PERSONAL MOBILITY AND SELF-ORGANIZED TRANSPORT SYSTEMS: A SOLUTION TO SURVIVE?

International audienceTransport systems in major cities of southern countries usually evoke apparently archaic services with anarchic organization. These stereotypes result from a lack of understanding of these systems. Today, several metropolises of southern countries have transport services without any centralized management. Alternative solutions have appeared which are based on individual initiatives. Owing to the weak standard of living in developing countries, individual cars owners are rare. A lot of megapolis exceeds one million people without public transportation system. Furthermore, in many cases bicycle is not used. However, despite a considerable technological delay, some megacities succeed to constitute an effective urban transport network, although it is informal. We offer an analysis of these systems in order to understand their spatial, social and economical structures. We focus on spatial dynamics and temporal fluctuations, treating specifically the case of Lima. We based on survey data sensed on the field with partnership of IRD in the course of 2012. The system of urban transportation is based on short‐term profitability of the different providers operating in a market. The economical sector concerned is defined as artisanal and governed by liberal principles. For service operators, profit maximization rests on the capacity to adapt to direct demand. Therefore, competitive and complementarity relations develop. It pushes the operators to open new routes to reach unexploited markets with the aim of earn better wages. This mode of operation allows for an extended coverage of the urban area

Identification of texture parameters influencing commercial cheese matrix disintegration and lipid digestion using an in vitro static digestion model

Cheese characteristics, such as composition or textural properties, can impact the matrix degradation rate which could modulate the bioaccessibility of fatty acids during digestion. The aim of this study was to identify texture parameters influencing cheese degradation in a gastrointestinal environment. A static in vitro digestion model has been used on nine commercial cheeses: young and aged cheddar, regular and light cream cheese, parmesan, feta, camembert, mozzarella, and sliced processed cheese. At the end of gastric digestion, camembert and mozzarella presented the lowest matrix disintegration whereas aged cheddar, regular and light cream cheeses showed the highest. For all cheeses, the fatty acid release was fast during the first 30 min of duodenal digestion and slowed down afterwards. A partial least square regression revealed that springiness, cohesiveness, and hardness were negatively correlated to the rate of cheese disintegration during gastric digestion. In addition, textural parameters were not correlated with free fatty acid release. By modulating cheese texture, it could be possible to influence matrix disintegration during gastrointestinal digestion which could have an impact on lipids release

Plant functional trait effects on runoff to design herbaceous hedges for soil erosion control

International audienceVegetation controls concentrated runoff and erosion in the European loess belt by increasing hydraulic roughness and sediment retention. Studies of plant effects on runoff velocity are usually based on a taxonomical characterisation and do not consider the effects of aboveground plant functional traits in attempts to understand soil erosion by water. This trait-based plant study investigates aboveground plant functional trait effects of herbaceous hedges on the hydraulic roughness to understand soil erosion. Eight aboveground morphological traits were measured on fourteen indigenous and perennial plant species (caespitose or comprising dry biomass in winter) from north-west Europe with a high morphological variability. For each trait, density-weighted traits were calculated. The effects of traits and density-weighted traits were examined using a runoff simulator with four discharges. The leaf density and area, as well as density-weighted stem and leaf areas, stem diameter and specific leaf area were positively correlated with the hydraulic roughness. Generalised linear models defined the best combinations of traits and density-weighted traits: (1) leaf density and leaf area, (2) density-weighted leaf area and density-weighted projected stem area, and (3) density-weighted leaf area and density-weighted stem diameter. Moreover, the effects of leaf density, leaf area and density-weighted specific leaf area, varied depending on the discharge. This study is one of the first characterisation of aboveground trait effects on hydraulic roughness and highlights that vegetation with large stem density, diameter and leaf area plays a significant role in minimising soil erosion. The selection of plant species can derive from these plant trait effects to design reconstructed herbaceous hedges to minimise soil erosion

Reflexivity as a tool for medical students to identify and address gender bias in clinical practice: a qualitative study

ABSTRACT Objectives Gender bias interferes with medical care for both men and women, leading to health inequalities. Reflexivity is used in medical education to improve health provision. This study aims to understand if a reflective approach integrated in medical practice enables raising awareness of gender bias during medical school teaching. Methods We conducted this study in general ambulatory medicine in Lausanne Hospital, Switzerland with 160 Master’s students. Through group discussions and reflection questionnaires, students were asked to discuss clinical cases they encountered focusing on potential gender bias. We analyzed the data using a thematic analysis approach. Results The reflection on the clinical reasoning steps from a real case identified gender bias at each stage of the clinical case management. The analysis revealed two factors that facilitated gender reflexivity: guidance from a gender expert and peer-to-peer exchange. Conclusions Our study shows that a reflective approach integrated in medical practice enables raising awareness of gender bias during medical teaching. It provides students with a systematic method they can apply in their future clinical work, thus improving care processes and experiences towards more equitable care

Intergranular penetration of liquid gold into stainless steel

Intergranular penetration of liquid 18 K gold into a superaustenitic stainless steel, which occurs during laser welding of these two materials, has been studied using a C-ring device which can be put under tensile stresses by a screw. It is shown that liquid gold at 1000 degrees C penetrates the immersed stainless steel C-ring at grain boundaries, but only when tensile stresses are applied. Based on the thickness of the peritectic phase that forms all along the liquid crack and on the transverse gold diffusion profile in steel, penetration velocities on the order of 10 mu m s(-1) are deduced. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Une lesion cutanée persistante non cicatricielle depuis 3 ans: le pyoderma gangrenosum

Le pyoderma gangrenosum (PG) est une dermatose neutrophilique non infectieuse rare souvent méconnue. Il se présente généralement par des ulcérations cutanées inflammatoires, très douloureuses et d'évolution rapide. Il est fréquemment retrouvé dans un contexte de néoplasie, de pathologies inflammatoires digestives, rhumatologiques et/ou hématologiques. Son diagnostic est très souvent tardif après de multiples échecs thérapeutiques. Nous rapportons un cas de pyoderma gangrenosum dont le diagnostic n'a pas été criant. Un patient a été admis dans notre service pour une lésion dermatologique persistante et d'évolution défavorable malgré les débridements et l'administration d'antibiotiques. Il était suivi pour un cancer de la prostate, une hypertension artérielle et un asthme. Du fait des anomalies biologiques observées telles qu'une hyperleucocytose à polynucléaires neutrophiles avec myélémie à myélocytes et métamyélocytes, sans blastose sanguine et une anémie normochrome normocytaire, une leucémie myéloïde chronique a été évoquée chez ce patient. Elle a par la suite été infirmée devant les différents examens complémentaires non concluants. C'est ainsi que le diagnostic de PG a été évoqué et confirmé à l'examen anatomopathologique montrant un aspect histopathologique d'un tissu de granulation concordant avec un pyoderma gangrenosum et une absence de signe histologique de malignité. L'institution d'un traitement à base de corticothérapie a abouti à la guérison

Why not do away with tiered water pricing in Brussels?

In 2005, the Brussels-Capital Region switched from linear pricing to progressive pricing per person because the latter was supposed to be social and ecological. We show that poor households do not consume less water per person than rich households in Belgium and Brussels. Tiered pricing therefore does not benefit poor households and is not social. We also point out that there is no evidence that progressive pricing has encouraged Brussels residents to reduce their already low water consumption. It would therefore not be environmentally friendly either. On the other hand, progressive pricing has a number of disadvantages and leads to serious problems of equity. We therefore advocate a return to linear water pricing for all in Brussels.In 2005 is het Brussels Hoofdstedelijk Gewest overgeschakeld van een lineaire tarifering voor water naar een progressieve tarifering per persoon, omdat zo’n progressief tariefbeleid sociaal en ecologisch zou zijn. Wij tonen aan dat arme huishoudens niet minder water per persoon verbruiken dan rijke huishoudens in België en in Brussel. Een progressieve tarifering is bijgevolg niet in het voordeel van arme huishoudens en is dus niet sociaal. Ook benadrukken we dat niets erop wijst dat het progressieve tarief de Brusselaars heeft gestimuleerd om hun reeds lage waterverbruik verder te verminderen. Milieuvriendelijker is het dus evenmin. De progressieve tarifering heeft echter een aantal nadelen, met ernstige problemen op het gebied van rechtvaardigheid als gevolg. Wij pleiten er dan ook voor dat er voor alle Brusselaars opnieuw een lineair watertarief wordt gehanteerd.En 2005, la Région de Bruxelles-Capitale est passée d’une tarification linéaire de l’eau à une tarification progressive par personne, car cette dernière était supposée être sociale et écologique. Nous montrons que les ménages pauvres ne consomment pas moins d’eau par personne que les ménages riches en Belgique et à Bruxelles. La tarification progressive n’avantage donc pas les ménages pauvres et n’est pas sociale. Nous mettons également en évidence que rien n’indique que la tarification progressive ait incité les Bruxellois·es à réduire leur consommation d’eau, qui est déjà basse. Elle ne serait dès lors pas non plus écologique. Par contre, la tarification progressive comporte une série d’inconvénients et entraine de sérieux problèmes d’équité. Nous préconisons dès lors le retour à une tarification linéaire de l’eau pour tou·te·s à Bruxelles

Waarom geen einde maken aan de progressieve tarifering voor water in Brussel?

In 2005 is het Brussels Hoofdstedelijk Gewest overgeschakeld van een lineaire tarifering voor water naar een progressieve tarifering per persoon, omdat zo’n progressief tariefbeleid sociaal en ecologisch zou zijn. Wij tonen aan dat arme huishoudens niet minder water per persoon verbruiken dan rijke huishoudens in België en in Brussel. Een progressieve tarifering is bijgevolg niet in het voordeel van arme huishoudens en is dus niet sociaal. Ook benadrukken we dat niets erop wijst dat het progressieve tarief de Brusselaars heeft gestimuleerd om hun reeds lage waterverbruik verder te verminderen. Milieuvriendelijker is het dus evenmin. De progressieve tarifering heeft echter een aantal nadelen, met ernstige problemen op het gebied van rechtvaardigheid als gevolg. Wij pleiten er dan ook voor dat er voor alle Brusselaars opnieuw een lineair watertarief wordt gehanteerd.En 2005, la Région de Bruxelles-Capitale est passée d’une tarification linéaire de l’eau à une tarification progressive par personne, car cette dernière était supposée être sociale et écologique. Nous montrons que les ménages pauvres ne consomment pas moins d’eau par personne que les ménages riches en Belgique et à Bruxelles. La tarification progressive n’avantage donc pas les ménages pauvres et n’est pas sociale. Nous mettons également en évidence que rien n’indique que la tarification progressive ait incité les Bruxellois·es à réduire leur consommation d’eau, qui est déjà basse. Elle ne serait dès lors pas non plus écologique. Par contre, la tarification progressive comporte une série d’inconvénients et entraine de sérieux problèmes d’équité. Nous préconisons dès lors le retour à une tarification linéaire de l’eau pour tou·te·s à Bruxelles.In 2005, the Brussels-Capital Region switched from linear pricing to progressive pricing per person because the latter was supposed to be social and ecological. We show that poor households do not consume less water per person than rich households in Belgium and Brussels. Tiered pricing therefore does not benefit poor households and is not social. We also point out that there is no evidence that progressive pricing has encouraged Brussels residents to reduce their already low water consumption. It would therefore not be environmentally friendly either. On the other hand, progressive pricing has a number of disadvantages and leads to serious problems of equity. We therefore advocate a return to linear water pricing for all in Brussels

Microbial and diagenetic steps leading to the mineralisation of Great Salt Lake microbialites.

12 pagesInternational audienceMicrobialites are widespread in modern and fossil hypersaline environments, where they provide a unique sedimentary archive. Authigenic mineral precipitation in modern microbialites results from a complex interplay between microbial metabolisms, organic matrices and environmental parameters. Here, we combined mineralogical and microscopic analyses with measurements of metabolic activity in order to characterise the mineralisation of microbial mats forming microbialites in the Great Salt Lake (Utah, USA). Our results show that the mineralisation process takes place in three steps progressing along geochemical gradients produced through microbial activity. First, a poorly crystallized Mg-Si phase precipitates on alveolar extracellular organic matrix due to a rise of the pH in the zone of active oxygenic photosynthesis. Second, aragonite patches nucleate in close proximity to sulfate reduction hotspots, as a result of the degradation of cyanobacteria and extracellular organic matrix mediated by, among others, sulfate reducing bacteria. A final step consists of partial replacement of aragonite by dolomite, possibly in neutral to slightly acidic porewater. This might occur due to dissolution-precipitation reactions when the most recalcitrant part of the organic matrix is degraded. The mineralisation pathways proposed here provide pivotal insight for the interpretation of microbial processes in past hypersaline environments