Statistics of the interaural parameters for dichotic tones in diotic noise (N0SψN_0 S_\psi)

Stimuli consisting of an interaurally phase-shifted tone in diotic noise -- often referred to as $N_0 S_\psi$ -- are commonly used in the field of binaural hearing. As a consequence of mixing diotic noise with a dichotic tone, this type of stimulus contains random fluctuations in both interaural phase- and level-difference. This study reports the joint probability density functions of the two interaural differences as a function of amplitude and interaural phase of the tone. Furthermore, a second joint probability density function for interaural phase differences and the instantaneous power of the stimulus is derived

A hemispheric two-channel code accounts for binaural unmasking in humans

The ability to localize sound sources relies on differences between the signals at the two ears. These differences are also the basis for binaural unmasking, an improvement in detecting or understanding a sound masked by sources from other locations. The neurocomputational operation that underlies binaural unmasking is still a matter of debate. Current models rely on the cross-correlation function of the signals at the two ears, the neuronal substrate of which has been observed in the barn owl but not in mammals. This disagreement lead to the formulation of an alternative coding mechanism where interaural differences are encoded using the neuronal activity within two hemispheric channels. This mechanism agrees with mammalian physiology but has not yet been shown to account for binaural unmasking in humans. This study introduces a new mathematical formulation for the two-channel model, which is then used to explain the outcome of an extensive library of psychoacoustic experiments

Integrated multipoint-laser endoscopic airway measurements by transoral approach

Objectives: Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope. Methods: The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements. Results: The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ± 2.53%. A Spearman correlation coefficient of 0.95

Imaging visually-evoked cortical activity

This work will significantly inform our understanding of \u27neural plasticity\u27, the ability of the brain to respond and reorganize to environmental changes or following an injury or disorder. It is also our hope that the results of this program will inform the design of devices to restore hearing - it might enable tuning of those devices to restore sensory representations in the brain in a patient-specific manner. We believe this will significantly reduce the impact of cognitive disorders that arise as a result of abnormal perception both in children and in older adults.https://ir.lib.uwo.ca/brainscanprojectsummaries/1003/thumbnail.jp

Repression of anti-proliferative factor Tob1 in osteoarthritic cartilage

Osteoarthritis is the most common degenerative disorder of the modern world. However, many basic cellular features and molecular processes of the disease are poorly understood. In the present study we used oligonucleotide-based microarray analysis of genes of known or assumed relevance to the cellular phenotype to screen for relevant differences in gene expression between normal and osteoarthritic chondrocytes. Custom made oligonucleotide DNA arrays were used to screen for differentially expressed genes in normal (n = 9) and osteoarthritic (n = 10) cartilage samples. Real-time polymerase chain reaction (PCR) with gene-specific primers was used for quantification. Primary human adult articular chondrocytes and chondrosarcoma cell line HCS-2/8 were used to study changes in gene expression levels after stimulation with interleukin-1β and bone morphogenetic protein, as well as the dependence on cell differentiation. In situ hybridization with a gene-specific probe was applied to detect mRNA expression levels in fetal growth plate cartilage. Overall, more than 200 significantly regulated genes were detected between normal and osteoarthritic cartilage (P < 0.01). One of the significantly repressed genes, Tob1, encodes a protein belonging to a family involved in silencing cells in terms of proliferation and functional activity. The repression of Tob1 was confirmed by quantitative PCR and correlated to markers of chondrocyte activity and proliferation in vivo. Tob1 expression was also detected at a decreased level in isolated chondrocytes and in the chondrosarcoma cell line HCS-2/8. Again, in these cells it was negatively correlated with proliferative activity and positively with cellular differentiation. Altogether, the downregulation of the expression of Tob1 in osteoarthritic chondrocytes might be an important aspect of the cellular processes taking place during osteoarthritic cartilage degeneration. Activation, the reinitiation of proliferative activity and the loss of a stable phenotype are three major changes in osteoarthritic chondrocytes that are highly significantly correlated with the repression of Tob1 expression

An interaural electrode pairing clinical research system for binaural cochlear implants

Bilateral cochlear implants (BiCIs) have succeeded in improving the spatial hearing performance of bilateral CI users, albeit with considerable variability across implantees. Limited success can be caused by an interaural mismatch of the place-of-stimulation that arises from electrode arrays being inserted at different depths in each cochlea. In comparison to subjective pairing methods such as pitch matching, one promising objective measure based on electrically evoked auditory brainstem responses (EABR), the binaural interaction component (BIC), could be used to optimize the interaural electrode pairing (IEP) in BiCIs. Matched interaural electrodes are expected to facilitate binaural functions such as binaural fusion, localization, or detection of signals in noise. An IEP system, currently under development for clinical research, is proposed. The system offers subjective and objective IEP methods for BiCI: a psychoacoustic test module for pitch ranking and interaural pulse time difference (IPTD) sensitivity, and a binaural and monaural EABR recording module to derive the BIC. Psychoacoustic and IEP measures from one implantee are presented.Peer reviewe

Both systemic and local application of Granulocyte-colony stimulating factor (G-CSF) is neuroprotective after retinal ganglion cell axotomy

<p>Abstract</p> <p>Background</p> <p>The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF) plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC) axotomy model to compare effects of local and systemic application of neuroprotective molecules.</p> <p>Results</p> <p>We found that the <it>G-CSF receptor </it>is robustly expressed by RGCs <it>in vivo </it>and <it>in vitro</it>. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs <it>in vitro</it>.</p> <p>Conclusion</p> <p>We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.</p

Umweltzone Leipzig: Messtechnische Begleitung der Einführung der Umweltzone in der Stadt Leipzig: Teil 3: Immissionssituation 2010-2013 und Wirkung der Umweltzone

Die Einführung der Umweltzone in Leipzig wird durch Messungen an Luftmessstationen wissenschaftlich begleitet. Neben den gesetzlich vorgegebenen Schadstoffen werden erstmalig Ruß und ultrafeine Partikel überwacht. Der dritte Teil der Berichterstattung dokumentiert die Ergebnisse bis 2013. Die Umweltzone bewirkte eine beschleunigte Modernisierung der Fahrzeugflotte in der Stadt. In verkehrsnaher Außenluft wurden ein deutlicher Rückgang von Ruß und ultrafeinen Partikeln und eine Stagnation von Stickoxiden nachgewiesen. Erfolgreich wurden die hochtoxischen Bestandteile im Feinstaub gemindert