Allelochemicals of Pinus halepensis as Drivers of Biodiversity in Mediterranean Open Mosaic Habitats During the Colonization Stage of Secondary Succession

The Mediterranean region is recognized as a global biodiversity hotspot. However, over the last 50 years or so, the cessation of traditional farming has given way to strong afforestation at the expense of open habitats. Pinus halepensis Miller, known to synthesize a wide range of secondary metabolites, is a pioneer expansionist species colonizing abandoned agricultural land that present high species richness. Here, laboratory bioassays were used to study the potential impact of P. halepensis on plant diversity through allelopathy, and the role of microorganisms in these interactions. Germination and growth of 12 target species naturally present in fallow farmlands were tested according to concentration of aqueous extracts obtained from shoots of young pines (aged about 5 years), with or without the presence of soil microorganisms (autoclaved or natural soil). Under the highest concentrations and autoclaved soil, more than 80 % of target species were germination and/or growth-inhibited, and only two species were non-sensitive. Under more natural conditions (lower extracts concentrations and natural soil with microorganisms), only 50 % of species were still inhibited, one was non-sensitive, and five were stimulated. Thus, microorganisms alter the expression of allelochemicals released into the ecosystem, which highlights their key role in chemical plant-plant interactions. The results of allelopathic experiments conducted in the lab are consistent with the community patterns observed in the field. These findings suggest that allelopathy is likely to shape vegetation composition and participate to the control of biodiversity in Mediterranean open mosaic habitats.     

Étude de l'aspect cornbinatoire de la gestion des conflits dans un atelier discontinu

The combinatorial angle of management of batch processes or job‐shop for fine chemicals is presented. Indeed, the order of priority for product recipes, which allows one to determine the first batch to be loaded, has a strong combinatorial aspect. When dealing with stochastic algorithms, this aspect requires a precise and non‐redundant numbering of the orders of priority. A fairly complex mathematical study based on a family of pseudo‐orthogonal polynomials provides a non‐recursive formula easy to implement.     

Mass transport limitations in zeolite catalysts: the dehydration of 1-phenyl-ethanol to styrene

The dehydration of 1-phenyl-ethanol to styrene is a critical step in the styrene/propene oxide manufacturing process. An important challenge is to achieve deep dehydration while minimising the oligomerisation of styrene to heavy products that deactivate the catalyst. The present study shows that zeolite-based catalysts can meet the challenge when designed and operated such as to avoid diffusion limitations in the mesopores of the binder. Indeed we achieved high conversion (>90%), reasonable selectivity (>90%) and largely improved catalyst life (>150 h) by using full-extrudate catalysts of low zeolite content that are running at low temperature (220°C) and moderate WHSV (2 g/g_extrudate h)).     

Imaging E-selectin expression following traumatic brain injury in the rat using a targeted USPIO contrast agent

Introduction  The aim of this work was to map E-selectin expression in a traumatic brain injury model using a newly-designed MR contrast agent. Iron cores, responsible for susceptibility effects and therefore used as T2* contrast agents, need to be coated in order to be stabilized and need to be targeted to be useful. Methods  We have designed a molecule coating composed, at one end, of bisphosphonate to ensure anchorage of the coating on the iron core and, at the other end, of Fukuda’s defined heptapeptide known to target selectin binding sites. Conclusion  The synthesized nanoparticles were able to non-invasively target the traumatic brain lesion, inducing a specific T2* decrease of about 25% up to at least 70 min post-injection of the targeted contrast agent.     

Cryotolerance of Lactobacillus delbrueckii subsp. bulgaricus CFL1 is influenced by the physiological state during fermentation

To better understand the effects of freezing and frozen storage on different characteristics of the cell state, the influence of the physiological state, as defined by fermentation pH and harvesting time, and the freezing medium on the cryotolerance of Lactobacillus bulgaricus CFL1 was investigated. Esterase activity, membrane integrity, cultivability and acidification activity were quantified during culture with and without pH control, and during freezing and frozen storage at ?20 °C. The preservation of esterase activity and membrane integrity was not related to starter functionalities such as cultivability and acidification activity. Cell cryotolerance increased with fermentation time or when cells were harvested during culture at pH 5 and frozen, as compared with fermentations at pH 6 or without pH control. Long-term cell cryotolerance could be predicted by determining an early physiological parameter such as a low initial acidification activity when the cells are harvested.     

Influence of contact surface quality and contact material on the contact resistances of high current connections

At the connection between high current room temperature busbars, e.g. feeders for fusion machines, the contact resistance has to be low to avoid high electrical losses. Otherwise an excessive cooling is needed to prevent the busbar from local overheating caused by these losses. In order to determine the parameters, which are relevant to ensure a reproducible and reliable low contact resistance, detailed tests at room temperature with different high current connection types were performed.The contact resistance of aluminum–copper and copper–copper connection was measured for contact areas with different surfaces as e.g. polished, oxidized and gold plated contact area. In addition the change of the contact resistance during a long time operation and at different current densities was determined. Furthermore the effect of humidity, e.g. condensed water and over temperature, e.g. at an overload or a breakdown of the cooling system, on the contact resistance quality were analyzed.     

Molecular Study of a Hoxa2 Gain-of-Function in Chondrogenesis: A Model of Idiopathic Proportionate Short Stature

In a previous study using transgenic mice ectopically expressing Hoxa2 during chondrogenesis, we associated the animal phenotype to human idiopathic proportionate short stature. Our analysis showed that this overall size reduction was correlated with a negative influence of Hoxa2 at the first step of endochondral ossification. However, the molecular pathways leading to such phenotype are still unknown. Using protein immunodetection and histological techniques comparing transgenic mice to controls, we show here that the persistent expression of Hoxa2 in chondrogenic territories provokes a general down-regulation of the main factors controlling the differentiation cascade, such as Bapx1, Bmp7, Bmpr1a, Ihh, Msx1, Pax9, Sox6, Sox9 and Wnt5a. These data confirm the impairment of chondrogenic differentiation by Hoxa2 overexpression. They also show a selective effect of Hoxa2 on endochondral ossification processes since Gdf5 and Gdf10, and Bmp4 or PthrP were up-regulated and unmodified, respectively. Since Hoxa2 deregulation in mice induces a proportionate short stature phenotype mimicking human idiopathic conditions, our results give an insight into understanding proportionate short stature pathogenesis by highlighting molecular factors whose combined deregulation may be involved in such a disease.     

'I Think Home is More than a Building': Young Home(less) People on the Cusp of Home,Self and Something Else

This paper explores research undertaken with young home(less) people in Sydney in which I specifically pursue ideas of home and belonging in the inner city. In a context in which young home(less) people are seen to 'lack' both identity and place, the responses of young people indicate the fragility and importance of relations of space and self.     

Removal of total dissolved solids, nitrates and ammonium ions from drinking water using charge-barrier capacitive deionisation

A charge-barrier capacitive deionisation system was tested for electrochemical removal of Total Dissolved Solids (TDS), nitrates and ammonium ions. Several experiments were conducted with inorganic species spiked in tap water. The system efficiency was first evaluated using experimental statistical designs with different concentrations of NaCl (150 to 3000 mg/L). The raw water conductivity and the targeted residual TDS in treated water were the key process variables. Power consumption increased linearly as the difference between these two values increased. Water recovery rate and electrical consumption, which varied respectively from 63.9% to 95.8% and from 0.45 to 5.35 kWh/m³, were adequately described by a simple linear regression model (R²: 0.98 and 0.99, respectively). Additional experiments performed on nitrates (100 mg N-NO₃/L) and ammonium ions (1000 mg N-NH₄/L) showed high levels of removal. A rise in TDS concentration led to a decrease in their removal due to the competition for electrodes carbon adsorption sites. It was concluded from this study that this technology offers an innovative alternative for demineralising water. However, assays should be conducted in natural waters and in a steady-state manner to confirm data obtained and get long-term performance.