Contributions du traitement automatique de la parole à l'étude des voyelles orales du français

International audienceLe traitement automatique de la parole peut concrètement contribuer à éclairer de nombreuses questions concernant la variabilité phonémique à l'oral. L'exploitation de grandes masses de données permet ainsi de dégager de grandes tendances, dont une interprétation plus fine repose ensuite à la fois sur un éclairage linguistique et sur un certain nombre de précautions méthodologiques. Nous allons focaliser l'étude sur la variabilité des voyelles orales en français. Des mesures de durée et de formants, à partir des grands corpus PFC et ESTER utilisés à la fois par les chercheurs en linguistique et en traitement automatique de la parole permettront d'illustrer l'impact de divers paramètres, notamment le style de parole, la position syllabique et l'origine régionale des locuteurs. Enfin la réalisation des voyelles mi-fermées antérieures sera examinée à l'aide de classification automatique de variantes dans un cadre bayésien. ABSTRACT. Automatic speech processing methods and tools can contribute to shedding light on many issues relating to phonemic variability in speech. The processing of huge amounts of speech thus allows to extract main tendencies, for which detailed interpretations then require both linguistic and methodological insights. The experimental study focuses on the variability of French oral vowels in the PFC and ESTER corpora, which are widely used both by linguists and researchers in automatic speech processing. Duration and formant measures allow to illustrate global variations depending on different parameters, which include speech style, syllable position and the speakers' regional origins. The last part addresses the phonetic realization of close-mid front vowels, using automatic classification in a Bayesian framework. MOTS-CLÉS : traitement automatique de la parole, RAP, alignement de la parole, transcription phonémique, classification, grands corpus, variation phonologique et phonétique, f0, durée, suivi de formants, voyelles moyennes, harmonie vocalique

Paraquat, diuron and atrazine for the renewal of chemical weed control in northern Cameroon

Au Nord-Cameroun, le paraquat est vulgarisé depuis 1987 et le diuron et l'atrazine depuis 1992, à la suite des recommandations de la SODECOTON et des tests réalisés par l'IRA en collaboration avec le CIRAD. Le paraquat montre une efficacité importante et rapide. Pour limiter les risques de toxicité et optimiser ce traitement, il est conseillé de fractionner les doses en applications de 200 grammes par hectare, à réaliser de préférence le soir ou par temps couvert. Les conditions d'emploi sont diversifiées (traitement de pré-labour, traitement à forte dose en cas de végétation importante d'adventices). Le glyphosate et le glufosinate sont utilisables en traitement de pré-semis, mais leur mode d'application est plus contraignant. Dans la zone cotonnière, les conseils de désherbage comprennent aussi l'emploi du diuron à sur cotonnier et l'atrazine par hectare sur maïs. L'atrazine est un herbicide très intéressant pour lutter contre C. benghalensis dans les cultures de maïs et en traitement de pré-levée des sorghos. L'effet du diuron sur C. benghalensis est moindre, son emploi est recommandé en culture cotonnière. En outre, le diuron et l'atrazine peuvent être associés au paraquat pour lutter contre les vivaces. Les traitements de pré-levée préconisés dans cette région cotonnière se révèlent rentables grâce aux gains de temps de travail et de production obtenus. Un appui de logistique et de formation est assuré par la SODECOTO

Alternative treatments in the control of psoroptic mange in a flock of organic production sheep.

Abstract The aim of the experiment was to verify the efficacy of the treatment of psoroptic mange in a flock of Churra sheep farmed under organic production conditions, using alternative methods. One group, C Control (N=9), was given no treatment, a second group, TAH Antihomotoxic (N=10), was intramuscularly administered an antihomotoxic preparation every two days, thus receiving a total of seven injections over a two-week period. The third group, TCI Citronella (N=10), was topically administered a 1% solution of 50%essential Citronella Java oil and 50% Potassium Soap twice daily, in each milking, during the two-week period. A fourth group, TCIT Citronella+Thymol (N=10), was topically administered Citronella with 1% mother tincture of Thymol to boost the acaricide activity. The results obtained were analysed by ANOVA for scores and improvement of lesions. At the end of the experiment, TCI and TCIT showed significantly fewer lesions (P<0.05) than the control group and TAH, no differences being detected between the latter two groups. Improvement was significantly higher (P<0.05) in TCI (45%) and TCTT (48%) in comparison with the control group,which only showed 3% improvement. TAH improved by 30% (P<0.05) in comparison with the control group. There were no significant differences between TCI and TCIT. In conclusion, treatment with essential Citronella Java oil and potassium soap can be used as an alternative to conventional methods to control psoroptic mange

Impact of Human Immunodeficiency Virus Infection on the Outcome of Treatment and Survival of Tuberculosis Patients in Mwanza, Tanzania.

Little is known about the outcome of tuberculosis (TB) treatment and subsequent survival of human immunodeficiency virus (HIV) infected patients treated under routine programme conditions in a developing country. We followed a cohort of HIV-positive and HIV-negative tuberculosis patients during therapy and assessed their vital and tuberculosis status 3 years after completion of treatment in Mwanza, Tanzania. Newly diagnosed and relapse tuberculosis cases consecutively registered over a 6-month period were enrolled into an epidemiological study of TB/HIV. Treatment outcome was based on information in tuberculosis treatment registers. Patients surviving treatment were assessed 3 years later by personal interview. Cause of death was determined by verbal autopsy. Of 561 patients enrolled into the study, 505 patients alive at completion of treatment were eligible for assessment at 3 years. Except for mortality, HIV infection was not statistically associated with differing treatment outcomes. At time of follow-up, the overall mortality was 19% and was associated with HIV infection (hazard ratio [hr] 3.7, 95% confidence interval [CI] 2.6-5.2) and age 35 years and over (hr 1.5, 95% CI 1.02-2.1), but not with type of tuberculosis, gender, or initial drug resistance. By life table analysis, probability of survival at 4 years was 35% for HIV-positive patients compared to 90% for HIV-negative patients. Although no relapse cases were diagnosed, verbal autopsy suggested equivalent low rates of relapse in both groups. These results demonstrate the effectiveness of the current approach to the treatment of tuberculosis patients regardless of HIV status. However, HIV-related mortality remains high both during and following completion of treatment, and further studies are needed to determine if this mortality might be reduced by simple interventions which are feasible in developing countries.\u

Flow diagnostics

The measurement of flow properties within fluid handling systems is of utmost importance for efficient operation and control of such systems. For single phase flow systems, extensive research has been carried out world over to diagnose the flow properties both globally and locally. Considerable advancements are being made to perfect these technologies. For multiphase flows there is still a lot of scope for technological development that needs to take place to diagnose the flow conditions accurately efficiently and effectively. In this present paper two methods are described that can be used effectively for measurement of flow properties in solid-liquid flows and gas-liquid flows. One of the methods relies on isokinetic sampling used in conjunction with impact probe for the determination of solid distribution and solid velocity in solid-liquid flows through a pipeline. The other method relies on electrical resistance method to calculate local flow velocity corresponding to the dispersed phase as well as volume fraction and interfacial area concentration

Hyperspectral images segmentation: a proposal

Hyper-Spectral Imaging (HIS) also known as chemical or spectroscopic imaging is an emerging technique that combines imaging and spectroscopy to capture both spectral and spatial information from an object. Hyperspectral images are made up of contiguous wavebands in a given spectral band. These images provide information on the chemical make-up profile of objects, thus allowing the differentiation of objects of the same colour but which possess make-up profile. Yet, whatever the application field, most of the methods devoted to HIS processing conduct data analysis without taking into account spatial information.Pixels are processed individually, as an array of spectral data without any spatial structure. Standard classification approaches are thus widely used (k-means, fuzzy-c-means hierarchical classification...). Linear modelling methods such as Partial Least Square analysis (PLS) or non linear approaches like support vector machine (SVM) are also used at different scales (remote sensing or laboratory applications). However, with the development of high resolution sensors, coupled exploitation of spectral and spatial information to process complex images, would appear to be a very relevant approach. However, few methods are proposed in the litterature. The most recent approaches can be broadly classified in two main categories. The first ones are related to a direct extension of individual pixel classification methods using just the spectral dimension (k-means, fuzzy-c-means or FCM, Support Vector Machine or SVM). Spatial dimension is integrated as an additionnal classification parameter (Markov fields with local homogeneity constrainst [5], Support Vector Machine or SVM with spectral and spatial kernels combination [2], geometrically guided fuzzy C-means [3]...). The second ones combine the two fields related to each dimension (spectral and spatial), namely chemometric and image analysis. Various strategies have been attempted. The first one is to rely on chemometrics methods (Principal Component Analysis or PCA, Independant Component Analysis or ICA, Curvilinear Component Analysis...) to reduce the spectral dimension and then to apply standard images processing technics on the resulting score images i.e. data projection on a subspace. Another approach is to extend the definition of basic image processing operators to this new dimensionality (morphological operators for example [1, 4]). However, the approaches mentioned above tend to favour only one description either directly or indirectly (spectral or spatial). The purpose of this paper is to propose a hyperspectral processing approach that strikes a better balance in the treatment of both kinds of information....Cet article présente une stratégie de segmentation d’images hyperspectrales liant de façon symétrique et conjointe les aspects spectraux et spatiaux. Pour cela, nous proposons de construire des variables latentes permettant de définir un sous-espace représentant au mieux la topologie de l’image. Dans cet article, nous limiterons cette notion de topologie à la seule appartenance aux régions. Pour ce faire, nous utilisons d’une part les notions de l’analyse discriminante (variance intra, inter) et les propriétés des algorithmes de segmentation en région liées à celles-ci. Le principe générique théorique est exposé puis décliné sous la forme d’un exemple d’implémentation optimisé utilisant un algorithme de segmentation en région type split and merge. Les résultats obtenus sur une image de synthèse puis réelle sont exposés et commentés

Outcomes and safety of concomitant nevirapine and rifampicin treatment under programme conditions in Malawi.

SETTING: Thyolo District Hospital, rural Malawi. OBJECTIVES: To report on 1) clinical, immunological and virological outcomes and 2) safety among human immunodeficiency virus (HIV) infected patients with tuberculosis (TB) who received concurrent nevirapine (NVP) and rifampicin (RMP) based treatment. DESIGN: Retrospective cohort study. METHODS: Analysis of programme data, June-December 2007. RESULTS: Of a total of 156 HIV-infected TB patients who started NVP-based antiretroviral treatment, 136 (87%) completed TB treatment successfully, 16 (10%) died and 5 (4%) were transferred out. Mean body weight and CD4 gain (adults) were respectively 4.4 kg (95%CI 3.3-5.4) and 140 cells/mm(3) (95%CI 117-162). Seventy-four per cent of patients who completed TB treatment and had a viral load performed (n = 74) had undetectable levels (<50 copies/ml), while 17 (22%) had a viral load of 50-1000 copies/ml. Hepatotoxicity was present in 2 (1.3%) patients at baseline. Two patients developed Grade 2 and one developed Grade 3 alanine transaminase enzyme elevations during TB treatment (incidence rate per 10 years of follow-up 4.2, 95%CI 1.4-13.1). There were no reported deaths linked to hepatotoxicity. CONCLUSIONS: In a rural district in Malawi, concomitant NVP and RMP treatment is associated with good TB treatment outcomes and appears safe. Further follow-up of patients would be useful to ascertain the longer-term effects of this concurrent treatment

Chlore et conductance stomatique chez le cocotier

Les effets d'une carence en chlorure sur le fonctionnement stomatique et sur l'équilibre hydrique du cocotier ont été analysés sur des plantules cultivées en hydroponie et soumises à un stress osmotique (-0,5 MPa). Les mouvements stomatiques ont été suivis au poromètre, et les mouvements d'ions associés étudiés au moyen d'une microsonde électronique. On a mis en évidence l'existence d'une navette de K@+ et Cl- des cellules subsidiaires latérales vers les cellules de garde. Ce mouvement a un double rôle à l'ouverture stomatique, puisque, simultanément, il réduit la turgescence des cellules subsidiaires latérales et augmente la turgescence des cellules de garde. Dans nos conditions, la carence en Cl@- entraîne au niveau stomatique un retard à l'ouverture d'environ 3 h en début de journée. En cas de contrainte hydrique, la carence entraîne chez le cocotier une réduction de l'ouverture stomatique et une diminution de la capacité d'osmorégulation. Les potentiels hydriques et osmotiques prennent des valeurs moins négatives aboutissant à une diminution de la turgescence foliaire. Le cocotier carencé en Cl@- a ainsi une moins bonne aptitude à tolérer les déficits hydrique

Comparison of Generic and Proprietary Sodium Stibogluconate for the Treatment of Visceral Leishmaniasis in Kenya.

OBJECTIVE: To compare the use of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis (kala-azar). METHODS: A total of 102 patients with confirmed kala-azar were treated in a mission hospital in West Pokot region, Kenya, with sodium stibogluconate (20 mg/kg/day for 30 days)--either as Pentostam (PSM) or generic sodium stibogluconate (SSG); 51 patients were allocated alternately to each treatment group. FINDINGS: There were no significant differences in baseline demographic characteristics or disease severity, or in events during treatment. There were 3 deaths in the PSM group and 1 in the SSG group; 2 patients defaulted in each group. Only 1 out of 80 test-of-cure splenic aspirates was positive for Leishmania spp.; this patient was in the SSG group. Follow-up after > or = 6 months showed that 6 out of 58 patients had relapsed, 5 in the SSG group and 1 in the PSM group. No outcome variable was significantly different between the two groups. CONCLUSION: The availability of cheaper generic sodium stibogluconate, subject to rigid quality controls, now makes it possible for the health authorities in kala-azar endemic areas to provide treatment to many more patients in Africa