0 | EPFL Graph Search

0 (zero) is a number representing an empty quantity. As a number, 0 fulfills a central role in mathematics as the additive identity of the integers, real numbers, and other algebraic structures. In place-value notation such as decimal, 0 also serves as a numerical digit to indicate that that position's power of 10 is not multiplied by anything or added to the resulting number. This concept appears to have been difficult to discover. Common names for the number 0 in English are zero, nought, naught (nɔːt), nil. In contexts where at least one adjacent digit distinguishes it from the letter O, the number is sometimes pronounced as oh or o (oʊ). Informal or slang terms for 0 include zilch and zip. Historically, ought, aught (ɔːt), and cipher have also been used. Etymology Names for the number 0 and Names for the number 0 in English The word zero came into the English language via French zéro from the Italian zero, a contraction of the Venetian zevero form of Italian zefiro via

La pollution par les microplastiques: analyse d'échantillons sédimentaires benthiques

Marine Decrey

La pollution des milieux aquatiques par les microplastiques a été démontrée dans le milieu marin mais touche également les lacs et rivières. Cependant la recherche s’est focalisée jusqu’à présent sur la pollution à la surface des eaux ou sur les plages. Récemment des premières études ont prouvés que les sédiments benthiques sont également concernés par cette pollution. Le but de ce projet est donc d’échantillonner des sédiments benthiques et de développer une méthode de traitement afin d’y extraire les microplastiques de plus de 0.3 mm. Des sédiments provenant de l’embouchure de la Venoge ainsi que de la baie de Vidy ont été prélevés à l’aide d’une benne à sédiments. Différents tests de traitement ont été effectués puis une méthode a été développée afin d’extraire les microplastiques des sédiments. Cette méthode comprend un tamisage, une dissolution de la matière organique ainsi qu’une séparation par la densité à l’aide d’une solution saturée de iodure de sodium. Elle permet d’extraire les microplastiques d’une taille supérieure à 0.3 mm de manière efficace. De plus cette méthode permet l’extraction de tous les types de plastiques, même les plus denses, mais ne nécessite pas de matériel spécifique. Les résultats montrent que la plupart des microplastiques présents dans les sédiments ont une taille inférieure à 1 mm. Il est alors fort probable que des particules de taille inférieure à 0.3 mm soient alors présentes en grande quantité.

2015

Microfluidic-based immunohistochemistry for breast cancer diagnosis: a comparative clinical study

Fabio Aimi, Saska Brajkovic, Diego Gabriel Dupouy, Martinus Gijs

Breast cancer is a highly heterogeneous disease. The efficacy of tailored therapeutic strategies relies on the precise detection of diagnostic biomarkers by immunohistochemistry (IHC). Therefore, considering the increasing incidence of breast cancer cases, a concomitantly time-efficient and accurate diagnosis is clinically highly relevant. Microfluidics is a promising innovative technology in the field of tissue diagnostic, enabling for rapid, reliable, and automated immunostaining. We previously reported the microfluidic-based HER2 (human epidermal growth factor receptor 2) detection in breast carcinomas to greatly correlate with the HER2 gene amplification level. Here, we aimed to develop a panel of microfluidic-based IHC protocols for prognostic and therapeutic markers routinely assessed for breast cancer diagnosis, namely HER2, estrogen/progesterone receptor (ER/PR), and Ki67 proliferation factor. The microfluidic IHC protocol for each marker was optimized to reach high staining quality comparable to the standard procedure, while concomitantly shortening the staining time to 16 min-excluding deparaffinization and antigen retrieval step-with a turnaround time reduction up to 7 folds. Comparison of the diagnostic score on 50 formaldehyde-fixed paraffin-embedded breast tumor resections by microfluidic versus standard staining showed high concordance (overall agreement: HER2 94%, ER 95.9%, PR 93.6%, Ki67 93.7%) and strong correlation (rho coefficient: ER 0.89, PR 0.88, Ki67 0.87; p < 0.0001) for all the analyzed markers. Importantly, HER2 genetic reflex test for all discordant cases confirmed the scores obtained by the microfluidic technique. Overall, the microfluidic-based IHC represents a clinically validated equivalent approach to the standard chromogenic staining for rapid, accurate, and automated breast cancer diagnosis.

2019

Variability of Muscle Synergies in Hand Grasps: Analysis of Intra- and Inter-Session Data

Una Pale

Background. Muscle synergy analysis is an approach to understand the neurophysiological mechanisms behind the hypothesized ability of the Central Nervous System (CNS) to reduce the dimensionality of muscle control. The muscle synergy approach is also used to evaluate motor recovery and the evolution of the patients’ motor performance both in single-session and longitudinal studies. Synergy-based assessments are subject to various sources of variability: natural trial-by-trial variability of performed movements, intrinsic characteristics of subjects that change over time (e.g., recovery, adaptation, exercise, etc.), as well as experimental factors such as different electrode positioning. These sources of variability need to be quantified in order to resolve challenges for the application of muscle synergies in clinical environments. The objective of this study is to analyze the stability and similarity of extracted muscle synergies under the effect of factors that may induce variability, including inter- and intra-session variability within subjects and inter-subject variability differentiation. The analysis was performed using the comprehensive, publicly available hand grasp NinaPro Database, featuring surface electromyography (EMG) measures from two EMG electrode bracelets. Methods. Intra-session, inter-session, and inter-subject synergy stability was analyzed using the following measures: variance accounted for (VAF) and number of synergies (NoS) as measures of reconstruction stability quality and cosine similarity for comparison of spatial composition of extracted synergies. Moreover, an approach based on virtual electrode repositioning was applied to shed light on the influence of electrode position on inter-session synergy similarity. Results. Inter-session synergy similarity was significantly lower with respect to intra-session similarity, both considering coefficient of variation of VAF (approximately 0.2–15% for inter vs. approximately 0.1% to 2.5% for intra, depending on NoS) and coefficient of variation of NoS (approximately 6.5–14.5% for inter vs. approximately 3–3.5% for intra, depending on VAF) as well as synergy similarity (approximately 74–77% for inter vs. approximately 88–94% for intra, depending on the selected VAF). Virtual electrode repositioning revealed that a slightly different electrode position can lower similarity of synergies from the same session and can increase similarity between sessions. Finally, the similarity of inter-subject synergies has no significant difference from the similarity of inter-session synergies (both on average approximately 84–90% depending on selected VAF). Conclusion. Synergy similarity was lower in inter-session conditions with respect to intra-session. This finding should be considered when interpreting results from multi-session assessments. Lastly, electrode positioning might play an important role in the lower similarity of synergies over different sessions.