
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Ingår i: Journal of the American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 64:11, s. 2242-2250
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo investigate the role of a fall risk assessment, using the Downton Fall Risk Index (DFRI), in predicting fall-related injury, fall-related head injury and hip fracture, and death, in a large cohort of older women and men residing in Sweden. ParticipantsOlder adults (mean age 82.4 7.8) who had a fall risk assessment using the DFRI at baseline (N = 128,596). MeasurementsInformation on all fall-related injuries, all fall-related head injuries and hip fractures, and all-cause mortality was collected from the Swedish Patient Register and Cause of Death Register. The predictive role of DFRI was calculated using Poisson regression models with age, sex, height, weight, and comorbidities as covariates, taking time to outcome or end of study into account. ResultsDuring a median follow-up of 253 days (interquartile range 90-402 days) (>80,000 patient-years), 15,299 participants had a fall-related injury, 2,864 a head injury, and 2,557 a hip fracture, and 23,307 died. High fall risk (DFRI 3) independently predicted fall-related injury (hazard ratio (HR) = 1.43, 95% confidence interval (CI) = 1.39-1.49), hip fracture (HR = 1.51, 95% CI =1.38-1.66), head injury (HR = 1.12, 95% CI = 1.03-1.22), and all-cause mortality (HR = 1.39, 95% CI = 1.35-1.43). DFRI more strongly predicted head injury (HR = 1.29, 95% CI = 1.21-1.36 vs HR = 1.08, 95% CI = 1.04-1.11) and hip fracture (HR = 1.41, 95% CI = 1.30-1.53 vs HR = 1.08, 95% CI = 1.05-1.11) in 70-year old men than in 90-year old women (P
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| 28. |
- Sandgren, Kristina, et al.
(författare)
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Radiation dosimetry of [Ga-68]PSMA-11 in low-risk prostate cancer patients
- 2019
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Ingår i: EJNMMI Physics. - : Springer. - 2197-7364. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: 68Ga-labeled Glu-NH-CO-NH-Lys(Ahx)-HBED-CC ([68Ga]PSMA-11) has been increasingly used to image prostate cancer using positron emission tomography (PET)/computed tomography (CT) both during diagnosis and treatment planning. It has been shown to be of clinical value for patients both in the primary and secondary stages of prostate cancer. The aim of this study was to determine the effective dose and organ doses from injection of [68Ga]PSMA-11 in a cohort of low-risk prostate cancer patients.Methods: Six low-risk prostate cancer patients were injected with 133–178 MBq [68Ga]PSMA-11 and examined with four PET/CT acquisitions from injection to 255 min post-injection. Urine was collected up to 4 h post-injection, and venous blood samples were drawn at 45 min, 85 min, 175 min, and 245 min post-injection. Kidneys, liver, lungs, spleen, salivary and lacrimal glands, and total body where delineated, and cumulated activities and absorbed organ doses calculated. The software IDAC-Dose 2.1 was used to calculate absorbed organ doses according to the International Commission on Radiological Protection (ICRP) publication 107 using specific absorbed fractions published in ICRP 133 and effective dose according to ICRP Publication 103. We also estimated the absorbed dose to the eye lenses using Monte Carlo methods.Results: [68Ga]PSMA-11 was rapidly cleared from the blood and accumulated preferentially in the kidneys and the liver. The substance has a biological half-life in blood of 6.5 min (91%) and 4.4 h (9%). The effective dose was calculated to 0.022 mSv/MBq. The kidneys received approximately 40 mGy after an injection with 160 MBq [68Ga]PSMA-11 while the lacrimal glands obtained an absorbed dose of 0.12 mGy per administered MBq. Regarding the eye lenses, the absorbed dose was low (0.0051 mGy/MBq).Conclusion: The effective dose for [68Ga]PSMA-11 is 0.022 mSv/MBq, where the kidneys and lacrimal glands receiving the highest organ dose.
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| 29. |
- Tan, He, 2013-, et al.
(författare)
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Development and evaluation of a software requirements ontology
- 2016
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Ingår i: SKY 2016 - 7th International Workshop on Software Knowledge, Proceedings - In conjuction with IC3K 2016. - : SciTePress. - 9789897582028 ; , s. 11-18
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Konferensbidrag (refereegranskat)abstract
- This paper presents an ontology which has been developed to represent the requirements of a software component pertaining to an embedded system in the avionics industry. The ontology was built based on the software requirements documents and was used to support advanced methods in the subsequent stages of the software development process. In this paper it is described theprocess that was used to build the ontology. Two pertinent quality measures that were applied to the ontology, i.e. usability and applicability, are also described, as well as the methods used to evaluate the quality measures and the result of these evaluations.
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| 30. |
- Tan, He, 2013-, et al.
(författare)
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Evaluation of an Application Ontology
- 2017
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Ingår i: The Joint Ontology Workshops. - : CEUR-WS.
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Konferensbidrag (refereegranskat)abstract
- The work presented in this paper demonstrates an evaluation procedure for a real-life application ontology, coming from the avionics domain. The focus of the evaluation has specifically been on three ontology quality features, namely usability, correctness and applicability. In the paper, the properties of the three features are explained in the context of the application domain, the methods and tools used for the evaluation of the features are presented, and the evaluation results are presented and discussed. The results indicate that the three quality features are significant in the evaluation of our application ontology, that the proposed methods and tools allow for the evaluation of the three quality features and that the inherent quality of the application ontology can be confirmed.
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| 31. |
- Tarasov, Vladimir, 1966-, et al.
(författare)
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Application of inference rules to a software requirements ontology to generate software test cases
- 2017
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Ingår i: OWL: Experiences and Directions – Reasoner Evaluation. - Cham : Springer. - 9783319546278 ; , s. 82-94
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Bokkapitel (refereegranskat)abstract
- Testing of a software system is resource-consuming activity. One of the promising ways to improve the efficiency of the software testing process is to use ontologies for testing. This paper presents an approach to test case generation based on the use of an ontology and inference rules. The ontology represents requirements from a software requirements specification, and additional knowledge about components of the software system under development. The inference rules describe strategies for deriving test cases from the ontology. The inference rules are constructed based on the examination of the existing test documentation and acquisition of knowledge from experienced software testers. The inference rules are implemented in Prolog and applied to the ontology that is translated from OWL functional-style syntax to Prolog syntax. The first experiments with the implementation showed that it was possible to generate test cases with the same level of detail as the existing, manually produced, test cases.
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| 32. |
- Tarasov, Vladimir, 1966-, et al.
(författare)
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Ontology-based Software Test Case Generation (OSTAG)
- 2015
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Ingår i: European Projects in Knowledge Applications and Intelligent Systems - Volume 1: EPS Lisbon 2016. - : SciTePress. - 9789897583568 ; , s. 135-159
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Konferensbidrag (refereegranskat)abstract
- Testing is a paramount quality assurance activity in every software developmentproject, especially for embedded, safety critical systems. During thetest process, a lot of effort is put into the generation of test cases. The presentedOSTAG project aimed at developing methods and techniques to automate thesoftware test case generation for black-box testing. The proposed approach wasbased on the creation of a software requirements ontology and the applicationof inference rules on the ontology to derive test cases. The ontology representsknowledge of the requirements, the software system and the corresponding applicationdomain while the inference rules formalize knowledge from documentsand experienced testers in the domain of test planning and test case generation.A software prototype of the approach was implemented and one of the industrialproject partners evaluated the results. An alternative method for generating testcases, based on genetic algorithms, was also explored.
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| 33. |
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