Application of full-reference video quality metrics in IPTV

Executing an accurate full-reference metric such as VQM can take minutes in an average computer for just one user. Therefore, it can be unfeasible to analyze all the videos received by users in an IPTV network for example consisting of 10.000 users using a single computer running the VQM metric. One solution can be to use a lightweight no-reference metrics in addition to the full-reference metric mentioned. Lightweight no-reference metrics can be used for discarding potential situations to evaluate because they are accurate enough for that task, and then the full-reference metric VQM can be used when more accuracy is needed. The work in this paper is focused on determining the maximum number of situations/users that can be analyzed simultaneously using the VQM metric in a computer with good performance. The full-reference metric is applied on the transmitter using a method specified in the recommendation ITU BT.1789. The best performance achieved was 112.8 seconds per process

Psychophysiology-based QoE assessment : a survey

We present a survey of psychophysiology-based assessment for quality of experience (QoE) in advanced multimedia technologies. We provide a classification of methods relevant to QoE and describe related psychological processes, experimental design considerations, and signal analysis techniques. We summarize multimodal techniques and discuss several important aspects of psychophysiology-based QoE assessment, including the synergies with psychophysical assessment and the need for standardized experimental design. This survey is not considered to be exhaustive but serves as a guideline for those interested to further explore this emerging field of research

A common framework for the evaluation of psychophysiological visual quality assessment

The assessment of perceived quality based on psychophysiological methods recently gained attraction as it potentiallyovercomes certain flaws of psychophysical approaches. Although studies report promising results, it is not possible toarrive at decisive and comparable conclusions that recommend the use of one or another method for a specific applicationor research question. The video quality expert group started a project on psychophysiological quality assessment to studythese novel approaches and to develop a test plan that enables more systematic research. This test plan comprises of a specificallydesigned set of quality annotated video sequences, suggestions for psychophysiological methods to be studied inquality assessment, and recommendations for the documentation and publications of test results. The test plan is presentedin this article.Celtc-Next 5G Perfecta (2018-00735

The Correlation between F-wave Motor Unit Number Estimation (F-MUNE) and Functional Recovery in Stroke Patients

The aim of this study was to follow up the changes in the number of motor units according to the Brünnstrom stage through a motor unit number estimation of the F-wave (F-MUNE) after a stroke, and to identify the functional significance of F-MUNE. Twenty-five patients (15 men, 10 women) with a first unilateral stroke were recruited. The maximal M-potential was evoked by the supramaximal stimulation of the median nerve at the wrist, and the maximal stimulation intensity was determined on both hemiplegic and unaffected hands. The reproducible all-or-none F-wave was evoked in 30% of the maximal stimulation intensity and was constantly stimulated at that level. The prototypes of the F-wave were chosen, and the values of F-MUNE were calculated by dividing the amplitude of the maximal M-potential by the mean amplitude of the F-prototype. The changes in F-MUNE were compared according to the progression of the Brünnstrom stage and correlated with those of the functional scales. The mean motor unit numbers decreased significantly in the hemiplegic side compared with the unaffected side. According to the progression of the Brünnstrom stage, the values of F-MUNE were reduced significantly by increasing the amplitude and recruitment of the F-prototype, and the functional scores also improved. These results show that the F-MUNE equation did not show a functional recovery-related increase in stroke patients

Minimisation of image watermarking side effects through subjective optimisation

This study investigates the use of structural similarity index (SSIM) on the minimised side effect to image watermarking. For the fast implementation and more compatibility with the standard discrete cosine transform (DCT)-based codecs, watermark insertion is carried out on the DCT coefficients and hence an SSIM model for DCT-based watermarking is developed. For faster implementation, the SSIM index is maximised over independent 4 × 4 non-overlapped blocks, but the disparity between the adjacent blocks reduces the overall image quality. This problem is resolved through optimisation of overlapped blocks, but, the higher image quality is achieved at a cost of high computational complexity. To reduce the computational complexity while preserving the good quality, optimisation of semi-overlapped blocks is introduced. The authors show that while SSIM-based optimisation over overlapped blocks has as high as 64 times the complexity of the 4 × 4 non-overlapped method, with semi-overlapped optimisation the high quality of overlapped method is preserved only at a cost of less than 8 times the non-overlapped method

PD-L1 Expression in Endometrial Carcinoma Cells and Intratumoral Immune Cells Differences Across Histologic and TCGA-based Molecular Subgroups

Programmed death-ligand 1 (PD-L1) is a biomarker that may predict the response to anti-programmed death 1/PD-L1 immunotherapy. We evaluated the expression of PD-L1 in carcinoma cells (Ca) and immune cells (ICs) across histopathologic and The Cancer Genome Atlas (TCGA) molecular subgroups of endometrial carcinoma (EC). Our study included 842 patients with EC. Direct sequencing of polymerase epsilon (POLE) exonuclease domain hot spots and conventional immunohistochemistry (MLH1, PMS2, MSH2, MSH6, p53) were conducted to identify TCGA classification-based molecular subgroups of EC: POLE-mutated, mismatch repair deficient, no specific molecular profile, and p53 aberrant. Multiplex immunohistochemistry was performed to evaluate PD-L1 expression in Ca and tumor-infiltrating ICs. PD-L1 expression in Ca and in ICs was detected in 8.6% and 27.7% of the cases, respectively. A combined positive score (CPS) was >= 1% in 19.4% of the samples. PD-L1 positivity in Ca and ICs, and CPS correlated with tumor T-cell density (P= 1% (P=0.037) positivity compared with early disease. In conclusion, PD-L1 expression profiles differ between molecular subclasses, histologic subtypes, and disease stage of EC. Prospective studies are needed to explore the predictive value of various PD-L1 scoring systems within the subgroups of EC. CPS presents methodological advantages over cell type-specific scoring systems.Peer reviewe

Combined arm stretch positioning and neuromuscular electrical stimulation during rehabilitation does not improve range of motion, shoulder pain or function in patients after stroke:a randomised trial

QuestionDoes static stretch positioning combined with simultaneous neuromuscular electrical stimulation (NMES) in the subacute phase after stroke have beneficial effects on basic arm body functions and activities?DesignMulticentre randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis.ParticipantsForty-six people in the subacute phase after stroke with severe arm motor deficits (initial Fugl-Meyer Assessment arm score ≤ 18).InterventionIn addition to conventional stroke rehabilitation, participants in the experimental group received arm stretch positioning combined with motor amplitude NMES for two 45-minute sessions a day, five days a week, for eight weeks. Control participants received sham arm positioning (ie, no stretch) and sham NMES (ie, transcutaneous electrical nerve stimulation with no motor effect) to the forearm only, at a similar frequency and duration.Outcome measuresThe primary outcome measures were passive range of arm motion and the presence of pain in the hemiplegic shoulder. Secondary outcome measures were severity of shoulder pain, restrictions in performance of activities of daily living, hypertonia, spasticity, motor control and shoulder subluxation. Outcomes were assessed at baseline, mid-treatment, at the end of the treatment period (8 weeks) and at follow-up (20 weeks).ResultsMultilevel regression analysis showed no significant group effects nor significant time × group interactions on any of the passive range of arm motions. The relative risk of shoulder pain in the experimental group was non-significant at 1.44 (95% CI 0.80 to 2.62).ConclusionIn people with poor arm motor control in the subacute phase after stroke, static stretch positioning combined with simultaneous NMES has no statistically significant effects on range of motion, shoulder pain, basic arm function, or activities of daily living.Trial registrationNTR1748.</p

Investigating various thresholds as immunohistochemistry cutoffs for observer agreement

Background: Clinical translation of immunohistochemistry (IHC) biomarkers requires reliable and reproducible cutoffs or thresholds for interpretation of immunostaining. Most IHC biomarker research focuses on the clinical relevance (diagnostic, prognostic, or predictive utility) of cutoffs, with less emphasis on observer agreement using these cutoffs. From the literature, we identified 3 commonly used cutoffs of 10% positive epithelial cells, 20% positive epithelial cells, and moderate to strong staining intensity (+2/+3 hereafter) to use for investigating observer agreement. Materials and Methods: A series of 36 images of microarray cores stained for 4 different IHC biomarkers, with variable staining intensity and percentage of positive cells, was used for investigating interobserver and intraobserver agreement. Seven pathologists scored the immunostaining in each image using the 3 cutoffs for positive and negative staining. Kappa ([kappa]) statistic was used to assess the strength of agreement for each cutoff. Results: The interobserver agreement between all 7 pathologists using the 3 cutoffs was reasonably good, with mean [kappa] scores of 0.64, 0.59, and 0.62, respectively, for 10%, 20%, and +2/+3 cutoffs. A good agreement was observed for experienced pathologists using the 10% cutoff, and their agreement was statistically higher than for junior pathologists (P=0.02). In addition, the mean intraobserver agreement for all 7 pathologists using the 3 cutoffs was reasonably good, with mean [kappa] scores of 0.71, 0.60, and 0.73, respectively, for 10%, 20%, and +2/+3 cutoffs. For all 3 cutoffs, a positive correlation was observed with perceived ease of interpretation (P&lt;0.003). Finally, cytoplasmic-only staining achieved higher agreement using all 3 cutoffs than mixed staining patterns. Conclusions: All 3 cutoffs investigated achieve reasonable strength of agreement, modestly decreasing interobserver and intraobserver variability in IHC interpretation. These cutoffs have previously been used in cancer pathology, and this study provides evidence that these cutoffs can be reproducible between practicing pathologists

Alterations of Muscle Synergies During Voluntary Arm Reaching Movement in Subacute Stroke Survivors at Different Levels of Impairment

Motor system uses muscle synergies as a modular organization to simplify the control of movements. Motor cortical impairments, such as stroke and spinal cord injuries, disrupt the orchestration of the muscle synergies and result in abnormal movements. In this paper, the alterations of muscle synergies in subacute stroke survivors were examined during the voluntary reaching movement. We collected electromyographic (EMG) data from 35 stroke survivors, ranging from Brunnstrom Stage III to VI, and 25 age-matched control subjects. Muscle synergies were extracted from the activity of 7 upper-limb muscles via nonnegative matrix factorization under the criterion of 95% variance accounted for. By comparing the structure of muscle synergies and the similarity of activation coefficients across groups, we can validate the increasing activation of pectoralis major muscle and the decreasing activation of elbow extensor of triceps in stroke groups. Furthermore, the similarity of muscle synergies was significantly correlated with the Brunnstrom Stage (R = 0.52, p < 0.01). The synergies of stroke survivors at Brunnstrom Stage IV–III gradually diverged from those of control group, but the activation coefficients remained the same after stroke, irrespective of the recovery level