How geographic distance and depth drive ecological variability and isolation of demersal fish communities in an archipelago system (Cape Verde, Eastern Atlantic Ocean)

Cape Verde is a tropical oceanic ecosystem, highly fragmented and dispersed, with islands physically isolated by distance and depth. To understand how isolation affects the ecological variability in this archipelago, we conducted a research project on the community structure of the 18 commercially most important demersal fishes. An index of ecological distance based on species relative dominance (Di) is developed from Catch Per Unit Effort, derived from an extensive database of artisanal fisheries. Two ecological measures of distance between islands are calculated: at the species level, DDi, and at the community level, DD (sum of DDi). A physical isolation factor (Idb) combining distance (d) and bathymetry (b) is proposed. Covariance analysis shows that isolation factor is positively correlated with both DDi and DD, suggesting that Idb can be considered as an ecological isolation factor. The effect of Idb varies with season and species. This effect is stronger in summer (May to November), than in winter (December to April), which appears to be more unstable. Species react differently to Idb, independently of season. A principal component analysis on the monthly (DDi) for the 12 islands and the 18 species, complemented by an agglomerative hierarchical clustering, shows a geographic pattern of island organization, according to Idb. Results indicate that the ecological structure of demersal fish communities of Cape Verde archipelago, both in time and space, can be explained by a geographic isolation factor. The analytical approach used here is promising and could be tested in other archipelago systems.

The flipped-broadcast learning system, application on Azores

On this work we suggest a teaching solution that can be implemented in Azores, an archipelago of nine islands of Portugal, based in already known system of e-learning, with a twist based on the flipped method. Structured in a cooperative way, the organization of the system allows to isolated groups of people to have access to a certain level of teaching, if they cannot have the possibility to have physical presence in school due to problems emerging from territory discontinuity. Our suggestion can be elaborate in a model that can be adapted to any level of education, and can be adapted also in cases that a cut of budget exists. We suggest the name of fb-learning: Flipped Broadcast Learning.

Molecular evolution of the Drosophila olfactory system

The olfactory system is an attractive model to study the genetic mechanisms underlying evolution of the nervous system. This sensory system mediates the detection and behavioural responses to an enormous diversity of volatile chemicals in the environment and displays rapid evolution, as species acquire, modify and discard olfactory receptors and circuits to adapt to new olfactory stimuli. Drosophilids provide an attractive model to study these processes. The availability of 12 sequenced genomes of Drosophila species occupying diverse ecological niches provides a rich resource for genomic analyses. Moreover, one of these species, Drosophila melanogaster, is amenable to a powerful combination of genetic and electrophysiological analyses. D. melanogaster has two distinct families of olfactory receptors to detect odours, the well-characterised Odorant Receptors (ORs) and the recently identified lonotropic Receptors (IRs). In my thesis, I have provided new insights into the genetic mechanisms underlying olfactory system evolution through three distinct, but interrelated projects. First, I performed a comparative genomic analysis of the IR repertoire in 12 sequenced Drosophila species, which has revealed that the olfactory IRs are highly conserved across species. By contrast, a large fraction of IRs that are not expressed in the olfactory system - and which may be gustatory receptors - are much more variable in sequence and gene copy number. Second, to identify ligands for IR expressing olfactory sensory neurons, I have performed an electrophysiological screen in D. melanogaster using a panel of over 160 odours. I found that the IRs respond to a number of amines, aldehydes and acids, contrasting with the chemical specificity of the OR repertoire, which is mainly tuned to esters, alcohols and ketones. Finally, the identification of ligands for IRs in this species allowed me to investigate in detail the molecular and functional evolution of a tandem array of IRs, IR75a/IR75b/IR75c, in D. sechellia. This species is endemic to the Seychelles archipelago and highly specialised to breed on the fruits of Morinda citrifolia, which is repulsive and toxic for other Drosophila species. These studies led me to discover that receptor loss, changes in receptor specificity and changes in receptor expression have likely played an important role during the evolution of these IRs in D. sechellia. These changes may explain, in part, the unique chemical ecology of this species. - Le système olfactif est un excellent modèle pour étudier les mécanismes génétiques impliqués dans l'étude de l'évolution du système nerveux. Ce système sensoriel permet la détection de nombreux composés volatils présents dans l'environnement et est à la base des réponses comportementales. Il est propre à chaque espèce et évolue rapidement en modifiant ou en éliminant des récepteurs et leurs circuits olfactifs correspondants pour s'adapter à de nouvelles odeurs. Pour étudier le système olfactif et son évolution, nous avons décidé d'utiliser la drosophile comme modèle. Le séquençage complet de 12 souches de drosophiles habitant différentes niches écologiques permet une analyse génomique conséquente. De plus, l'une de ces espèces Drosophila melanogaster permet la combinaison d'analyses génétiques et électrophysiologiques. En effet, D. melanogaster possède 2 familles distinctes de récepteurs olfactifs qui permettent la détection d'odeurs: les récepteurs olfactifs (ORs) étant les mieux caractérisés et les récepteurs ionotropiques (IRs), plus récemment identifiés. Au cours de ma thèse, j'ai apporté des nouvelles connaissances qui m'ont permis de mieux comprendre les mécanismes génétiques à la base de l'évolution du système olfactif au travers de trois projets différents, mais interdépendants. Premièrement, j'ai réalisé une analyse génomique comparative de l'ensemble des IRs dans les 12 souches de drosophiles séquencées jusqu'à présent. Ceci a montré que les récepteurs olfactifs IRs sont hautement conservés parmi l'ensemble de ces espèces. Au contraire, une grande partie des IRs qui ne sont pas exprimés dans le système olfactif, et qui semblent être des récepteurs gustatifs, sont beaucoup plus variables dans leur séquence et dans le nombre de copie de gènes. Deuxièmement, pour identifier les ligands des récepteurs IRs exprimés par les neurones sensoriels olfactifs, j'ai réalisé une étude électrophysiologique chez D. melanogaster e η testant l'effet de plus de 160 composés chimiques sur les IRs. J'ai trouvé que les IRs répondent à un nombre d'amines, d'aldéhydes et d'acides, contrairement aux récepteurs olfactifs ORs qui eux répondent principalement aux esthers, alcools et cétones. Finalement, l'identification de ligands pour les IRs dans ces espèces m'a permis d'étudier en détail l'évolution fonctionnelle et moléculaire des IR75a/IR75b/IR75c dans D. sechellia. Cette espèce est endémique de l'archipel des Seychelles et se nourrit spécifiquement du fruit Morinda citrifolia qui est répulsif et toxique pour d'autres souches de drosophiles. Ces études m'ont poussé à découvrir que, la perte de IR75a, le changement dans la spécificité de IR75b ainsi que le changement dans l'expression de IR75c ont probablement joué un rôle important dans l'évolution des IRs chez D. sechellia. Ces changements peuvent expliquer, en partie, l'écologie chimique propre à cette espèce. Résumé français large public Le système olfactif permet aux animaux de détecter des milliers de molécules odorantes, les aidant ainsi à trouver de la nourriture, à distinguer si elle est fraîche ou avariée, à trouver des partenaires sexuels, ainsi qu'à éviter les prédateurs. Selon l'environnement et le mode de vie des espèces, le système olfactif doit détecter des odeurs très diverses ; en effet, un moustique qui recherche du sang humain pour se nourrir doit détecter des odeurs bien différentes d'une abeille qui recherche des fleurs. Dans ma thèse, j'ai essayé de comprendre comment les systèmes olfactifs d'une espèce évoluent pour s'adapter aux exigences induites par son environnement. Un très bon modèle pour étudier cela est la drosophile dont les différentes espèces se nichent dans des habitats très divers. Pour ce faire, j'ai étudié les récepteurs olfactifs de différentes espèces de la drosophile. Ces récepteurs sont des protéines qui se lient à des odeurs spécifiques. Lorsqu'ils se lient, ils activent un neurone qui envoie un signal électrique au cerveau. Ce signal est ensuite traité par ce dernier qui indique à la mouche si l'odeur est attractive ou répulsive. J'ai identifié les récepteurs olfactifs de plusieurs espèces de drosophile et étudié s'il y avait des différences entre elles. La plupart des récepteurs sont similaires entre les espèces, cependant dans l'une d'entre elles, certains récepteurs sont différents. Ce fait est particulièrement intéressant car cette espèce de drosophile se nourrit de fruits que les autres espèces n'apprécient pas. Comme nous ne savons pas quels récepteurs se lient à quelles odeurs, j'ai testé un grand nombre de composants odorants. Ceci m'a permis de constater que, effectivement, certains changements produits dans ces récepteurs expliquent pourquoi cette espèce aime particulièrement ces fruits. En outre, mes résultats contribuent à mieux comprendre les changements génétiques qui sont impliqués dans l'évolution du système olfactif.

Islandora Archipelago: Update on the Project & Community

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Subglacial bedform evidence for a major palaeo-ice stream and its retreat phases in Amundsen Gulf, Canadian Arctic Archipelago

Ascertaining the location of palaeo-ice streams is crucial in order to produce accurate reconstructions of palaeo-ice sheets and examine interactions with the ocean-climate system. This paper reports evidence for a major ice stream in Amundsen Gulf, Canadian Arctic Archipelago. Mapping from satellite imagery (Landsat ETM+) and digital elevation models, including bathymetric data, is used to reconstruct flow-patterns on southwestern Victoria Island and the adjacent mainland (Nunavut and Northwest Territories). Several flow-sets indicative of ice streaming are found feeding into the marine trough and cross-cutting relationships between these flow-sets (and utilising previously published radiocarbon dates) reveal several phases of ice stream activity centred in Amundsen Gulf and Dolphin and Union Strait. A large erosional footprint on the continental shelf indicates that the ice stream (ca. 1000 km long and ca. 150 km wide) filled Amundsen Gulf, probably at the Last Glacial Maximum. Subsequent to this, the ice stream reorganised as the margin retreated back along the marine trough, eventually splitting into two separate low-gradient lobes in Prince Albert Sound and Dolphin and Union Strait. The location of this major ice stream holds important implications for ice sheet-ocean interactions and specifically, the development of Arctic Ocean ice shelves and the delivery of icebergs into the western Arctic Ocean during the late Pleistocene. Copyright (C) 2006 John Wiley & Sons, Ltd.

Genetic variability and efficiency of DNA microsatellite markers for paternity testing in horse breeds from the Brazilian Marajó archipelago

In this study, 15 microsatellite DNA loci used in comparative tests by the International Society for Animal Genetics were applied to the evaluation of genetic diversity and management, and the efficiency of paternity testing in Marajoara horses and Puruca ponies from the Marajó Archipelago. Based on the genotyping of 93 animals, mean allelic diversity was estimated as 9.14 and 7.00 for the Marajoara and Puruca breeds, respectively. While these values are similar to those recorded in most European breeds, mean levels of heterozygosity were much lower (Marajoara 49%, Puruca 40%), probably as a result of high levels of inbreeding in the Marajó populations. The mean informative polymorphic content of this 15-marker system was over 50% in both breeds, and was slightly higher in the Marajoara horses. The discriminative power and exclusion probabilities derived from this system were over 99% for both populations, emphasizing the efficacy of these markers for paternity testing and genetic management in the two breeds.

Frequency control support of a wind-solar isolated system by a hydropower plant with long tail-race tunnel

Pumped storage hydro plants (PSHP) can provide adequate energy storage and frequency regulation capacities in isolated power systems having significant renewable energy resources. Due to its high wind and solar potential, several plans have been developed for La Palma Island in the Canary archipelago, aimed at increasing the penetration of these energy sources. In this paper, the performance of the frequency control of La Palma power system is assessed, when the demand is supplied by the available wind and solar generation with the support of a PSHP which has been predesigned for this purpose. The frequency regulation is provided exclusively by the PSHP. Due to topographic and environmental constraints, this plant has a long tail-race tunnel without a surge tank. In this configuration, the effects of pressure waves cannot be neglected and, therefore, usual recommendations for PID governor tuning provide poor performance. A PI governor tuning criterion is proposed for the hydro plant and compared with other criteria according to several performance indices. Several scenarios considering solar and wind energy penetration have been simulated to check the plant response using the proposed criterion. This tuning of the PI governor maintains La Palma system frequency within grid code requirements.

La Galite Archipelago (Tunisia, North Africa): stratigraphic and petrographic revision and insights for geodynamic evolution of the Maghrebian Chain

The location of the La Galite Archipelago on the Internal/External Zones of the Maghrebian Chain holds strong interest for the reconstruction of the geodynamic evolution of the Mesomediterranean Microplate-Africa Plate Boundary Zone. New stratigraphic and petrographic data on sedimentary successions intruded upon by plutonic rocks enabled a better definition of the palaeogeographic and palaeotectonic evolutionary model of the area during the early-middle Miocene. The lower Miocene sedimentary units (La Galite Flysch and Numidian-like Flysch) belong to the Mauritanian (internal) and Massylian (external) sub-Domains of the Maghrebian Chain, respectively. These deposits are related to a typical syn-orogenic deposition in the Maghrebian Flysch Basin Domain, successively backthrusted above the internal units. The backthrusting age is post-Burdigalian (probably Langhian-Serravallian) and the compressional phase represents the last stage in the building of the accretionary wedge of the Maghrebian orogen. These flysch units may be co-relatable to the similar well-known formations along the Maghrebian and Betic Chains. The emplacement of potassic peraluminous magmatism, caused local metamorphism in the Late Serravallian-Early Tortonian (14–10 Ma), after the last compressional phase (backthrusting), during an extensional tectonic event. This extensional phase is probably due to the opening of a slab break-off in the deep subduction system. La Galite Archipelago represents a portion of the Maghrebian Flysch Basin tectonically emplaced above the southern margin of the “Mesomediterranean Microplate” which separated the Piemontese-Ligurian Ocean from a southern oceanic branch of the Tethys (i.e. the Maghrebian Flysch Basin). The possible presence of an imbricate thrust system between La Galite Archipelago and northern Tunisia may be useful to exclude the petroleum exploration from the deformed sectors of the offshore area considered.

Obesity And Inflammation And The Effect On The Hematopoietic System.

Bone marrow is organized in specialized microenvironments known as 'marrow niches'. These are important for the maintenance of stem cells and their hematopoietic progenitors whose homeostasis also depends on other cell types present in the tissue. Extrinsic factors, such as infection and inflammatory states, may affect this system by causing cytokine dysregulation (imbalance in cytokine production) and changes in cell proliferation and self-renewal rates, and may also induce changes in the metabolism and cell cycle. Known to relate to chronic inflammation, obesity is responsible for systemic changes that are best studied in the cardiovascular system. Little is known regarding the changes in the hematopoietic system induced by the inflammatory state carried by obesity or the cell and molecular mechanisms involved. The understanding of the biological behavior of hematopoietic stem cells under obesity-induced chronic inflammation could help elucidate the pathophysiological mechanisms involved in other inflammatory processes, such as neoplastic diseases and bone marrow failure syndromes.

The Value Of The 2005 International Society Of Urological Pathology (isup) Modified Gleason Grading System As A Predictor Of Biochemical Recurrence After Radical Prostatectomy.

To compare time and risk to biochemical recurrence (BR) after radical prostatectomy of two chronologically different groups of patients using the standard and the modified Gleason system (MGS). Cohort 1 comprised biopsies of 197 patients graded according to the standard Gleason system (SGS) in the period 1997/2004, and cohort 2, 176 biopsies graded according to the modified system in the period 2005/2011. Time to BR was analyzed with the Kaplan-Meier product-limit analysis and prediction of shorter time to recurrence using univariate and multivariate Cox proportional hazards model. Patients in cohort 2 reflected time-related changes: striking increase in clinical stage T1c, systematic use of extended biopsies, and lower percentage of total length of cancer in millimeter in all cores. The MGS used in cohort 2 showed fewer biopsies with Gleason score ≤ 6 and more biopsies of the intermediate Gleason score 7. Time to BR using the Kaplan-Meier curves showed statistical significance using the MGS in cohort 2, but not the SGS in cohort 1. Only the MGS predicted shorter time to BR on univariate analysis and on multivariate analysis was an independent predictor. The results favor that the 2005 International Society of Urological Pathology modified system is a refinement of the Gleason grading and valuable for contemporary clinical practice.

The Applicability Of Ordered Mesoporous Sba-15 And Its Hydrophobic Glutaraldehyde-bridge Derivative To Improve Ibuprofen-loading In Releasing System.

The mesoporous SBA-15 silica with uniform hexagonal pore, narrow pore size distribution and tuneable pore diameter was organofunctionalized with glutaraldehyde-bridged silylating agent. The precursor and its derivative silicas were ibuprofen-loaded for controlled delivery in simulated biological fluids. The synthesized silicas were characterized by elemental analysis, infrared spectroscopy, (13)C and (29)Si solid state NMR spectroscopy, nitrogen adsorption, X-ray diffractometry, thermogravimetry and scanning electron microscopy. Surface functionalization with amine containing bridged hydrophobic structure resulted in significantly decreased surface area from 802.4 to 63.0 m(2) g(-1) and pore diameter 8.0-6.0 nm, which ultimately increased the drug-loading capacity from 18.0% up to 28.3% and a very slow release rate of ibuprofen over the period of 72.5h. The in vitro drug release demonstrated that SBA-15 presented the fastest release from 25% to 27% and SBA-15GA gave near 10% of drug release in all fluids during 72.5 h. The Korsmeyer-Peppas model better fits the release data with the Fickian diffusion mechanism and zero order kinetics for synthesized mesoporous silicas. Both pore sizes and hydrophobicity influenced the rate of the release process, indicating that the chemically modified silica can be suggested to design formulation of slow and constant release over a defined period, to avoid repeated administration.

Electronic And Structural Study Of Pt-modified Au Vicinal Surfaces: A Model System For Pt-au Catalysts.

Two single crystalline surfaces of Au vicinal to the (111) plane were modified with Pt and studied using scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS) in ultra-high vacuum environment. The vicinal surfaces studied are Au(332) and Au(887) and different Pt coverage (θPt) were deposited on each surface. From STM images we determine that Pt deposits on both surfaces as nanoislands with heights ranging from 1 ML to 3 ML depending on θPt. On both surfaces the early growth of Pt ad-islands occurs at the lower part of the step edge, with Pt ad-atoms being incorporated into the steps in some cases. XPS results indicate that partial alloying of Pt occurs at the interface at room temperature and at all coverage, as suggested by the negative chemical shift of Pt 4f core line, indicating an upward shift of the d-band center of the alloyed Pt. Also, the existence of a segregated Pt phase especially at higher coverage is detected by XPS. Sample annealing indicates that the temperature rise promotes a further incorporation of Pt atoms into the Au substrate as supported by STM and XPS results. Additionally, the catalytic activity of different PtAu systems reported in the literature for some electrochemical reactions is discussed considering our findings.

Inhibitory Effects Of A Cured Antibacterial Bonding System On Viability And Metabolic Activity Of Oral Bacteria.

To evaluate the antimicrobial efficacy of Clearfil SE Protect (CP) and Clearfil SE Bond (CB) after curing and rinsed against five individual oral microorganisms as well as a mixture of bacterial culture prepared from the selected test organisms. Bacterial suspensions were prepared from single species of Streptococcus mutans, Streptococcus sobrinus, Streptococcus gordonii, Actinomyces viscosus and Lactobacillus lactis, as well as mixed bacterial suspensions from these organisms. Dentin bonding system discs (6 mm×2 mm) were prepared, cured, washed and placed on the bacterial suspension of single species or multispecies bacteria for 15, 30 and 60 min. MTT, Live/Dead bacterial viability (antibacterial effect), and XTT (metabolic activity) assays were used to test the two dentin system's antibacterial effect. All assays were done in triplicates and each experiment repeated at least three times. Data were submitted to ANOVA and Scheffe's f-test (5%). Greater than 40% bacteria killing was seen within 15 min, and the killing progressed with increasing time of incubation with CP discs. However, a longer (60 min) period of incubation was required by CP to achieve similar antimicrobial effect against mixed bacterial suspension. CB had no significant effect on the viability or metabolic activity of the test microorganisms when compared to the control bacterial culture. CP was significantly effective in reducing the viability and metabolic activity of the test organisms. The results demonstrated the antimicrobial efficacy of CP both on single and multispecies bacterial culture. CP may be beneficial in reducing bacterial infections in cavity preparations in clinical dentistry.