Prediction of 18-month survival in patients with primary myelodysplastic syndrome. A regression model and scoring system based on the combination of chromosome findings and the Bournemouth score.

The predictive potential of six selected factors was assessed in 72 patients with primary myelodysplastic syndrome using univariate and multivariate logistic regression analysis of survival at 18 months. Factors were age (above median of 69 years), dysplastic features in the three myeloid bone marrow cell lineages, presence of chromosome defects, all metaphases abnormal, double or complex chromosome defects (C23), and a Bournemouth score of 2, 3, or 4 (B234). In the multivariate approach, B234 and C23 proved to be significantly associated with a reduction in the survival probability. The similarity of the regression coefficients associated with these two factors means that they have about the same weight. Consequently, the model was simplified by counting the number of factors (0, 1, or 2) present in each patient, thus generating a scoring system called the Lausanne-Bournemouth score (LB score). The LB score combines the well-recognized and easy-to-use Bournemouth score (B score) with the chromosome defect complexity, C23 constituting an additional indicator of patient outcome. The predicted risk of death within 18 months calculated from the model is as follows: 7.1% (confidence interval: 1.7-24.8) for patients with an LB score of 0, 60.1% (44.7-73.8) for an LB score of 1, and 96.8% (84.5-99.4) for an LB score of 2. The scoring system presented here has several interesting features. The LB score may improve the predictive value of the B score, as it is able to recognize two prognostic groups in the intermediate risk category of patients with B scores of 2 or 3. It has also the ability to identify two distinct prognostic subclasses among RAEB and possibly CMML patients. In addition to its above-described usefulness in the prognostic evaluation, the LB score may bring new insights into the understanding of evolution patterns in MDS. We used the combination of the B score and chromosome complexity to define four classes which may be considered four possible states of myelodysplasia and which describe two distinct evolutional pathways.

Simultaneous identification of multiple mammalian species from mixed forensic samples based on mtDNA control region length polymorphism

Molecular species identification in mixed or contaminated biological material has always been problematic. We developed a simple and accurate method for mammal DNA identification in mixtures, based on interspecific mitochondrial DNA control region length polymorphism. Contrary to other published methods dealing with species mixtures, our protocol requires a single universal primer pair and amplification step, and is not based on a pre-defined panel of species. This protocol has been routinely employed by our laboratory for species identification in dozens of human and animal forensic caseworks. Six representative forensic caseworks involving the specific identification of mixed animal samples are reported in this paper, in order to demonstrate the applicability and usefulness of the method.

Decoding stimulus-related information from single-trial EEG responses based on voltage topographies

Neuroimaging studies typically compare experimental conditions using average brain responses, thereby overlooking the stimulus-related information conveyed by distributed spatio-temporal patterns of single-trial responses. Here, we take advantage of this rich information at a single-trial level to decode stimulus-related signals in two event-related potential (ERP) studies. Our method models the statistical distribution of the voltage topographies with a Gaussian Mixture Model (GMM), which reduces the dataset to a number of representative voltage topographies. The degree of presence of these topographies across trials at specific latencies is then used to classify experimental conditions. We tested the algorithm using a cross-validation procedure in two independent EEG datasets. In the first ERP study, we classified left- versus right-hemifield checkerboard stimuli for upper and lower visual hemifields. In a second ERP study, when functional differences cannot be assumed, we classified initial versus repeated presentations of visual objects. With minimal a priori information, the GMM model provides neurophysiologically interpretable features - vis à vis voltage topographies - as well as dynamic information about brain function. This method can in principle be applied to any ERP dataset testing the functional relevance of specific time periods for stimulus processing, the predictability of subject's behavior and cognitive states, and the discrimination between healthy and clinical populations.

Development of bioreporter assays for the detection of bioavailability of long-chain alkanes based on the marine bacterium Alcanivorax borkumensis strain SK2.

Long-chain alkanes are a major component of crude oil and therefore potentially good indicators of hydrocarbon spills. Here we present a set of new bacterial bioreporters and assays that allow to detect long-chain alkanes. These reporters are based on the regulatory protein AlkS and the alkB1 promoter from Alcanivorax borkumensis SK2, a widespread alkane degrader in marine habitats. Escherichia coli cells with the reporter construct reacted strongly to octane in short-term (6 h) aqueous suspension assays but very slightly only to tetradecane, in line with what is expected from its low water solubility. In contrast, long-term assays (up to 5 days) with A. borkumensis bioreporters showed strong induction with tetradecane and crude oil. Gel-immobilized A. borkumensis reporter cells were used to demonstrate tetradecane and crude oil bioavailability at a distance from a source. Alcanivorax borkumensis bioreporters induced fivefold more rapid and more strongly when allowed physical contact with the oil phase in standing flask assays, suggesting a major contribution of adhered cells to the overall reporter signal. Using the flask assays we further demonstrated the effect of oleophilic nutrients and biosurfactants on oil availability and degradation by A. borkumensis. The fluorescence signal from flask assays could easily be captured with a normal digital camera, making such tests feasible to be carried out on, e.g. marine oil responder vessels in case of oil accidents.

Patterns of split sex ratio in ants have multiple evolutionary causes based on different within-colony conflicts.

Split sex ratio-a pattern where colonies within a population specialize in either male or queen production-is a widespread phenomenon in ants and other social Hymenoptera. It has often been attributed to variation in colony kin structure, which affects the degree of queen-worker conflict over optimal sex allocation. However, recent findings suggest that split sex ratio is a more diverse phenomenon, which can evolve for multiple reasons. Here, we provide an overview of the main conditions favouring split sex ratio. We show that each split sex-ratio type arises due to a different combination of factors determining colony kin structure, queen or worker control over sex ratio and the type of conflict between colony members.

Predicting the potential for lightning activity in mediterranean storms based on the WRF model dynamic and microphysical fields

A new parameter is introduced: the lightning potential index (LPI), which is a measure of the potential for charge generation and separation that leads to lightning flashes in convective thunderstorms. The LPI is calculated within the charge separation region of clouds between 0 C and 20 C, where the noninductive mechanism involving collisions of ice and graupel particles in the presence of supercooled water is most effective. As shown in several case studies using the Weather Research and Forecasting (WRF) model with explicit microphysics, the LPI is highly correlated with observed lightning. It is suggested that the LPI may be a useful parameter for predicting lightning as well as a tool for improving weather forecasting of convective storms and heavy rainfall.

Acceptance of inflammatory bowel disease treatment recommendations based on appropriateness ratings : do practicing gastroenterologists agree with experts?

BACKGROUND: Appropriateness criteria for the treatment of Crohn's disease (CD) and ulcerative colitis (UC) have been developed by experts' panels. Little is known about the acceptance of such recommendations by care providers. The aim was to explore how treatment decisions of practicing gastroenterologists differ from experts using a vignette case study and a focus group. METHODS: Seventeen clinical vignettes were drawn from clinical indications evaluated by the expert panel. A vignette case questionnaire asking for treatment options in 9-10 clinical situations was submitted to 26 practicing gastroenterologists. For each vignette case, practitioners' answers on treatments deemed appropriate were compared to panel decisions. Qualitative analysis was made based on focus group discussion to explore acceptance and divergence reasons. RESULTS: 239 clinical vignettes were completed, 98 for CD and 141 for UC. Divergence between proposed treatments and results from panels was more frequent for CD (34%) than for UC (27%). Among UC clinical vignettes, the main divergences with the panel were linked to 5-ASA failure assessment and to situations where stopping treatment was the main decision. For CD, the care provider propositions diverged with the panel in mild-to-moderate active disease, where practitioners were more prone to an accelerated step up than the panel's recommendations. CONCLUSIONS: In about one third of vignettes cases, IBD treatment propositions made by practicing gastroenterologists diverged as compared to expert recommendations. Practicing gastroenterologists may experience difficulties in applying recommendations in daily practice.

An Efficient Segmentation Method for Ultrasound Images based on a Semi-supervised Approach and Patch-based Features

Segmenting ultrasound images is a challenging problemwhere standard unsupervised segmentation methods such asthe well-known Chan-Vese method fail. We propose in thispaper an efficient segmentation method for this class ofimages. Our proposed algorithm is based on asemi-supervised approach (user labels) and the use ofimage patches as data features. We also consider thePearson distance between patches, which has been shown tobe robust w.r.t speckle noise present in ultrasoundimages. Our results on phantom and clinical data show avery high similarity agreement with the ground truthprovided by a medical expert.

Analysis of warm season thunderstorms using an object-oriented tracking method based on radar and total lightning data

Monitoring thunderstorms activity is an essential part of operational weather surveillance given their potential hazards, including lightning, hail, heavy rainfall, strong winds or even tornadoes. This study has two main objectives: firstly, the description of a methodology, based on radar and total lightning data to characterise thunderstorms in real-time; secondly, the application of this methodology to 66 thunderstorms that affected Catalonia (NE Spain) in the summer of 2006. An object-oriented tracking procedure is employed, where different observation data types generate four different types of objects (radar 1-km CAPPI reflectivity composites, radar reflectivity volumetric data, cloud-to-ground lightning data and intra-cloud lightning data). In the framework proposed, these objects are the building blocks of a higher level object, the thunderstorm. The methodology is demonstrated with a dataset of thunderstorms whose main characteristics, along the complete life cycle of the convective structures (development, maturity and dissipation), are described statistically. The development and dissipation stages present similar durations in most cases examined. On the contrary, the duration of the maturity phase is much more variable and related to the thunderstorm intensity, defined here in terms of lightning flash rate. Most of the activity of IC and CG flashes is registered in the maturity stage. In the development stage little CG flashes are observed (2% to 5%), while for the dissipation phase is possible to observe a few more CG flashes (10% to 15%). Additionally, a selection of thunderstorms is used to examine general life cycle patterns, obtained from the analysis of normalized (with respect to thunderstorm total duration and maximum value of variables considered) thunderstorm parameters. Among other findings, the study indicates that the normalized duration of the three stages of thunderstorm life cycle is similar in most thunderstorms, with the longest duration corresponding to the maturity stage (approximately 80% of the total time).

Compaction of growth media based on Sphagnum peat during one-year culturing of container seedlings

Tiivistelmä: Turvepohjaisten kasvualustojen tiivistyminen yksivuotisessa paakkutaimikasvatuksessa

Description of a tertiary swiss university hospital palliative population based on the International Classifiaction of Disease (ICD) : a retrospective pilot study

Introduction : L'équipe mobile de soins palliatifs intra hospitalière (EMSP) du Centre Hospitalier Universitaire Vaudois (CHUV) a été mise en place en 1996. Il s'agit d'une des premières équipes interdisciplinaire de consultants mise à disposition d'un hôpital tertiaire. Le CHUV est l'hôpital de proximité de la ville de Lausanne (850 lits) mais aussi un hôpital de référence pour le reste du canton. En 2007, il y a eu 38'359 patients hospitalisés au CHUV. Les facteurs d'évaluation du taux d'utilisation d'une équipe mobile de soins palliatifs consultantes sont variés et complexes. Plusieurs méthodes sont décrites dans la littérature pour tenter de répondre à cette problématique. Avant de pouvoir évaluer l'utilisation de notre équipe mobile consultante de soins palliatifs intra hospitalière, il nous est apparu nécessaire de mieux décrire et définir la population qui meurt dans notre institution. McNamara et collègues ont proposé des critères qui classifient une population palliative comme « minimale », « intermédiaire » ou « maximale ». L'objectif de cette étude est de déterminer le taux de patients décédés au CHUV sur une période de 4 mois (Γ1 février au 31 mai 2007) suivie par notre EMSP en utilisant la méthode de classification «minimal » et « maximal ». Méthode : les archives médicales du CHUV ont été analysées pour chaque patient adulte décédé pendant la période sélectionnée. Les populations « maximal » et « minimal » de ces patients ont été ensuite déterminées selon des critères basés sur les codes diagnostiques figurants sur les certificats de décès. De ces deux populations, nous avons identifié à partir de notre base de données, les patients qui ont été suivie par notre EMSP. Le CHUV utilise les mêmes codes diagnostiques (International Classification of Disease, ICD) que ceux utilisés dans la classification de McNamara. Une recherche pilote effectuée dans les archives médicales du CHUV manuellement en analysant en profondeur l'ensemble du dossier médical a révélé que la classification de la population « minimal » pouvait être biaisée notamment en raison d'une confusion entre la cause directe du décès (complication d'une maladie) et la maladie de base. Nous avons estimé le pourcentage d'erreur de codification en analysé un échantillon randomisé de patients qui remplissait les critères « minimal ». Résultats : sur un total de 294 décès, 263 (89%) remplissaient initialement les critères « maximal » et 83 (28%) les critères «minimal», l'analyse de l'échantillon randomisé de 56 dossiers de patients sur les 180 qui ne remplissaient pas les critères « minimal » ont révélé que 21 (38%) auraient dus être inclus dans la population « minimal ». L'EMSP a vu 67/263 (25.5%) de la population palliative « maximal » et 56/151 (37.1%) de la population palliative « minimal ». Conclusion : cette étude souligne l'utilité de la méthode proposée par McNamara pour déterminer la population de patients palliatifs. Cependant, notre travail illustre aussi une limite importante de l'estimation de la population « minima » en lien avec l'imprécision des causes de décès figurant sur les certificats de décès de notre institution. Nos résultats mettent aussi en lumière que l'EMSP de notre institution est clairement sous- utilisée. Nous prévoyons une étude prospective de plus large envergure utilisant la même méthodologie afin d'approfondir les résultats de cette étude pilote.