Statistical framework for video decoding complexity modeling and prediction

Video decoding complexity modeling and prediction is an increasingly important issue for efficient resource utilization in a variety of applications, including task scheduling, receiver-driven complexity shaping, and adaptive dynamic voltage scaling. In this paper we present a novel view of this problem based on a statistical framework perspective. We explore the statistical structure (clustering) of the execution time required by each video decoder module (entropy decoding, motion compensation, etc.) in conjunction with complexity features that are easily extractable at encoding time (representing the properties of each module's input source data). For this purpose, we employ Gaussian mixture models (GMMs) and an expectation-maximization algorithm to estimate the joint execution-time - feature probability density function (PDF). A training set of typical video sequences is used for this purpose in an offline estimation process. The obtained GMM representation is used in conjunction with the complexity features of new video sequences to predict the execution time required for the decoding of these sequences. Several prediction approaches are discussed and compared. The potential mismatch between the training set and new video content is addressed by adaptive online joint-PDF re-estimation. An experimental comparison is performed to evaluate the different approaches and compare the proposed prediction scheme with related resource prediction schemes from the literature. The usefulness of the proposed complexity-prediction approaches is demonstrated in an application of rate-distortion-complexity optimized decoding

Pressure and Temperature Changes in In Vitro Applications with the Laser and Their Implications for Middle Ear Surgery

Background. The purpose of this study was to evaluate the thermal and pressure effects using a Titan Sapphire chirped-pulse amplifier system configured to deliver ultrashort pulses of 180 femtoseconds (fs) in an inner ear model. Materials and Methods. Temperature increases and heat exchange processes in the fluid (physiological saline) were examined in a calorically and physiologically approximated cochlea model for applying laser parameters effective in the creation of footplate perforations. Results. In the effective energy density range, the highest temperature increases achieved with the Carbon dioxide (CO2) laser were about 11 degrees C. The lowest temperature maxima were 6 degrees C with the Er:YAG laser (Yttrium-Aluminum-Oxide doted with Erbium3+-ions) and <5 degrees C with the femtosecond laser. Comparison of the laser-induced pressure with the limit graph published by Pfander indicated that the use of the fs laser is unobjectionable for fluences <1 J/cm2. Conclusions. Our investigations demonstrated that the application of the fs laser in middle ear surgery presents a new and promising addition to the range of ultrashort wavelength lasers used for this purpose

Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (n = 50) was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest) was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed

Long-term growth patterns of vestibular schwannomas after stereotactic radiotherapy: delayed re-growth

Purpose: To determine the long-term outcomes of patients with vestibular schwannomas (VS) after stereotactic radiosurgery (SRS) who experience delayed tumour regrowth. Methods: We carried out a retrospective case series in tertiary university settings. We included patients with VS with initial response to SRS and delayed regrowth, assessing a database of 735 patients with VS and 159 patients who had SRS as sole treatment. Following SRS, all patients had clinical follow-up and serial magnetic resonance imaging (MRI). We documented the post-SRS clinical assessment, pre- and post-SRS VS size as per MRI in predetermined time periods, response to treatment and rate of (re-) growth and the final outcome in each case. Results: We identified six patients with good initial response but delayed VS regrowth at a faster rate than pre-SRS. The mean growth rate for these VS was 0.347 mm/month (range 0.04–0.78 mm/month) prior to treatment; the mean growth rate at the time of delayed re-growth was 0.48 mm/month (range 0.17–0.75 mm/month); this did not reach the level of statistical significance (p = 0.08). This regrowth occurred at a mean time of 42 months (range 36–66 months) post-SRS and stopped 22 months (mean, range 12–36 months) post regrowth detection in all cases. Conclusions: Given that delayed post-SRS VS regrowth can occur in approximately 4% of the treated cases, it is important to continue close clinical and radiological follow-up. Despite this abnormal behaviour, VS do stop growing again; still, patients should be made aware of the possibility of this uncommon VS behaviour following SRS

Analysis of patient variables including socioeconomic indicators and their association with recurrence rates and persistence of benign paroxysmal positional vertigo: a retrospective case series

No abstract available

The history and evolution of vestibular schwannoma surgery: a comprehensive review

Vestibular schwannoma (VS) surgery has had a compelling historical evolution. This article aimed to provide a detailed narrative historical review of the chronological progression and conception of surgical VS management. Acknowledgment of the development, revision, and transformation of VS surgery over the decades facilitate a comprehensive understanding of current clinical practice and the scope for further procedural evolution. Following the commencement of VS surgery in the late 18th century, procedures and management have been perpetually revised and augmented, culminating in drastically improved surgical outcomes. This article draws upon the primary source material to provide augmented acuity into the principal pioneers and landmark cases that define the surgery’s trajectory. Moreover, the article includes original interpretive artwork by the first author along with a detailed timeline to facilitate enhanced perspicacity of this unique and salient constituent in surgical history

Mastoid obliteration with synthetic materials: a review of the literature

Canal wall down mastoidectomy is a surgical technique used for the eradication of middle ear disease. The remaining large mastoid bowl is associated with a number of issues; one of the main techniques that have been developed in order to avoid such problems is the obliteration of the mastoid cavity. The materials used for this reason are either biological or synthetic. The purpose of this survey is to review the published literature related to the therapeutic value of mastoid obliteration with synthetic materials. We searched Web of Science, PubMed, and MEDLINE from 2008 to 2018 using the criteria mastoid obliteration, canal wall down mastoidectomy, chronic otitis media, and cholesteatoma. The search focused on papers concerning the mastoid obliteration with synthetic material, as we focused on looking for outcomes and reported complications. Out of a total of 244 citations, 15 articles were identified, where patients underwent mastoid obliteration with synthetic materials. Most authors used bioactive glass as a filler material. Mastoid obliteration resulted in a decrease in the complications associated with the open mastoid cavity. On the basis of the available limited literature, it seems that mastoid obliteration with synthetic materials is a valuable and safe surgical technique for patients who undergo canal wall down mastoidectomy. The bioactive glass appears to be the most reliable synthetic material

Sustained virologic response to therapy of recurrent hepatitis C after liver transplantation is related to early virologic response and dose adherence

Sustained virologic response (SVR) after antiviral therapy for recurrent hepatitis C virus (HCV) infection in liver transplant (LT) recipients is consistently lower than that achieved in non-LT patients. We evaluated efficacy and safety of pegylated interferon (IFN) and ribavirin (RBV) therapy in LT recipients with recurrent HCV and factors associated with SVR. All subjects with histologic evidence of recurrent HCV were intended to be treated for 48 weeks with full-dose pegylated IFN; target dose of RBV was 800 mg/day. Thirty-five LT recipients with recurrent HCV, median age 48.5 years, 77% genotype 1, and median pretreatment HCV RNA 6.4 log 10 IU/mL were treated between January 2000 and February 2006. Antiviral therapy was discontinued prematurely in 15 subjects as a result of adverse events. Median overall treatment duration was 46 weeks. Early virologic response at week 12 was seen in 17 (49%) and an end-of-treatment virological response in 19 (54%) patients. SVR was achieved in 13 patients (37%), and all 9 patients followed for >1 year after treatment had durable response. Patients with SVR had significantly lower pretreatment HCV RNA (5.7 vs. 6.5 log 10 IU/mL, P = 0.003), more likely to have a week 12 virological response (85% vs. 27%, P = 0.0009) and received higher cumulative doses of pegylated IFN (75% vs. 33%, P = 0.029) and RBV (90% vs. 26%, P = 0.016) compared with patients whose disease did not respond to therapy. In conclusion, SVR was achieved in 37% of patients with recurrent hepatitis C after LT. Similar to non-LT patients, those with lower pretreatment HCV RNA, a week 12 virological response, and pegylated IFN and RBV dose adherence were more likely to achieve SVR. Liver Transpl, 2007. © 2007 AASLD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56160/1/21121_ftp.pd

Can serum hyaluronic acid replace simple non-invasive indexes to predict liver fibrosis in HIV/Hepatitis C coinfected patients?

<p>Abstract</p> <p>Background</p> <p>Hyaluronic acid (HA) serum levels correlate with the histological stages of liver fibrosis in hepatitis C virus (HCV) monoinfected patients, and HA alone has shown very good diagnostic accuracy as a non-invasive assessment of fibrosis and cirrhosis. The aim of this study was to evaluate serum HA levels as a simple non-invasive diagnostic test to predict hepatic fibrosis in HIV/HCV-coinfected patients and to compare its diagnostic performance with other previously published simple non-invasive indexes consisting of routine parameters (HGM-1, HGM-2, Forns, APRI, and FIB-4).</p> <p>Methods</p> <p>We carried out a cross-sectional study on 201 patients who all underwent liver biopsies and had not previously received interferon therapy. Liver fibrosis was determined via METAVIR score. The diagnostic accuracy of HA was assessed by area under the receiver operating characteristic curves (AUROCs).</p> <p>Results</p> <p>The distribution of liver fibrosis in our cohort was 58.2% with significant fibrosis (F≥2), 31.8% with advanced fibrosis (F≥3), and 11.4% with cirrhosis (F4). Values for the AUROC of HA levels corresponding to significant fibrosis (F≥2), advanced fibrosis (F≥3) and cirrhosis (F4) were 0.676, 0.772, and 0.863, respectively. The AUROC values for HA were similar to those for HGM-1, HGM-2, FIB-4, APRI, and Forns indexes. The best diagnostic accuracy of HA was found for the diagnosis of cirrhosis (F4): the value of HA at the low cut-off (1182 ng/mL) excluded cirrhosis (F4) with a negative predictive value of 99% and at the high cut-off (2400 ng/mL) confirmed cirrhosis (F4) with a positive predictive value of 55%. By utilizing these low and high cut-off points for cirrhosis, biopsies could have theoretically been avoided in 52.2% (111/201) of the patients.</p> <p>Conclusions</p> <p>The diagnostic accuracy of serum HA levels increases gradually with the hepatic fibrosis stage. However, HA is better than other simple non-invasive indexes using parameters easily available in routine clinical practice only for the diagnosing of cirrhosis.</p