| 1. |
- Lungaro, Pietro, et al.
(author)
-
Gaze-Aware Streaming Solutions for the Next Generation of Mobile VR Experiences
- 2018
-
In: IEEE Transactions on Visualization and Computer Graphics. - : IEEE Computer Society. - 1077-2626 .- 1941-0506. ; 24:4, s. 1535-1544
-
Journal article (peer-reviewed)abstract
- This paper presents a novel approach to content delivery for video streaming services. It exploits information from connected eye-trackers embedded in the next generation of VR Head Mounted Displays (HMDs). The proposed solution aims to deliver high visual quality, in real time, around the users' fixations points while lowering the quality everywhere else. The goal of the proposed approach is to substantially reduce the overall bandwidth requirements for supporting VR video experiences while delivering high levels of user perceived quality. The prerequisites to achieve these results are: (1) mechanisms that can cope with different degrees of latency in the system and (2) solutions that support fast adaptation of video quality in different parts of a frame, without requiring a large increase in bitrate. A novel codec configuration, capable of supporting near-instantaneous video quality adaptation in specific portions of a video frame, is presented. The proposed method exploits in-built properties of HEVC encoders and while it introduces a moderate amount of error, these errors are indetectable by users. Fast adaptation is the key to enable gaze-aware streaming and its reduction in bandwidth. A testbed implementing gaze-aware streaming, together with a prototype HMD with in-built eye tracker, is presented and was used for testing with real users. The studies quantified the bandwidth savings achievable by the proposed approach and characterize the relationships between Quality of Experience (QoE) and network latency. The results showed that up to 83% less bandwidth is required to deliver high QoE levels to the users, as compared to conventional solutions.
|
|
| 2. |
- Philipsson, Johanna, et al.
(author)
-
Acute severe depression induced by stimulation of the right globus pallidus internus
- 2017
-
In: Neurocase. - : Routledge. - 1355-4794 .- 1465-3656. ; 23:1, s. 84-87
-
Journal article (peer-reviewed)abstract
- Depressive symptoms may occur after Deep Brain Stimulation (DBS) in the subthalamic nucleus. This is often explained by reduced pharmacological treatment after surgery, and not as a direct effect of DBS. Pallidal DBS seems not to be associated with such side effects and have not, to our knowledge, previously been reported. We present a patient with acute depressive symptoms induced by pallidal DBS. We believe this case strengthen the hypothesis that the basal ganglia and structures involved in the functional connectome of these nucleuses play a role not only in regulation of movement but also in regulation of mood.
|
|
| 3. |
- Sjöberg, Rickard L., et al.
(author)
-
Blood Metabolomic Predictors of 1-Year Outcome in Subarachnoid Hemorrhage
- 2015
-
In: Neurocritical Care. - : Springer. - 1541-6933 .- 1556-0961. ; 23:2, s. 225-232
-
Journal article (peer-reviewed)abstract
- Delayed neurological deficit (DND) is the most important cause of morbidity and mortality in patients with subarachnoid hemorrhage (SAH) whose aneurysms have been secured. However, the methods currently used to predict the development of DND, such as trans-cranial Doppler or levels biochemical markers in blood and cerebrospinal fluid are not very accurate. Venous blood was drawn from 50 patients with SAH, admitted to the neurosurgical department UmeAyen University Hospital, at day 1-3 and day 7 after the bleed. The clinical status of the patients was followed up approximately 1 year after this episode and classified according to the Glasgow Outcome Score (GOS). Results showed considerable differences in blood metabolomic patterns between day 1-3 and 7 after the hemorrhage. Fifty-six out of 98 metabolites could be identified from our in-house library and 17 of these metabolites changed significantly from day 1-3 to 7 after the bleed. One of these, myo-inositol, was predictive of clinical outcome even after correction for multiple testing. An estimation of the diagnostic accuracy of high levels of this substance in predicting good outcome (GOS 4-5) yielded a sensitivity of .763 and a specificity of .5 at the optimal cut off point. SAH is an event with a profound effect on blood metabolomics profiles. Myo-inositol might be an interesting compound for future study to focus on in the search for metabolic markers in venous blood of delayed neurological deterioration in SAH patients.
|
|
| 4. |
|
|
| 5. |
- Sjöberg, Rickard L.
(author)
-
Five myths about witch-hunts
- 2019
-
In: Washington Post. - Washington DC : Nash Holdings LLC.. ; , s. B3-B3
-
Journal article (pop. science, debate, etc.)
|
|
| 6. |
- Sjöberg, Rickard L., et al.
(author)
-
Laterality and deep brain stimulation of the subthalamic nucleus : applying a dichotic listening task to patients treated for Parkinson's disease
- 2015
-
In: Neurocase. - : Informa UK Limited. - 1355-4794 .- 1465-3656. ; 21:5, s. 601-606
-
Journal article (peer-reviewed)abstract
- Ear advantage during a dichotic listening task tends to mirror speech lateralization. Previous studies in stroke patients have shown that lesions in the dominant hemisphere often seem to produce changes in ear advantage. In this study six Parkinson's disease (PD) patients treated for motor symptoms with deep brain stimulation (DBS) of the left subthalamic nucleus (STN) were tested preoperatively and at approximately 6 and 18months postoperatively with a dichotic listening task. Results show a significant decline of the right ear advantage over time. In three of the patients a right ear advantage preoperativley changed to a left ear advantage 18months postoperatively. This suggests the possibility that additional longitudinal studies of this phenomenon could serve as a model for understanding changes in indirect measures of speech lateralization in stroke patients.
|
|
| 7. |
- Sjöberg, Rickard L, et al.
(author)
-
Role of monoamine-oxidase-A-gene variation in the development of glioblastoma in males : a case control study
- 2019
-
In: Journal of Neuro-Oncology. - : Springer. - 0167-594X .- 1573-7373. ; 145:2, s. 287-294
-
Journal article (peer-reviewed)abstract
- Background: The Mono-amine oxidase-A (MAO-A) enzyme is involved in the degradation and regulation of catecholamines such as serotonin, dopamine, epinephrine and nor-epinephrine. Preclinical studies suggest that this enzyme may contribute to an environment favorable for growth of malignant glioma. The MAO-A gene is located on the X-chromosome and has at least one functional genetic polymorphism. The aim of the present study was to explore possible effects of MAO-A genotype on development of glioblastoma in males.Methods: Genotypes for 437 glioma cases and 876 population-based controls from the Swedish Glioma International Case–Control study (GICC) were compared. We analyzed the germline DNA using the Illumina Oncoarray. We selected seven single nucleotide polymorphisms (SNPs) located in the MAO-A gene, and imputed genotypes based on data from the 1000 genomes project. We used 1579 male glioblastoma cases and 1875 controls comprising the whole GICC cohort for subsequent validation of findings.Results: The rs144551722 SNP was a significant predictor of development of glioblastoma in males (p-value = 0.0056) but not in females even after correction for multiple testing. We conducted haplotype analysis to confirm an association between MAO-A gene and risk of glioblastoma (p-value = 0.016). We found similar results in the validation sample.Conclusions: These results suggest the possibility of a role for the MAO-A enzyme and the MAO-A gene in the development of glioblastoma in males.
|
|
| 8. |
- Sjöberg, Rickard L., et al.
(author)
-
The supplementary motor area syndrome and cognitive control
- 2019
-
In: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 129, s. 141-145
-
Journal article (peer-reviewed)abstract
- The Supplementary Motor Area (SMA)-syndrome is a transient disturbance of the ability to initiate voluntary motor and speech actions that will often occur immediately after neurosurgical resections in the dorsal superior frontal gyrus but will typically have disappeared after 3 months. The purpose of the present study was to investigate the extent to which this syndrome is associated with alterations in cognitive control. Five patients who were to different extents affected by the SMA-syndrome after surgery for WHO grade II gliomas in the left hemisphere, were tested with the color word interference (Stroop) test; the Bergen dichotic listening test and for letter and category verbal fluency before surgery, 1–2 days after surgery and approximately 3 months after surgery. Results suggest that the motor symptoms known as the SMA syndrome co-occur with pronounced deficits in cognitive control.
|
|
| 9. |
- Sjöberg, Rickard L
(author)
-
Witch persecutions and torture : Comment on Alison and Alison (2017)
- 2017
-
In: American Psychologist. - : American Psychological Association (APA). - 0003-066X .- 1935-990X. ; 72:7, s. 703-704
-
Journal article (peer-reviewed)abstract
- In their article Alison and Alison (2017) argue that historical experiences speak against the efficacy of torture. In this comment experiences from the witch persecutions in Europe during the 15th to 17th centuries that support this notion are discussed. Converging data suggests that torture was often instrumental in making large numbers of suspects confess to flying children through the air to nocturnal satanic meetings, during this period. A comparison of the number of false self incriminating confessions given during the Swedish witch trial in the parish of Rättvik 1671 (before royal sanction of torture was given) and the parish of Ockelbo 1675 (after royal sanction of torture was given) is used to illustrate this point.
|
|
| 10. |
- Sjöberg, Ylva, 1982-, et al.
(author)
-
Geophysical mapping of palsa peatland permafrost
- 2015
-
In: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 9, s. 465-478
-
Journal article (peer-reviewed)abstract
- Permafrost peatlands are hydrological and biogeochemicalhotspots in the discontinuous permafrost zone.Non-intrusive geophysical methods offer a possibility tomap current permafrost spatial distributions in these environments.In this study, we estimate the depths to the permafrosttable and base across a peatland in northern Sweden,using ground penetrating radar and electrical resistivitytomography. Seasonal thaw frost tables (at 0.5m depth),taliks (2.1–6.7m deep), and the permafrost base (at 16mdepth) could be detected. Higher occurrences of taliks werediscovered at locations with a lower relative height of permafrostlandforms, which is indicative of lower ground icecontent at these locations. These results highlight the addedvalue of combining geophysical techniques for assessing spatialdistributions of permafrost within the rapidly changingsporadic permafrost zone. For example, based on a back-ofthe-envelope calculation for the site considered here, we estimatedthat the permafrost could thaw completely within thenext 3 centuries. Thus there is a clear need to benchmark currentpermafrost distributions and characteristics, particularlyin under studied regions of the pan-Arctic.
|
|
