Another Kind of Knowledge: Aristotle's Phronêsis from an Epistemological Point of View

In my thesis, I defend the idea that Aristotle's notion of phronêsis (practical wisdom) is best understood as a kind of practical knowledge. I interpret phronêsis as the knowledge we display when we make the correct decision to act. In a particular situation that demands a specific response, we have practical knowledge of what to do when we make the best decision possible. This interpretation of phronêsis involves that it is possible to evaluate our decisions epistemically, that is, to evaluate whether we really know what to do or not. Aristotle provides a tool for the evaluation of our decisions, which is a definite kind of argument and which the tradition has called the 'practical syllogism'. The practical syllogism stands as the explanation of our decisions or actions. We invoke it when we want to explain or justify why we act as we do. My claim is that the components of the practical syllogism enable one to evaluate not only the moral character of our actions, but also the epistemic strength of our decisions. Correspondingly, a decision is morally right, i.e. virtuous, if the agent considers the right moral principle to apply, and if he is aware of the relevant circumstances of the situation (moral evaluation). Moreover, a decision displays practical knowledge if the agent meets three conditions (epistemic evaluation): he must desire the moral principle for its own sake; he must have experience in spotting the relevant circumstances of the situation; and he must be able to closely connect these circumstances with the moral principle. This interpretation of phronêsis differs from other more traditional interpretations in the emphasis it puts on phronêsis as knowledge. Other interpretations focus more on the moral dimension on phronêsis, without taking its epistemic value seriously. By contrast, I raise seriously the question of what it takes to genuinely know what one should do in a particular situation. -- Dans ma thèse, je défends l'idée que la notion aristotélicienne de phronêsis (sagesse pratique) doit être interprétée comme connaissance pratique. Je comprends la phronêsis comme étant la connaissance que nous avons lorsque nous prenons une bonne décision. Dans une situation particulière qui demande une réponse précise, nous avons une connaissance pratique lorsque nous prenons la meilleure décision possible. Cette interprétation de la phronêsis implique qu'il est possible d'évaluer nos décisions de manière épistémique, c'est-à-dire, d'évaluer si nous savons vraiment ce qu'il faut faire ou non. Ma position est qu'Aristote fournit un outil pour évaluer épistémiquement nos décisions, qui consiste en un certain type d'argument et que la tradition a appelé le 'syllogisme pratique'. Le syllogisme pratique correspond à l'explication de nos décisions ou de nos actions. Nous invoquons un syllogisme pratique lorsque nous voulons expliquer ou justifier pourquoi nous agissons comme nous le faisons. Les éléments du syllogisme pratique permettent d'évaluer non seulement le caractère moral de nos actions, mais aussi la force épistémique de nos décisions. Par conséquent, une décision est moralement correcte, i.e. vertueuse, si l'agent considère le bon principe moral, et s'il est attentif aux circonstances pertinentes de la situation (évaluation morale). En outre, une décision inclut la connaissance pratique si l'agent remplit trois conditions (évaluation épistémique) : il doit désirer le principe moral pour lui-même, il doit avoir de l'expérience pour déceler les circonstances pertinentes, et il doit pouvoir lier intimement ces circonstances avec le principe moral. Cette interprétation de la phronêsis diffère d'autres interprétations plus traditionnelles par l'emphase mise sur la phronêsis en tant que connaissance. D'autres interprétations se concentrent plus sur la dimension morale de la phronêsis, sans se préoccuper sérieusement de sa valeur épistémique. Au contraire, je pose sérieusement la question des conditions nécessaires pour réellement savoir ce qu'il faut faire dans une situation donnée.

Rockfall susceptibility assessment and remote geological mapping with LiDAR point clouds

Characterizing the geological features and structures in three dimensions over inaccessible rock cliffs is needed to assess natural hazards such as rockfalls and rockslides and also to perform investigations aimed at mapping geological contacts and building stratigraphy and fold models. Indeed, the detailed 3D data, such as LiDAR point clouds, allow to study accurately the hazard processes and the structure of geologic features, in particular in vertical and overhanging rock slopes. Thus, 3D geological models have a great potential of being applied to a wide range of geological investigations both in research and applied geology projects, such as mines, tunnels and reservoirs. Recent development of ground-based remote sensing techniques (LiDAR, photogrammetry and multispectral / hyperspectral images) are revolutionizing the acquisition of morphological and geological information. As a consequence, there is a great potential for improving the modeling of geological bodies as well as failure mechanisms and stability conditions by integrating detailed remote data. During the past ten years several large rockfall events occurred along important transportation corridors where millions of people travel every year (Switzerland: Gotthard motorway and railway; Canada: Sea to sky highway between Vancouver and Whistler). These events show that there is still a lack of knowledge concerning the detection of potential rockfalls, making mountain residential settlements and roads highly risky. It is necessary to understand the main factors that destabilize rocky outcrops even if inventories are lacking and if no clear morphological evidences of rockfall activity are observed. In order to increase the possibilities of forecasting potential future landslides, it is crucial to understand the evolution of rock slope stability. Defining the areas theoretically most prone to rockfalls can be particularly useful to simulate trajectory profiles and to generate hazard maps, which are the basis for land use planning in mountainous regions. The most important questions to address in order to assess rockfall hazard are: Where are the most probable sources for future rockfalls located? What are the frequencies of occurrence of these rockfalls? I characterized the fracturing patterns in the field and with LiDAR point clouds. Afterwards, I developed a model to compute the failure mechanisms on terrestrial point clouds in order to assess the susceptibility to rockfalls at the cliff scale. Similar procedures were already available to evaluate the susceptibility to rockfalls based on aerial digital elevation models. This new model gives the possibility to detect the most susceptible rockfall sources with unprecented detail in the vertical and overhanging areas. The results of the computation of the most probable rockfall source areas in granitic cliffs of Yosemite Valley and Mont-Blanc massif were then compared to the inventoried rockfall events to validate the calculation methods. Yosemite Valley was chosen as a test area because it has a particularly strong rockfall activity (about one rockfall every week) which leads to a high rockfall hazard. The west face of the Dru was also chosen for the relevant rockfall activity and especially because it was affected by some of the largest rockfalls that occurred in the Alps during the last 10 years. Moreover, both areas were suitable because of their huge vertical and overhanging cliffs that are difficult to study with classical methods. Limit equilibrium models have been applied to several case studies to evaluate the effects of different parameters on the stability of rockslope areas. The impact of the degradation of rockbridges on the stability of large compartments in the west face of the Dru was assessed using finite element modeling. In particular I conducted a back-analysis of the large rockfall event of 2005 (265'000 m3) by integrating field observations of joint conditions, characteristics of fracturing pattern and results of geomechanical tests on the intact rock. These analyses improved our understanding of the factors that influence the stability of rock compartments and were used to define the most probable future rockfall volumes at the Dru. Terrestrial laser scanning point clouds were also successfully employed to perform geological mapping in 3D, using the intensity of the backscattered signal. Another technique to obtain vertical geological maps is combining triangulated TLS mesh with 2D geological maps. At El Capitan (Yosemite Valley) we built a georeferenced vertical map of the main plutonio rocks that was used to investigate the reasons for preferential rockwall retreat rate. Additional efforts to characterize the erosion rate were made at Monte Generoso (Ticino, southern Switzerland) where I attempted to improve the estimation of long term erosion by taking into account also the volumes of the unstable rock compartments. Eventually, the following points summarize the main out puts of my research: The new model to compute the failure mechanisms and the rockfall susceptibility with 3D point clouds allows to define accurately the most probable rockfall source areas at the cliff scale. The analysis of the rockbridges at the Dru shows the potential of integrating detailed measurements of the fractures in geomechanical models of rockmass stability. The correction of the LiDAR intensity signal gives the possibility to classify a point cloud according to the rock type and then use this information to model complex geologic structures. The integration of these results, on rockmass fracturing and composition, with existing methods can improve rockfall hazard assessments and enhance the interpretation of the evolution of steep rockslopes. -- La caractérisation de la géologie en 3D pour des parois rocheuses inaccessibles est une étape nécessaire pour évaluer les dangers naturels tels que chutes de blocs et glissements rocheux, mais aussi pour réaliser des modèles stratigraphiques ou de structures plissées. Les modèles géologiques 3D ont un grand potentiel pour être appliqués dans une vaste gamme de travaux géologiques dans le domaine de la recherche, mais aussi dans des projets appliqués comme les mines, les tunnels ou les réservoirs. Les développements récents des outils de télédétection terrestre (LiDAR, photogrammétrie et imagerie multispectrale / hyperspectrale) sont en train de révolutionner l'acquisition d'informations géomorphologiques et géologiques. Par conséquence, il y a un grand potentiel d'amélioration pour la modélisation d'objets géologiques, ainsi que des mécanismes de rupture et des conditions de stabilité, en intégrant des données détaillées acquises à distance. Pour augmenter les possibilités de prévoir les éboulements futurs, il est fondamental de comprendre l'évolution actuelle de la stabilité des parois rocheuses. Définir les zones qui sont théoriquement plus propices aux chutes de blocs peut être très utile pour simuler les trajectoires de propagation des blocs et pour réaliser des cartes de danger, qui constituent la base de l'aménagement du territoire dans les régions de montagne. Les questions plus importantes à résoudre pour estimer le danger de chutes de blocs sont : Où se situent les sources plus probables pour les chutes de blocs et éboulement futurs ? Avec quelle fréquence vont se produire ces événements ? Donc, j'ai caractérisé les réseaux de fractures sur le terrain et avec des nuages de points LiDAR. Ensuite, j'ai développé un modèle pour calculer les mécanismes de rupture directement sur les nuages de points pour pouvoir évaluer la susceptibilité au déclenchement de chutes de blocs à l'échelle de la paroi. Les zones sources de chutes de blocs les plus probables dans les parois granitiques de la vallée de Yosemite et du massif du Mont-Blanc ont été calculées et ensuite comparés aux inventaires des événements pour vérifier les méthodes. Des modèles d'équilibre limite ont été appliqués à plusieurs cas d'études pour évaluer les effets de différents paramètres sur la stabilité des parois. L'impact de la dégradation des ponts rocheux sur la stabilité de grands compartiments de roche dans la paroi ouest du Petit Dru a été évalué en utilisant la modélisation par éléments finis. En particulier j'ai analysé le grand éboulement de 2005 (265'000 m3), qui a emporté l'entier du pilier sud-ouest. Dans le modèle j'ai intégré des observations des conditions des joints, les caractéristiques du réseau de fractures et les résultats de tests géoméchaniques sur la roche intacte. Ces analyses ont amélioré l'estimation des paramètres qui influencent la stabilité des compartiments rocheux et ont servi pour définir des volumes probables pour des éboulements futurs. Les nuages de points obtenus avec le scanner laser terrestre ont été utilisés avec succès aussi pour produire des cartes géologiques en 3D, en utilisant l'intensité du signal réfléchi. Une autre technique pour obtenir des cartes géologiques des zones verticales consiste à combiner un maillage LiDAR avec une carte géologique en 2D. A El Capitan (Yosemite Valley) nous avons pu géoréferencer une carte verticale des principales roches plutoniques que j'ai utilisé ensuite pour étudier les raisons d'une érosion préférentielle de certaines zones de la paroi. D'autres efforts pour quantifier le taux d'érosion ont été effectués au Monte Generoso (Ticino, Suisse) où j'ai essayé d'améliorer l'estimation de l'érosion au long terme en prenant en compte les volumes des compartiments rocheux instables. L'intégration de ces résultats, sur la fracturation et la composition de l'amas rocheux, avec les méthodes existantes permet d'améliorer la prise en compte de l'aléa chute de pierres et éboulements et augmente les possibilités d'interprétation de l'évolution des parois rocheuses.

Rockfall detection from LIDAR point clouds: A clustering approach using R

The analysis of rockfall characteristics and spatial distribution is fundamental to understand and model the main factors that predispose to failure. In our study we analysed LiDAR point clouds aiming to: (1) detect and characterise single rockfalls; (2) investigate their spatial distribution. To this end, different cluster algorithms were applied: 1a) Nearest Neighbour Clutter Removal (NNCR) in combination with the Expectation?Maximization (EM) in order to separate feature points from clutter; 1b) a density based algorithm (DBSCAN) was applied to isolate the single clusters (i.e. the rockfall events); 2) finally we computed the Ripley's K-function to investigate the global spatial pattern of the extracted rockfalls. The method allowed proper identification and characterization of more than 600 rockfalls occurred on a cliff located in Puigcercos (Catalonia, Spain) during a time span of six months. The spatial distribution of these events proved that rockfall were clustered distributed at a welldefined distance-range. Computations were carried out using R free software for statistical computing and graphics. The understanding of the spatial distribution of precursory rockfalls may shed light on the forecasting of future failures.

Cigarette électronique : le point en 2015 [Electronic cigarette: what do we know in 2015?].

La cigarette électronique produit de la vapeur à inhaler contenant du propylène-glycol, des arômes et de la nicotine libérée rapidement. 6,7% de la population suisse, surtout des fumeurs, ont essayé la cigarette électronique et 0,1% l'utilise quotidiennement. Malgré l'incertitude due au bas niveau de preuves, la cigarette électronique pourrait être efficace pour cesser ou réduire le tabagisme. La sécurité de la cigarette électronique est démontrée à court terme mais pas à long terme ; sa toxicité semble très inférieure à celle du tabac. Les non-fumeurs et les jeunes utilisent peu la cigarette électronique qui ne semble pas les amener au tabagisme. Les mesures de santé publique recommandées sont la régulation du produit avec contrôle de la qualité ainsi que l'interdiction d'usage dans les lieux publics, de publicité et de vente aux mineurs. Electronic cigarettes are devices producing vapour containing propylene-glycol, flavourings and quickly delivered nicotine. 6.7% of the Swiss population, mainly smokers, experimented the electronic cigarette while 0.1% use it daily. Despite uncertainty due to the low level of evidence, electronic cigarettes might be effective for smoking cessation and reduction. The safety of electronic cigarettes is demonstrated at short-term but not at long-term; however its eventual toxicity is likely to be much lower than tobacco. Use of electronic cigarettes by non-smokers and youth who do not smoke is low and seems unlikely to lead them to tobacco use. Recommended public health measures include product regulation with quality control, ban in public places, prohibition of advertising and sales to minors.

An inhibitor of HIV-1 protease modulates constitutive eIF2α dephosphorylation to trigger a specific integrated stress response.

Inhibitors of the HIV aspartyl protease [HIV protease inhibitors (HIV-PIs)] are the cornerstone of treatment for HIV. Beyond their well-defined antiretroviral activity, these drugs have additional effects that modulate cell viability and homeostasis. However, little is known about the virus-independent pathways engaged by these molecules. Here we show that the HIV-PI Nelfinavir decreases translation rates and promotes a transcriptional program characteristic of the integrated stress response (ISR). Mice treated with Nelfinavir display hallmarks of this stress response in the liver, including α subunit of translation initiation factor 2 (eIF2α) phosphorylation, activating transcription factor-4 (ATF4) induction, and increased expression of known downstream targets. Mechanistically, Nelfinavir-mediated ISR bypassed direct activation of the eIF2α stress kinases and instead relied on the inhibition of the constitutive eIF2α dephosphorylation and down-regulation of the phophatase cofactor CReP (Constitutive Repressor of eIF2α Phosphorylation; also known as PPP1R15B). These findings demonstrate that the modulation of eIF2α-specific phosphatase cofactor activity can be a rheostat of cellular homeostasis that initiates a functional ISR and suggest that the HIV-PIs could be repositioned as therapeutics in human diseases to modulate translation rates and stress responses.

Tabacologie: mise au point 2015 [Smoking cessation: update 2015].

La prévalence mondiale du tabagisme est environ cinq fois plus importante chez les hommes que chez les femmes, toutefois cet écart tend à s'égaliser. En ce qui concerne les conséquences sur la santé du tabagisme, les femmes semblent plus susceptibles que les hommes. Elles sont notamment plus à risque de présenter certains cancers pulmonaires ou de décéder de maladies cardiovasculaires. Si les hommes sont moins enclins à demander de l'aide pour arrêter de fumer, les femmes quant à elles ont moins de succès dans leurs tentatives d'arrêt et les traitements semblent moins efficaces chez ces dernières. Des interventions d'aide à l'arrêt et des mesures de prévention du tabagisme adaptées aux spécificités de genre ont le potentiel d'améliorer la prise en charge des fumeurs et de diminuer les disparités de genre en santé. Smoking remains a major public health problem in Switzerland and is responsible for about 9000 deaths annually. In 2013, a quarter of the Swiss population (15 and over) were smokers and more than half of them wanted to quit smoking. This article provides an update of Swiss clinical practice guidelines published in 2011 and covers several new features, including views regarding smoking reduction, gradual quitting, use of nicotine replacement therapy for a short period prior to quitting, nicotine mouth spray marketing and the reimbursement of varenicline and bupropion treatments (under certain conditions) by basic health insurance. An algorithm summarizes the different stages of management of patients who smoke.

L'année 2014 mise en perspective par les internistes hospitaliers [What is new in 2014 for the specialist in hospital internal medicine? The point of view of university hospital chief residents].

The year 2014 was rich in significant advances in all areas of internal medicine. Many of them have an impact on our daily practice and on the way we manage one problem or another. From the use of the ultrasound for the diagnosis of pneumonia to the choice of the site of venous access and the type of line, and the increasing complexity of choosing an oral anticoagulant agent, this selection offers to the readers a brief overview of the major advances. The chief residents in the Service of internal medicine of the Lausanne University hospital are pleased to share their readings.

Le point sur la pratique infirmière avancée [Update on advanced practice nursing].

NlmCategory="UNASSIGNED">We report outcomes of a clinical audit examining criteria used in clinical practice to rationalize endotracheal tube (ETT) suction, and the extent these matched criteria in the Endotracheal Suction Assessment Tool(ESAT)©. A retrospective audit of patient notes (N = 292) and analyses of criteria documented by pediatric intensive care nurses to rationalize ETT suction were undertaken. The median number of documented respiratory and ventilation status criteria per ETT suction event that matched the ESAT© criteria was 2 [Interquartile Range (IQR) 1-6]. All criteria listed within the ESAT© were documented within the reviewed notes. A direct link was established between criteria used for current clinical practice of ETT suction and the ESAT©. The ESAT©, therefore, reflects documented clinical decision making and could be used as both a clinical and educational guide for inexperienced pediatric critical care nurses. Modification to the ESAT© requires "preparation for extubation" to be added.

The Vitamin A Derivative All-Trans Retinoic Acid Repairs Amyloid-β-Induced Double-Strand Breaks in Neural Cells and in the Murine Neocortex.

The amyloid-β peptide or Aβ is the key player in the amyloid-cascade hypothesis of Alzheimer's disease. Aβ appears to trigger cell death but also production of double-strand breaks (DSBs) in aging and Alzheimer's disease. All-trans retinoic acid (RA), a derivative of vitamin A, was already known for its neuroprotective effects against the amyloid cascade. It diminishes, for instance, the production of Aβ peptides and their oligomerisation. In the present work we investigated the possible implication of RA receptor (RAR) in repair of Aβ-induced DSBs. We demonstrated that RA, as well as RAR agonist Am80, but not AGN 193109 antagonist, repair Aβ-induced DSBs in SH-SY5Y cells and an astrocytic cell line as well as in the murine cortical tissue of young and aged mice. The nonhomologous end joining pathway and the Ataxia Telangiectasia Mutated kinase were shown to be involved in RA-mediated DSBs repair in the SH-SY5Y cells. Our data suggest that RA, besides increasing cell viability in the cortex of young and even of aged mice, might also result in targeted DNA repair of genes important for cell or synaptic maintenance. This phenomenon would remain functional up to a point when Aβ increase and RA decrease probably lead to a pathological state.