Inverse filtering and principal component analysis techniques for speech dereverberation

In this work, we present a single channel approach for early and late reverberation suppression. This approach can be decomposed into two stages. The first stage employs the inverse filter to augment the signal-to-reverberant energy ratio. The second stage uses the kernel PCA algorithm to enhance the obtained dereverberant signal. It consists in extracting the main non-linear features from the speech signal after inverse filtering. Our approach appears to be efficient mainly in far field conditions and in highly reverberant environments

Electroglottographic Measures Based on GCI and GOI Detection Using Multiscale Product

This paper deals with glottal parameter estimation such as local pitch and open quotient from electroglottographic signal (EGG). This estimation is based on glottal closing instants and glottal opening instants determined by a multi-scale product of this signal. Wavelet transform of EGG signal is made with a quadratic spline function. Wavelet coefficients calculated on different dyadic scales, show modulus maxima at localized discontinuities of EGG signal. The detected maxima and minima correspond to the glottal opening and closing instants called GOIs and GCIs. To improve the estimate precision, we operate the multi-scale product of wavelet transform coefficients of three successive dyadic scales. This processing enhances edge detection. A Multi-scale product is a nonlinear combination of successive scales; it reduces noise and spurious peaks. We apply cubic root amplitude on the product to improve the representation of weak amplitudes. The method has a good representation of GCI and a best detection of GOI. The method was tested on the Keele University database; it is effective and robust in multiple cases even for a typical signal showing undetermined GOIs and multiple peaks at GCIs. Finally precise measurement of these instants allows accurate estimation of prosodic parameters as local pitch and open quotient

Chemical composition, antioxidant and antibacterial activities of Brocchia Cinerea from South-East of Morocco

The essential oil of wild-growing medicinal specie Brocchia cinerea from oasis of Tata (Southeast of Morocco) was studied for chemical composition, antioxydant and antibacterial activities. The essential oil is extracted using a clevenger distillation apparatus. The antioxidant activity was determined by measuring the free radical scavenging power of DPPH and the antibacterial activity by broth dilution method Gas chromatography-mass spectrometry (GC/MS) results revealed that the major compounds of Brocchia cinerea are Thujone, Camphor and Eucalyptol. The antibacterial test of Brochia cinerea essential oil revealed a strong antibacterial activity against Listeria innocua, Pseudomonas aeruginosa and Staphylococcus aureus (MIC<1 µL) and also a high scavenging effect of DPPH (IC50=0.080± 0.014)

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Comparison of a Commercial Enzyme-Linked Immunosorbent Assay (ELISA) with the Modified Agglutination Test (MAT) for the Detection of Antibodies against Toxoplasma gondii in a Cohort of Hunting Dogs

Toxoplasmosis is a zoonotic disease, caused by the protozoan Toxoplasma gondii, affecting most warm-blooded animals. Assessing the seroprevalence of T. gondii in different animal species gives a good estimate of the global circulation of the parasite and the risk for human infections. However, the seroprevalence of T. gondii in dogs is not studied as much as other species, despite their close contact with wildlife and humans in rural or urban environments and evidence that dogs can also be a potential source for human contaminations. A commercial enzyme-inked immunosorbent assay (ELISA) kit to detect anti-T. gondii antibodies in sera of hunting dogs potentially naturally infected, was compared to the modified agglutination test (MAT), used as the reference method. The ELISA presented a sensitivity of 76.5% (CI 95%: 60.0&ndash;87.6) and a specificity of 87.7% (CI 95%: 76.7&ndash;93.9) and a substantial agreement with the MAT for the detection of canine anti-T. gondii antibodies. Both tests can therefore be used widely for epidemiology studies on T. gondii infections in dogs. With a mean seroprevalence of T. gondii infection in hunting dogs from northern Algeria of 36.8% (CI 95%: 34.9&ndash;38.7), this study also highlights the importance of T. gondii seroprevalence studies in companion animals to assess infectious risk for human populations

Synchronous primary neoplasia in patients with oropharyngeal cancer: Impact of tumor HPV status. A GETTEC multicentric study

International audiencePatients with oropharyngeal squamous cell carcinoma (OPSCC) display a significant risk of synchronous primary neoplasia (SPN) which could impact their management. The aims of this study were to evaluate the risk and distribution of SPN in OPSCC patients according to their HPV (p16) status, the predictive factors of SPN and the impact of SPN on therapeutic strategy and oncologic outcomes.Material and methods: All OPSCC patients treated from 2009 to 2014 were included in this multicentric retrospective study. Univariate analyses were conducted using Chi-2 and Fisher exact tests. For multivariate analyses, all variables associated with a p ≤ 0.10 in univariate analysis were included in logistic regression models.Results: Among the 1291 patients included in this study, 75 (5.8%) displayed a SPN which was preferentially located in the upper aerodigestive tract, lung and esophagus. Comorbidity level (p = 0.03), alcohol (p = 0.005) and tobacco (p = 0.01) consumptions, and p16 tumor status (p < 0.0001) were significant predictors of SPN. In multivariate analysis, p16+ status was significantly associated with a lower risk of SPN (OR = 0.251, IC95% [0.133;0.474]). Patients with a SPN were more frequently referred for non-curative treatment (p = 0.02). In patients treated with curative intent, there was no impact of SPN on the therapeutic strategy (surgical vs. non-surgical treatment). We observed no overall survival differences between patients with or without SPN.Conclusion: P16 tumor status is the main predictive factor of SPN in OPSCC patients. This study provides crucial results which should help adapt the initial work-up and the global management of OPSCC patients

Upfront surgery or definitive radiotherapy for p16+ oropharyngeal cancer. A GETTEC multicentric study

International audienceBackground: The aim of this study was to assess the impact of the initial therapeutic strategy on oncologic outcomes in patients with HPV-positive OPSCC.Methods: All p16-positive OPSCCs treated from 2009 to 2014 in 7 centers were retrospectively included and classified according to the therapeutic strategy: surgical strategy (surgery ± adjuvant radiotherapy and chemotherapy) vs. non-surgical strategy (definitive radiotherapy ± chemotherapy). Univariate, multivariate propensity score matching analyses were performed to compare overall (OS), disease-specific (DSS) and recurrence-free survival (RFS).Results: 382 patients were included (surgical group: 144; non-surgical group: 238). Five-year OS, DSS and RFS were 89.2, 96.8 and 83.9% in the surgical group and 84.2, 87.1 and 70.4% in the non-surgical group, respectively. These differences were statistically significant for DSS and RFS after multivariate analysis, but only for RFS after propensity score matching analysis.Conclusion: In p16+ OPSCC patients, upfront surgery results in higher RFS than definitive radiotherapy ± chemotherapy but does not impact OS

Metachronous second primary neoplasia in oropharyngeal cancer patients: Impact of tumor HPV status. A GETTEC multicentric study

International audienceIntroduction: Patients with oropharyngeal squamous cell carcinoma (OPSCC) display a significant risk to develop a metachronous second primary neoplasia (MSPN). HPV and non-HPV-related OPSCC are 2 distinct entities with biological, clinical and prognostic differences. The aims of our study were to analyze the impact of tumor HPV status and other relevant clinical factors, such as tobacco and/or alcohol (T/A) consumption, on the risk and distribution of MSPN in OPSCC patients and to assess the impact of MSPN on patient survival.Material and methods: All OPSCC patients treated from 2009 to 2014 were included in this multicentric retrospective study. P16 immunohistochemical expression was used as a surrogate maker of tumor HPV status. The impact of tumor p16 status on the risk of MSPN was assessed in uni- and multivariate analyses. Overall survival (OS) was determined by Kaplan-Meier analysis.Results: Among the 1291 patients included in this study, 138 (10.7%) displayed a MSPN which was preferentially located in the head and neck area (H&N), lung and esophagus. Multivariate analyses showed that p16- tumor status (p = 0.003), T/A consumption (p = 0.005) and soft palate tumor site (p = 0.009) were significantly associated with a higher risk of MSPN. We found no impact of p16 tumor status on the median time between index OPSCC diagnosis and MSPN development, but a higher proportion of MSPN arising outside the H&N, lung and esophagus was found in p16 + than in p16- patients. MSPN development had an unfavorable impact (p = 0.04) on OS only in the p16 + patient group.Conclusion: P16 tumor status and T/A consumption were the main predictive factors of MSPN in OPSCC patients. This study provides crucial results with a view to tailoring global management and follow-up of OPSCC patients