Distribution des épiphytes de Côte d’Ivoire : effets des zones phytogéographiques et des variations pluviométriques

La gestion de la diversité biologique se présente comme un défi majeur du fait des problèmes liés à la connaissance et à la préservation des ressources biologiques. Cette étude est une contribution à une meilleure connaissance de la diversité végétale de la Côte d’Ivoire à travers celles des épiphytes. Les espèces épiphytiques présentes dans les Herbiers du CNF (UCJ) et du CSRS ont été recensées. Ces informations ont été complétées par une revue bibliographique sur les épiphytes de Côte d’Ivoire. Les données recueillies ont été triées et corrigées. Les noms et les coordonnées géographiques ont été vérifiés. La compilation des listes corrigées a permis d’avoir un nombre d’occurrences des espèces recensées en Côte d’Ivoire avec la position géographique pour chaque récolte. Ces travaux présentent 380 espèces épiphytiques qui se repartissent entre 110 genres, 32 familles et 21 ordres. Les espèces les plus récoltées sont : Culcasia scandens (209 occurrences), Culcasia angolensis (180 occurrences), Piper guineense (91 occurrences), Cercestis afzelii (86 occurrences) et Bulbophyllum falcatum (75 occurrences). On rencontre des espèces épiphytiques sur tout le territoire ivoirien. Néanmoins, on note de fortes concentrations des récoltes dans le Sud et l’Ouest montagneux. Les modélisations et les cartographies effectuées permettent d’observer que l’espèce Culcasia angolensis qui se retrouve uniquement dans les espaces de forêt est certainement plus sensible au stress hydrique. On peut donc dire que Culcasia angolensis ne supporte pas une longue dessiccation comparativement à Culcasia scandens.Mots-clés : épiphytes, maxent, composition floristique. Distribution of the epiphytes listed in Côte d'Ivoire according to the phyto-geographical zones and rainfall variations'The management of biological diversity is presented as a major challenge because of the problems involved in the knowledge and the safeguarding of the biological resources. This study is a contribution with a better knowledge of plant diversity of the Côte d'Ivoire through those of the epiphytes. The epiphytic species present in the Herbarium of the CNF (UCJ) and the CSRS were listed. This information was supplemented by a bibliographical review on the epiphytes of Côte d'Ivoire. The data collected were sorted and corrected. The names and geographical co-ordinates were checked. The compilation of the corrected lists conducted to census the occurred epiphytes listed in Côte d'Ivoire. A total number of 380 epiphytic species were recorded. They belonged to 110 genera, 32 families and 21 orders. The most collected species were: Culcasia scandens (209 occurrences), Culcasia angolensis (180 occurrences), Piper guineense (91 occurrences), Cercestis afzelii (86 occurrences) and Bulbophyllum falcatum (75 occurrences). Epiphytic species are met in the entire territory of Côte d’Ivoire with a strong concentration in the South and mountainous west region. Modellings and mapping carried out allow us to observe that the species Culcasia angolensis which is found only forests is certainly more sensitive to the hydrous stress. One can thus say that Culcasia angolensis does not support a long desiccation compared to Culcasia scandensKeywords: epiphytes, Maxent, plant species composition

Efficient total syntheses of louisianins C and D

[[abstract]]An efficient synthetic route for the preparation of louisianins C and D was developed starting with the commercially available 4-cyanopyridine. Louisianins C and D were synthesized in seven steps and with overall yields 22% and 20%, respectively, following a novel cyclization-decarboxylation sequence involving 4-bromo-6,7-dihydrocyclopenta[c]pyridin-5-one as the key intermediate. (C) 2008 Elsevier Ltd. All rights reserved

Use of the q-Gaussian mutation in evolutionary algorithms

Copyright @ Springer-Verlag 2010.This paper proposes the use of the q-Gaussian mutation with self-adaptation of the shape of the mutation distribution in evolutionary algorithms. The shape of the q-Gaussian mutation distribution is controlled by a real parameter q. In the proposed method, the real parameter q of the q-Gaussian mutation is encoded in the chromosome of individuals and hence is allowed to evolve during the evolutionary process. In order to test the new mutation operator, evolution strategy and evolutionary programming algorithms with self-adapted q-Gaussian mutation generated from anisotropic and isotropic distributions are presented. The theoretical analysis of the q-Gaussian mutation is also provided. In the experimental study, the q-Gaussian mutation is compared to Gaussian and Cauchy mutations in the optimization of a set of test functions. Experimental results show the efficiency of the proposed method of self-adapting the mutation distribution in evolutionary algorithms.This work was supported in part by FAPESP and CNPq in Brazil and in part by the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant EP/E060722/1 and Grant EP/E060722/2

A multidrug ABC transporter with a taste for salt.

BACKGROUND: LmrA is a multidrug ATP-binding cassette (ABC) transporter from Lactococcus lactis with no known physiological substrate, which can transport a wide range of chemotherapeutic agents and toxins from the cell. The protein can functionally replace the human homologue ABCB1 (also termed multidrug resistance P-glycoprotein MDR1) in lung fibroblast cells. Even though LmrA mediates ATP-dependent transport, it can use the proton-motive force to transport substrates, such as ethidium bromide, across the membrane by a reversible, H(+)-dependent, secondary-active transport reaction. The mechanism and physiological context of this reaction are not known. METHODOLOGY/PRINCIPAL FINDINGS: We examined ion transport by LmrA in electrophysiological experiments and in transport studies using radioactive ions and fluorescent ion-selective probes. Here we show that LmrA itself can transport NaCl by a similar secondary-active mechanism as observed for ethidium bromide, by mediating apparent H(+)-Na(+)-Cl(-) symport. Remarkably, LmrA activity significantly enhances survival of high-salt adapted lactococcal cells during ionic downshift. CONCLUSIONS/SIGNIFICANCE: The observations on H(+)-Na(+)-Cl(-) co-transport substantiate earlier suggestions of H(+)-coupled transport by LmrA, and indicate a novel link between the activity of LmrA and salt stress. Our findings demonstrate the relevance of investigations into the bioenergetics of substrate translocation by ABC transporters for our understanding of fundamental mechanisms in this superfamily. This study represents the first use of electrophysiological techniques to analyze substrate transport by a purified multidrug transporter

Microbial fuel cells: a green and alternative source for bioenergy production

Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

Carbon nanotube composites for glucose biosensor incorporated with reverse iontophoresis function for noninvasive glucose monitoring

Author name used in this publication: Yao, Yan-Dong.Version of RecordPublishe

A Characterization of Scale Invariant Responses in Enzymatic Networks

An ubiquitous property of biological sensory systems is adaptation: a step increase in stimulus triggers an initial change in a biochemical or physiological response, followed by a more gradual relaxation toward a basal, pre-stimulus level. Adaptation helps maintain essential variables within acceptable bounds and allows organisms to readjust themselves to an optimum and non-saturating sensitivity range when faced with a prolonged change in their environment. Recently, it was shown theoretically and experimentally that many adapting systems, both at the organism and single-cell level, enjoy a remarkable additional feature: scale invariance, meaning that the initial, transient behavior remains (approximately) the same even when the background signal level is scaled. In this work, we set out to investigate under what conditions a broadly used model of biochemical enzymatic networks will exhibit scale-invariant behavior. An exhaustive computational study led us to discover a new property of surprising simplicity and generality, uniform linearizations with fast output (ULFO), whose validity we show is both necessary and sufficient for scale invariance of enzymatic networks. Based on this study, we go on to develop a mathematical explanation of how ULFO results in scale invariance. Our work provides a surprisingly consistent, simple, and general framework for understanding this phenomenon, and results in concrete experimental predictions

Dispersive flies optimisation and medical imaging

One of the main sources of inspiration for techniques applicable to complex search space and optimisation problems is nature. This paper introduces a new metaheuristic—Dispersive Flies Optimisation (DFO)—whose inspiration is beckoned from the swarming behaviour of flies over food sources in nature. The simplicity of the algorithm facilitates the analysis of its behaviour. A series of experimental trials confirms the promising performance of the optimiser over a set of benchmarks, as well as its competitiveness when compared against three other well-known population based algorithms. The convergence-independent diversity of DFO algorithm makes it a potentially suitable candidate for dynamically changing environment. In addition to diversity, the performance of the newly introduced algorithm is investigated using the three performance measures of accuracy, efficiency and reliability and its outperformance is demonstrated in the paper. Then the proposed swarm intelligence algorithm is used as a tool to identify microcalcifications on the mammographs. This algorithm is adapted for this particular purpose and its performance is investigated by running the agents of the swarm intelligence algorithm on sample mammographs whose status have been determined by the experts. Two modes of the algorithms are introduced in the paper, each providing the clinicians with a different set of outputs, highlighting the areas of interest where more attention should be given by those in charge of the care of the patients

How do you say ‘hello’? Personality impressions from brief novel voices

On hearing a novel voice, listeners readily form personality impressions of that speaker. Accurate or not, these impressions are known to affect subsequent interactions; yet the underlying psychological and acoustical bases remain poorly understood. Furthermore, hitherto studies have focussed on extended speech as opposed to analysing the instantaneous impressions we obtain from first experience. In this paper, through a mass online rating experiment, 320 participants rated 64 sub-second vocal utterances of the word ‘hello’ on one of 10 personality traits. We show that: (1) personality judgements of brief utterances from unfamiliar speakers are consistent across listeners; (2) a two-dimensional ‘social voice space’ with axes mapping Valence (Trust, Likeability) and Dominance, each driven by differing combinations of vocal acoustics, adequately summarises ratings in both male and female voices; and (3) a positive combination of Valence and Dominance results in increased perceived male vocal Attractiveness, whereas perceived female vocal Attractiveness is largely controlled by increasing Valence. Results are discussed in relation to the rapid evaluation of personality and, in turn, the intent of others, as being driven by survival mechanisms via approach or avoidance behaviours. These findings provide empirical bases for predicting personality impressions from acoustical analyses of short utterances and for generating desired personality impressions in artificial voices

From skeleton to cytoskeleton: osteocalcin transforms vascular fibroblasts to myofibroblasts via angiotensin II and Toll-like receptor 4

RATIONALE: The expression of osteocalcin is augmented in human atherosclerotic lesions. How osteocalcin triggers vascular pathogenesis and remodeling is unclear. OBJECTIVE: To investigate whether osteocalcin promotes transformation of adventitial fibroblast to myofibroblasts and the molecular mechanism involved. METHODS AND RESULTS: Immunohistochemistry indicated that osteocalcin was expressed in the neointima of renal arteries from diabetic patients. Western blotting and wound-healing assay showed that osteocalcin induced fibroblast transformation and migration, which were attenuated by blockers of the renin-angiotensin system and protein kinase Cδ (PKCδ), toll-like receptor 4 (TLR4) neutralizing antibody, and antagonist and inhibitors of free radical production and cyclooxygenase-2. Small interfering RNA silencing of TLR4 and PKCδ abolished fibroblast transformation. Angiotensin II level in the conditioned medium from the osteocalcin-treated fibroblasts was found elevated using enzyme immunoassay. Culturing of fibroblasts in conditioned medium collected from differentiated osteoblasts promoted fibroblast transformation. The expression of fibronectin, TLR4, and cyclooxygenase-2 is augmented in human mesenteric arteries after 5-day in vitro exposure to osteocalcin. CONCLUSIONS: Osteocalcin transforms adventitial fibroblasts to myofibroblasts through stimulating angiotensin II release and subsequent activation of PKCδ/TLR4/reactive oxygen species/cyclooxygenase-2 signaling cascade. This study reveals that the skeletal hormone osteocalcin cross-talks with vascular system and contributes to vascular remodeling.published_or_final_versio