Towards the Clinical Use of Phytoplankton Carotenoid Pigments to Cure Cancer

International audienceBeyond their major ecolophysiological functions, phytoplankton pigments exert biological and pharmacological activities in human cells that allow considering their clinical use to cure various pathologies. Although much of our knowledge relating to their cell pharmacology and bioactivity has come from in vitro studies in cell culture models, recent in vivo studies have validated the potential of phytoplankton carotenoid pigments to limit inflammation and metabolic disorders, retinal diseases, degenerative diseases, tumor progression, and hepatotoxicity. Aside from these promising results, additional studies are now required to precise their pharmacokinetics, pharmacological targets, and clinical efficacy in humans. The availability of highly purified pigments at rational costs will be a milestone to set up clinical trials and develop new therapies using microalgae pigments. This short paper focuses on the great potential of phytoplankton carotenoid pigments to prevent and cure cancers. Marine and freshwater microalgae have evolved a wide range of pigments that belong to the chlorophylls, carotenoids and phycobiliproteins families. Extensive research has proved that microalgae pigments exert significant biological and pharmacological activities in human cells. Beyond their well-known antioxidant activity, used as a commercial argument to sell algae-based cosmetics and nutraceutics, it is now clearly established that microalgae pigments have a great potential as health nutrients to prevent cancer, as biotechnological probes for cancer diagnosis and as anticancer drugs to trigger cancer cells apoptosis, prevent tumor angiogenesis, reduce the risk of metastasis, sensitize cancer cells to chemotherapy, destroy cancer cells by tumor phototherapy and filter UV to limit cancer cells initiation. Numerous studies aiming to identify antiproliferative molecules from microalgae extracts led to the isolation of carotenoids and to the demonstration of their high antiproliferative, cytostatic, cytotoxic, and/or pro-apoptotic activity in cancer cell cultures [1,2]. As an example, our research team performed the bioguided isolation of pigments from Duniella tertiolecta and found that violaxanthin was the most antiproliferative molecule contained in Dt dichloromethane extract [3]. We also recently reported the strong antiproliferative activity of zeaxanthin and β-cryptoxanthin in human invasive melanoma cells, after their bioguided isolation from Cyanophora paradoxa ethanolic extracts [4]

Négocier l’urbanisation pour un littoral durable : des Parcs Naturels Régionaux facteurs d’intégration ou de fragmentation des enjeux ?

L’étude de plusieurs parcs ou projets de parcs naturels régionaux (PNR) littoraux montre que l’obtention ou le renouvellement de leur label crée une controverse autour d’un même objet : la maîtrise de l’urbanisation littorale. Le cas du golfe du Morbihan nous a permis de suivre et analyser un processus de négociation entre les acteurs du territoire autour d’une réponse à apporter aux exigences de maîtrise posées par des instances nationales représentant l’intérêt général environnemental. Du processus, à la fois coopératif et conflictuel, résulte une norme de développement durable territorialisé, de nouvelles proximités et des innovations. Un éclairage comparatif avec deux autres cas a permis d’identifier des récurrences et des différences dans la façon d’affronter des problématiques similaires. Il en ressort deux modèles de gouvernance territoriale du développement durable, le PNR étant soit un espace de négociation de normes de développement durable territorialisé qui s’imposent à tous, soit le support d’une action supplétive, voire corrective dans le cadre d’une distribution des compétences des organisations gestionnaires.The study of several coastal Regional Natural Parks (PNR) or park projects has shown that obtaining or renewing their certification label can cause controversy over a specific issue, namely the control of coastal urbanisation. By concentrating on the case of the Gulf of Morbihan, we were able to monitor and analyse the negotiation process between several local actors with regard to meeting requirements of national institutions representing the environmental general interest. The process, being at the same time cooperative and conflictual, provides a place-based sustainable development norm, new proximities, innovations. A comparative analysis of two other cases enabled us to identify recurrences and differences in the way similar issues are dealt with. Two models of local sustainable development governance emerged, with the PNR being either a negotiation space for area-based sustainable development standards applicable for everyone, or a platform for a default or even corrective action when allocating managing organisations’ skills and missions

Measuring Marine Protected Areas’ Conservation Effort: A Different Look at Three Deeply-Rooted Illusions

As a major tool for policies to protect biodiversity, the current idea of Marine Protected Areas is based on a triptych (a status, a perimeter, and regulations) that is intended to ensure their effectiveness, with the conservation effort assessed by adding up the classified surface areas. Based on an international comparative analysis using 13 differentiated case studies, we take another look at three founding illusions according to which (a) the MPA status corresponds to protection (b) on the level of the classified perimeter, and (c) founded upon regulations laid down to be respected. Our analysis shows that the status is an activatable capital, whose activation may encounter various obstacles that we have listed; that we should distinguish between two levels and types of protection, active and passive, rather than stick to the classified perimeter; that the lack of specific regulations means nothing with regard to the lack of protection; and that MPAs with a legal arsenal at their disposal use these rules first and foremost as a medium for dialogue with stakeholders, with various aims. This analysis leads us to specify what MPAs actually are, and to suggest new means and indicators to assess the conservation efforts made

Mode shape phase change detection in wind turbine under anisotropy variation

International audienceFault detection by modal analysis is a highly developed field in civil engineering. For wind turbines, a loss of isotropy for the rotor can be the consequence of a defect in the angle of attack (pitch) of the blades, or the accumulation of ice, or else the presence of structural defects resulting in a loss of stiffness on one or more blades. It is highly desirable to apply classical OMA techniques, and this despite the rotation of the blades. It is shown in this paper that it is possible to apply LTI approaches on wind turbines similarly to the methodology usually applied to standard civil engineering structures using an approximate Fourier modeling of the eigenmodes. The monitoring of anisotropy using the mode shapes of the estimated modes is validated with an example where a global loss of stiffness of 5% of a rotor blade is simulated

Line intensity measurements of methane’s ν3-band using a cw-OPO

We report on absolute line strength measurements of P(1), R(0) and R(1) singlet lines in the 3:3 μm ν3 (C–H stretching) band of methane 12CH4 at referencetemperature T = 296 K. Line strength measurements are performed at low pressure (P <1 Torr) using direct absorption spectroscopy technique based on a widely tunable continuous-wave singly resonant optical parametric oscillator. The 1σ overall accuracy in line strength determinations ranges between 7 and 8 % mostly limited by pressure and frequency measurements. A comparison with previous reported values is made. Our results show good agreement with the HITRAN 2012 database

Periodic System Approximation for Operational Modal Analysis of Operating Wind Turbine

International audienceThe inherent modelling of the operational wind turbines and rotating machines do not agree in general with the assumptions of the operational modal analysis (OMA) methods developed for civil engineering, where time invariant systems are considered. Current OMA methods for rotating machines introduce datapre-processing to adapt classical identification methods. However, they show strong limitations and rely on strong assumptions, such as the isotropy of the rotor, making them hardly applicable in practice. To overcome these limitations, this paper proposes to employ the Floquet theory of periodic system to approximate rotating systems as time invariant systems. Thus, classical identification methods can be used to retrieve the parametric signature of the periodic systems. This Floquet-based approximation gives a physical meaning to the identified eigenmodes. The proposed approach is validated on both a small numerical model and an aero-servo-elastic numerical model of a rotating 10MW wind turbine, with isotropic and anisotropic rotors, using the stochastic subspace identification to retrieve the modes and their uncertainty

Line intensity measurements of methane’s ν3-band using a cw-OPO

We report on absolute line strength measurements of P(1), R(0) and R(1) singlet lines in the 3:3 μm ν3 (C–H stretching) band of methane 12CH4 at referencetemperature T = 296 K. Line strength measurements are performed at low pressure (P <1 Torr) using direct absorption spectroscopy technique based on a widely tunable continuous-wave singly resonant optical parametric oscillator. The 1σ overall accuracy in line strength determinations ranges between 7 and 8 % mostly limited by pressure and frequency measurements. A comparison with previous reported values is made. Our results show good agreement with the HITRAN 2012 database

Détection d'anisotropie d'un rotor d'éolienne par suivi du changement de phase des modes propres

National audienceFault detection by modal analysis is a highly developed field in civil engineering. Despite the rotation of the blades, it is possible to apply it and develop similar approaches for wind turbines using a Fourier modeling of the eigenmodes. A loss of isotropy for the rotor can be the consequence of a defect in the angle of attack (pitch) of the blades, of the accumulation of ice or else the presence of structural defects resulting in a loss of stiffness on one or more blades. The monitoring of this effect using the deformations of the estimated modes is validated with an example where a global drop in stiffness of 5% of a rotor blade is simulated.La détection de défaut par analyse modale est un domaine très développé dans le génie civil. Malgré la rotation des pales, il est possible de l'appliquer et de développer des approches similaires pour les éoliennes en utilisant une modélisation des modes propres en base de Fourier. Une perte d'isotropie du rotor peut être la conséquence d'un défaut d'angle d'attaque (pitch) des pales, de l'accumulation de glace ou bien de la présence de défauts structurels entraînant une perte de raideur sur une ou plusieurs pales. La surveillance de ce phénomène à partir des déformées des modes estimés est validée avec un exemple où une baisse globale de raideur de 5% d'une pale du rotor est simulée

Clarification of Most Relevant Concepts Related to the Microalgae Production Sector

Microalgae (including cyanobacteria) are the basis for an emerging worldwide industry but still face significant bottlenecks in contributing to the global economy. It is an enormous challenge to translate experiences from established industries such as aquaculture and agriculture to the microalgae sector. In particular, this includes the challenge of adapting regulations that apply to such macroscopic production and mindsets, to the microscopic world of microalgae and to the scale-up to a million times smaller. Current European and country-based regulations do not always, indeed rarely, consider relevant specific issues that limit the path for innovation and growth applicable to the microalgae sector. In this work, the boundaries for the main issues impacting this sector are presented and discussed. Examples and possible analytical frameworks are presented in a question and answer format. Relevant key topics and related boundaries are discussed: What are algae and how do microalgae differ from macroalgae? Why are algae and specifically microalgae relevant? Is algae cultivation an aquaculture process? Can algae and specifically microalgae be classified as vegetables and their production be classified as agriculture or are they an industrial process? How is algaculture compared with other agricultural sectors? What are organic algae? Can microalgae be grown in wastewater and how can they be used? What are toxic algae? What are the bottlenecks for microalgae culture scale-up? How does the microalgae biodiversity contribute to their development? We conclude that microalgae are developing as a novel agricultural enterprise that can provide major benefits to a sustainable circular economy and environment but require appropriate regulations and support from governments and businesses, recognising its unique attributes and potential

Digital expression profiling of novel diatom transcripts provides insight into their biological functions

Background: Diatoms represent the predominant group of eukaryotic phytoplankton in the oceans and are responsible for around 20% of global photosynthesis. Two whole genome sequences are now available. Notwithstanding, our knowledge of diatom biology remains limited because only around half of their genes can be ascribed a function based onhomology-based methods. High throughput tools are needed, therefore, to associate functions with diatom-specific genes. Results: We have performed a systematic analysis of 130,000 ESTs derived from Phaeodactylum tricornutum cells grown in 16 different conditions. These include different sources of nitrogen, different concentrations of carbon dioxide, silicate and iron, and abiotic stresses such as low temperature and low salinity. Based on unbiased statistical methods, we have catalogued transcripts with similar expression profiles and identified transcripts differentially expressed in response to specific treatments. Functional annotation of these transcripts provides insights into expression patterns of genes involved in various metabolic and regulatory pathways and into the roles of novel genes with unknown functions. Specific growth conditions could be associated with enhanced gene diversity, known gene product functions, and over-representation of novel transcripts. Comparative analysis of data from the other sequenced diatom, Thalassiosira pseudonana, helped identify several unique diatom genes that are specifically regulated under particular conditions, thus facilitating studies of gene function, genome annotation and the molecular basis of species diversity. Conclusions: The digital gene expression database represents a new resource for identifying candidate diatom-specific genes involved in processes of major ecological relevance