Howling and Entrainment in Hearing Aids: A Review

This review focuses on howling and entrainment artifacts in digital hearing aids. The howling may occur (especially at high gains), essentially due to the close proximity of the input microphone and the output loudspeaker. The entrainment, on the other hand, occurs when the input to the hearing aids is periodic, for example, music signals or alarm signals with strong tonal characteristics. We give details on methods for howling avoidance, which are mainly based on adaptive filtering-based acoustic feedback cancellation. We also give an overview of many recent works on entrainment in hearing aids. Finally, we remark that efficient acoustic feedback cancellation scheme which can avoid howling, can also well manage the entrainment artifact

A framework for automatic heart sound analysis without segmentation

<p>Abstract</p> <p>Background</p> <p>A new framework for heart sound analysis is proposed. One of the most difficult processes in heart sound analysis is segmentation, due to interference form murmurs.</p> <p>Method</p> <p>Equal number of cardiac cycles were extracted from heart sounds with different heart rates using information from envelopes of autocorrelation functions without the need to label individual fundamental heart sounds (FHS). The complete method consists of envelope detection, calculation of cardiac cycle lengths using auto-correlation of envelope signals, features extraction using discrete wavelet transform, principal component analysis, and classification using neural network bagging predictors.</p> <p>Result</p> <p>The proposed method was tested on a set of heart sounds obtained from several on-line databases and recorded with an electronic stethoscope. Geometric mean was used as performance index. Average classification performance using ten-fold cross-validation was 0.92 for noise free case, 0.90 under white noise with 10 dB signal-to-noise ratio (SNR), and 0.90 under impulse noise up to 0.3 s duration.</p> <p>Conclusion</p> <p>The proposed method showed promising results and high noise robustness to a wide range of heart sounds. However, more tests are needed to address any bias that may have been introduced by different sources of heart sounds in the current training set, and to concretely validate the method. Further work include building a new training set recorded from actual patients, then further evaluate the method based on this new training set.</p

Clinical Significance of Serum Soluble T Cell Regulatory Molecules in Clear Cell Renal Cell Carcinoma

To clarify the role of serum soluble T cell regulatory molecules in clear cell renal cell carcinoma (CCRCC), we measured the serum levels of soluble interleukin-2 receptor (sIL-2R), soluble B7-H3 (sB7-H3), and soluble cytotoxic T lymphocyte associated antigen-4 (sCTLA-4) in 70 CCRCC patients and 35 healthy controls. We investigated correlations between the serum levels of these soluble T cell regulatory molecules and the pathological grade, clinical stage, and prognosis of CCRCC. We also assessed the relations among each of these soluble molecules. As a result, the serum level of sIL-2R was significantly higher in CCRCC patients than in healthy controls ( &lt; 0.05). In addition, elevation of serum sIL-2R was significantly correlated with the clinical stage ( &lt; 0.001), and the survival of patients with high sIL-2R levels was shorter than that of patients with low sIL-2R levels ( &lt; 0.05). Furthermore, the serum level of sB7-H3 was also significantly correlated with the clinical stage ( &lt; 0.05), while the sIL-2R and sB7-H3 levels showed a positive correlation with each other ( = 0.550, &lt; 0.0001). These results indicate that the serum level of sIL-2R reflects tumor progression in CCRCC patients. In addition, the possibility was suggested that the IL-2/IL-2R and B7-H3 pathways may be involved in the progression of CCRCC

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Fast and Accurate Generalized Harmonic Analysis Using Newton's Method

A fast and accurate method for Generalized Harmonic Analysis (GHA) is proposed. The proposed method estimates the parameters of a sinusoid and subtracts it from a target signal one by one. The frequency of the sinusoid is estimated around a peak of Fourier spectrum using Newton's method, which is much faster than search methods. The amplitude and the phase are estimated to minimize the squared sum of the residue after extraction of estimated sinusoids from the target signal. A method to improve the accuracy of sinudoidal parameters using multi-dimensional Newton's method is also proposed. This method is applied to the extracted sinusoidal parameters and minimizes the partial derivative vector of the squared error. Audio signals are analyzed by the proposed methods, which confirms the accuracy compared to the previous method.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Signal Processing Theory and Methods II (7 October 2009)