Precise Near-to-Head Acoustics with Binaural Synthesis

For enhanced immersion into a virtual scene more than just the visual sense should be addressed by a Virtual Reality system. Additional auditory stimulation appears to have much potential, as it realizes a multisensory system. This is especially useful when the user does not have to wear any additional hardware, e.g., headphones. Creating a virtual sound scene with spatially distributed sources requires a technique for adding spatial cues to audio signals and an appropriate reproduction. In this paper we present a real-time audio rendering system that combines dynamic crosstalk cancellation and multi-track binaural synthesis for virtual acoustical imaging. This provides the possibility of simulating spatially distributed sources and, in addition to that, near-to-head sources for a freely moving listener in room-mounted virtual environments without using any headphones. A special focus will be put on near-to-head acoustics, and requirements in respect of the head-related transfer function databases are discussed.

[Partial femur head necrosis in adults--results with intertrochanteric osteotomy and revascularization]

Osteotomy and revascularization have both been used for many years in the therapy of partial aseptic necrosis of the femoral head in the adult. We first attempted a combination of the two techniques in 1978. Stress on the necrotic sector was relieved by intertrochanteric osteotomy, and the necrotic part of the bone was revascularized with a pedicled iliac crest bone graft based on the deep circumflex iliac vessels. Long-term results are now available in 45 hips in 38 patients, with a mean follow-up time of 32 months. Clinically, 71% of the hips were rated very good or good, and among those classed as stage II before surgery the results were rated as very good or good in as many as 90%. Subjective evaluation of the hips by the patients confirmed these results: 85% of the hips were judged to be optimal or markedly improved compared with before operation. Radiological evaluation showed further flattening of the femoral head in one case. A segmental collapse of the femoral head, i.e. stage III lesion according to Ficat, occurred in 2 hips with stage II preoperatively. In 6 hips with stage III necrosis preoperatively secondary arthritis developed. Computerized tomograms taken of all 25 hips from which metal implants had been removed showed signs of integration of the graft in 68%. Scintigraphy with 99-Tc-diphosphonate showed a homogeneous uptake in 42.8% and a non-homogeneous uptake in the remaining 57.2% of the cases. So-called photopenia was not observed in any of the hip joints treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms For Automatic And Robust Registration Of 3D Head Scans

wo methods for registering laser-scans of human heads and transforming them to a new semantically consistent topology defined by a user-provided template mesh are described. Both algorithms are stated within the Iterative Closest Point framework. The first method is based on finding landmark correspondences by iteratively registering the vicinity of a landmark with a re-weighted error function. Thin-plate spline interpolation is then used to deform the template mesh and finally the scan is resampled in the topology of the deformed template. The second algorithm employs a morphable shape model, which can be computed from a database of laser-scans using the first algorithm. It directly optimizes pose and shape of the morphable model. The use of the algorithm with PCA mixture models, where the shape is split up into regions each described by an individual subspace, is addressed. Mixture models require either blending or regularization strategies, both of which are described in detail. For both algorithms, strategies for filling in missing geometry for incomplete laser-scans are described. While an interpolation-based approach can be used to fill in small or smooth regions, the model-driven algorithm is capable of fitting a plausible complete head mesh to arbitrarily small geometry, which is known as "shape completion". The importance of regularization in the case of extreme shape completion is shown.

Conserved leucine residue in the head region of morbillivirus fusion protein regulates the large conformational change during fusion activity

Paramyxovirus cell entry is controlled by the concerted action of two viral envelope glycoproteins, the fusion (F) and the receptor-binding (H) proteins, which together with a cell surface receptor mediate plasma membrane fusion activity. The paramyxovirus F protein belongs to class I viral fusion proteins which typically contain two heptad repeat regions (HR). Particular to paramyxovirus F proteins is a long intervening sequence (IS) located between both HR domains. To investigate the role of the IS domain in regulating fusogenicity, we mutated in the canine distemper virus (CDV) F protein IS domain a highly conserved leucine residue (L372) previously reported to cause a hyperfusogenic phenotype. Beside one F mutant, which elicited significant defects in processing, transport competence, and fusogenicity, all remaining mutants were characterized by enhanced fusion activity despite normal or slightly impaired processing and cell surface targeting. Using anti-CDV-F monoclonal antibodies, modified conformational F states were detected in F mutants compared to the parental protein. Despite these structural differences, coimmunoprecipitation assays did not reveal any drastic modulation in F/H avidity of interaction. However, we found that F mutants had significantly enhanced fusogenicity at low temperature only, suggesting that they folded into conformations requiring less energy to activate fusion. Together, these data provide strong biochemical and functional evidence that the conserved leucine 372 at the base of the HRA coiled-coil of F(wt) controls the stabilization of the prefusogenic state, restraining the conformational switch and thereby preventing extensive cell-cell fusion activity.

DNA methylation patterns at the IGF2-H19 locus in sperm of Swiss Landrace and Swiss Large White boars

DNA methylation patterns at the IGF2-H19 locus were investigated in sperm DNA from Swiss Landrace (SL) and Swiss Large White (LW) boars. The putative IGF2 differentially methylated regions (DMR) 0, 1 and 2, a quantitative trait nucleotide (QTN) region in the intron 3 and a CpG island in the intron 4 of the IGF2 gene as well as three regions around porcine CTCF binding sites within the H19 differentially methylated domain (DMD) were selected for the DNA methylation analysis. In both breeds putative IGF2 DMR0, 1, 2 and H19 DMD were hypermethylated. Significant differences in DNA methylation content were found between the two breeds in the two DMD regions proximal to the H19 gene. The IGF2 QTN region and the CpG island in the IGF2 intron 4 were hypomethylated in sperm DNA of both breeds. The methylation analysis revealed significantly more methylated CpG sites in the intron 4 of sperm from the LW breed than in that from SL. No difference was found in global DNA methylation between the two breeds. These results indicate differences in DNA methylation patterns between breeds and it remains to be established whether variation in DNA methylation patterns impacts on phenotypic traits.

Head Tracking Based Avatar Control for Virtual Environment Teamwork Training

Virtual environments (VE) are gaining in popularity and are increasingly used for teamwork training purposes, e.g., for medical teams. One shortcoming of modern VEs is that nonverbal communication channels, essential for teamwork, are not supported well. We address this issue by using an inexpensive webcam to track the user's head. This tracking information is used to control the head movement of the user's avatar, thereby conveying head gestures and adding a nonverbal communication channel. We conducted a user study investigating the influence of head tracking based avatar control on the perceived realism of the VE and on the performance of a surgical teamwork training scenario. Our results show that head tracking positively influences the perceived realism of the VE and the communication, but has no major influence on the training outcome.

Physical examination during chemoradiation predicts outcome of locally advanced head and neck cancer. Secondary results of a randomized phase III trial (SAKK 10/94)

OBJECTIVES To analyze the prognostic value of clinical tumor response during chemoradiation for locally advanced head and neck cancer. PATIENTS AND METHODS The locoregional response at 50.4Gy was assessed by physical examination (PE) in patients treated within the randomized trial SAKK 10/94 using hyperfractionated radiotherapy (RT), median total dose 74.4Gy with or without cisplatin 20mg/m(2) chemotherapy on 5 consecutive days during weeks 1 and 5 or 6 of RT. Response was classified as a complete response (CR), complete response with uncertainty (Cru), partial response (PR), stable disease (SD), or progressive disease (PD). The primary endpoint was time to treatment failure (TTF) due to any cause. Secondary endpoints included locoregional-recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS). Univariate and multivariate Cox proportional hazards (PH) models were applied to analyze the associations between survival endpoints and clinical tumor response. RESULTS A total of 136, 131 and 97 patients were evaluable for response at the primary tumor, lymph nodes and both sites combined, respectively. At 50.4Gy 57/136 (42%), 46/131 (35%) and 21/97 (22%) patients had a good response (CR/Cru vs. PR/SD) at the primary tumor, the lymph nodes, and both sites combined, respectively. The median follow-up times were 11.4, 9.6 and 11.4years for the three groups. Good responses were all significantly associated with improved TTF, LRRFS, DMFS and OS in univariate analysis whereas good response at the primary tumor and lymph nodes remained significantly associated with TTF and OS after multivariate Cox PH models. CONCLUSIONS Locoregional response at 50.4Gy was identified as predictor of oncologic outcome. PE during treatment should not be underestimated in clinical practice.

Taxane-containing induction chemotherapy followed by definitive chemoradiotherapy. Outcome in patients with locally advanced head and neck cancer

BACKGROUND Induction chemotherapy followed by definitive chemoradiotherapy is an intensified treatment approach for locally advanced squamous cell carcinoma of the head and neck (HNSCC) that might be associated with high rates of toxicity. MATERIALS AND METHODS The data of 40 consecutive patients who underwent induction chemotherapy with docetaxel-containing regimens followed by intensity-modulated radiotherapy (IMRT) and concomitant systemic therapy for unresectable locally advanced HNSCC were retrospectively analyzed. Primary objectives were RT-related acute and late toxicity. Secondary objectives were response to induction chemotherapy, locoregional recurrence-free survival (LRRFS), overall survival (OS), and influencing factors for LRRFS and OS. RESULTS The median follow-up for surviving patients was 21 months (range, 2-53 months). Patients received a median of three cycles of induction chemotherapy followed by IMRT to 72 Gy. Three patients died during induction chemotherapy and one during chemoradiotherapy. Acute RT-related toxicity was of grade 3 and 4 in 72 and 3 % of patients, respectively, mainly dysphagia and dermatitis. Late RT-related toxicity was mainly xerostomia and bone/cartilage necrosis and was of grade 3 and 4 in 15 % of patients. One- and 2-year LRRFS and OS were 72 and 49 % and 77 and 71 %, respectively. CONCLUSION Induction chemotherapy followed by chemoradiotherapy using IMRT was associated with a high rate of severe acute and late RT-related toxicities in this selected patient cohort. Four patients were lost because of fatal complications. Induction chemotherapy did not compromise the delivery of full-dose RT; however, the use of three cycles of concomitant cisplatin was impaired.

Eye-head coordination abnormalities in schizophrenia

Eye-movement abnormalities in schizophrenia are a well-established phenomenon that has been observed in many studies. In such studies, visual targets are usually presented in the center of the visual field, and the subject's head remains fixed. However, in every-day life, targets may also appear in the periphery. This study is among the first to investigate eye and head movements in schizophrenia by presenting targets in the periphery of the visual field.

Analysis of eye and head coordination in a visual peripheral recognition task

Coordinated eye and head movements simultaneously occur to scan the visual world for relevant targets. However, measuring both eye and head movements in experiments allowing natural head movements may be challenging. This paper provides an approach to study eye-head coordination: First, we demonstra- te the capabilities and limits of the eye-head tracking system used, and compare it to other technologies. Second, a beha- vioral task is introduced to invoke eye-head coordination. Third, a method is introduced to reconstruct signal loss in video- based oculography caused by cornea reflection artifacts in order to extend the tracking range. Finally, parameters of eye- head coordination are identified using EHCA (eye-head co- ordination analyzer), a MATLAB software which was developed to analyze eye-head shifts. To demonstrate the capabilities of the approach, a study with 11 healthy subjects was performed to investigate motion behavior. The approach presented here is discussed as an instrument to explore eye-head coordination, which may lead to further insights into attentional and motor symptoms of certain neurological or psychiatric diseases, e.g., schizophrenia.

Measurement and meaning of head movements in everyday face-to-face communicative interaction

Methodological approaches in which data on nonverbal behavior are collected usually involve interpretive methods in which raters must identify a set of defined categories of behavior. However, present knowledge about the qualitative aspects of head movement behavior calls for recording detailed transcriptions of behavior. These records are a prerequisite for investigating the function and meaning of head movement patterns. A method for directly collecting data on head movement behavior is introduced. Using small ultrasonic transducers, which are attached to various parts of an index person's body (head and shoulders), a microcomputer defines receiver-transducers distances. Three-dimensional positions are calculated by triangulation. These data are used for further calculations concerning the angular orientation of the head and the direction, size, and speed of head movements (in rotational, lateral, and sagittal dimensions).

One-year head to head comparison of the neointimal response between sirolimus eluting stent with reservoir technology and everolimus eluting stent: an optical coherence tomography study

OBJECTIVE to compare the vascular healing process between the sirolimus-eluting NEVO and the everolimus-eluting Xience stent by optical coherence tomography (OCT) at 1-year follow-up. BACKGROUND Presence of durable polymer on a drug-eluting metallic stent may be the basis of an inflammatory reaction with abnormal healing response. The NEVO stent, having a bioresorbable polymer eluted by reservoir technology, may overcome this problem. METHODS All consecutive patients, who received NEVO or Xience stent implantation between September 2010 and October 2010 in our institution, were included. Vascular healing was assessed at 1-year as percentage of uncovered struts, neointimal thickness (NIT), in-stent/stent area obstruction and pattern of neointima. RESULTS A total 47 patients (2:1 randomization, n = 32 NEVO, n = 15 Xience) were included. Eighteen patients underwent angiographic follow-up (eight patients with nine lesions for NEVO vs. 10 patients with 11 lesions for Xience). The angiographic late loss was numerically higher but not statistically different in NEVO compared with Xience treated lesions (0.38 ± 0.47 mm vs. 0.18 ± 0.27 mm; P = 0.171). OCT analysis of 4,912 struts demonstrated similar rates of uncovered struts (0.5 vs. 0.7%, P = 0.462), higher mean NIT (177.76 ± 87.76 µm vs. 132.22 ± 30.91 µm; P = 0.170) and in stent/stent area obstruction (23.02 ± 14.74% vs. 14.17 ± 5.94%, P = 0.120) in the NEVO as compared with Xience. CONCLUSION The NEVO stent with a reservoir technology seems to exhibit more neointimal proliferation as compared to Xience stent. The findings of our study, which currently represent the unique data existing on this reservoir technology, would need to be confirmed in a large population.

What is the incidence of intracranial bleeding in patients with mild traumatic brain injury? A retrospective study in 3088 Canadian CT head rule patients

OBJECTIVE Only limited data exists in terms of the incidence of intracranial bleeding (ICB) in patients with mild traumatic brain injury (MTBI). METHODS We retrospectively identified 3088 patients (mean age 41 range (7-99) years) presenting with isolated MTBI and GCS 14-15 at our Emergency Department who had undergone cranial CT (CCT) between 2002 and 2011. Indication for CCT was according to the "Canadian CT head rules." Patients with ICB were either submitted for neurosurgical treatment or kept under surveillance for at least 24 hours. Pearson's correlation coefficient was used to correlate the incidence of ICB with age, gender, or intake of coumarins, platelet aggregation inhibitors, or heparins. RESULTS 149 patients (4.8%) had ICB on CCT. No patient with ICB died or deteriorated neurologically. The incidence of ICB increased with age and intake of anticoagulants without clinically relevant correlation (R = 0.11; P < 0.001; R = -0.06; P < 0.001). CONCLUSION Our data show an incidence of 4.8% for ICB after MTBI. However, neurological deterioration after MTBI seems to be rare, and the need for neurosurgical intervention is only required in selected cases. The general need for CCT in patients after MTBI is therefore questionable, and clinical surveillance may be sufficient when CCT is not available.

Correlation between subjective evaluation of symptoms and objective findings in early recurrent head and neck squamous cell carcinoma

IMPORTANCE This study addresses the value of patients' reported symptoms as markers of tumor recurrence after definitive therapy for head and neck squamous cell carcinoma. OBJECTIVE To evaluate the correlation between patients' symptoms and objective findings in the diagnosis of local and/or regional recurrences of head and neck squamous cell carcinomas in the first 2 years of follow-up. DESIGN Retrospective single-institution study of a prospectively collected database. SETTING Regional hospital. PARTICIPANTS We reviewed the clinical records of patients treated for oral cavity, oropharyngeal, laryngeal, and hypopharyngeal carcinomas between January 1, 2008, and December 31, 2009, with a minimum follow-up of 2 years. MAIN OUTCOMES AND MEASURES Correlation between symptoms and oncologic status (recurrence vs remission) in the posttreatment period. RESULTS Of the 101 patients included, 30 had recurrences. Pain, odynophagia, and dysphonia were independently correlated with recurrence (odds ratios, 16.07, 11.20, and 5.90, respectively; P < .001). New-onset symptoms had the best correlation with recurrences. Correlation was better between 6 to 12 and 18 to 21 months after therapy and in patients initially treated unimodally (P < .05). Primary stage and tumor site had no effect. CONCLUSIONS AND RELEVANCE The correlation between symptoms and oncologic status is low during substantial periods within the first 2 years of follow-up. New-onset symptoms, especially pain, odynophagia, or dysphonia, better correlate with tumor recurrence, especially in patients treated unimodally.

Recurrence due to neoplastic seeding in head and neck cancer: report of two cases and review of the literature

AIMS AND BACKGROUND Tumor progression due to seeding of tumor cells after definitive treatment for squamous cell carcinomas of the head and neck is an uncommon condition that can considerably worsen the outcome of patients with head and neck cancer. METHODS AND STUDY DESIGN We report two cases of recurrence due to neoplastic seeding from oropharyngeal and oral cancer, respectively. We performed a literature review with MEDLINE as the main search engine. RESULTS Seeding was found to occur most often in tracheotomy scars and gastrostomy sites. The oral cavity, hypopharynx and oropharynx were the primary sites in most cases, and advanced tumor stage seemed to be a risk factor for seeding. Treatment options include salvage surgery, which requires thorough resections, radiotherapy when possible, and palliative management. The prognosis of such events is poor. CONCLUSION Although neoplastic seeding is a well-known phenomenon in cancer surgery, many questions remain unanswered, especially regarding preventive measures and management strategies.